The volume of the world production of mechatronic devices is increasing annually, covering more and more new areas. Today mechatronic modules and systems are widely used in the following areas:
machine tools and equipment for the automation of technological
processes;
robotics (industrial and special);
aviation, space and military equipment;
automotive industry (e.g. anti-lock braking systems,
vehicle motion stabilization and automatic parking systems);
non-traditional vehicles (e-bicycles, cargo
carts, electric rollers, wheelchairs);
office equipment (for example, photocopiers and fax machines);
elements of computing technology (for example, printers, plotters,
floppy drives);
medical equipment (rehabilitation, clinical, service);
household appliances (washing, sewing, dishwashers and other machines);
micromachines (for medicine, biotechnology,
telecommunications);
control and measuring devices and machines;
‑
photo and video equipment;
simulators for training pilots and operators;
show industry (sound and lighting systems).
One of the main trends in the development of modern mechanical engineering is the introduction of mechatronic technological machines and robots into the technological process of production. The mechatronic approach to the construction of new generation machines is to transfer the functional load from mechanical units to intelligent components that can be easily reprogrammed for a new task and at the same time are relatively cheap.
The mechatronic approach to design does not imply expansion, but rather the replacement of functions traditionally performed by mechanical elements of the system with electronic and computer units.
Understanding the principles of constructing intelligent elements of mechatronic systems, methods for developing control algorithms and their software implementation is a prerequisite for the creation and implementation of mechatronic technological machines.
The proposed methodological guide refers to the educational process in the specialty "Application of mechatronic systems", are intended to study the principles of development and implementation of control algorithms for mechatronic systems based on electronic and computer units and contain information on three laboratory work. All laboratory works are combined into a single complex, the purpose of which is to create and implement a control algorithm for a mechatronic technological machine.
At the beginning of each laboratory work, a specific goal is indicated, then its theoretical and practical parts follow. All work is carried out at a specialized laboratory complex.
The main trend in the development of modern industry is the intellectualization of production technologies based on the use of mechatronic technological machines and robots. In many areas of industry, mechatronic systems (MS) are replacing traditional mechanical machines that no longer meet modern quality requirements.
The mechatronic approach to the construction of new generation machines consists in transferring the functional load from mechanical assemblies to intelligent components that are easily reprogrammed for a new task and at the same time are relatively cheap. The mechatronic approach to the design of technological machines involves replacing the functions traditionally performed by the mechanical elements of the system with electronic and computer units. Back in the early 90s of the last century, the overwhelming majority of machine functions were implemented mechanically; in the next decade, mechanical units were gradually replaced by electronic and computer units.
Currently, in mechatronic systems, the scope of functions is almost equally divided between mechanical, electronic and computer components. Qualitatively new requirements are imposed on modern technological machines:
ultra-high speed of movement of working bodies;
ultra-high accuracy of movements required for the implementation of nanotechnology;
maximum compactness of the design;
intelligent behavior of a machine operating in changing and uncertain environments;
implementation of movements of working bodies along complex contours and surfaces;
the ability of the system to reconfigure depending on the specific task or operation being performed;
high reliability and operational safety.
All these requirements can only be met using mechatronic systems. Mechatronic technologies are included in the number of critical technologies of the Russian Federation.
In recent years, the creation of technological machines of the fourth and fifth generations with mechatronic modules and intelligent control systems has been developed in our country.
These projects include the MC-630 mechatronic machining center, the MC-2, Hexamekh-1 machining centers, and the ROST-300 robot machine.
Further development was received by mobile technical robots, which can independently move in space and have the ability to perform technological operations. An example of such robots is robots for use in underground communications: RTK-100, RTK-200, RTK "Rokot-3".
The main advantages of mechatronic systems include:
elimination of multi-stage transformation of energy and information, simplification of kinematic chains and, consequently, high accuracy and improved dynamic characteristics of machines and modules;
constructive compactness of modules;
the possibility of combining mechatronic modules into complex mechatronic systems and complexes that allow quick reconfiguration;
relatively low cost of installation, configuration and maintenance of the system due to modular design, unification of hardware and software platforms;
the ability to perform complex movements through the use of methods of adaptive and intelligent control.
An example of such a system is the system for regulating the force interaction of the working body with the object of work during machining, control of technological influences (thermal, electrical, electrochemical) on the object of work with combined processing methods; control of auxiliary equipment (conveyors, loading devices).
In the process of movement of the mechanical device, the working body of the system directly affects the object of work and provides quality indicators of the automated operation being performed. Thus, the mechanical part is an object of control in the MS. In the process of performing MS functional movement, the external environment has a disturbing effect on the working body, which is the final link of the mechanical part. Examples of such actions are cutting forces in machining operations, contact forces and moments of forces during shaping and assembly, and the reaction force of a liquid jet during hydraulic cutting operations.
In addition to the working body, the MS includes a block of drives, computer control devices, the upper level for which is a human operator, or another computer that is part of a computer network; sensors designed to transmit information to the control device about the actual state of the machine blocks and the movement of the MS.
The computer control device performs the following main functions:
organization of management of functional movements of the MS;
control of the process of mechanical movement of the mechatronic module in real time with the processing of sensory information;
interaction with a human operator through a human-machine interface;
organization of data exchange with peripheral devices, sensors and other system devices.
Mechatronic modules are increasingly used in various transport systems.
Fierce competition on automotive market forces specialists in this field to search for new advanced technologies. Today, one of the main challenges for developers is creating "smart" electronic devices that can reduce the number of road traffic accidents (RTA). The result of work in this area was the creation of an integrated vehicle safety system (SCBA), which is able to automatically maintain a given distance, stop the car at a red traffic light, warn the driver that he is crossing a turn at a speed higher than is allowed by the laws of physics. Even shock sensors with a radio signaling device have been developed, which, when the car hits an obstacle or collision, calls an ambulance.
All these electronic devices accident prevention fall into two categories. The first includes devices in the car that operate independently of any signals from external sources of information (other cars, infrastructure). They process information from an airborne radar (radar). The second category is systems whose operation is based on data received from information sources located near the road, in particular from lighthouses, which collect information about the traffic situation and transmit it via infrared rays to passing cars.
SKBA has united a new generation of the above devices. It receives both radar signals and infrared rays of "thinking" beacons, and in addition to the basic functions provides non-stop and calm movement for the driver on unregulated intersections of roads and streets, limits the speed of movement on bends and in residential areas outside the established speed limits. Like all autonomous systems, SCBA requires the vehicle to be equipped with anti-lock braking system brakes (ABS) and an automatic transmission.
SKBA includes a laser rangefinder that constantly measures the distance between the vehicle and any obstacle along the way - moving or stationary. If a collision is likely, and the driver does not slow down, the microprocessor gives the command to relieve pressure on the accelerator pedal and apply the brakes. A small screen on the dashboard flashes with a hazard warning. At the request of the driver, the on-board computer can set a safe distance depending on the road surface - wet or dry.
SKBA is able to drive a car, focusing on the white lines of the road surface markings. But for this it is necessary that they are clear, since they are constantly "read" by the onboard video camera. Image processing then determines the position of the machine in relation to the lines, and the electronic system acts on the steering accordingly.
On-board infrared receivers SKBA operate in the presence of transmitters placed at regular intervals along the carriageway. The beams propagate in a straight line and over a short distance (up to about 120 m), and the data transmitted by encoded signals can neither be drowned out nor distorted.
Rice. 3.1 Integrated vehicle security system: 1 - infrared receiver; 2 - weather sensor (rain, humidity); 3 - throttle valve drive of the power supply system; 4 - computer; 5 - auxiliary solenoid valve in the brake drive; 6 - ABS; 7 - range finder; 8 - automatic transmission gear; 9 - vehicle speed sensor; 10 - auxiliary solenoid valve for steering; 11 - accelerator sensor; 12 - steering sensor; 13 - signal table; 14 - electronic vision computer; 15 - television camera; 16 - screen.
In fig. 3.2 presents the weather sensor of the company " Boch ". Depending on the model, an infrared LED and one to three photodetectors are placed inside. The LED emits an invisible beam at an acute angle to the surface of the windshield. If it's dry outside, all the light is reflected back and hits the photodetector (this is how the optical system is designed). Since the beam is modulated by pulses, the sensor will not react to extraneous light. But if there are drops or a layer of water on the glass, the conditions of refraction change, and part of the light goes into space. This is detected by a sensor and the controller calculates the appropriate wiper mode. Along the way, this device can close the electric sunroof in the roof, raise the glass. The sensor has 2 more photodetectors, which are integrated into a common housing with a weather sensor. The first is for automatic switching on headlights when it gets dark or the car enters a tunnel. The second, switches the "high" and "low" light. Whether these features are enabled depends on the specific vehicle model.
Figure 3.2 How the weather sensor works
Anti-lock brakes braking systems(ABS),its necessary components are wheel speed sensors, an electronic processor (control unit), servo valves, an electrically driven hydraulic pump and a pressure accumulator. Some early ABSs were "three-channel", i.e. controlled the front brakes individually, but completely released all the rear brakes when any of the rear wheels began to block. This saved some amount of cost and design complexity, but resulted in lower efficiency than a full four-channel system in which each brake is individually controlled.
ABS has a lot to do with traction control system(PBS), whose action could be considered as “reverse ABS”, since the PBS works on the principle of detecting the moment when one of the wheels begins to spin quickly compared to the other (the moment when slipping starts) and giving a signal to slow down this wheel. Wheel speed sensors can be common, and therefore the most effective method To prevent the drive wheel from spinning by reducing its speed is to apply an instant (and, if necessary, repeated) brake action, braking impulses can be received from the ABS valve block. In fact, if ABS is present, this is all that is required to provide both the PBS - plus some additional software and an additional control unit to reduce engine torque or fuel input as needed, or directly intervene in the throttle pedal control system. ...
In fig. 3.3 is a diagram electronic system car power supply: 1 - ignition relay; 2 - central switch; 3 - storage battery; 4 - an exhaust gas neutralizer; 5 - oxygen sensor; 6 - air filter; 7 - mass air flow sensor; 8 - diagnostics block; 9 - regulator idle move; 10 - throttle position sensor; 11 - throttle pipe; 12 - ignition module; 13 - phase sensor; 14 - nozzle; 15 - fuel pressure regulator; 16 - coolant temperature sensor; 17 - candle; 18 - crankshaft position sensor; 19 - knock sensor; twenty - fuel filter; 21 - controller; 22 - speed sensor; 23 - fuel pump; 24 - turn-on relay fuel pump; 25 - gas tank.
Rice. 3.3 Simplified diagram of the injection system
One of component parts SCBA is an airbag ( airbag ) (see Fig. 3.4), the elements of which are located in different parts of the car. Inertial sensors located in the bumper, at the engine board, in the pillars or in the armrest area (depending on the car model), in the event of an accident, send a signal to the electronic control unit. In most modern SKBA front sensors are designed for impact forces at speeds of 50 km / h or more. Side kicks are triggered at weaker impacts. From the electronic control unit, the signal flows to the main module, which consists of a compactly laid cushion connected to a gas generator. The latter is a tablet with a diameter of about 10 cm and a thickness of about 1 cm with a crystalline nitrogen-generating substance. An electrical impulse ignites an igniter in the "tablet" or melts a wire, and the crystals turn into gas at the speed of an explosion. The whole process described is very fast. The “average” pillow is inflated in 25 ms. The surface of the European standard airbag rushes towards the chest and face at a speed of about 200 km / h, and the American one - about 300. Therefore, in cars equipped with an airbag, manufacturers strongly advise you to buckle up and not sit close to the steering wheel or dashboard. The most "advanced" systems have devices that identify the presence of a passenger or child seat and, accordingly, either disconnecting or correcting the degree of inflation.
Rice. 3.4. Car airbag:
1 - seat belt tensioner; 2 - airbag; 3 - airbag; for the driver; 4 - control unit and central sensor; 5 - executive module; 6 - inertial sensors
In addition to conventional cars, great attention is paid to the creation of lightweight Vehicle(LTS) with an electric drive (sometimes they are called non-traditional). This group of vehicles includes electric bicycles, rollers, wheelchairs, electric vehicles with autonomous power sources. The development of such mechatronic systems is carried out by the Scientific and Engineering Center "Mechatronics" in cooperation with a number of organizations.
Engine weight 4.7 kg,
Rechargeable battery 36V, 6 A * h,
The basis for the creation of LTS are mechatronic modules of the "motor-wheel" type based, as a rule, on high-torque electric motors. Table 3.1 shows the technical characteristics of mechatronic motion modules for light vehicles. The world LTS market tends to expand and, according to forecasts, its capacity by 2000 was 20 million units, or in value terms, 10 billion dollars.
Table 3 .1
|
LTS with electric drive |
Technical indicators |
||||||
|
Maximum speed, km / h |
Working voltage, V |
Power, kw |
Rated moment, Nm |
Rated current, |
Weight, kg |
||
|
Armchairs - strollers |
0,15 |
||||||
|
Electro- bicycles |
|||||||
|
Rollers |
|||||||
|
Minielectro- mobiles |
|||||||
Sea transport.MS are increasingly used to intensify the work of the crews of sea and river vessels associated with the automation and mechanization of the main technical means, which include the main power plant with service systems and auxiliary mechanisms, the electric power system, general ship systems, steering devices and engines.
Complex automatic systems keeping a vessel on a given trajectory (SCS) or a vessel intended for exploration of the World Ocean on a given profile line (SCS) are systems that provide the third level of control automation. The use of such systems allows:
To increase the economic efficiency of sea transportation by implementing the best trajectory, vessel movement, taking into account the navigational and hydrometeorological conditions of navigation;
To increase the economic efficiency of oceanographic, hydrographic and marine geological exploration work by increasing the accuracy of keeping the vessel on a given profile line, expanding the range of wind wave disturbances, which ensure the required quality of control, and increasing the operating speed of the vessel;
Solve the problems of implementing the optimal trajectory of the vessel when it diverges from hazardous objects; to improve the safety of navigation in the vicinity of navigational hazards due to more precise control of the vessel's movement.
Integrated automatic motion control systems according to a given geophysical research program (ASUD) are designed to automatically bring the ship to a given profile line, automatically hold the geological and geophysical vessel on the investigated profile line, maneuver when transitioning from one profile line to another. The system under consideration makes it possible to improve the efficiency and quality of marine geophysical research.
Under sea conditions, it is impossible to use conventional methods of preliminary exploration (prospecting party or detailed aerial photography), therefore the seismic method of geophysical research has become the most widespread (Fig. 3.5). A geophysical vessel 1 tows on a cable-rope 2 a pneumatic gun 3, which is a source of seismic vibrations, a seismographic streamer 4, on which receivers of reflected seismic vibrations are located, and an end buoy 5. The bottom profiles are determined by recording the intensity of seismic vibrations reflected from the boundary layers 6 different -breeds.
Rice. 3.5. Scheme of conducting geophysical surveys.
To obtain reliable geophysical information, the vessel must be held at a given position relative to the bottom (profile line) with high accuracy, despite the low speed of movement (3-5 knots) and the presence of towed devices of considerable length (up to 3 km) with limited mechanical strength.
Anjutz has developed an integrated MS, which ensures keeping the vessel on a given trajectory. In fig. 3.6 is a block diagram of this system, which includes: gyrocompass 1; lag 2; appliances navigation complexes determining the position of the vessel (two or more) 3; autopilot 4; mini-computer 5 (5 a - interface, 5 b - central storage, 5 v - central processing unit); punched tape reader 6; plotter 7; display 8; keyboard 9; steering gear 10.
With the help of the system under consideration, it is possible to automatically bring the vessel to the programmed trajectory, which is set by the operator using the keyboard, which determines the geographic coordinates of the turning points. In this system, regardless of the information coming from any one group of instruments of the traditional radio navigation complex or satellite communication devices that determine the position of the vessel, the coordinates of the likely position of the vessel are calculated from the data issued by the gyrocompass and the log.
Rice. 3.6. Block diagram of an integrated MS for keeping a ship on a given trajectory
The course control using the system under consideration is carried out by the autopilot, the input of which receives information about the value of the given course ψ backside generated by the minicomputer taking into account the error in the position of the vessel. The system is assembled in a control panel. In its upper part there is a display with controls for adjusting the optimal image. Below, on the inclined field of the console, there is an autopilot with control levers. On the horizontal field of the control panel there is a keyboard, with the help of which programs are entered into the mini-computer. A switch is also located here, with the help of which the control mode is selected. A mini-computer and an interface are located in the basement of the console. All peripheral equipment is placed on special stands or other consoles. The system under consideration can operate in three modes: "Course", "Monitor" and "Program". In the "Heading" mode, the preset course is held using the autopilot according to the gyrocompass readings. The "Monitor" mode is selected when the transition to the "Program" mode is being prepared, when this mode is interrupted or when the transition to this mode is completed. They switch to the "Course" mode when malfunctions of the minicomputer, power supplies or radio navigation complex are detected. In this mode, the autopilot operates independently of the minicomputer. In the "Program" mode, the course is controlled according to the data of radio navigation devices (position sensors) or a gyrocompass.
Maintenance of the ship restraint system at the ZT is carried out by the operator from the console. The choice of a group of sensors for determining the position of the vessel is made by the operator according to the recommendations presented on the display screen. At the bottom of the screen is a list of all commands allowed for this mode that can be entered using the keyboard. Accidental pressing of any forbidden key is blocked by the computer.
Aviation technology.The successes achieved in the development of aviation and space technology, on the one hand, and the need to reduce the cost of targeted operations, on the other, stimulated the development of a new type of technology - remotely piloted aircraft (RPV).
In fig. 3.6 is a block diagram of the system remote control RPV flight - HIMAT ... The main component of a remote piloting system HIMAT is a remote control ground point. The RPV flight parameters are received at the ground point via a radio communication line from the aircraft, received and decoded by the telemetry processing station and transmitted to the ground part of the computer system, as well as to the information display devices at the ground control point. In addition, a picture of the external view, displayed with the help of a television camera, is received from the RPV. The television image displayed on the screen of the ground workstation of a human operator is used to control the aircraft during air maneuvers, approach and landing itself. The cockpit of the ground station for remote control (operator's workstation) is equipped with instruments that display information about the flight and the state of the RPV complex equipment, as well as means for controlling the aircraft. In particular, the human operator has the roll and pitch control sticks and pedals of the aircraft, as well as the engine control stick. In the event of failure of the main control system, the control system commands are issued by means of a special console of discrete commands of the RPV operator.
Rice. 3.6 RPV remote piloting system HIMAT:
- carrier B-52; 2 - backup control system on the plane TF -104 G ; 3 - telemetry line with the ground; 4 - RPV HIMAT ; 5 - lines of telemetric communication with RPV; 5 - ground station for remote piloting
Doppler ground speed and drift angle meters (DPSS) are used as an autonomous navigation system providing dead reckoning. Such a navigation system is used in conjunction with a heading system that measures the course with a vertical sensor that generates roll and pitch signals, and an onboard computer that implements the dead reckoning algorithm. Together, these devices form a Doppler navigation system (see Figure 3.7). To increase the reliability and accuracy of measuring the current coordinates of the aircraft, DISS can be combined with speed meters.
Rice. 3.7 Diagram of a Doppler navigation system
5. Mechatronic vehicles
Mechatronic modules are increasingly used in various transport systems. In this manual, we will limit ourselves to a brief analysis of only light vehicles (LTS) with an electric drive (sometimes they are called non-traditional). This group of vehicles, new for the domestic industry, includes electric bicycles, rollers, wheelchairs, and electric vehicles with autonomous power sources.
LTS are an alternative to motor vehicles internal combustion and are currently used in ecologically clean areas (medical and recreational, tourist, exhibition, park complexes), as well as in retail and warehouse premises. Consider the technical characteristics of a prototype electric bike:
Maximum speed 20 km / h,
Drive rated power 160 W,
Rated speed 160 rpm,
Maximum torque 18 Nm,
Engine weight 4.7 kg,
Rechargeable battery 36V, 6 А "h,
Driving autonomously 20 km.
The basis for the creation of LTS are mechatronic modules of the "motor-wheel" type based, as a rule, on high-torque electric motors. Table 3 shows the technical characteristics of mechatronic motion modules for light vehicles.
|
LTS with electric drive |
Technical indicators |
|||||
|
Maximal speed, km / h |
Working voltage, V |
Power, kWt |
Rated moment, Nm |
Rated current, A |
Weight, kg |
|
|
Wheelchairs |
0.15 |
|||||
|
Electric bicycles |
||||||
|
Rollers |
||||||
|
Mini electric vehicles |
ON |
|||||
The world LTS market tends to expand and, according to forecasts, its capacity by 2000 will amount to 20 million units, or in value terms, 10 billion dollars.
The volume of the world production of mechatronic devices is increasing annually, covering more and more new areas. Today mechatronic modules and systems are widely used in the following areas:
Machine tools and equipment for the automation of technological
processes;
Robotics (industrial and special);
Aviation, space and military equipment;
Automotive (e.g. anti-lock braking systems,
vehicle motion stabilization and automatic parking systems);
Non-traditional vehicles (e-bicycles, cargo
carts, electric rollers, wheelchairs);
Office equipment (for example, photocopiers and fax machines);
Elements of computing technology (for example, printers, plotters,
floppy drives);
Medical equipment (rehabilitation, clinical, service);
Household appliances (washing, sewing, dishwashers and other machines);
Micromachines (for medicine, biotechnology,
telecommunications);
Control and measuring devices and machines;
Photo and video equipment;
Simulators for training pilots and operators;
Show industry (sound and lighting systems).
LIST OF REFERENCES
1.
Yu. V. Poduraev "Fundamentals of Mechatronics" Textbook. Moscow. - 2000. 104 s.
2.
http://ru.wikipedia.org/wiki/Mechatronics
3.
http://mau.ejournal.ru/
4.
http://mechatronica-journal.stankin.ru/
Analysis of the structure of mechatronic systems of mechatronic modules
Tutorial
In the discipline "Design of mechatronic systems"
in the specialty 220401.65
"Mechatronics"
g. Togliatti 2010
Krasnov S.V., Lysenko I.V. Design of mechatronic systems. Part 2. Design of electromechanical modules of mechatronic systems
Annotation. The textbook includes information about the composition of the mechatronic system, the place of electromechatronic modules in mechatronic systems, the structure of electromechatronic modules, their types and features, includes the stages and methods of designing mechatronic systems. criteria for calculating the load characteristics of modules, criteria for the selection of drives, etc.
1 Analysis of the structure of mechatronic systems of mechatronic modules 5
1.1 Analysis of the structure of the mechatronic system 5
1.2 Equipment analysis of mechatronic module drives 12
1.3 Analysis and classification of electric motors 15
1.4 Analysis of the structure of drive control systems 20
1.5 Technologies of forming a control signal. PWM modulation and PID regulation 28
1.6 Analysis of drives and numerical control systems of machine tools 33
1.7 Power and output mechanical converters of drives of mechatronic modules 39
1.8 Feedback sensors of mechatronic module drives 44
2 Basic concepts and methodologies for the design of mechatronic systems (MS) 48
2.1 Basic design principles for mechatronic systems 48
2.2 Description of the design stages of MS 60
2.3 Manufacturing (implementation) of MS 79
2.4 Testing the MS 79
2.5 Quality assessment of MS 83
2.6 Documentation for MS 86
2.7 Economic efficiency of MS 87
2.8 Development of measures to ensure safe working conditions with electromechanical modules 88
3. Methods for calculating parameters and design of mechatronic modules 91
3.1 Functional modeling of the mechatronic module design process 91
3.2 Steps for designing a mechatronic module 91
3.3 Analysis of selection criteria for motors of mechatronic systems 91
3.4 Analysis of the basic mathematical apparatus for calculating drives 98
3.5 Calculation of the required power and selection of ED feeds 101
3.6 Engine management direct current on regulation 110
3.7 Description of modern hardware and software solutions for controlling the executive elements of machine tools 121
List of sources and literature 135
Mechatronics is studying the synergistic combination of precision mechanics units with electronic, electrical and computer components in order to design and manufacture qualitatively new modules, systems, machines and a complex of machines with intelligent control of their functional movements.
Mechatronic system - a set of mechatronic modules (computer core, information devices-sensors, electromechanical (motor drives), mechanical (executive elements - cutters, robot arms, etc.), software (specially - control programs, system - operating systems and environments, drivers).
Mechatronic module - a separate unit of the mechatronic system, a set of hardware and software that move one or more executive bodies.
Integrated mechatronic elements are selected by the developer at the design stage, and then the necessary engineering and technological support is provided.
The methodological basis for the development of MS is the methods of parallel design, that is, simultaneous and interconnected in the synthesis of all components of the system. Basic objects are mechatronic modules that perform movement, as a rule, along one coordinate. In mechatronic systems, to ensure a high quality of implementation of complex and precise movements, methods of intelligent control are used (new ideas in control theory, modern computers).
The main components of a traditional mechatronic machine are:
Mechanical devices, the final link of which is the working body;
Drive unit including power converters and power motors;
Computer control devices, the level for which is a human operator, or another computer included in a computer network;
Sensor devices designed to transmit information about the actual state of the machine blocks and the movement of the mechatronic system to the control device.
Thus, the presence of three mandatory parts: electromechanical, electronic, computer, connected by energy and information flows is the primary feature that distinguishes a mechatronic system.
Thus, for the physical implementation of the mechatronic system, 4 main functional blocks are theoretically required, which are shown in Figure 1.1.
Figure 1.1 - Block diagram of the mechatronic system
If the operation is based on hydraulic, pneumatic or combined processes, then appropriate converters and feedback sensors are required.
Mechatronics is a scientific and technical discipline that studies the construction of a new generation of electromechanical systems with fundamentally new qualities and, often, record parameters. Typically, a mechatronic system is a combination of electromechanical components proper with the latest power electronics, which are controlled by various microcontrollers, PCs or other computing devices. At the same time, the system in a truly mechatronic approach, despite the use of standard components, is built as monolithic as possible, the designers try to combine all parts of the system together without using unnecessary interfaces between the modules. In particular, using the ADCs built directly into microcontrollers, intelligent power converters, etc. This gives a reduction in weight and dimensions, an increase in system reliability and other advantages. Any system that controls a group of drives can be considered mechatronic. In particular, if she controls a group of spacecraft jet engines.
Figure 1.2 - Composition of the mechatronic system
Sometimes the system contains units that are fundamentally new from a design point of view, such as electromagnetic suspensions, which replace conventional bearing units.
Consider a generalized structure of machines with computer control focused on the tasks of automated mechanical engineering.
The external environment for machines of this class is the technological environment, which contains various main and auxiliary equipment, technological equipment and work objects. When the mechatronic system performs a given functional movement, the objects of work have a disturbing effect on the working body. Examples of such actions are cutting forces for machining operations, contact forces and moments of forces during assembly, and the reaction force of a liquid jet during a hydraulic cutting operation.
External environments can be broadly divided into two main classes: deterministic and non-deterministic. Deterministic environments include environments for which the parameters of disturbing influences and characteristics of work objects can be predetermined with the degree of accuracy required for designing an MS. Some environments are non-deterministic in nature (for example, extreme environments: underwater, underground, etc.). The characteristics of technological environments can usually be determined using analytical and experimental studies and methods of computer modeling. For example, to assess the cutting forces during machining, a series of experiments are carried out on special research installations, the parameters of vibration effects are measured on vibration stands, followed by the formation of mathematical and computer models of disturbing effects based on experimental data.
However, organizing and conducting such studies often requires too complex and expensive equipment and measuring technologies. So for a preliminary assessment of the force effects on the working body during the operation of robotic flash removal from cast products, it is necessary to measure the actual shape and dimensions of each workpiece.
Figure 1.3 - Generalized diagram of a mechatronic system with computer motion control
In such cases, it is advisable to apply the methods of adaptive control, which make it possible to automatically correct the law of motion of the MS directly in the course of the operation.
The structure of a traditional machine includes the following main components: a mechanical device, the final link of which is the working body; block of drives, including power converters and executive motors; a computer control device, the upper level for which is a human operator, or another computer included in a computer network; sensors designed to transmit information to the control device about the actual state of the machine blocks and the movement of the MS.
Thus, the presence of three mandatory parts - mechanical (more precisely electromechanical), electronic and computer, connected by energy and information flows, is the primary feature that distinguishes mechatronic systems.
The electromechanical part includes mechanical links and transmissions, working body, electric motors, sensors and additional electrical elements (brakes, clutches). The mechanical device is designed to convert the movements of the links into the required movement of the working body. The electronic part consists of microelectronic devices, power converters and electronics of measuring circuits. The sensors are designed to collect data on the actual state of the external environment and objects of work, the mechanical device and the drive unit with subsequent primary processing and transmission of this information to the computer control device (UCU). The UCU of a mechatronic system usually includes a high-level computer and motion controllers.
The computer control device performs the following main functions:
Control of the process of mechanical movement of a mechatronic module or multidimensional system in real time with processing of sensory information;
Organization of the control of functional movements of the MS, which involves the coordination of the control of the mechanical movement of the MS and related external processes. As a rule, discrete inputs / outputs of the device are used to implement the function of controlling external processes;
Interaction with a human operator through a human-machine interface in offline programming modes (off-line) and directly during the movement of the MS (on-line mode);
Organization of data exchange with peripheral devices, sensors and other system devices.
The task of the mechatronic system is to transform the input information from the upper control level into a purposeful mechanical movement with control based on the feedback principle. It is characteristic that electrical energy (less often hydraulic or pneumatic) is used in modern systems as an intermediate energy form.
The essence of the mechatronic approach to design is the integration into a single functional module of two or more elements, possibly even of different physical nature. In other words, at the design stage, at least one interface is excluded from the traditional machine structure as a separate device, while maintaining the physical essence of the transformation performed by this module.
Ideally for the user, the mechatronic module, having received information about the control goal at the input, will perform the specified functional movement with the desired quality indicators. The hardware combination of elements into single structural modules must be accompanied by the development of integrated software. The MS software should provide a direct transition from the design of the system through its mathematical modeling to the control of functional motion in real time.
The use of the mechatronic approach in the creation of computer-controlled machines determines their main advantages over traditional automation tools:
Relatively low cost due to a high degree of integration, unification and standardization of all elements and interfaces;
High quality implementation of complex and accurate movements due to the use of intelligent control methods;
High reliability, durability and noise immunity;
Constructive compactness of modules (up to miniaturization in micromachines),
Improved weight, size and dynamic characteristics of machines due to the simplification of kinematic chains;
The ability to integrate functional modules into complex systems and complexes for specific customer tasks.
The classification of the actuators of the mechatronic system is shown in Figure 1.4.
Figure 1.4 - Classification of drives of the mechatronic system
Figure 1.5 shows a schematic diagram of an electromechatronic unit based on a drive.
Figure 1.5 - Diagram of the electromechatronic unit
In various fields of technology, drives are widely used that perform power functions in control systems for various objects. Automation of technological processes and industries, in particular, in mechanical engineering, is impossible without the use of various drives, which include: actuators determined by the technological process, motors and motor control system. In drives of MC control systems (technological machines, automatic machines MA, PR, etc.), executive motors that differ significantly in physical effects are used. Realization of such physical effects as magnetism (electric motors), gravity in the form of conversion of hydraulic and air flows into mechanical movement, expansion of the medium (internal combustion engines, jet, steam, etc.); electrolysis (capacitive motors), together with the latest advances in microprocessor technology, makes it possible to create modern drive systems (PS) with improved technical characteristics. The connection of the power parameters of the drive (torque, effort) with the kinematic parameters (angular speed of the output shaft, the speed of the linear movement of the IM rod) is determined by the mechanical characteristics of electric, hydraulic, pneumatic and other drives, in aggregate or separately solving problems movement (working, idling) of the mechanical part of the MS (technological equipment). In this case, if it is required to regulate the output parameters of the machine (power, speed, energy), then the mechanical characteristics of the motors (drives) should be appropriately modified as a result of controlling the control devices, for example, the level of the supply voltage, current, pressure, liquid or gas flow rate.
Ease of generating mechanical movements directly from electrical energy in drive systems with electric motor, i.e. in electromechanical systems EMC, predetermines a number of advantages of such a drive over hydraulic and pneumatic drives. Currently, electric motors of constant and alternating current are produced by manufacturing plants from tenths of a watt to tens of megawatts, which makes it possible to meet the demand for them (according to the required power) both for use in industry and for many types of transport, in everyday life.
Hydraulic drives MS (technological equipment and PR), in comparison with electric drives, are widely used in transport, mining, construction, road, track, land reclamation and agricultural machines, lifting and transport mechanisms, aircraft and underwater vehicles. They have a significant advantage over the electromechanical drive where significant workloads are required with small dimensions, for example, in braking systems or automatic transmissions of cars, rocket and space technology. The wide applicability of hydraulic drives is due to the fact that the tension of the working environment in them is much greater than the tension of the working environment in electric motors and industrial pneumatic drives. In real hydraulic drives, the tension of the working medium in the direction of motion transmission is 6-100 MPa with flexible control due to the regulation of the fluid flow by hydraulic devices that have various controls, including electronic ones. The compactness and low inertia of the hydraulic drive ensure an easy and quick change in the direction of the MI movement, and the use of electronic control equipment provides acceptable transient processes and a given stabilization of the output parameters.
To automate the control of MS (various technological equipment, automatic machines and PR), pneumatic drives based on pneumatic motors are also widely used to implement both translational and rotary movements. However, due to the significant difference in the properties of the working medium of pneumatic and hydraulic drives, their technical characteristics differ due to the significant compressibility of gases in comparison with the compressibility of a dropping liquid. With a simple design, good economic performance and sufficient reliability, but low control properties, pneumatic drives cannot be used in positional and contour modes of operation, which somewhat reduces the attractiveness of their use in MS ( technical systems TS).
Determining the most acceptable type of energy in the drive with the possible attainable efficiency of its use during the operation of technological or equipment for other purposes is a rather complicated task and may have several solutions. First of all, each drive must satisfy its service purpose, the necessary power and kinematic characteristics. The determining factors in achieving the required power and kinematic characteristics, ergonomic indicators of the developed drive can be: drive speed, positioning accuracy and control quality, weight restrictions and overall dimensions, the location of the drive in general layout equipment. The final decision, with the comparability of the determining factors, is made based on the results of an economic comparison of various options for the selected type of drive in terms of starting and operating costs for its design, manufacture and operation.
Table 1.1 - Classification of electric motors
There is a point of view that mechatronic technologies include technologies of new materials and composites, microelectronics, photonics, microbionics, laser and other technologies.
However, at the same time, there is a substitution of concepts and, instead of mechatronic technologies, which are implemented on the basis of the use of mechatronic objects, these works deal with the technology of manufacturing and assembling such objects.
Most scientific workers now believe that mechatronic technologies only form and implement the necessary laws of executive movements of computer-controlled mechanisms, as well as aggregates based on them, or analyze these movements to solve diagnostic and prognostic problems.
In machining, these technologies are aimed at ensuring accuracy and productivity that cannot be achieved without the use of mechatronic objects, the prototypes of which are metal-cutting machines with open CNC systems. In particular, such technologies make it possible to compensate for errors that arise due to oscillation of the tool relative to the workpiece.
However, preliminary it should be noted that mechatronic technologies include the following stages:
Technological problem statement;
Creation of a model of the process in order to obtain the law of the executive motion;
Development of software and information support for implementation;
Supplementing the information management and design base of a typical mechatronic object that implements the proposed technology, if necessary.
An adaptive method for increasing the vibration resistance of a lathe.
In the conditions of using a variety of cutting tools, machined parts of complex shapes and a wide range of both machined and tool materials, the likelihood of self-oscillation and loss of vibration resistance of the machine's technological system increases sharply.
This entails a reduction in processing intensity or additional capital investments in the technological process. A promising way to reduce the level of self-oscillation is to change the cutting speed during processing.
This method is quite simple to implement technically and has an effective impact on the cutting process. Previously, this method was implemented as a priori regulation based on preliminary calculations, which limits its application, since it does not allow taking into account the variety of causes and variability of the conditions for the occurrence of vibrations.
Adaptive systems for regulating the cutting speed with on-line control of the cutting force and its dynamic component are much more effective.
The mechanism for reading the level of self-oscillations during machining with a variable cutting speed can be represented as follows.
Suppose that when processing a part with a cutting speed V 1, the technological system is in conditions of self-oscillation. In this case, the frequency and phase of oscillations on the machined surface coincide with the frequency and phase of oscillations of the cutting force and the cutter itself (these oscillations are expressed in the form of crushing, waviness and roughness).
When moving to the speed V 2, oscillations on the machined surface of the part relative to the cutter during the subsequent revolution (when processing "on the track") occurs with a different frequency and synchronism of oscillations, that is, their phase coincidence is violated. Due to this, in conditions of processing "on the trail", the intensity of self-oscillations decreases, and high-frequency harmonics appear in their spectrum.
Over time, natural resonance frequencies begin to dominate in the spectrum and the process of self-oscillations is intensified again, which requires a repeated change in the cutting speed.
It follows from what has been said that the main parameters of the described method are the magnitude of the change in the cutting speed V, as well as the sign and frequency of this change. The effectiveness of the effect of changing the cutting speed on the processing performance should be assessed by the duration of the auto-oscillation recovery period. The larger it is, the longer the reduced level of self-oscillations remains.
The development of a method for adaptive control of cutting speed involves the simulation of this process based on a mathematical model of self-oscillations, which should:
Take into account the dynamics of the cutting process;
Consider tracking processing;
Adequately describe the cutting process under conditions of self-oscillation.
Mechatronic modules are increasingly used in various transport systems.
A modern car as a whole is a mechatronic system that includes mechanics, electronics, various sensors, an on-board computer that monitors and regulates the activities of all car systems, informs the user and brings control from the user to all systems. The automotive industry at the present stage of its development is one of the most promising areas for the introduction of mechatronic systems due to the increased demand and increasing motorization of the population, as well as due to the presence of competition between individual manufacturers.
If you classify modern car according to the control principle, it belongs to anthropomorphic devices, since its movement is controlled by a person. Already now we can say that in the foreseeable future the automotive industry should expect the emergence of cars with the possibility of autonomous control, i.e. with intelligent motion control system.
Fierce competition in the automotive market forces specialists in this field to search for new advanced technologies. Today, one of the main challenges for developers is creating "smart" electronic devices that can reduce the number of road traffic accidents (RTA). The result of work in this area was the creation of an integrated vehicle safety system (SCBA), which is able to automatically maintain a given distance, stop the car at a red traffic light, warn the driver that he is crossing a turn at a speed higher than is allowed by the laws of physics. Even shock sensors with a radio signaling device have been developed, which, when the car hits an obstacle or collision, calls an ambulance.
All of these electronic accident prevention devices fall into two categories. The first includes devices in the car that operate independently of any signals from external sources of information (other cars, infrastructure). They process information from an airborne radar (radar). The second category is systems whose operation is based on data received from information sources located near the road, in particular from lighthouses, which collect information about the traffic situation and transmit it via infrared rays to passing cars.
SKBA has united a new generation of the above devices. It receives both radar signals and infrared rays of "thinking" beacons, and in addition to the basic functions provides non-stop and calm movement for the driver on unregulated intersections of roads and streets, limits the speed of movement on bends and in residential areas outside the established speed limits. Like all autonomous systems, SKBA requires the vehicle to be equipped with anti-lock braking systems (ABS) and an automatic transmission.
SKBA includes a laser rangefinder that constantly measures the distance between the vehicle and any obstacle along the way - moving or stationary. If a collision is likely, and the driver does not slow down, the microprocessor gives the command to relieve pressure on the accelerator pedal and apply the brakes. A small screen on the dashboard flashes with a hazard warning. At the request of the driver, the on-board computer can set a safe distance depending on the road surface - wet or dry.
SKBA (Figure 5.22) is able to drive a car, focusing on the white lines of the road surface marking. But for this it is necessary that they are clear, since they are constantly "read" by the onboard video camera. Image processing then determines the position of the machine in relation to the lines, and the electronic system acts on the steering accordingly.
On-board infrared receivers SKBA operate in the presence of transmitters placed at regular intervals along the carriageway. The beams propagate in a straight line and over a short distance (up to about 120 m), and the data transmitted by encoded signals can neither be drowned out nor distorted.
Rice. 5.22. Integrated vehicle security system: 1 - infrared receiver; 2 - weather sensor (rain, humidity); 3 - throttle valve drive of the power supply system; 4 - computer; 5 - auxiliary solenoid valve in the brake drive; 6 - ABS; 7 - range finder; 8 - automatic transmission; 9 - vehicle speed sensor; 10 - auxiliary solenoid valve for steering; 11 - accelerator sensor; 12 - steering sensor; 13 - signal table; 14 - electronic vision computer; 15 - television camera; 16 - screen.
In fig. 5.23 shows a Boch weather sensor. Depending on the model, an infrared LED and one to three photodetectors are placed inside. The LED emits an invisible beam at an acute angle to the surface of the windshield. If it's dry outside, all the light is reflected back and hits the photodetector (this is how the optical system is designed). Since the beam is modulated by pulses, the sensor will not react to extraneous light. But if there are drops or a layer of water on the glass, the conditions of refraction change, and part of the light goes into space. This is detected by a sensor and the controller calculates the appropriate wiper mode. Along the way, this device can close the electric sunroof in the roof, raise the glass. The sensor has 2 more photodetectors, which are integrated into a common housing with a weather sensor. The first is designed to automatically turn on the headlights when it gets dark or the car enters the tunnel. The second, switches the "high" and "low" light. Whether these features are enabled depends on the specific vehicle model.
Figure 5.23. How the weather sensor works
Anti-lock braking systems (ABS), its necessary components - wheel speed sensors, electronic processor (control unit), servo valves, an electrically driven hydraulic pump and a pressure accumulator. Some early ABSs were "three-channel", i.e. controlled the front brakes individually, but completely released all the rear brakes when any of the rear wheels began to block. This saved some amount of cost and design complexity, but resulted in lower efficiency than a full four-channel system in which each brake is individually controlled.
The ABS has much in common with the traction control system (PBS), whose action could be considered as “reverse ABS”, since the PBS works on the principle of detecting the moment when one of the wheels begins to spin quickly compared to the other (the moment when the slip starts) and giving a signal to slow down this wheel. Wheel speed sensors can be shared, and therefore the most effective way to prevent the drive wheel from spinning by decreasing its speed is to apply instant (and, if necessary, repeated) brake action, braking pulses can be received from the ABS valve block. In fact, if ABS is present, this is all that is required to provide an RBM - plus some additional software and an additional control unit to reduce engine torque or fuel input as needed, or directly intervene in the throttle pedal control system. ...
In fig. 5.24 shows a diagram of the electronic power supply system of the car: 1 - ignition relay; 2 - central switch; 3 - storage battery; 4 - an exhaust gas neutralizer; 5 - oxygen sensor; 6 - air filter; 7 - mass air flow sensor; 8 - diagnostics block; 9 - idle speed regulator; 10 - throttle position sensor; 11 - throttle pipe; 12 - ignition module; 13 - phase sensor; 14 - nozzle; 15 - fuel pressure regulator; 16 - coolant temperature sensor; 17 - candle; 18 - crankshaft position sensor; 19 - knock sensor; 20 - fuel filter; 21 - controller; 22 - speed sensor; 23 - fuel pump; 24 - relay for turning on the fuel pump; 25 - gas tank.
Rice. 5.24. Simplified diagram of the injection system
One of the components of the SKBA is an airbag (see Fig. 5.25.), The elements of which are located in different parts of the car. Inertial sensors located in the bumper, at the engine board, in the pillars or in the armrest area (depending on the car model), in the event of an accident, send a signal to the electronic control unit. In most modern SKBA front sensors are designed for impact forces at speeds of 50 km / h or more. Side kicks are triggered at weaker impacts. From the electronic control unit, the signal flows to the main module, which consists of a compactly laid cushion connected to a gas generator. The latter is a tablet with a diameter of about 10 cm and a thickness of about 1 cm with a crystalline nitrogen-generating substance. An electrical impulse ignites an igniter in the "tablet" or melts a wire, and the crystals turn into gas at the speed of an explosion. The whole process described is very fast. The “average” pillow is inflated in 25 ms. The surface of the European standard airbag rushes towards the chest and face at a speed of about 200 km / h, and the American one - about 300. Therefore, in cars equipped with an airbag, manufacturers strongly advise to buckle up and not sit close to the steering wheel or dashboard. In the most "advanced" systems, there are devices that identify the presence of a passenger or a child seat and, accordingly, either turn off or correct the degree of inflation.
Figure 5.25 Vehicle airbag:
1 - seat belt tensioner; 2 - airbag; 3 - airbag; for the driver; 4 - control unit and central sensor; 5 - executive module; 6 - inertial sensors
More details on the modern automotive MS can be found in the manual.
In addition to conventional cars, much attention is paid to the creation of light vehicles (LTS) with an electric drive (sometimes they are called non-traditional). This group of vehicles includes electric bicycles, rollers, wheelchairs, electric vehicles with autonomous power sources. The development of such mechatronic systems is carried out by the Scientific and Engineering Center "Mechatronics" in cooperation with a number of organizations. LTS are an alternative to transport with internal combustion engines and are currently used in ecologically clean areas (medical and recreational, tourist, exhibition, park complexes), as well as in retail and warehouse premises. Technical specifications prototype electric bike:
Maximum speed 20 km / h,
Drive rated power 160 W,
Rated speed 160 rpm,
Maximum torque 18 Nm,
Engine weight 4.7 kg,
Rechargeable battery 36V, 6 A * h,
Driving autonomously 20 km.
The basis for the creation of LTS are mechatronic modules of the "motor-wheel" type based, as a rule, on high-torque electric motors.
Sea transport. MS are increasingly used to intensify the work of the crews of sea and river vessels associated with the automation and mechanization of the main technical means, which include the main power plant with service systems and auxiliary mechanisms, the electric power system, general ship systems, steering devices and engines.
Integrated automatic systems for keeping a vessel on a given trajectory (CPSS) or a vessel intended for exploration of the World Ocean on a given profile line (CPSS) are systems that provide the third level of control automation. The use of such systems allows:
To increase the economic efficiency of sea transportation by implementing the best trajectory, vessel movement, taking into account the navigational and hydrometeorological conditions of navigation;
To increase the economic efficiency of oceanographic, hydrographic and marine geological exploration work by increasing the accuracy of keeping the vessel on a given profile line, expanding the range of wind wave disturbances, which ensure the required quality of control, and increasing the operating speed of the vessel;
Solve the problems of implementing the optimal trajectory of the vessel when it diverges from hazardous objects; to improve the safety of navigation in the vicinity of navigational hazards due to more precise control of the vessel's movement.
Integrated automatic motion control systems according to a given geophysical research program (ASUD) are designed to automatically bring the ship to a given profile line, automatically hold the geological and geophysical vessel on the investigated profile line, maneuver when transitioning from one profile line to another. The system under consideration makes it possible to improve the efficiency and quality of marine geophysical research.
In sea conditions, it is impossible to use the usual methods of preliminary exploration (prospecting party or detailed aerial photography), therefore the seismic method of geophysical research has become the most widespread (Fig. 5.26). A geophysical vessel 1 tows on a cable-rope 2 a pneumatic gun 3, which is a source of seismic vibrations, a seismographic streamer 4, on which receivers of reflected seismic vibrations are located, and an end buoy 5. The bottom profiles are determined by recording the intensity of seismic vibrations reflected from the boundary layers 6 different rocks.
Figure 5.26. Scheme of conducting geophysical surveys.
To obtain reliable geophysical information, the vessel must be held at a given position relative to the bottom (profile line) with high accuracy, despite the low speed of movement (3-5 knots) and the presence of towed devices of considerable length (up to 3 km) with limited mechanical strength.
Anjutz has developed an integrated MS, which ensures keeping the vessel on a given trajectory. In fig. 5.27 presents a block diagram of this system, which includes: gyrocompass 1; lag 2; instruments of navigation systems that determine the position of the vessel (two or more) 3; autopilot 4; mini-computer 5 (5a - interface, 5b - central storage device, 5c - central processing unit); punched tape reader 6; plotter 7; display 8; keyboard 9; steering gear 10.
With the help of the system under consideration, it is possible to automatically bring the vessel to the programmed trajectory, which is set by the operator using the keyboard, which determines the geographic coordinates of the turning points. In this system, regardless of the information coming from any one group of instruments of the traditional radio navigation complex or satellite communication devices that determine the position of the vessel, the coordinates of the likely position of the vessel are calculated from the data issued by the gyrocompass and the log.
Figure 5.27. Block diagram of an integrated MS for keeping a ship on a given trajectory
The control of the course with the help of the system under consideration is carried out by the autopilot, the input of which receives information about the value of the given course ψback, generated by the minicomputer taking into account the error in the position of the vessel. The system is assembled in a control panel. In its upper part there is a display with controls for adjusting the optimal image. Below, on the inclined field of the console, there is an autopilot with control levers. On the horizontal field of the control panel there is a keyboard, with the help of which programs are entered into the mini-computer. A switch is also located here, with the help of which the control mode is selected. A mini-computer and an interface are located in the basement of the console. All peripheral equipment is placed on special stands or other consoles. The system under consideration can operate in three modes: "Course", "Monitor" and "Program". In the "Heading" mode, the preset course is held using the autopilot according to the gyrocompass readings. The "Monitor" mode is selected when the transition to the "Program" mode is being prepared, when this mode is interrupted or when the transition to this mode is completed. They switch to the "Course" mode when malfunctions of the minicomputer, power supplies or radio navigation complex are detected. In this mode, the autopilot operates independently of the minicomputer. In the "Program" mode, the course is controlled according to the data of radio navigation devices (position sensors) or a gyrocompass.
Maintenance of the ship restraint system at the ZT is carried out by the operator from the console. The choice of a group of sensors for determining the position of the vessel is made by the operator according to the recommendations presented on the display screen. At the bottom of the screen is a list of all commands allowed for this mode that can be entered using the keyboard. Accidental pressing of any forbidden key is blocked by the computer.
Aviation technology. The successes achieved in the development of aviation and space technology, on the one hand, and the need to reduce the cost of targeted operations, on the other, stimulated the development of a new type of technology - remotely piloted aircraft (RPV).
In fig. 5.28 presents a block diagram of the remote control system of the RPV flight - HIMAT. The main component of the HIMAT remote control system is the remote control ground station. The RPV flight parameters are received at the ground point via a radio communication line from the aircraft, received and decoded by the telemetry processing station and transmitted to the ground part of the computer system, as well as to the information display devices at the ground control point. In addition, a picture of the external view, displayed with the help of a television camera, is received from the RPV. The television image displayed on the screen of the ground workstation of a human operator is used to control the aircraft during air maneuvers, approach and landing itself. The cockpit of the ground station for remote control (operator's workstation) is equipped with instruments that display information about the flight and the state of the RPV complex equipment, as well as means for controlling the aircraft. In particular, the human operator has the roll and pitch control sticks and pedals of the aircraft, as well as the engine control stick. In the event of failure of the main control system, the control system commands are issued by means of a special console of discrete commands of the RPV operator.
Figure 5.28. RPV remote piloting system HIMAT:
carrier B-52; 2 - backup control system on the TF-104G aircraft; 3 - telemetry line with the ground; 4 - RPV HIMAT; 5 - telemetry lines with RPV; 5 - ground station for remote piloting
Doppler ground speed and drift angle meters (DPSS) are used as an autonomous navigation system providing dead reckoning. Such a navigation system is used in conjunction with a heading system that measures the course with a vertical sensor that generates roll and pitch signals, and an onboard computer that implements the dead reckoning algorithm. Together, these devices form a Doppler navigation system (see Figure 5.29). To increase the reliability and accuracy of measuring the current coordinates of the aircraft, DISS can be combined with speed meters
Figure 5.29. Diagram of a Doppler navigation system
The miniaturization of electronic elements, the creation and serial production of special types of sensors and indicator devices that reliably operate in difficult conditions, as well as a sharp reduction in the cost of microprocessors (including those specially designed for cars) created the conditions for the transformation of vehicles into MS of a fairly high level.
High speed land transport on a magnetic suspension is a good example of a modern mechatronic system. So far, the world's only commercial transport system of this kind was commissioned in China in September 2002 and connects Pudong International Airport with downtown Shanghai. The system was developed, manufactured and tested in Germany, after which the train cars were transported to China. The guiding track, located on a high overpass, was manufactured locally in China. The train accelerates to a speed of 430 km / h and covers 34 km in 7 minutes (the maximum speed can reach 600 km / h). The train hovers over the guide track, there is no friction on the track, and the main resistance to movement is provided by air. Therefore, the train is given an aerodynamic shape, the joints between the cars are closed (Figure 5.30).
To prevent the train from falling on the track in the event of an emergency power outage, it has powerful storage batteries, the energy of which is enough to smoothly stop the train.
With the help of electromagnets, the distance between the train and the guide track (15 mm) during movement is maintained with an accuracy of 2 mm, which makes it possible to completely eliminate the vibration of the cars, even on maximum speed... The number and parameters of the supporting magnets are trade secrets.
Rice. 5.30. Magnetic suspension train
The transport system on a magnetic suspension is completely computer controlled, since at such a high speed a person does not have time to react to emerging situations. The computer also controls the acceleration and deceleration of the train, taking into account also the turns of the track, so passengers do not feel discomfort during acceleration.
The described transport system is distinguished by high reliability and unprecedented precision in the execution of the traffic schedule. Over the first three years of operation, over 8 million passengers were transported.
Today, the leaders in maglev technology (an abbreviation for magnetic levitation used in the West) are Japan and Germany. In Japan, the maglev set a world record for the speed of rail transport - 581 km / h. But Japan has not yet advanced further than setting records, trains run only on experimental lines in Yamanashi prefecture, with a total length of about 19 km. In Germany, the development of maglev technology is carried out by the Transrapid company. Although the commercial version of the Maglev has not caught on in Germany itself, the trains are operated at the Emsland Proving Ground by Transrapid, which has successfully implemented a commercial version of the Maglev in China for the first time in the world.
As an example of already existing transport mechatronic systems (TMS) with autonomous control, one can cite a robotic machine from VisLab and the laboratory of machine vision and intelligent systems of the University of Parma.
Four robotic cars have covered an unprecedented path for autonomous vehicles of 13 thousand kilometers from Italian Parma to Shanghai. This experiment was intended to be a tough test for the intelligent autonomous driving system TMS. It was also tested in city traffic, for example, in Moscow.
Robot cars were built on the basis of minibuses (Figure 5.31). They differed from ordinary cars not only in autonomous control, but also in pure electric traction.
Rice. 5.31. VisLab autonomous vehicle
On the roof of the TMC, solar panels were located to power critical equipment: a robotic system that turns the steering wheel and presses the gas and brake pedals, and computer components of the car. The rest of the energy was supplied by electrical outlets as we traveled.
Each robot car was equipped with four laser scanners in the front, two pairs of stereo cameras looking forward and backward, three cameras covering a 180-degree field of view in the front "hemisphere" and a satellite navigation system, as well as a set of computers and programs that allow the machine to make decisions in certain situations.
Another example of a mechatronic transport system with autonomous control is the RoboCar MEV-C robotic electric vehicle of the Japanese company ZMP (Figure 5.32).
Figure 5.32. RoboCar MEV-C robotic electric vehicle
The manufacturer positions this TMC as a machine for further advanced developments. The autonomous control device includes the following components: a stereo camera, a 9-axis wireless motion sensor, a GPS module, a temperature and humidity sensor, a laser rangefinder, Bluetooth, Wi-Fi and 3G chips, and a CAN protocol that coordinates the joint operation of all components ... The RoboCar MEV-C measures 2.3 x 1.0 x 1.6 m and weighs 310 kg.
The modern representative of the mechatronic transport system is the transcooter, which belongs to the class of light vehicles with an electric drive.
Trans-scooters are a new type of transformable multifunctional land vehicles for individual use with an electric drive, mainly intended for people with disabilities (Figure 5.33). The main distinguishing feature of the transcooter from other land vehicles is the ability to pass through flights of stairs and the implementation of the principle of multifunctionality, and therefore transformability in a wide range.
Rice. 5.33. Appearance one of the samples of the trans scooter of the "Kangaroo" family
The propeller of the transcooter is made on the basis of a mechatronic module of the "motor-wheel" type. The functions and, accordingly, the configurations provided by the "Kangaroo" family of trans scooters are as follows (Figure 5.34):
- "Scooter" - movement at high speed on a long base;
- "Chair" - maneuvering on a short base;
- "Balance" - movement while standing in the gyrostabilization mode on two wheels;
- "Compact-vertical" - movement while standing on three wheels in the gyro-stabilization mode;
- "Curb" - overcoming the curb right away while standing or sitting ( individual models have an additional function "Oblique curb" - overcoming the curb at an angle of up to 8 degrees);
- "Ladder up" - climbing the steps of the stairs forward, sitting or standing;
- "Ladder down" - descent along the steps of the stairs forward, while sitting;
- "At the table" - low seating position, feet on the floor.
Rice. 5.34. Basic configurations of a transcooter on the example of one of its variants
The trans scooter consists of an average of 10 compact high-torque electric drives with microprocessor control. All drives are of the same type - valve DC motors controlled by signals from Hall sensors.
To control such devices, a multifunctional microprocessor control system (CS) with an on-board computer is used. The architecture of the transcooter control system is two-tier. The lower level is servicing the drive itself, the upper level is the coordinated operation of the drives according to a given program (algorithm), testing and monitoring the operation of the system and sensors; external interface - remote access. As a top-level controller ( on-board computer) uses the PCM-3350 from Advantech, made in the PC / 104 format. The lower-level controller is a Texas Instruments specialized microcontroller TMS320F2406 for controlling electric motors. The total number of low-level controllers responsible for the operation of individual units is 13: ten drive controllers; steering head controller, which is also responsible for indicating the information displayed on the display; residual capacity controller battery; battery charge and discharge controller. Data exchange between the on-board computer of the transcooter and peripheral controllers is supported via a common bus with a CAN interface, which allows minimizing the number of wires and achieving a real data transfer rate of 1 Mbit / s.
Tasks of the on-board computer: control of electric drives, service of commands from the steering head; calculation and display of the residual battery charge; solving the trajectory problem for moving up the stairs; the possibility of remote access. The following individual programs are implemented via the on-board computer:
Acceleration and deceleration of a scooter with controlled acceleration / deceleration, which is personally adapted for the user;
A program that implements the algorithm for the operation of the rear wheels when cornering;
Longitudinal and transverse gyro stabilization;
Overcoming the curb up and down;
Up and down stairs
Adaptation to the size of the steps;
Identification of staircase parameters;
Wheelbase changes (from 450 to 850 mm);
Monitoring of scooter sensors, drive control units, battery;
Emulation based on the readings of the parking radar sensors;
Remote access to control programs, changing settings via the Internet.
The transcooter has 54 sensors that allow it to adapt to the environment. Among them: Hall sensors built into the valve electric motors; absolute angle encoders that determine the position of the components of the transcooter; resistive steering wheel rotation sensor; infrared distance sensor for parking radar; inclinometer, which allows you to determine the inclination of the scooter while driving; accelerometer and angular rate sensor for gyro stabilization control; radio frequency receiver for remote control; a resistive linear displacement transducer for determining the position of the chair relative to the frame; shunts for measuring motor current and residual battery capacity; potentiometric speed controller; strain gauge weight sensor to control the weight of the device.
The general block diagram of the CS is shown in Figure 5.35.
Rice. 5.35. Block diagram of a control system with a trans-scooter of the "Kangaroo" family
RMC - absolute angle encoders, DX - Hall sensors; BU - control unit; ZhKI - liquid crystal indicator; MKL - left wheel motor; MCP - right wheel motor; BMS - Power Management System; LAN - a port for external connection of an on-board computer for programming, settings, etc .; T - electromagnetic brake.
