GB2127586A - Method and apparatus for controlling modular systems - Google Patents

Abstract

For control purposes, each of the individually variable components (11-13) is associated with an autonomously operating control unit (14-16) provided with setpoints (34-36) from a common master computer (25). The various control circuits are replaceable without necessarily requiring the replacement of the master computer, and their operability is independent of the master computer condition. The superordinate master computer responds to system-oriented characteristics (27), measured variables (28) and further information (33) for the purpose of optimizing the overall operation. <IMAGE>

Description

SPECIFICATION Method and apparatus for controlling modular systems This invention relates to a method for the electronic control of a modular system which in its entirety forms a functional entity and the functional modules of which are individually variable.

In diverse field of application, use is made of machine groups the various units or modules of which are functionally interrelated and require control to various criteria determined by economic, functional and manufacturing aspects.

The control methods are selected, again with due consideration given the above aspects, to suit the specific application, where wide use is made of computers to assist the control process.

Computer-controlled control units enable the functional cycle of a system to be optimized from user-defined aspects. German laid open print DE-OS 3 049 938 discloses an electronic central control unit to drive the respective actuating elements of an internal-combustion engine and of two water pumps driven by the prime mover.

Central control provisions of this nature require rather fast data processing and signal computation methods to suit the control cycle, which severely restricts the potential application of computers and due to allowance of control or modulating signals for the control cycle. Said previously disclosed method is also embarrassed by the disadvantage of central control failure immobilizing the entire control system and, with it, the IC engine and pump installation.

An object of the present invention is to provide a method of operating in a maximally simple manner a multi-module system safely and optimaliy to satisfy in its entirety the requirements imposed.

The invention provides a method for the electronic control of a modular system which in its entirety forms a functional entity and the functional modules of which are individually variable, wherein autonomously operating control units are used for each of the various functional modules and setpoints are provided by a master computer for the various control circuits to optimize the overall system, the said setpoints varying with the specific operation and application and being computed to certain application criteria from measured variables and other control signals.

In this manner, flexible, universally applicable control provisions are achieved that can be implemented by simple manufacturing means for the largely safe and optimum operation of a system.

The allocation of autonomous control circuits to the functional components of a modular system provides added safety over the known method in that failure of the master computer will have no impact on the continued operation of the control circuits or components and, thus, of the overall installation. Another result is that the master computer can be shut down for servicing or program modification also while the system is in operation and without necessarily interrupting system operations.

The method of the present invention provides another important advantage in that a system can be controlled with due consideration given all desirable system-related and external quantities while at the same time the modules or control circuits are replaceable without necessitating constructional changes to the remaining components or to the master computer. This makes it possible, therefore, to replace damaged control circuits and, moreover, to replace component modules and integrate commercial components together with associated control units into the system control. This merely requires adaptation of the computer program.

As a result of the independent operability of the individual control circuits the selection of a computer is not as narrow as it is with said known method, considering that with the method of the present invention, computer operations will not have to be timed to suit the control circuit cycle.

Serial transfer of data from the computer to the control modules permits slow transmission, enabling use to be made of slow computers on the one hand and of comprehensive programs allowing for all conceivable impacts on setpoint selection for optimized system operation on the other.

The method of the present invention provides an advantage also in that a universally usable master computer can be provided which is fitted with a large number of ports for the control circuits. Adaptation to the respective application can then be merely by software.

For adaptation to the respective application, the property data of the functional modules, as the performance characteristics and other characteristics specific to the module, are stored in the master computer, and the setpoints are computed from these data in accordance with characteristics specific to the system.

The method of the present invention is suitable especially for the control of power transmission systems comprising any number of prime movers and converters the performance characteristics of which can optimally be linked from overall strategic aspects to compute the setpoints. In the present case and in other cases where transient external factors may affect system operations, such as pressure, temperature and external influences bearing an operational speed, these factors are advantageously allowed to enter in the computation of the setpoint in the form of suitable superordinate modulating signals. This enables the overall system or individual functional modules to be adapted to the respective requirements enveloped to exploit rises caused by the situation at the moment in, e.g. efficiency, for economizing primary energy.

Similarly, memories associated with the power transmission system can be considered in the control effort, for the reason that peculiarities of the functional modules known to the master computer is included as the type of storage.

Where the storage can be made in hydropneumatic, mechanical, electrical or chemical form.

Embodiments of the present invention are shown in Figs. 1 to 3 of the accompanying drawings.

In Fig. 1 the control method is applied to a general modular system consisting of, e.g. three machine units 11-13 combined to form a functional entity 10. The units 11-13 are each associated'with a control unit 14-1 6 to individually receive from its associated machine the signals 1 7-1 9 and process them to form actuating signals 20-22. The control units 14-1 6 are designed such that they can autonomously control the associated machine unit in due consideration of functionally essential criteria.

The various control circuits 11, 17, 14, 20; 12, 18, 15,21;and 13,19, 16, 23 are related toa superordinate master computer 25 communicating with numerous signal transmitters and receivers through a data bus 26.

A liberally comprehensive design of the master computer will make for a universally applicable master computer which is suitable for series production and which can be used for any modular system and any data input pattern. The storage of attributes 27 specific to the system, such as characteristics and performance envelopes of the individual machine units 11-13 and the functional entity 10, the input of test signals 28 consisting of the output variables 29-31 of the functional modules 11-1 3 and external quantities 32, such as pressure and temperature, and of further superordinate control signals, as perhaps by operating personnel, will ensure in conjunction with a suitable computer program, that the master computer develops setpoints (34-36) for the control circuits that ensure optimum operation of the functional entity 10 in accordance with desirable optimization criteria.

Finally, information stations 38, such as recorders and digital indicators, can be provided for the periodical or continuous display of functional data diagnosis, etc.

Disruption in the data buses, or breakdown of the master computer will have no effect on the continued operation of the system to be controlled. The individual components 11-10, 12-1 5, and 1 3-10, respectively, can maintain normal operation -- with certain optimization criteria restricted -- because of the autonomous operation of the associated control units 14-1 6.

In this manner, also brief interruption in the supply of the regulating variable while the system is in operation can safely be allowed for the purpose of making changes or repairs in the data transfer circuits or in the master computer. Also, system components can be replaced or combined in any fashion, such as practiced in motor vehicle construction and in other fields. In this manner, the same functional units are often fitted with different types of modules as required for the application or desired by the customer.

A control system as just described may find use in, e.g., power transmission systems, such as they are used in power stations. This is exemplified by the embodiment illustrated in Fig. 2. The functional entity comprises of a prime mover 40, a power converter 41 and a driven machine 42, where the prime mover 40 is associated with an output control unit 43 and an actuating element 44. The output control unit 43 receives speed signals from the prime mover 45 and status signals 46 of the actuating element 44 for independent control of the prime mover with due consideration given its performance envelope.

Similarly the converter 41, together with a superordinate transmission ratio control 47, forms an independent control circuit 41, 49, 47, 48 which additionally responds to the output speed 50.

The system is also fitted with an energy storage unit 51 able to withdraw energy from and restore it to the converter as needed.

These control circuits are related to a master computer 53 to motivate individual control such that the outputs from the overall system and boundary conditions are linked together for optimum operation of the overall system in accordance with specific criteria. For the purpose, the computer receives informational data on input speed 45, output speed 50, storage status 52 of the energy storage unit 51 and, through auxiliary sensors 55, information on pressure, temperature, exhaust gas and similar system data as well as operating conditions 56. Using these data and in observance of system-oriented criteria, the master computer develops setpoints 60 and 61 going to the output control unit 43 and the transmission ratio control unit 47, respectively.The transfer of these setpoints 60 and 61 is independent of the speed required for the control cycle, which normally is inevitably very high especially considering that the control circuits operate autonomously. It will therefore be possible to consider in the computer program a great number of criteria and data to maximally approximate the setpoints 60, 61 to their ideal values even if this slows the transfer of data from the master computer to the control circuits.

Fig. 3 illustrates another application for the power train 65 to 67 of a motor vehicle, where a first module 65, which is here exemplified by a diesel engine, is associated with an autonomous control circuit 68, and the gearbox 66 with an autonomous control circuit 69. The control circuits 68 and 69 are supplied, through a data bus 70, with setpoints 72 and 73, respectively, from a computer 71 remotely accommodated in the vehicle. For the purpose, the computer receives output or operating signals 75 from the vehicle 67 and the power train, respectively. The computer 71 also accepts operating signals 76 entered by the vehicle operator. An information output point 77 can be connected to the data bus 70 if required.

The control method here described will also enable the integration of complex information systems operated by the master computer. An embodiment for vehicle applications is illustrated in Fig. 4, where an information system 77' exchanges data with the master computer 71. The annunciation system 80 associated with the information system enables the display of the signals transferred to the master computer to serve in the control process. The system can be expanded to include diagnosis units 81 and further additional data inputs, as perhaps the skid protection condition 82 of an antiblocking system to give the vehicle operator comprehensive information on the condition of the vehicle, on consumption and on sources of malfunction.

The radio equipment required in many commercial vehicles can be included in the information system.

Claims (9)

1. Method for the electronic control of a modular system which in its entirety forms a functional entity and the functional modules of which are individually variable, wherein autonomously operating control units are used for each of the various functional modules and setpoints are provided by a master computer for the various control circuits to optimize the overall system, the said setpoints varying with the specific operation and application and being computed to certain application criteria from measured variables and other control signals.

2. A method as claimed in Claim 1, wherein the master computer is adapted to store data regarding the properties of the functional modules and the setpoints are computed from these data in accordance with specific system criteria.

3. A method as claimed in Claim 1 or 2, wherein computation of the setpoint is influenced by superordinate modulating signals for adaptation to the respective requirements profile of the overall system or of individual functional modules.

4. A method substantially as herein described with reference to any one of the embodiments shown in the accompanying drawings.

5. Apparatus for carrying out the method as claimed in any one of the preceding claims comprising a master computer and at least one control circuit, wherein the various functional modules to form a variable modular system are autonomous control circuits which are subordinate to the master computer so as to receive setpoints from it.

6. Apparatus as claimed in Claim 5, wherein the control circuits are adapted to follow moduleoriented criteria.

7. Apparatus as claimed in claim 5 or 6 for the control of a modular power transmission system consisting of at least one prime mover and at least one converter, wherein the prime mover or prime movers and the converter(s) each form, together with the respective associated control unit autonomous control circuits which are subordinate to the master computer.

8. Apparatus as claimed in Claim 7, wherein the master computer is adapted to store the component properties resulting from the type of storage of the input energy required to power the prime mover.

9. Apparatus substantially as herein described with reference to any one of the embodiments shown in the accompanying drawings.