Electropermanent Magnet-based Motors

An electropermanent linear actuator, comprising:

• a stator section, the stator section comprising:
• a plurality of electropermanent magnets;
• and
• at least one coil located around each electropermanent magnet, the coil being configured to pass sequential current pulses that change the magnetization of the electropermanent magnet, the change in magnetization persisting after current is removed from the coil;
• a forcer section, the forcer section, the forcer section having more than one degree of freedom so as to be moveable in more than one direction, the forcer section being connected to and movable with respect to the stator section in response to the persistent changes in the magnetization of the plurality of electropermanent magnets;
• actuator drive circuitry configured to control at least one of the timing, magnitude, and shape of the sequential current pulses for precise control of at least one of the position or speed of the actuator, the voltage and duration of the pulses being of sufficient magnitude to change the magnetization of the plurality of electropermanent magnets such that the change in magnetization will persist after cessation of the current, the voltage and current returning substantially to zero between pulses;
• and
• a feedback control mechanism configured to determine, based on actuator velocity or position, when a next one of the sequential current pulses should be issued, the issuance of the pulses being timed such that the actuator will continue to move throughout the duration of the period of absence of applied current that occurs between the sequential pulses.

An electropermanent inchworm motor, comprising:

• an electropermanent linear actuator, comprising:
• a stator section, the stator section comprising:
• at least one electropermanent magnet;
• and
• at least one coil located around the electropermanent magnet, the coil being configured to pass sequential current pulses that change the magnetization of the electropermanent magnet, the change in magnetization persisting after current is removed from the coil;
• a forcer section, the forcer section being constrained to have substantial movement in only one linear direction, the forcer section being connected to and movable with respect to the stator section in response to the persistent changes in the magnetization of the at least one electropermanent magnet;
• actuator drive circuitry configured to control at least one of the timing, magnitude, and shape of the sequential current pulses for precise control of at least one of the position or speed of the actuator, the voltage and duration of the pulses being of sufficient magnitude to change the magnetization of the at least one electropermanent magnet such that the change in magnetization will persist after cessation of the current, the voltage and current returning substantially to zero between pulses;
• and
• a feedback control mechanism configured to determine, based on actuator velocity or position, when a next one of the sequential current pulses should be issued, the issuance of the pulses being timed such that the actuator will continue to move throughout the duration of the period of absence of applied current that occurs between the sequential pulses;
• and
• at least two clamps configured to hold the inchworm motor to a surface and to alternately grip and release the surface as the inchworm motor moves across the surface.