| 摘要 |
PURPOSE:To detect real abnormality by obtaining a variation between two continuous sampling values of A/D convertor and deciding to be abnormality if abnormal variation higher than predetermined level has occurred more than predetermined times within predetermined time thereby removing independent disturbance. CONSTITUTION:Analog output current from steering ratio sensor 57 is converted through A/D converter 60 into digital signal which is fed to control means F. The control means F will set the maximum allowable variation of sampling value on the basis of the maximum variation of sampling value during two continuous samplings through A/D converter 60 under normal state while consid ering the influence of noise. Furthermore, it is decided whether abnormal varia tion exceeding over said maximum allowable value has occurred more than predetermined times within predetermined continuous samplings and if the answer is YES, it is decided to be abnormality of steering ratio sensor 57 by means of abnormality detecting circuit 61. |
