Power tool including field-oriented control electronic clutch
OwnerErik P. Botheinventor
Life of this patent
Estimating the term…
Abstract
A power tool includes an electric motor, a first sensor configured to monitor an electrical property of the electric motor and an electronic controller. The electronic controller is configured to determine at least one of a quadrature-axis current and a direct-axis current of the electric motor based on sensor signals from the first sensor, determine a rotational speed of the electric motor, determine an estimated torque output based on (i) at least one of the quadrature-axis current and the direct-axis current and (ii) the rotational speed, and output a command to brake the electric motor in response to the estimated torque output crossing a threshold.
Claims20
A power tool comprising:
- an electric motor;
- a first sensor configured to monitor an electrical property of the electric motor;
- an electronic controller configured to:
- determine at least one of a quadrature-axis current and a direct-axis current of the electric motor based on sensor signals from the first sensor,
- determine a rotational speed of the electric motor,
- determine an estimated torque output based on (i) at least one of the quadrature-axis current and the direct-axis current and (ii) the rotational speed, and
- output, in response to the estimated torque output crossing a threshold, a command to brake the electric motor.
A method comprising:
- determining at least one of a quadrature-axis current and a direct-axis current of an electric motor of a power tool based on sensor signals from a first sensor, the first sensor being configured to monitor an electrical property of the electric motor;
- determining a rotational speed of the electric motor;
- determining an estimated torque output based on (i) at least one of the quadrature-axis current and the direct-axis current and (ii) the rotational speed;
- and
- outputting, in response to the estimated torque output crossing a threshold, a command to brake the electric motor.
A non-transitory computer-readable storage medium comprising executable instructions that, when executed by an electronic processor, causes the electronic processor to:
- determine at least one of a quadrature-axis current and a direct-axis current of an electric motor of a power tool based on sensor signals from a first sensor, the first sensor being configured to monitor an electrical property of the electric motor;
- determine a rotational speed of the electric motor;
- determine an estimated torque output based on (i) at least one of the quadrature-axis current and the direct-axis current and (ii) the rotational speed;
- and
- output, in response to the estimated torque output crossing a threshold, a command to brake the electric motor.
Dependencies are inferred from the claim text.