JPS6228843A - Vehicle mounted computer equipment - Google Patents

Abstract

PURPOSE:To prevent diagnosis information from being erased by connecting a by-pass circuit in parallel with a main power supply switch of an automobile so that the circuit is automatically closed at the detection of a fault. CONSTITUTION:The by-pass circuit is connected in parallel with the key switch 2 for the power supply switch and the 1st relay contact 10A and the 2nd relay 12 having a contact 12A to be closed when a self-diagnosis circuit B detects a defective position is connected to the by-pass circuit. Even if power supply to other respective control circuits is interrupted by the contact 10A of the relay 10, power is supplied only to a computer circuit 4 through the contact 12A.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a computer device mounted on a vehicle for controlling automatic driving of a vehicle, and particularly to a power supply circuit of a vehicle-mounted computer device including a self-diagnosis circuit. used for.

〔overview〕

The present invention provides a vehicle-mounted computer device equipped with a self-diagnosis circuit, which is equipped with two systems of power switch circuits, and when a failure location is automatically detected, receives power from another system even if the main switch is turned off, thereby preventing the loss of diagnostic information. By preventing this, it is possible to ensure that the failure status is understood.

[Conventional technology]

BACKGROUND ART In order to reduce the burden of driving operations on the driver and improve controllability by program-controlling the driving operations of automobiles, it is widely practiced to install computers in vehicles to control automatic driving.

Furthermore, this vehicle computer is equipped with a self-diagnosis circuit,
There is a system that periodically programs failure diagnosis of computer circuits.

[Problem that the invention seeks to solve]

However, in a vehicle computer, when the vehicle is stopped, the key switch, which is the main power switch of the vehicle, is opened, and therefore the power of the vehicle computer is also disconnected. Therefore, there is a drawback that the diagnostic information stored inside the computer is also lost.

SUMMARY OF THE INVENTION An object of the present invention is to solve this drawback and provide a vehicle-mounted computer device that can retain diagnostic information necessary for fault diagnosis even when the key switch is turned off.

[Means for solving problems]

The present invention provides a vehicle-mounted computer device equipped with means for executing a fault diagnosis program, in which a power supply circuit thereof is connected via a circuit that passes through a main power switch of the vehicle and a second switch that bypasses the main power switch. The present invention is characterized in that two systems of circuits are provided, and means is provided for automatically closing the second switch when a fault location is detected after the fault diagnosis program is executed.

[For production]

A bypass circuit is provided in parallel with a key switch, which is the main power switch of an automobile, and a circuit is provided in this circuit that is automatically closed when a fault location is detected by a program of a self-diagnosis circuit.

This ensures that the diagnostic information held in the computer is not lost.

〔Example〕

An embodiment of the present invention will be described based on the drawings.

The figure is a block configuration diagram configuring the circuit of this embodiment.

Control power for the vehicle, which is program-controlled by a computer, is input from a battery 1 to a computer 4 via a key switch 2, which is a main power switch. On the other hand, the engine control section 5, clutch control section 6, air conditioner control section 7, and transmission control section 8, which are each control circuit of the automobile, are supplied with control power from the key switch 2 and from the input/output interface 3 of the computer 4. control signals are respectively input.

The central control device 4A of the combiator 4 stores a fault diagnosis program, and when a fault location is detected by this fault diagnosis program, the self-diagnosis circuit 4B sends out a signal.
Contact 10A of relay 10 connected in series to key switch 2 is opened, power supply is cut off, and each control circuit of the automobile is turned off.

However, power is supplied to the transmission control section 8 until gear A of the transmission is returned to the neutral position by the operation of the gear neutral position return section 11.

Here, the feature of the present invention is that a bypass circuit is provided in parallel with the key switch 2 and the contact 10A of the first relay, and this circuit has a contact that is closed when the self-diagnosis circuit 4B detects a fault location. Second relay 1 with 12A
This is due to connecting 2.

That is, even if the power supply to the other control circuits is cut off by the contact 10A of the first relay 10, the power is supplied to only the computer circuit by the contact 12A of the second relay 12, and the above diagnostic information is thereby transmitted. can be prevented from disappearing. Reference numeral 13 is a diode for preventing power from flowing backward into circuits other than the computer 4.

〔Effect of the invention〕

As explained above, the present invention retains the diagnostic information retained by the self-diagnosis of the vehicle-mounted computer device without losing it, so that the failure situation can be recognized even after a service person can be involved. This has a great effect on repair and recovery measures and considering failure countermeasures.

[Brief explanation of drawings]

The figure is a block configuration diagram showing the configuration of a circuit according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Battery, 2... Key switch, 3... Computer input/output interface, 4... Computer, 4A... Central control unit, 4B... Self-diagnosis circuit (DAC), 5. ...Engine control section, 6.. Clutch control section, 7.. Air conditioner control section, 8.. Transmission control section, 9.. Interface for diagnostic circuit, 10.
...First relay, IOA... Contact of relay (10), 11... Gear neutral position return section (GN return), 12
...Second relay, 12A... Contact of relay (12), 13... Diode, 14... Diagnosis result display section (DAC display section) 15... Manual switch. Patent applicant Hino Motors Co., Ltd. Agent Patent Attorney Nao Takashi Ide 1 Block configuration diagram of the embodiment

Claims (1)

[Claims] (1) In a vehicle-mounted computer device equipped with means for executing a fault diagnosis program, its power supply circuit includes a circuit that passes through the main power switch of the vehicle and a circuit that passes through a second switch that bypasses the main power switch. A vehicle-mounted computer device comprising: two systems, and means for automatically closing the second switch when a failure location is detected after the failure diagnosis program is executed.