| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent an abnormal operation caused by a failure or the like of a motor control unit, while suppressing the use of an expensive component such as a microcomputer, in an electric power steering device using a brushless motor. <P>SOLUTION: A failure determining circuit 24 is provided to detect the failure of the microcomputer 20 or the like based on a detection signal Ts of steering torque applied to a handle and a detection signal Im of total current of D.C side current of an inverter circuit 45 in a motor driving circuit 50. The failure determining circuit 24 makes a failure detection signal Sf1 active (H level) when the total current is larger than a prescribed value despite of the steering torque detection signal Ts being in the vicinity of a torque neutral point. In this case, unless a determination releasing switch 14 is turned on, the failure detection signal Sf1 is to be inputted to a relay drive circuit 30 through a switch circuit 28. Accordingly, relays 60 to 62 are driven and the current supplied from the battery 8 to the brushless motor through the motor driving circuit 50 is shut off. <P>COPYRIGHT: (C)2004,JPO |
