ORIGINAL POINT RESET SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an original point reset system which judges whether a motor and a block means come into contact with each other or not based on the speed detection value and the speed command value of the motor and protects the motor from its breakage due to the contact caused to the block means for a machine device which once secures a contact between the block means and a movable object and resets this object to its original point. SOLUTION: The original point reset system includes a 1st subtracter 13 that calculates the difference between the movement command value X of a movable object 1 and the count value Xf that is obtained by the rotation angle signal produced by an encoder 6 attached to a motor 3, a multiplier 14 which multiplies the subtraction value of the subtracter 13 by the position gain Kp and outputs the moving speed command value S of the object 1 that is proportional to the subtraction value, a 2nd subtracter 15 which subtracts the moving speed value Sf calculated from the count value Xf from the command value S of the multiplier 14, and a judgement means 12 which compares the speed deviationΔS outputted from the subtracter 15 and a prescribed deviation reference value and judges the contact between the object 1 and a block member 5 when the deviationΔS is larger than the deviation reference value.