Automatic steering control system and method

Abstract

The steering angle with respect to the running distance is changed by changing the steering angular velocity in accordance with the steering angle and the vehicle speed (line A′) such that the turning rate has a linear relationship with the moving distance (line B′).

1 . An automatic steering control system which automatically changes a steering angle in accordance with a target route determined, the automatic steering control system being characterized in that: 
 the automatic steering control system controls a steering angular velocity such that a turning rate linearly changes with respect to a moving distance when changing the turning rate.    
     
     
         2 . The automatic steering control system according to  claim 1 , characterized in that: 
 the automatic steering control system changes automatically the steering angle of a vehicle wheel drive device ( 2 ,  4 ) for manipulating a wheel of a vehicle so that the vehicle takes the target route, and controls the steering angular velocity such that the turning rate of the vehicle linearly changes with respect to the moving distance of the vehicle when changing the turning rate.    
     
     
         3 . The automatic steering control system according to  claim 2 , characterized in that: 
 the steering angular velocity is changed in proportion to vehicle speed and an inverse of a value obtained by normalizing a change amount of the turning rate with respect to the steering angle by a minimum value of the change amount of the turning rate.    
     
     
         4 . The automatic steering control system according to any one of  claims 1  to  3 , characterized in that: 
 the turning rate is determined using an algorithm formulated to linearize the relationship of the steering angle with respect to the moving distance.  
 
     
     
         5 . The automatic steering control system according to any one of  claims 1  to  4 , characterized in that: 
 the steering angular velocity is changed in accordance with the moving distance.  
 
     
     
         6 . An automatic steering control method for automatically changing a steering angle in accordance with a target route determined, the automatic steering control method being characterized in that: 
 a steering angular velocity is controlled such that a turning rate linearly changes with respect to a moving distance when changing the turning rate.    
     
     
         7 . The method according to  claim 6 , characterized in that: 
 the steering angle is changed automatically such that a vehicle takes the target route, and    the steering angular velocity is controlled such that the turning rate of the vehicle linearly changes with respect to the moving distance of the vehicle when changing the turning rate.    
     
     
         8 . The method according to of  claim 7 , characterized in that: 
 the steering angular velocity is changed in proportion to vehicle speed and an inverse of a value obtained by normalizing a change amount of the turning rate with respect to the steering angle by a minimum value of the change amount of the turning rate.    
     
     
         9 . The method according to any one of  claims 6  to  8 , characterized in that: 
 the turning rate is determined using an algorithm formulated to linearize the relationship of the steering angle with respect to the moving distance.  
 
     
     
         10 . The method according to any one of  claims 6  to  9 , characterized in that: 
 the steering angular velocity is changed in accordance with the moving distance.