Antiskid control device

• US 4,955,671 A
• Filed: 02/08/1989
• Issued: 09/11/1990
• Est. Priority Date: 02/10/1988
• Status: Expired due to Term

• Current Assignee: Advics Company Limited (Aisin Corp.)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Higashimura, Hideaki
• Primary Examiner(s): Olszewski, Robert P.
• Assistant Examiner(s): Graham, Matthew C.
• Application Number:
  US07/310,829
• Time in Patent Office: 580 Days
• Field of Search: 303/92, 303/93, 303/9.63
• US Class Current: 303/122.06
• CPC Class Codes: B60T 2270/416 Wheel speed sensor failure
• CPC Class Codes: B60T 8/885 using electrical circuitry

Abstract

An antiskid control device is for use with the brake assembly of a motor vehicle. It includes a program for detecting any malfunction of wheel speed sensors of the non-driven wheels. The program is adapted to judge when the non-driven wheel sensors are out of order and to give a signal notifying the abnormality of the sensors, if the wheel speed values detected by the non-driven wheels are kept out of a predetermined range for a predetermined period while the wheel speeds detected by the driven wheel speed sensors are above a predetermined point. Thus, a possible malfunction of the antilock device itself resulting from wrong information transmitted from the troubled non-driven wheel sensors will be identified and prevented.

Claims

1. In an antiskid control device of an automotive vehicle, the antiskid control device having a processing/lock state detecting means for executing logical operations on the basis of wheel speed signal supplied from a wheel speed detecting unit to determine whether the wheels are entering into a locking state and whether the wheels are recovering from a locking state, and for transmitting signals to reduce, hold and increase a breaking pressure on the basis of the thus executed logical operations, the antiskid control device further including solenoid activating means for actuating solenoids for pressure control valves in hydraulic circuits in response to the signals transmitted from the processing/lock state detecting means, the improvement comprising a malfunction detecting means for detecting a malfunction of the wheel speed detecting means, said malfunction detecting means comprising:

means for detecting a first state in which a predetermined one of the driven wheels has reached a predetermined speed;

means for detecting a second state in which a difference in wheel speed between said predetermined driven wheel and all of the non-driven wheels has exceeded a predetermined value during said first state;

count timer means for increasing a count thereof during said second state; and

malfunction indication means for indicating a malfunction of the wheel speed detecting means in response to said count of said count timer exceeding a predetermined value.

2. An antiskid control device, comprising:

wheel speed detecting means for outputting wheel speed signals indicative of a wheel speed of each driven wheel and each non-driven wheel of a vehicle; and

,

a sensor malfunction detecting means for periodically reading at control cycle intervals the wheel speed signals output by said wheel speed detecting means, and for detecting a malfunction of said wheel speed detecting means and for outputting an indication of a thus detected malfunction, said indication being output when a wheel speed of said non-driven wheels is indicated by said wheel speed detecting means as being out of a predetermined range for a predetermined period of time equal to one control cycle interval, while a wheel speed of said driven wheels is indicated by said wheel speed detecting means as being higher than a predetermined speed.

3. An antiskid control device as recited in claim 2, further comprising:

a processing and lock state detecting means for determining whether each wheel of the vehicle is entering into a locking state and whether each wheel of the vehicle is recovering from a locking state, and for outputting control signals for controlling a brake pressure of the vehicle in accordance with the thus determined locking state status of each wheel.