Power tool and control method thereof

A power tool, comprising:

• a housing;
• an electric motor disposed in the housing;
• a driver circuit electrically connected to the electric motor to drive the electric motor to operate;
• a speed detection device configured to acquire a rotational speed of the electric motor;
• and
• a control device connected to the speed detection device and the driver circuit, wherein the control device outputs a control signal to the driver circuit to control rotation of the electric motor;
• the control device is configured to:
• acquire the rotational speed of the electric motor, and control the motor to be in a start-up stage when the rotational speed of the electric motor is less than or equal to a preset target rotational speed;
• when the electric motor is in the start-up stage, obtain a rotational speed variation of the electric motor within a preset time based on the rotational speed of the electric motor, and turn off the electric motor when the rotational speed variation is less than a rotational speed variation threshold.

A control method of a power tool, wherein the power tool comprises:

• a housing;
• an electric motor disposed in the housing;
• a driver circuit electrically connected to the electric motor to drive the electric motor to operate;
• a speed detection device configured to acquire a rotational speed of the electric motor;
• and
• a control device electrically connected to at least the driver circuit to control the electric motor to operate;
• wherein the control method comprises:
• acquiring the rotational speed of the electric motor when the electric motor is in a start-up stage, obtaining a rotational speed variation of the electric motor within a preset time based on the rotational speed of the electric motor, and turning off the electric motor when the rotational speed variation is less than a rotational speed variation threshold.