Abstract: Broadly speaking, embodiments of the present techniques provide techniques for generating haptic feedback or haptic sensations, and in particular to techniques for outputting haptic feedback which varies depending on the input. The haptic feedback is delivered by a shape memory alloy (SMA) actuator that controls the movement of a component based on the required haptic feedback/sensation.

Abstract: Broadly speaking, embodiments of the present techniques provide shape memory alloy (SMA) actuation apparatus for moving a moveable component relative to a static component or support structure and along a notional primary axis. The SMA actuation apparatus may comprise a biasing element to resist motion of the moveable component in particular directions relative to the primary axis, or may comprise an arrangement of SMA actuator wires that provides the biasing function.

Abstract: A device for depth mapping of an object comprises an emitter comprising a laser and an optical component, an actuator and a control processor unit. The actuator is arranged to change the relative position and/or relative orientation of the optical component to the laser. The control processor unit is configured to receive information relating to change in the location and/or orientation of the device during use of the device, and to instruct the actuator to change the relative position and/or relative orientation of the optical component to the laser so as to compensate for change in the location and/or orientation of the device during use of the device.

Abstract: Broadly speaking, embodiments of the present techniques provide apparatuses and methods for controlling the position and/or orientation of a moveable component of an actuator, using at least two shape memory alloy (SMA) actuator wires and at least one sensor for sensing position/orientation of the moveable component.

Abstract: A device for depth mapping of an object comprises an emitter comprising a laser and an optical component, an actuator and a control processor unit. The actuator is arranged to change the relative position and/or relative orientation of the optical component to the laser. The control processor unit is configured to receive information relating to change in the location and/or orientation of the device during use of the device, and to instruct the actuator to change the relative position and/or relative orientation of the optical component to the laser so as to compensate for change in the location and/or orientation of the device during use of the device.

Abstract: Methods and apparatus are disclosed for actuating a shape-memory alloy actuator. An example method comprises a measurement phase, in which a voltage is applied across a bridge comprising a sense resistor to measure the resistance of the shape-memory alloy actuator, and a drive phase, in which a bypass unit is used to bypass the sense resistor while still driving current through the shape-memory alloy actuator in order to drive the shape-memory alloy actuator.

Abstract: Methods and apparatus are disclosed for actuating a shape-memory alloy actuator. An example method comprises a measurement phase, in which a voltage is applied across a bridge comprising a sense resistor to measure the resistance of the shape-memory alloy actuator, and a drive phase, in which a bypass unit is used to bypass the sense resistor while still driving current through the shape-memory alloy actuator in order to drive the shape-memory alloy actuator.

Abstract: An SMA actuation arrangement comprises: an SMA actuator arranged on contraction caused by heating to drive movement of a movable element relative to a support structure; a current source operative to supply drive current through the SMA actuator to heat the SMA actuator; and a detector circuit operative to detect a measure of the resistance of the SMA actuator. While detecting a measure of the resistance of the SMA actuator and controlling the drive current on the basis of the measure of the resistance of the SMA actuator; there is derived a measure of an electrical characteristic of the SMA actuator that is representative of the ambient temperature. While applying closed-loop control an offset is added to the control signal which reduces the steady-state value of an error between the measure of the resistance of the SMA actuator and a target value.

Abstract: An example set-up method for a loudspeaker system capable of generating at least one directed beam of audio sound includes emitting directional beams of set-up sound signals from the loudspeaker system into a room, registering at least one reflection of the emitted signals at one or more locations within the room, and evaluating the registered reflected signals to obtain data for use in configuring the surround sound system.

Abstract: An SMA actuation apparatus comprises: an SMA actuator arranged to drive movement of a movable element; a current supply supplying a drive current; a detection circuit detecting a measure of the resistance of the SMA actuator; and a control unit operative to generate a closed-loop control signal supplied to current supply for controlling the power of the drive current to drive the resistance of the SMA actuator to a target value. The control unit derives: an estimate of a characteristic temperature of the SMA actuation apparatus on the basis of the supplied power, using a thermal model; and a resistance offset on the basis thereof. The closed-loop control signal is generated on the basis of the error between the measure of the resistance of the SMA actuator and the target value of the resistance of the SMA actuator, adjusted by the resistance offset to compensate for variations in resistance.

Abstract: A miniature camera lens actuation apparatus comprises a support structure, a camera lens element supported on the support structure by a suspension system; and an SMA actuator connected between the support structure and the movable element to drive movement of the camera lens element. The control circuit may include a drive circuit and a sensor circuit which have separate electrical connections to the SMA actuator to reduce the impact of the resistance of the electrical connections on the sensing. The control circuit may vary the drive signal in response to a temperature signal indicative of the ambient temperature. An endstop limits movement to prevent extension of the SMA actuator in its unheated state beyond a maximum length which is at or below the length corresponding the local maximum resistance of the resistance-length curve. Control of position is effected using resistance of the SMA actuator as a measure of position.

Abstract: An SMA actuation apparatus comprises: an SMA actuator arranged to drive movement of a movable element; a current supply supplying a drive current; a detection circuit detecting a measure of the resistance of the SMA actuator; and a control unit operative to generate a closed-loop control signal supplied to current supply for controlling the power of the drive current to drive the resistance of the SMA actuator to a target value. The control unit derives: an estimate of a characteristic temperature of the SMA actuation apparatus on the basis of the supplied power, using a thermal model; and a resistance offset on the basis thereof. The closed-loop control signal is generated on the basis of the error between the measure of the resistance of the SMA actuator and the target value of the resistance of the SMA actuator, adjusted by the resistance offset to compensate for variations in resistance.

Abstract: An SMA actuation arrangement comprises: an SMA actuator arranged on contraction caused by heating to drive movement of a movable element relative to a support structure; a current source operative to supply drive current through the SMA actuator to heat the SMA actuator; and a detector circuit operative to detect a measure of the resistance of the SMA actuator. Whilst detecting a measure of the resistance of the SMA actuator and controlling the drive current on the basis of the measure of the resistance of the SMA actuator; there is derived a measure of an electrical characteristic of the SMA actuator that is representative of the ambient temperature. Whilst applying closed-loop control an offset is added to the control signal which reduces the steady-state value of an error between the measure of the resistance of the SMA actuator and a target value.

Abstract: A method of generating filter coefficients to provide a desired nth order filter response comprises adding one or more substantially co-located pole and zero pairs to form an (n+m)th order filter having the desired nth order filter response.