Apparatus for cost effective wireless actuator using SMA and MRC

• US 9,777,715 B2
• Filed: 01/14/2015
• Issued: 10/03/2017
• Est. Priority Date: 01/14/2015
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Laifenfeld, Moshe, Suplin, Vladimir
• Primary Examiner(s): Chan, Kawing
• Assistant Examiner(s): BROWN, BRADLEY R
• Application Number:
  US14/597,143
• Publication Number:
  US 20160201655A1
• Time in Patent Office: 993 Days
• Field of Search: 318117
• CPC Class Codes: B23Q 15/00 Automatic control or regulation of feed movement, cutting velocity or position of tool or work programme-control G05B19/00, e.g. numerical programme-control G05B19/18
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• CPC Class Codes: F03G 7/06 using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like using thermal expansion of non-vaporising liquids F01K
• CPC Class Codes: F03G 7/06147 Magnetic shape memory alloys, e.g. ferro-magnetic alloys
• CPC Class Codes: F03G 7/065 using a shape memory element
• CPC Class Codes: G01R 27/02 Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant by measuring phase angle only G01R25/00
• CPC Class Codes: G01R 35/005 Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references G01R33/0035, G01R35/002 take precedence
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A system and method for wirelessly controlling a shape memory alloy (SMA) actuator using magnetic resonant coupling (MRC). The SMA actuator is part of a receiver circuit including an actuator coil, where the SMA actuator is configured into a certain shape. The system includes a transmitter circuit having a transmitter coil and a controller, where the transmitter coil receives an AC current that causes the transmitter coil to generate an oscillating magnetic field in resonance with the actuator coil in the receiver circuit and be magnetically coupled thereto. The current induced in the actuator coil creates heat that reconfigures the SMA actuator to provide the actuation.

Claims

1. A magnetic resonant coupling (MRC) actuation circuit comprising:

a transmitter circuit including a controller, a base coil, a variable current source and a tuning capacitor, said variable current source selectively providing a predetermined alternating current to the base coil in combination with a capacitance provided by the tuning capacitor so as to generate an oscillating magnetic field at a predetermined frequency; and

at least one receiver circuit including a shape memory alloy (SMA) actuator and an actuator coil, said controller selectively providing the frequency of the oscillating magnetic field to be tuned to the actuator coil through MRC so as to heat the SMA actuator and cause it to change its configuration,

where the controller adjusts the transmitter circuit to fine tune the oscillating magnetic field, based on a change of phase of reflected impedance of the receiver circuit, when the SMA actuator changes its configuration.

2. The MRC circuit according to claim 1 wherein the receiver circuit includes a variable capacitor in electrical communication with the SMA actuator and the actuator coil, said SMA actuator operating as a resistive load in the at least one receiver circuit.

3. The MRC circuit according to claim 1 wherein the SMA actuator operates both as an inductor and a parasitic capacitance in the receiver circuit.

4. The MRC circuit according to claim 1 wherein the at least one receiver circuit is a plurality of receiver circuits, wherein the controller changes the frequency of the oscillating magnetic field to be selectively tuned to all of the receiver circuits.

5. The MRC circuit according to claim 1 wherein the MRC circuit is a vehicle circuit and the actuator is a vehicle actuator.

6. The MRC circuit according to claim 5 wherein the transmitter circuit is separate from the vehicle and the receiver circuit is on the vehicle.

7. A magnetic resonant coupling (MRC) actuation circuit comprising:

a transmitter circuit including a controller, a base coil, a variable current source and a tuning capacitor, said variable current source selectively providing a predetermined alternating current to the base coil in combination with a capacitance provided by the tuning capacitor so as to generate an oscillating magnetic field at a predetermined frequency; and

a receiver circuit including a shape memory alloy (SMA) actuator being configured as an actuator coil, said controller selectively providing the frequency of the oscillating magnetic field to be tuned to the actuator through MRC so as to heat the actuator and cause it to change its configuration,

where the controller adjusts the transmitter circuit to fine tune the oscillating magnetic field, based on a change of phase of reflected impedance of the receiver circuit, when the SMA actuator changes its configuration.

8. The MRC circuit according to claim 7 wherein the receiver circuit includes a variable capacitor in electrical communication with the SMA actuator.

9. The MRC circuit according to claim 7 wherein the SMA actuator operates both as an inductor and a parasitic capacitance in the receiver circuit.

10. The MRC circuit according to claim 7 wherein the MRC circuit is a vehicle circuit and the actuator is a vehicle actuator.

11. The MRC circuit according to claim 10 wherein the transmitter circuit is separate from the vehicle and the receiver circuit is on the vehicle.

12. A magnetic resonant coupling (MRC) actuation circuit for actuating a device on a vehicle, said MRC circuit comprising:

a transmitter circuit including a controller, a base coil, a variable current source and a tuning capacitor, said variable current source selectively providing a predetermined alternating current to the base coil in combination with a capacitance provided by the tuning capacitor so as to generate an oscillating magnetic field at a predetermined frequency; and

a plurality of receiver circuits each including a shape memory alloy (SMA) actuator and an actuator coil, said controller selectively providing the frequency of the oscillating magnetic field to be separately tuned to the actuator coil in each of the receiver circuits through MRC so as to heat the SMA actuator and cause it to change its configuration,

where the controller adjusts the transmitter circuit to fine tune the oscillating magnetic field, based on a change of phase of reflected impedance of each of the receiver circuits, when the SMA actuator changes its configuration.

13. The MRC circuit according to claim 12 wherein each of the receiver circuits includes a variable capacitor in electrical communication with the SMA actuator and the actuator coil.

14. The MRC circuit according to claim 12 wherein the SMA actuator operates both as an inductor and a parasitic capacitance in the receiver circuits.

15. The MRC circuit according to claim 12 wherein the transmitter circuit is separate from the vehicle and the plurality of receiver circuits is on the vehicle.

16. The MRC circuit according to claim 12 wherein the actuator coil of each of the receiver circuits is positioned within a perimeter of the base coil and substantially on a same plane as the base coil.