Automatic optical-axis adjusting device for automatically adjusting optical axes of front lights of vehicle with reduced number of signals

• US 20020039296A1
• Filed: 10/02/2001
• Published: 04/04/2002
• Est. Priority Date: 10/03/2000
• Status: Active Grant

• Current Assignee: DENSO Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: DENSO Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yamada, Yuji, Nishimura, Kenichi, Miki, Yoshiyuki, Ohashi, Kunio
• Granted Patent: US 6,626,563 B2
• Time in Patent Office: Days
• US Class Current: 362/465
• CPC Class Codes: B60Q 1/12 due to steering position
• CPC Class Codes: B60Q 1/18 being additional front lights bracket mounted headlights B60Q1/0483
• CPC Class Codes: B60Q 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/122 Steering angle
• CPC Class Codes: B60Q 2300/128 Steering dead zone
• CPC Class Codes: B60Q 2300/134 Yaw

Abstract

A steering wheel is determined to be under a counter steering state when the following two conditions are both satisfied: (I) a steering angle measured with a steering angle sensor is equal to or greater than a predetermined angle; and (II) a steering direction does not coincide with a turning direction of the vehicle. The vehicle is determined to be under a slipping state when the following two conditions are both satisfied: (I) the steering angle is equal to or greater than the predetermined angle; (II) an absolute value of a change per unit time of a difference between a left wheel speed and a right wheel speed is equal to or greater than a predetermined value. Under both the counter steering state and the slipping state, adjustment of the optical axes of the swivel lights is stopped or modified.

Claims

1. An automatic optical-axis adjusting device for automatically adjusting an optical axis of at least one front light of a vehicle, said automatic optical-axis adjusting device comprising:

a steering angle measuring means for measuring a steering angle of a steering wheel of said vehicle;

a wheel speed measuring means for measuring left and right wheel speeds of left and right wheels of said vehicle, respectively;

a swivel control means for adjusting said optical axis of said at least one front light by turning said optical axis of said at least one front light in a right or left direction based on said steering angle measured with said steering angle measuring means;

a counter steering state determining means for determining whether said steering wheel is under a counter steering state, said steering wheel being determined to be under said counter steering state when the following two conditions are both satisfied;

(I) said steering angle measured with said steering angle measuring means is equal to or greater than a predetermined angle; and

(II) a steering direction of said steering wheel determined based on said steering angle does not coincide with a turning direction of said vehicle estimated based on a difference between said left wheel speed and said right wheel speed measured with said wheel speed measuring means; and

a swivel modifying means for stopping or modifying adjustment of said optical axis of said at least one front light through said swivel control means when said counter steering state determining means determines that said steering wheel is under said counter steering state.

3. An automatic optical-axis adjusting device according to claim 1, further comprising a slipping state determining means for determining whether said vehicle is under a slipping state, said vehicle being determined to be under said slipping state when the following two conditions are both satisfied:

(I) said steering angle measured with said steering angle measuring means is equal to or greater than said predetermined angle; and

(II) an absolute value of a change per unit time of said difference between said left wheel speed and said right wheel speed measured with said wheel speed measuring means is equal to or greater than a predetermined value, wherein

said swivel modifying means is also used for stopping or modifying said adjustment of said optical axis of said at least one front light through said swivel control means when said slipping state determining means determines that said vehicle is under said slipping state.

2. An automatic optical-axis adjusting device for automatically adjusting an optical axis of at least one front light of a vehicle, said automatic optical-axis adjusting device comprising:

a steering angle measuring means for measuring a steering angle of a steering wheel of said vehicle;

a wheel speed measuring means for measuring left and right wheel speeds of left and right wheels of said vehicle, respectively;

a swivel control means for adjusting said optical axis of said at least one front light by turning said optical axis of said at least one front light in a right or left direction based on said steering angle measured with said steering angle measuring means;

a slipping state determining means for determining whether said vehicle is under a slipping state, said vehicle being determined to be under said slipping state when the following two conditions are both satisfied;

(I) said steering angle measured with said steering angle measuring means is equal to or greater than a predetermined angle; and

(II) an absolute value of a change per unit time of a difference between said left wheel speed and said right wheel speed measured with said wheel speed measuring means is equal to or greater than a predetermined value; and

a swivel modifying means for stopping or modifying adjustment of said optical axis of said at least one front light through said swivel control means when said slipping state determining means determines that said vehicle is under said slipping state.