Methods for controlling SMA actuators
AssigneeCambridge Mechatronics Limited
InventorsAndrew Benjamin David Brown, Daniel Burbridge
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Abstract
Broadly speaking, embodiments of the present techniques provide methods for driving shape memory alloy (SMA) actuator wires in a more power-efficient manner.
Claims20
A method for controlling opposed shape memory alloy actuator wires that apply opposed forces to a moveable part, the method comprising:
- carrying out control of at least an aspect of the configuration of the moveable part by driving each of the opposed wires, wherein the control is carried out with a particular average drive signal that is an average of drive signals to all of the opposed wires;
- and
- increasing the average drive signal, thereby increasing the average power of the opposed wires, so as to increase a size of an allowable range of drive signals for at least one of the opposed wires.
A method of controlling opposed SMA actuator wires in an SMA actuation apparatus wherein at times when a relatively high amplitude or relatively high slew rate or relatively high power differential is demanded, the average power applied to all the wires increases and at times when a relatively low amplitude or relatively low slew rate or relatively low power differential is demanded, the average power applied to all the wires decreases.
Dependencies are inferred from the claim text.