Apparatus for estimating quantity of state relating to motor, and electric tool

An apparatus for estimating a quantity of state relating to a motor, comprising:

• a motor model that includes at least inputs comprising a voltage applied to the motor and a torque acting on the motor, and outputs comprising a current flowing through the motor and a rotation speed of the motor;
• a comparator that calculates a difference between the current in an actual motor and the current output from the motor model;
• and
• an amplifier that amplifies an output of the comparator at a predetermined gain,
• wherein:
• the voltage in the actual motor is input into the motor model,
• the motor model calculates the current and rotation speed outputs based on the voltage and torque inputs by performing a numerical calculation not including a differentiation operation,
• an output of the amplifier is set as an estimated value of the torque in the actual motor and is input into the motor model, and
• the rotation speed output from the motor model is set as an estimated value of the rotation speed in the actual motor.

An apparatus for estimating a quantity of state relating to a motor, comprising:

• a motor model that includes at least inputs comprising a voltage applied to the motor and a torque acting on the motor, and outputs comprising a rotation speed of the motor and a current flowing through the motor;
• a comparator that calculates a difference between the rotation speed in an actual motor and the rotation speed output from the motor model;
• and
• an amplifier that amplifies an output of the comparator at a predetermined gain,
• wherein:
• the voltage in the actual motor is input into the motor model,
• the motor model calculates the current and rotation speed outputs based on the voltage and torque inputs by performing a numerical calculation not including a differentiation operation,
• an output of the amplifier is set as an estimated value of the torque in the actual motor and is input into the motor model, and
• the current output from the motor model is set as an estimated value of the current in the actual motor.