| 摘要 |
<p>PURPOSE:To stabilize running of a vehicle by self-locking a worm gear, in the case of a steering angle variable mechanism with no return spring, while realizing electric fail safe by holding a motor speed signal, and obtaining a command current of making a motor speed zero from this signal by a feedforward, when a sensor and a microcomputer in a servo control system are simultaneously in trouble, in the case of a steering angle control device for the vehicle. CONSTITUTION:In a trouble detecting circuit 15 to which trouble information of a steering angle sensor 12 and a microcomputer 14 is input, a switch 16 is changed over to a side of a current ifr to turn off a switch 17 and to turn on a switch 18 when a trouble is detected in at least one of the above- mentioned. A circuit 20, based on a motor rotational speed signal omega input from a hold circuit 19, calculates a current command signal ifr of zeroing an initial value omega0 of the signal omega by a time constant tau. This signal is input to a current control amplifier 13 from the switch 16 to realize electric fail safe and a self lock of a worm gear.</p> |
