Communication control unit providing isolation of failure condition of electronic control unit

• US 4,835,671 A
• Filed: 09/17/1987
• Issued: 05/30/1989
• Est. Priority Date: 09/19/1986
• Status: Expired due to Fees

• Current Assignee: Nippondenso Company Limited 1-1 Showa-Cho Kariya-Shi Aichi Japan, Toyota Jidosha Kabushiki Kaisha 1 Toyota-Cho Toyota-Shi Aichi-Ken Japan
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hirabayashi, Yugi, Saito, Takao, Sato, Yoshihisa, Akiyama, Susumu, Ito, Katsunori, Ina, Katsuhiro, Tanigawa, Tetsuo
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): Gordon, P.
• Application Number:
  US07/098,048
• Time in Patent Office: 621 Days
• Field of Search: 364/186, 364/184, 371/9, 371/12, 371/14, 371/61, 371/68, 123/479
• US Class Current: 700/81
• 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: G05B 23/0291 Switching into safety or degraded mode, e.g. protection and supervision after failure
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/142 Reconfiguring to eliminate the error group management mechanisms in a peer-to-peer network H04L67/1044
• CPC Class Codes: G06F 11/2221 to test input/output devices or peripheral units

Abstract

A communication control unit for controlling communication between an electronic control unit and other equipment or other electronic control units, the communication control unit functioning to judge whether or not the operation of the electronic control unit is normal and, if it is judged that the electronic control unit is operating abnormally, the communication control unit acts to reset the electronic control unit to an initial operating status in order to attempt recovery from the abnormal condition, while halting transmission by the electronic control unit until it is judged that the electronic control unit has commenced to operate normally.

Claims

1. A communication control unit for controlling communication between an electronic control unit and other equipment, comprising:

judgement means for judging whether or not said electronic control unit is operating normally, and

transmission halting means controlled by said judgement means for resetting said electronic control unit to a reset condition and halting transmission therefrom if it is judged by said judgement means that said electronic control unit is operating abnormally and for maintaining said reset condition and halting of transmission by said electronic control unit until it is judged that said electronic control unit is operating normally, wherein said transmission halting means maintains said reset condition of said electronic control unit and halting of transmission by said electronic control unit for a first predetermined time interval, and in which upon completion of said first predetermined time interval said transmission halting means acts to terminate said reset condition of said electronic control unit and halts transmission by said electronic control unit after a second predetermined time interval has elapsed following completion of said first predetermined time interval, unless normal operation of said electronic control unit is judged to be restored within said second predetermined time interval.

2. A communication control unit for controlling communication between a corresponding electronic control unit and at least two other electronic control units, each of said electronic control units comprising a data processing unit, and all of said electronic control units mutually communicating via a single communication signal line, said communication control unit comprising:

a receiving circuit and a transmission circuit for coupling a corresponding electronic control unit to said communication signal line;

judgement means for judging whether or not a data processing unit of said corresponding electronic control unit is operating normally; and

transmission halting means controlled by said judgement means for resetting said data processing unit and halting operation of said transmission circuit if it is judged by said judgement means that said data processing unit is operating abnormally, and for maintaining said halting of transmission circuit operation together with continued operation of said receiving circuit until it is judged by said judgement means that said data processing unit is operating normally.

3. A communication control apparatus for a motor vehicle, the communication control apparatus having a single communication signal line and at least three electronic control units for controlling respective operating functions of said motor vehicle, each of said electronic control units comprising a data processing unit, a receiving circuit and a transmission circuit for transferring data to and from each other electronic control unit via said single communication signal line, each of said electronic control units further comprising:

a monitor circuit for monitoring the operation of said data processing unit to judge whether or not said data processing unit is operating normally; and

a transmission control circuit controlled by said monitor circuit such that when it is judged by said monitor circuit that said electronic control unit is operating abnormally, said data processing unit is reset and transmission of data from data processing unit by said transmission circuit is inhibited while data receiving operation by said receiving circuit is continued.