Steering angular velocity computing device and method

Abstract

A steering angular velocity computing device has a steering angle detector, a timer, and a steering angular velocity computing unit. The steering angle detector detects a change in a steering angle, the timer measures a required time from a time at the steering angle changed until a time at the steering angle next changed, and the steering angular velocity computing unit computes, after the detector has detected a change in the steering angle, the steering angular velocity by dividing an amount of change in the steering angle by the required time corresponding to the amount of change and outputs it. When the steering angular velocity is being reduced, the steering angular velocity computing unit outputs the steering angular velocity during a first extended output period longer than the required period. With this structure, the steering angular velocity is outputted with a good accuracy when the steering angular velocity is being reduced.

1 . A steering angular velocity computing device comprising: 
 a steering angle detector for detecting a change in steering angle;    a timer for measuring a required time from a time when the steering angle changed to a time when the steering angle next changed; and    a steering angular velocity computing unit for computing a steering angular velocity by dividing an amount of change of the steering angle during the required time by the required time, and outputting the steering angular velocity,    wherein, when the steering angular velocity is decreasing, the steering angular velocity computing unit outputs the steering angular velocity for a first extended output period longer than the required time.    
   
   
       2 . The steering angular velocity computing device of  claim 1 , wherein the first extended output period is obtained by multiplying the required time by a time coefficient.  
   
   
       3 . (canceled)  
   
   
       4 . The steering angular velocity computing device of  claim 1 , wherein the steering angle detector has a magnetic steering angle sensor.  
   
   
       5 . The steering angular velocity computing device of  claim 4 , wherein the steering angle detector includes: 
 a rotating body;    a magnet provided in a center of the rotating body; and    an anisotropic magnetic resistance element opposite the magnet.    
   
   
       6 . A steering angular velocity computing method comprising: 
 detecting a change in steering angle;    measuring a required time from a time when the steering angle changed until a time when the steering angle next changed;    computing a steering angular velocity by dividing an amount of change of the steering angle during the required time by the required time; and    outputting the steering angular velocity during a first extended output period longer than the required time.    
   
   
       7 .- 12 . (canceled)