Steering control system for a motor vehicle

• US 3,897,846 A
• Filed: 02/28/1974
• Issued: 08/05/1975
• Est. Priority Date: 03/01/1973
• Status: Expired due to Term

• Current Assignee: Naohiko Inoue
• Original Assignee: Naohiko Inoue
• Inventors: Inoue, Naohiko
• Primary Examiner(s): Schonberg, David
• Assistant Examiner(s): Pekar, John A.
• Application Number:
  US05/446,828
• Time in Patent Office: 523 Days
• Field of Search: 180/79.2R,79.1
• US Class Current: 180/422
• CPC Class Codes: B62D 6/04 responsive only to forces disturbing the intended course of the vehicle, e.g. forces acting transversely to the direction of vehicle travel

Abstract

The invention automatically restores to the original direction a motor vehicle'"'"''"'"'s deviated driving direction caused by a lateral disturbance. The lateral velocities at the front and rear of the vehicle are measured by front and rear velocity sensors, respectively. Also measured is the vehicle forward velocity. Electrical signals representing these velocities are fed into an electric computing circuit, from which an electrical signal representing the laterally deviated distance with respect to the original course is supplied to an auxiliary steering control device. Steerable road wheels are thereby controlled through a suitable hydraulic device, automatically correcting the laterally deviated driving direction to the original direction. The system is automatically de-energized in response to the driver'"'"''"'"'s turning of the steering wheel to manually correct the steering direction.

Claims

1. An automatic steering control system for automatically restoring to an original direction a laterally deviated motor vehicle, which comprises;

a manual steering control device controlled by a driver and being connected to steerable wheels of the vehicle;

an auxiliary steering control device operably associated with the steerable wheels for automatically controlling the steerable wheels to correct the laterally deviated motor vehicle'"'"''"'"'s direction;

a first velocity sensor being installed at the front end of the motor vehicle and adapted to sense the lateral velocity thereof and being connected to and supplying a first electrical signal to a computing circuit, said first electrical signal representing the lateral velocity of the front end;

a second velocity sensor being installed at the rear end of the motor vehicle and adapted to sense the lateral velocity thereof, and being connected to and supplying a second electrical signal to said computing circuit, said second electrical signal representing the lateral velocity of the rear end;

a third velocity sensor for sensing the motor vehicle'"'"''"'"'s forward velocity being connected to and supplying a third electrical signal to said computing circuit, said third electrical signal representing the forward velocity of the motor vehicle, said computing circuit computing the laterally deviated distance on the basis of said first, second and third electrical signals, and supplying a fourth electrical signal proportional to the computed deviated distance to said auxiliary steering control device;

a control circuit coupled to said computing circuit and controlling the operation thereof, and said first velocity sensor also being connected to and supplying said first electrical signal to said control circuit;

a steering angle sensor for sensing the driver-demanded steering angle being coupled to said control circuit and supplying thereto a fifth electrical signal representing the steering angle; and

said control circuit supplying a sixth electrical signal to said computing circuit for enabling computing operation thereof only when said first electrical signal exceeds a first predetermined value and at the same time said fifth electrical signal is smaller than a second predetermined value, said first predetermined value representing the extent of the lateral disturbance at the front end of the motor vehicle which is so large that the deviated driving direction thereof must be corrected, and said second predetermined value representing the small extent of the driver-demanded steering angle which is insufficient to correct the deviated driving direction, whilst said control circuit inhibiting operation of said computing circuit to compute and generate said fourth electrical signal when said fifth electrical signal exceeds said second predetermined value, and also when both of said first and fifth electrical signals are smaller than said first and second predetermined values, respectively.