Multiplex transmission system

• US 5,343,470 A
• Filed: 08/06/1993
• Issued: 08/30/1994
• Est. Priority Date: 09/13/1990
• Status: Expired due to Term

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Michihira, Osamu, Nobutoki, Yoshikazu, Sone, Akira, Hideshima, Masao
• Primary Examiner(s): Chin, Wellington
• Application Number:
  US08/102,953
• Time in Patent Office: 389 Days
• Field of Search: 370/85.1, 370/85.2, 370/85.3, 370/85.4, 370/85.5, 370/85.6, 370/85.15, 340/825.5, 340/825.51, 340/438, 340/439, 340/440, 340/441, 340/449, 340/450, 340/450.1, 340/450.2, 340/450.3, 340/451, 340/452, 340/455, 340/459 , 340/870.13
• US Class Current: 370/462
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: B60R 2016/0322 Temporary code for documents to be reclassified to G08C, H04L or H04Q
• CPC Class Codes: H04L 12/4013 Management of data rate on the bus systems modifying transmission characteristics according to link quality H04L1/0001
• CPC Class Codes: H04L 2012/40273 the transportation system being a vehicle

Abstract

In a multiplex transmission system wherein data is transmitted among a plurality of control units connected to a multiplex transmission line in decentralized fashion, communication is performed upon changing the period of the data transmission among the control units and the method of transmission, such as the order of priority of transmission, in dependence upon the travelling state of the vehicle equipped with the multiplex transmission system, the operating states of the control units or the control unit which is a party to the communication.

Claims

1. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another at a prescribed period, comprising:

informing means for informing each control unit of the travelling state of the vehicle by providing the each control unit with the information; and

transmission control means for changing the period in which the information is transmitted among the plurality of control units, the change being made by referring to a map which contains both the travelling state of the vehicle and corresponding information transmission periods.

2. The system according to claim 1, wherein said transmission control means decides an order of priority for transmission of information among the plurality of control units, and changes said order of priority in dependence upon the travelling state of the vehicle.

3. The system according to claim 1, wherein said transmission control means performs transmission of information with respect to a specific control unit periodically, and changes said specific control unit in dependence upon the travelling state of the vehicle, and wherein said specific control unit is specified from among said plurality of control units so as to act as a main control unit for obtaining a stable engine control

4. The system according to claim 1, wherein said transmission control means includes means for determining whether operation of each control unit is in a stable state or unstable state and changes the period of transmission of information during a time set by a timer, between one method when a control unit is in the stable state and another method when the control unit is in the unstable state, based upon results of the determination.

5. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another at a prescribed period, comprising:

informing means for informing each control unit of the travelling state of the vehicle by providing the each control unit with the information; and

transmission control means for changing the period in which the information is transmitted among the plurality of control units, the change being made in dependence upon the travelling state of the vehicle, wherein said transmission control means is adapted to change the period of transmission at starting of an engine in such a manner that the information is transmitted at a period shorter than said prescribed period.

6. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another, comprising:

means for specifying a communicating-party control unit from among the plurality of control units, with which the plurality of control units perform transmission and reception of information; and

transmission control means for performing transmission of information with respect to said specified communicating-party control unit periodically, and changing a period of the periodical transmission of information by referring to a map which contains both said specified communicating-party control unit and corresponding information transmission periods.

7. The system according to claim 6, wherein said transmission control means includes means for sensing a travelling state of the vehicle, wherein the period of transmission of information is changed in independence upon the specified communicating-party control unit and the travelling state of the vehicle.

8. The system according to claim 7, wherein said transmission control means includes means for determining whether operation of each control unit is in a stable state or unstable state and changes the period of transmission of information during a time set by a timer, between one method when a control unit is in the stable state and another method when the control unit is in the unstable state, based upon results of the determination.

9. The system according to claim 6, wherein said transmission control means includes means for determining whether operation of each control unit is in a stable state or unstable state and changes over transmission of information from periodic transmission to transmission in accordance with occurrence of an event, or from transmission in accordance with occurrence of an event to periodic transmission, in dependence upon the specified communication-party control unit and the travelling state of the vehicle, during a time set by a timer, between one method when a control unit is in the stable state and another method when the control unit is in the unstable state, based upon results of the determination.

10. The system according to claim 6, wherein said transmission control means performs transmission of information with respect to a specific control unit periodically, renders transmission of information with respect to the rest of said control units that is in accordance with occurrence of an event, and changes said specific control unit in dependence upon the travelling state of the vehicle, and wherein said specific control unit is specified from among said plurality of control units so as to act as a main control unit for obtaining a stable engine control.

11. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another, comprising:

first control means for performing control in such a manner the information necessary for controlling one of the plurality of control units is transmitted from the rest of said control units;

discriminating means for determining whether operation of each control unit is in a stable state or unstable state; and

second control means for changing the method of transmission control during a time set by a timer, which is performed by the first control means, between one method when a control unit is in the stable state and another method when the control unit is in the unstable state, based upon results of determination made by said discriminating means.

12. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another, comprising:

first control means for performing control in such a manner the information necessary for controlling one of the plurality of control units is transmitted from the rest of said control units;

discriminating means for determining whether operation of each control unit is in a stable state or unstable state; and

second control means for changing the method of transmission control during a time set by a timer, which is performed by the first control means, between one method when a control unit is in the stable state and another method when the control unit is in the unstable state, based upon results of determination made by said discriminating means, wherein said second control means is so adapted that when said discriminating means has determined that one of the plurality of control units has performed a system reset and is in the unstable state, said second control means changes the method of transmission control, which is performed by said first control means, for a predetermined time following the system reset in such a manner that said rest of said control units which transmit the information necessary for controlling said one of the plurality of control units perform transmission of information at a period shorter than that which prevails when said one of the plurality of control units is in the stable state.

13. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another, comprising:

first control means for performing control in such a manner the information necessary for controlling one of the plurality of control units is transmitted from the rest of said control units;

discriminating means for determining whether operation of each control unit is in a stable state or unstable state; and

second control means for changing the method of transmission control during a time set by a timer, which is performed by the first control means, between one method when a control unit is in the stable state and another method when the control unit is in the unstable state, based upon results of determination made by said discriminating means, wherein said second control means is so adapted that when said discriminating means has determined that said control unit is in the stable state, said second control means changes the method of transmission control, which is performed by said first control means, in such a manner that said rest of said control units which transmit the information necessary for controlling said control unit perform transmission of information in accordance with occurrence of an event, and when said discriminating means has determined that said control unit is in the unstable state, said second control means changes the method of transmission control, which is performed by said first control means, in such a manner that said rest of said control units perform transmission of information periodically.

14. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another at a prescribed period, comprising:

informing means for informing each control unit of the travelling state of the vehicle by providing the each control unit with the information; and

transmission control means for changing the period in which the information is transmitted among the plurality of control units, the change being made in dependence upon the travelling state of the vehicle, wherein said transmission control means is adapted to change the period of transmission at turning the vehicle in such a manner that the information is transmitted at a period shorter than said prescribed period.

15. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another at a prescribed period, comprising:

first control means for performing control in such a manner the information necessary for controlling one of the plurality of control units is transmitted from the rest of said control units;

discriminating means for determining whether operation of each control unit is in a stable state or unstable state; and

second control means for changing the period of transmission control, which is performed by the first control means, between one period when a control unit is in the stable state and another period when the control unit is in the unstable state, based upon results of determination made by said discriminating means.

16. The system according to claim 15, wherein said second control means is adapted to change the period of transmission at performing a system reset in such a manner that the information is transmitted at a period shorter than said prescribed period.

17. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another in a prescribed method, comprising:

determining means for determining a specific control unit from among the plurality of control units which transmit information necessary for controlling one of the plurality of control units;

informing means for informing each control unit of the travelling state of the vehicle by providing the each control unit with the information; and

transmission control means for changing the method of transmission of information, which is performed by the specific control unit, in dependence upon the travelling state of the vehicle, wherein the specific control unit relates to an engine control and said transmission control means is adapted to change the method of transmission at starting of the engine.

18. A multiplex transmission system, for use in an automotive vehicle, in which a plurality of control units connected in decentralized fashion to a common transmission line transmit and receive information to and from one another in a prescribed method, comprising:

determining means for determining a specific control unit from among the plurality of control units which transmit information necessary for controlling one of the plurality of control units;

informing means for informing each control unit of the travelling state of the vehicle by providing the each control unit with the information; and

transmission control means for changing the method of transmission of information, which is performed by the specific control unit, in dependence upon the travelling state of the vehicle, wherein the specific control unit relates to a turning of the vehicle and said transmission control means is adapted to change the method of transmission at turning the vehicle.