| 摘要 |
<p>PROBLEM TO BE SOLVED: To increase determination frequency in a steering device determining change in property of a steering transmission system by extending a period for determination.SOLUTION: A zero point history storing part 104 stores the maximum value and the minimum value of zero point in steering angle, and deletes the stored the maximum value of zero point or the minimum value of zero point whenever a predetermined period from respective renewal of the maximum value of zero point or the minimum value of zero point has elapsed. A property change determination part 116 determines that change in property of steering transmission system has been happened when the difference between the maximum value of zero point and the minimum value of zero point is over a first threshold while the predetermined period. An omen determination part 120 determines that it is an omen condition of change in property when the difference between the maximum value of zero point and the minimum value of zero point is over a second threshold smaller than the first threshold while the predetermined period. The property change determination part 116 determines the presence or absence of change in property of the steering transmission system based on an increment in the maximum value of zero point or the minimum value of zero point from the time point of the determination when it is determined the omen condition has been happened.</p> |
