GENERATING ELECTROMAGNETIC FORCES WITH FLUX FEEDBACK CONTROL
First Claim
1. An electromagnetic actuator comprising:
- a body configured to move along an axis;
a first pole adjacent and spaced apart from a first surface of the body, the first pole adapted to communicate magnetic flux with the first surface of the body;
a second pole adjacent and spaced apart from a second surface of the body, the second pole adapted to communicate magnetic flux with the second surface of the body, the body, the first pole, and the second pole magnetically coupled and defining a control magnetic circuit;
a bias pole adjacent and spaced apart from a lateral surface of the body, the bias pole adapted to communicate magnetic flux with the lateral surface of the body, the body, the first pole, and the bias pole defining a first bias magnetic circuit, and the body, the second pole, and the bias pole defining a second bias magnetic circuit;
a first flux sensor configured to measure a total magnetic flux between the first pole and the first surface of the body;
a second flux sensor configured to measure a total magnetic flux between the second pole and the second surface of the body;
a control coil in communication with the control magnetic circuit, adapted to produce a control magnetic flux in the control magnetic circuit; and
a controller coupled to the control coil configured to adjust the control magnetic flux in the control magnetic circuit based on the total fluxes measured by the first and second flux sensors and a command signal.
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Accused Products
Abstract
An electromagnetic actuator with flux feedback control includes two poles located on opposite sides of a soft-magnetic target. A bias flux is introduced that flows into both poles. Magnetic circuitry may be designed so that the total bias flux is independent or substantially independent of a position of the target with respect to the poles or the control flux. The electromagnetic actuator also includes flux sensors introduced into each gap between the poles and the target. The electromagnetic actuator further includes an actuator control circuit to command the current in the control coil to bring a difference between the readings of the two flux sensors to a targeted level. In some aspects, the force exerted on the actuator target in this arrangement may be proportional to the command signal regardless of the position of the actuator target, MMF drop in the soft-magnetic parts of the magnetic circuit, or the frequency.
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Citations
20 Claims
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1. An electromagnetic actuator comprising:
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a body configured to move along an axis; a first pole adjacent and spaced apart from a first surface of the body, the first pole adapted to communicate magnetic flux with the first surface of the body; a second pole adjacent and spaced apart from a second surface of the body, the second pole adapted to communicate magnetic flux with the second surface of the body, the body, the first pole, and the second pole magnetically coupled and defining a control magnetic circuit; a bias pole adjacent and spaced apart from a lateral surface of the body, the bias pole adapted to communicate magnetic flux with the lateral surface of the body, the body, the first pole, and the bias pole defining a first bias magnetic circuit, and the body, the second pole, and the bias pole defining a second bias magnetic circuit; a first flux sensor configured to measure a total magnetic flux between the first pole and the first surface of the body; a second flux sensor configured to measure a total magnetic flux between the second pole and the second surface of the body; a control coil in communication with the control magnetic circuit, adapted to produce a control magnetic flux in the control magnetic circuit; and a controller coupled to the control coil configured to adjust the control magnetic flux in the control magnetic circuit based on the total fluxes measured by the first and second flux sensors and a command signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for exerting a force on a moveable body, the method comprising:
communicating first bias magnetic flux through a first surface of the body; communicating second bias magnetic flux through a second surface of the body; communicating a control magnetic flux through the first and second surfaces of the body; measuring the fluxes communicated through the first and second surfaces; and adjusting the control magnetic flux based on the measured fluxes and a command signal. - View Dependent Claims (12, 13, 14, 15)
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16. An electric machine system, the system comprising:
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a first assembly that moves in relation to a second assembly along an axis of movement; a first structure fixed in relation to the second assembly, and adjacent and spaced apart from a first face of the first assembly, the first structure magnetically coupled with the first face of the first assembly; a second structure fixed in relation to the second assembly, and adjacent and spaced apart from a second face of the first assembly, the second structure magnetically coupled with the second face of the first assembly, the first assembly, the first structure, and the second structure defining a control magnetic circuit; a conductive coil fixed in relation to the second assembly and adapted to produce a magnetic flux in the control magnetic circuit; a soft-magnetic pole adjacent and spaced apart from a surface of the first assembly, the soft-magnetic pole magnetically coupled with the surface of the first assembly, the first assembly, the first structure, and the soft-magnetic pole defining a first bias magnetic circuit, and the first assembly, the second structure, and the soft-magnetic pole defining a second bias magnetic circuit; a permanent magnet adjacent the soft-magnetic pole, adapted to generate bias magnetic flux; a first sensor configured to measure a first total magnetic flux, the first total magnetic flux corresponding to a sum of the control magnetic flux and a first bias magnetic flux in the first bias magnetic circuit; a second sensor configured to measure a second total magnetic flux, the second total magnetic flux corresponding to a sum of the control magnetic flux and a second bias magnetic flux in the second bias magnetic circuit; and an electronics module configured to control current in the conductive coil to adjust the magnetic flux in the control magnetic circuit based on the total fluxes measured by the first and second flux sensors and a command. - View Dependent Claims (17, 18, 19, 20)
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Specification