Steering angle neutral position detection error protecting method and detection error protecting apparatus

• US 20040046346A1
• Filed: 06/18/2003
• Published: 03/11/2004
• Est. Priority Date: 06/20/2002
• Status: Active Grant

• Current Assignee: Toyoda Koki Kabushiki Kaisha
• Original Assignee: Toyoda Koki Kabushiki Kaisha
• Inventors: Kojo, Takahiro, Eki, Hirozumi, Nakatsu, Masatoshi, Kawamuro, Junji, Sugiyama, Michiyuki
• Granted Patent: US 7,028,804 B2
• Time in Patent Office: Days
• US Class Current: 280/93.502
• CPC Class Codes: B62D 15/024 Other means for determination of steering angle without directly measuring it, e.g. deriving from wheel speeds on different sides of the car
• CPC Class Codes: B62D 15/0245 Means or methods for determination of the central position of the steering system, e.g. straight ahead position

Abstract

In a neutral position detection error protecting apparatus, vehicle wheel velocities SFR, SFL of right/left driven wheels FR, FL are detected by vehicle wheel sensors 27a, 27b and a right/left wheel velocity difference VFD is obtained from vehicle wheel velocities VFR, VFL of the driven wheels FR, FL through vehicle wheel velocity signal abnormality determining processing 30b so as to detect steering angle information θh from the steering wheel 21. Then, when a condition that a right/left wheel velocity difference VFD is less than a predetermined velocity V1, a condition that a rotation angle of steering angle information θh is more than a predetermined value θk and a condition that a vehicle wheel velocity is more than a predetermined velocity V2 according to vehicle wheel velocities VFR, VFL of the driven wheels FR, FL are all satisfied in a predetermined period T, it is determined that there is any abnormality in the vehicle wheel velocities SFR, SFL (VFR, VFL) of the driven wheels FR, FL through vehicle wheel velocity signal abnormality determining processing 30b.

Claims

1. A steering angle neutral position detection error protecting method for a method of detecting a steering angle neutral position based on a right/left wheel velocity difference between vehicle driven wheels, comprising:

a vehicle wheel velocity detecting step of detecting a vehicle wheel velocity of each of right/left driven wheels;

a right/left wheel velocity difference computing step of obtaining a right/left wheel velocity difference from the vehicle wheel velocity of said driven wheels detected in said vehicle wheel velocity detecting step;

a steering angle detecting step of detecting a steering angle by a steering wheel; and

a detection error determining step of determining that if a condition that said right/left wheel velocity difference obtained by said right/left wheel velocity difference computing step is less than a first predetermined velocity, a condition that said steering angle detected by said steering angle detecting step is more than a predetermined value and a condition that the vehicle wheel velocity of said driven wheel detected by said vehicle wheel velocity detecting step is more than a second predetermined velocity are all satisfied in a predetermined period, there is any abnormality in the vehicle wheel velocity of said driven wheel detected by said vehicle wheel detecting step.

2. A steering angle neutral position detection error protecting apparatus for an apparatus for detecting a steering angle neutral position based on a right/left wheel velocity difference between vehicle driven wheels, comprising:

a vehicle wheel velocity detecting means for detecting a vehicle wheel velocity of each of right/left driven wheels;

a right/left wheel velocity difference computing means for obtaining a right/left wheel velocity difference from the vehicle wheel velocity of said driven wheels detected in said vehicle wheel velocity detecting means;

a steering angle detecting means for detecting a steering angle by a steering wheel; and

a detection error determining means for determining that if a condition that said right/left wheel velocity difference obtained by said right/left wheel velocity difference computing means is less than a first predetermined velocity, a condition that said steering angle detected by said steering angle detecting means is more than a predetermined value and a condition that the vehicle wheel velocity of said driven wheel detected by said vehicle wheel velocity detecting means is more than a second predetermined velocity are all satisfied in a predetermined period, there is any abnormality in the vehicle wheel velocity of said driven wheel etected by said vehicle wheel velocity detecting means.

3. A vehicle operation control apparatus having a steering angle detecting means for detecting a steering angle with reference to a neutral position of a steering angle detected based on a right/left wheel velocity difference between vehicle driven wheels and for executing a predetermined vehicle operation control based on the steering angle, said vehicle operation control apparatus further comprising the steering angle neutral position detection error protecting apparatus, wherein if it is determined that there is any abnormality in the vehicle wheel velocity of said driven wheels by said detection error determining means, said predetermined vehicle operation control is canceled.

4. The vehicle operation control apparatus according to claim 3 wherein said predetermined vehicle operation control is a transmission ratio changing control which is located halfway of a steering transmission system connecting the steering wheel with the driven wheels for changing the transmission ratio by driving an electric motor.