DEVICE FOR ESTIMATING STATE QUANTITY RELATED TO MOTOR AND ELECTRIC POWER TOOL

摘要

The present application provides a technique with which a quantity of state relating to a motor can be estimated with a high degree of precision on the basis of another quantity of state. The present application discloses an apparatus for estimating a quantity of state relating to a motor. The apparatus includes: a motor model that reflects a characteristic of a motor and includes at least inputs pertaining to a first quantity of state and a second quantity of state relating to the motor and an output pertaining to a third quantity of state relating to the motor; a comparator that calculates a difference between the third quantity of state in an actual motor and the third quantity of state output from the motor model; and an amplifier that amplifies an output of the comparator at a predetermined gain. In this apparatus, the first quantity of state in the actual motor is input into the motor model as the first quantity of state, and an output of the amplifier is input into the motor model as the second quantity of state. The apparatus then uses the output of the amplifier as an estimated value of the second quantity of state in the actual motor.