Power tool dynamic motor field weakening system and method
AssigneeMilwaukee Electric Tool Corporation
InventorAlex R. Kuhls
Life of this patent
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Abstract
Embodiments of the disclosure provide a system and method of operating a motor control algorithm in a power tool to utilize dynamic field weakening. The method includes operating the motor according to dynamic field weakening, measuring sensor readings, and sampling the sensor readings. The method also includes calculating an averaged sensor reading value, comparing the averaged sensor reading value to a predetermined sensor value, and continuing to operate according to dynamic field weakening if the averaged sensor reading has not exceeded the predetermined sensor value. The method further includes changing the motor control algorithm to a static motor commutation sequence if the averaged sensor reading has exceeded the predetermined sensor value.
Claims20
A method operating a power tool, the method comprising:
- calculating, via a controller, a threshold sensor value based on a signal from a sensor configured to sense an operating parameter of the power tool;
- operating a motor of the power tool according to dynamic field weakening by operating the motor above a rated speed by weakening a magnetic field when the threshold sensor value is below a predetermined sensor value;
- and
- operating the motor according to a static motor commutation sequence when the threshold sensor value exceeds the predetermined sensor value.
A method of operating a power tool, the method comprising:
- calculating, via a controller, a threshold sensor value based on a signal from a sensor configured to sample a current of a motor of the power tool;
- comparing, via the controller, the threshold sensor value to a transition point of a multi-stage hydraulic pump;
- accelerating the current of the motor of the power tool according to the dynamic field weakening based on a first stage of operation;
- and
- in response to determining the threshold sensor value exceeds the transition point, operating the motor of the power tool based on a static motor commutation sequence during a second stage of operation.
A power tool comprising:
- a motor having a rated speed
- a hydraulic actuator operated by the motor;
- a sensor;
- and
- a controller selectively operating the motor in a field weaking mode or a normal mode based on the sensor, the motor operable above a rated speed of the motor for the normal mode in the field weakening mode.
Dependencies are inferred from the claim text.