Apple Inc.

Hari Vasudevan

Denis G Chen

Darya Amin-Shahidi

Shingo Yoneoka

Juil Lee

Arman Hajati

Riccardo Tarelli

Fu-Ying Huang

Wesley Scott Smith

Krishna Prasad Vummidi Murali

Mi Hye Shin

Xin Alice Wu

Michael A Lehr

Kathryn K Wopat

Eileen A Mazzochette

Denis M Chen

Domenico Geria

A haptic actuator may include a base, a field member coupled to the base and that may include spaced apart permanent magnets. The haptic actuator may also include a coil having a loop shape defining a slotted opening therein, and a spring member suspending the coil so that the field member is within the slotted opening and permitting relative movement of the field member and the coil.

Haptic actuator including field member within slotted opening of suspended coil and related methods

Disclosed herein are reluctance actuators and methods for feedback control of their applied force. Embodiments of the reluctance actuators include an electromagnet positioned to deflect a metallic plate to provide a haptic output. The control of the force is provided without force sensors (sensorless control) by monitoring voltage and/or current (V/I) applied during an actuation. For a given intended force output, an electrical parameter value (flux, current, or other parameter) is read from a look up table (LUT). The LUT may store a present value of the inductance of the reluctance actuator. The feedback control may be a quasi-static control in which the LUT is updated after actuation based on the monitored V/I. The feedback control may be real-time, with a controller comparing an estimated electrical parameter value based on the measured V/I with the value from the LUT.

Methods to control force in reluctance actuators based on flux related parameters

A haptic system includes a haptic engine in which a reluctance motor is driven by a driver controller operated in conjunction with an impedance-estimator that uses amplitude-modulated calibration signals. An enveloped-calibration signal is superimposed on a haptic-drive signal to quickly, and accurately, estimate the driving coil's impedance, while minimizing power penalty.

Low-latency impedance estimation for controlling a reluctance motor

In an embodiment, a single-sided or double-sided moving magnet haptic engine comprises: a frame; one or more magnetic field sources mounted to the frame and operable to generate a magnetic field and a back electromotive force (EMF) voltage; a magnetic mass positioned within the frame and operable to move within the frame along a movement axis; a comparator mounted to the frame, the comparator operable to detect the magnetic field and to generate a signal indicating a crossing of one or more magnetic references by the magnetic field; and a processor coupled to the one or more sensors and operable to estimate a displacement of the magnetic mass on the movement axis based on the back EMF voltage and the signal. Other embodiments are directed to a single-sided or double-sided moving coil haptic engine.

Mass displacement estimation using back EMF and magnetic reference crossing

A system for providing closed-loop control of a linear resonant actuator using Back Electromotive Force (EMF) and inertial compensation is disclosed. In an embodiment, one or more inertial sensors are used to estimate low frequency motion of a haptic engine moving mass and compensate for the motion using a feedforward model, thus providing a more robust closed-loop control system for controlling the moving mass when subjected to low frequency disturbances by a user, for example, shaking or swinging the device.

Closed-loop control of linear resonant actuator using back EMF and inertial compensation

Disclosed is a system, method and apparatus for dynamic management of haptic module mechanical offset with gravity-induced position offset tracking. In an embodiment, a method comprises: determining, by a processor, a gravity-induced position offset of a mass in a haptic module; generating, by the processor, a position command for moving the mass from a sensor reference position to a mechanical resting position based at least in part on the gravity-induced position offset; and moving, by a closed-loop controller, the mass from the sensor reference position to the mechanical resting position in accordance with the position command.

Gravity-induced position offset tracking for dynamic management of haptic module mechanical offset

An electronic device can include a force and touch sensing system. In one embodiment, an input force sensor device of an electronic device is disclosed.

Pressure-based force and touch sensing

In an embodiment of a system for closed-loop control of a linear resonant actuator, a system processor coupled to a magnetic field sensor is configured to: receive a magnetic field sensor signal from a channel coupling a magnetic field sensor and the system processor; receive measurements of actuator current and actuator voltage from drive electronics; receive a temperature signal from a linear resonant actuator, the temperature signal indicating a temperature of the magnetic field sensor; calculate a first estimate of mass position using the magnetic field sensor signal, actuator current and a magnetic model; calculate an estimate of coil resistance based on the temperature signal, the actuator current, the actuator voltage and a thermal model; and calculate a second estimate of mass position and an estimate of mass velocity based on the first estimate of mass position, the actuator current, the actuator voltage and the estimated coil resistance.

Closed-loop control of linear resonant actuator using back EMF data and hall sensing

An electronic device may include a device housing and a haptic actuator carried by the device housing and that includes a haptic actuator housing and a field member movable within the haptic actuator housing. The electronic device may also include a motion sensor carried by the device housing to sense motion of the field member, an audio sensor carried by the device housing to sense audio noise from the haptic actuator, and a controller coupled to the haptic actuator, the motion sensor, and the audio sensor. The controller may be configured to drive the haptic actuator based upon sensed motion of the field member and audio noise from the haptic actuator.

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Los Gatos, CA, United States of America

Hari Vasudevan