Distributed control system and information system

Abstract

The present invention provides a real-time distributed system which can improve productivity of software by suppressing a volume of software change incident to change in the system configuration, and can send or receive a message requested to be sent or received corresponding to its priority. A middleware is contained in each of control units. Services of the middleware in each of the control units are as follows, that is, 1. tasks T1, . . . , Tn for executing starting AP modules and calling RT communication processing according to starting order information and the like in AP configuration information, and 2. RT communication service for executing sending and receiving messages Msgl, . . . , Msgn between the AP modules corresponding to the calling. The AP configuration information and the messages are generated by an information processor based on user defined information and transmitted to each of the units by on-line or off-line. Further, the real-time distributed system comprises a network controller for executing network communication by storing a plurality of sending and receiving messages, a network driver for executing network communication using the network controller, a network driver for executing network communication using the network controller, a network driver priority management means for determining priority of processing of the network driver corresponding to priorities of sent and received messages to be handled, and a scheduling means for executing processing of the network driver according to the priority of the processing of the network driver.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a distributed control system in which a plurality of built-in systems are connected with a field network such as a CAN (controller area network), a foundation field bus or the like. [0002] A distributed control system in which a plurality of built-in systems are connected with a field network has been applied to a power train control system of a vehicle, a field instrument control system of factory automation or process automation, a control system of a medical instrument or a robot. [0003] In an LON (local operating network) of a kind of field networks or in a standard communication protocol for automobile control OSEK-COM), a library method is employed. In the library method, an application program module (hereinafter, referred to as AP module) calls communication processing. A technology in connection with the library method is described, for example, in “OSEK / VDX Communication Version 2.0a (edited by OSEK group)...

AI Technical Summary

Benefits of technology

[0009] Further, according to the conventional memory transcribing method, traffic on the network is easily occurs because data on a common memory is periodically transferred and updated ny the communication processing.

[0010] A first object of the present invention is to provide a distributed control system which can easily guarantee the real-time operatability of end-to-end over a network and can suppress a volume of software change incident to change in the system configuration. A second object of the present invention is to provide an information processing system which can automatically produce information defining the control structure of each control unit on the distributed control system.

[0013] Therefore, a third object of the present invention is to provide a distributed control system which can send a message of the highest priority among messages required to be sent even if the network driver processing has been already started.

[0018] In the distributed control system, because the starting control means makes the application program and the communication control program into operation according to the module configuration information, the application program and the message communication processing program are completely separated from each other. Therefore, according to the distributed control system, even if the system configuration or the unit configuration is changed, the application can be executed under the new system configuration by changing only the set contents of the module configuration information without changing the software. That is, since a volume of software change incident to change in the system configuration can be suppressed to minimum, labor for matching the application to the new system can be reduced and productivity of software can be improved.

[0019] Further, in the distributed control system, since starting order of the application program and the communication control program on each of the control units can be changed by changing the set contents of the module configuration information on each of the control units, the application program and the communication control program can be easily started synchronously or asynchronously. Therefore, it is easy to shorten the worst executing time of sensor inputting to actuator outputting including the communication processing through the network, and it is easy to guarantee the real time operatability of end-to-end.

[0021] According to the information processing system, only by inputting the input information such as the system configuration information determining the starting order of all the application modules composing the application into the input receiving means, the information defining the control structure of each of the control units of the distributed control system, that is, any one of the module configuration information and the message object is automatically generated based on the input information. Therefore, the present information processing system is useful for easily insuring the real-time operatability of end-to-end of the distributed control system.

Problems solved by technology

However, in the conventional library method described above, it is difficult to guarantee the worst executing time of sensor inputting to actuator outputting including the communication processing through the network, that is, to guarantee the real time operatability of end-to-end because a communication process or the like is described in the AP module.

In other words, in a case where real-time operatability is independently guaranteed for each AP module in taking the starting timings of the AP module and communication processing into consideration, the AP module needs to be completely re-written ever change in the system configuration because the AP module does not have versatility at least in the real-time operation, and accordingly the real-time operatability of end-to-end is difficult to be guaranteed.

However, when the units of different kinds are interconnected and rewriting of the AP module on each of the units is impossible, the real-time operatability of end-to-end can not be guaranteed.

On the other hand, according to the conventional memory transcribing method described above, the worst executing time of each AP module and the worst executing time of communication processing are guaranteed because the AP module and the communication processing are separated from each other, but the data transmission delay occurs because the AP module and the communication processing are asynchronously started.

Therefore, the worst executing time from sensor input to actuator output including the communication processing through the network is not guaranteed.

From such a reason, it is considered that the conventional memory transcribing method is unsuitable for processing severe in requiring the worst executing time.

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