| 摘要 |
PROBLEM TO BE SOLVED: To prevent error in load torque estimation from increasing when a motor rotates at a low speed, and to avoid its unstable operation by controlling the driving torque of the motor on the basis of a first torque command. SOLUTION: In this controller, a first estimated load torque Tep1 estimated by a load torque estimating means 1 passes a manipulated variable reducing means 2, and its output is inputted into a torque adding means 7 as a second estimated load torque Tep2. The adding means 7 adds the second command Tref2 and the second torque Tep2 outputted from the decreasing means 2, and outputs it as a first torque command Tref1 to a torque controller 5 and the estimating means 1. The decreasing means 2 has a gain characteristic which limits an output value according to a speed ω, and an added quantity of an estimated load torque is gradually decreased as the absolute value of the speed becomes smaller. Consequently, unstable operation caused by increase of the error of load torque estimation which occurs when the motor rotates at a low speed is evaded. |
