Electronic control system having master/slave CPUs for a motor vehicle

• US 5,481,456 A
• Filed: 12/28/1994
• Issued: 01/02/1996
• Est. Priority Date: 09/04/1990
• Status: Expired due to Fees

• Current Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Ogura, Akira
• Primary Examiner(s): Ta, Khoi Q.
• Application Number:
  US08/365,328
• Time in Patent Office: 370 Days
• Field of Search: 364/132, 364/138, 364/424.01, 364/424.03, 364/424.1, 364/432, 364/431.04, 477/97
• US Class Current: 701/1
• 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: B60T 13/662 characterised by specified functions of the control system components
• CPC Class Codes: F02D 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue
• CPC Class Codes: F16H 59/00 Control inputs to control units of change-speed-, or reversing-gearings for conveying rotary motion
• CPC Class Codes: G05B 19/0421 Multiprocessor system
• CPC Class Codes: G05B 2219/21034 Address I-O
• CPC Class Codes: G05B 2219/2231 Master slave
• CPC Class Codes: G05B 2219/2237 Selection of master or slave
• CPC Class Codes: G05B 2219/25133 Serial parallel conversion
• CPC Class Codes: G05B 2219/25324 Modules connected to serial bus
• CPC Class Codes: G06F 15/8015 One dimensional arrays, e.g. rings, linear arrays, buses

Abstract

An electronic control system for a motor vehicle, having multiple sensors (M1) for detecting the operating condition parameters of the motor vehicle; a master controller (M4) from and to which communication lines are laid; and a plurality of slave controllers (M2) which convert the operating condition parameters detected by the sensors (M1) and various data items processed in the control system, into serial data items and transmit them to the master controller (M4) through the communication lines, and which control a plurality of components (M3) installed on the motor vehicle, on the basis of data items received from the master controller (M4); the master controller (M4) being connected with the plurality of slave controllers (M2) through the communication lines, to calculate controlling data items on the basis of various data items received as inputs from the respective slave controllers (M2), and converting the controlling data items into the serial data items and transmitting them to the respective slave controllers (M2) through the communication lines.

Claims

1. An electronic control system for a motor vehicle having, a plurality of parameter detecting means for sensing operating conditions of said motor vehicle and for generating an operating condition signal, and a plurality of actuating means for controlling said motor vehicle, the system comprising:

a plurality of slave control means responsive to said operating signals for controlling said actuating means and for producing a control signal;

master control means connected to each slave control means through a common serial bus for providing a respective control signal requesting said control signal to each of said slave control means for controlling of said actuating means;

said slave control means converts a requested control signal into a serial data signal and transmits said serial data to said master control means during a reception of said respective control signal;

said master control means integrally calculates an operating condition of the vehicle from said serial data signal and produces said respective control signal based on said operating condition of the vehicle so as to minimize transmission volume of said signals between said master and slave control means and to effectively control said motor vehicle; and

said slave control means comprising an ABS controller, an automatic transmission controller and an engine controller.

2. The electronic control system according to claim 1 wherein:

said parameter detecting means comprising an air flow meter, a crank angle sensor, a vehicle speed sensor and a wheel speed sensor.

3. The electronic control system according to claim 1, wherein:

said actuating means comprising an A/T actuator, an ABS brake actuator, a fuel injector and an ignition coil.

4. An electronic control system for a motor vehicle having, a plurality of parameter detecting means for sensing operating conditions of said motor vehicle and for generating an operating signal, and a plurality of actuating means for controlling said motor vehicle, the system comprising:

a plurality of slave control means responsive to said operating signal for controlling said actuating means and for producing a control signal;

master control means responsive to said control signal and connected to each slave control means for providing respective control signal to be used in calculation by said slave control means to control said actuating means; and

a communication circuit provided in each said slave control means and said master control means and connected to each other for converting said control signal into a serial form in order to transmit said respective control signals between said slave control means and said master control means in said serial form so as to reduce an occupancy of a property of the system by a data transmission task.

5. The electronic control system according to claim 4, wherein said communication control circuit further comprises;

a communication control circuit responsive to a communication clock signal for counting a data transmission number and for producing a communication finish signal;

a receiving circuit responsive to said control signal in serial form for converting into parallel form to store to a receiving register;

a transmitter circuit for converting said control signal in a transmitting register into serial form and for generating a control signal in serial form;

a comparing circuit for comparing first reception data of said control signal stored in said receiving register with said control signal stored in said transmitting register and for producing an output signal; and

an interrupt generator circuit responsive to said communication finish signal and said output signal for triggering a flip-flop and for producing an interrupt signal in order to write a data into a predetermined address of a main memory of one of said main control means and said slave control means in which said communication control means provided so as to establish easily and fast access, and improve communication.

6. The electronic control system according to claim 4, wherein said communication circuit further comprises;

a selector circuit responsive to a select signal and a system clock of said master control means for providing a communication clock signal.

7. The electronic control system for a motor vehicle according to claim 4, wherein said communication circuit comprises:

a selector circuit responsive to a select signal and a system clock of said slave control means for providing a monitor clock; and

a communication control circuit responsive to said monitor clock and said communication clock signal for detecting a malfunction of transmission and for producing a reset signal to said master control means.

8. A electronic control system for a motor vehicle which provides a plurality of equipment controlled by each electric controller having a microprocessor, a memory, an I/O interface and a bus-line connecting said microprocessor, said memory and said I/O interface with each other, the system comprising:

a master controller providing a microprocessor, a memory, and a bus-line connecting said microprocessor and said memory with each other for processing a control data in order to control said each electronic controller;

a sensor connected to at least one of said each electronic controller for sensing conditions being regarded to control said each equipment and for transmitting a parameter signal corresponding said condition to said each controller to be processed in said each electronic controller;

a communication line providing a serial data bus for transmitting a data in serial form; and

a communication circuit provided to each of said master controller and said each electronic controller, and connected to each other through said serial data bus, which communication circuit provide a transmitting register connected to each microprocessor through said bus-line for storing a transmitting data, a parallel/serial converter directly accessing to said transmitting register for converting said transmitting data into serial form to transmit toward another of said electronic controllers through said serial data bus, a serial/parallel converter for converting a received data from said other controller through said serial data bus into parallel form, a receiving register connected to said serial/parallel convertor for storing said received data and further connected to each microprocessor through said bus-line, and a interrupt signal generator responsive to an end of data transmission for generating interrupt signal to microprocessor to read out said received data from said receiving register.

9. The electronic control system for a motor vehicle according to claim 8 wherein said communication circuit further comprises:

clock divider responsive to clock signal of said microprocessor for generating communication clock signal; and

communication control circuit responsive to said communication clock signal for counting said communication clock signal to detect said end of data transmission.

10. The electronic control system for a motor vehicle according to claim 8 wherein said communication circuit, further comprises:

comparison circuit for comparing said transmitting data and said receiving data and for detecting data transmission incomplete to prohibit said interrupt generator generate interrupt signal.

11. The electronic control system for a motor vehicle according to claim 10 wherein said transmitting circuit transmits said serial data synchronized with said communication clock signal.

12. The electronic control system for a motor vehicle according to claim 8 wherein said communication circuit constructed on a one integrated circuit chip.

13. The electronic control system for a motor vehicle according to claim 12 wherein said integrated circuit chip of communication circuit provides a select signal terminal for alternating a master function and a slave function.