| 摘要 |
<p>PURPOSE:To improve the reliability of operation by providing a subCPU, which decides only the driving direction of an electric motor, separately from a CPU which decides the driving direction of electric motor and its torque in accordance with a steering control amount, in the case of a steering device to generate an assistant steering force by driving the electric motor by a PWM control. CONSTITUTION:A four-wheel steering device controls the electric motor 12 of a rear wheel steering device by a control circuit 22, for inputting output signals of a steering angle sensor 9 which detects a front wheel steering angle, car speed sensors 11, 21 additionally provided in front and rear wheels and a rear wheel steering angle sensor 20, through a driving circuit 23, and steers the rear wheel through a rear wheel steering mechanism. Here, the control circuit 22 is constituted by providing main and subCPUs 26, 27. Driving direction and driving toque of the electric motor 12 are decided and a PWM(pulse width modulation) signal is outputted by the main CPU 26, and the driving direction of the electric motor 12 is decided by the subCPU 27 to output a direction signal, and the electric motor 12 is controlled in its driving only in the case of agreement in the direction signals output from respective CPU 26, 27.</p> |
