Patents by Inventor Hari VASUDEVAN

Hari VASUDEVAN has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11837937
    Abstract: 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.
    Type: Grant
    Filed: August 10, 2020
    Date of Patent: December 5, 2023
    Assignee: Apple Inc.
    Inventors: Kathryn K. Wopat, Fu-Ying Huang, Hari Vasudevan, Xin Alice Wu, Shingo Yoneoka
  • Patent number: 11763971
    Abstract: 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.
    Type: Grant
    Filed: June 30, 2022
    Date of Patent: September 19, 2023
    Assignee: Apple Inc.
    Inventors: Darya Amin-Shahidi, Hari Vasudevan, Juil Lee, Denis G. Chen
  • Patent number: 11522483
    Abstract: 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.
    Type: Grant
    Filed: September 25, 2020
    Date of Patent: December 6, 2022
    Assignee: Apple Inc.
    Inventors: Denis G. Chen, Juil Lee, Hari Vasudevan, Riccardo Tarelli, Darya Amin-Shahidi
  • Publication number: 20220336132
    Abstract: 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.
    Type: Application
    Filed: June 30, 2022
    Publication date: October 20, 2022
    Inventors: Darya Amin-Shahidi, Hari Vasudevan, Juil Lee, Denis G. Chen
  • Patent number: 11380470
    Abstract: 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.
    Type: Grant
    Filed: September 24, 2019
    Date of Patent: July 5, 2022
    Assignee: Apple Inc.
    Inventors: Darya Amin-Shahidi, Hari Vasudevan, Juil Lee, Denis M. Chen
  • Publication number: 20210175831
    Abstract: 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.
    Type: Application
    Filed: September 25, 2020
    Publication date: June 10, 2021
    Inventors: Denis G. Chen, Juil Lee, Hari Vasudevan, Riccardo Tarelli, Darya Amin-Shahidi
  • Publication number: 20210090773
    Abstract: 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.
    Type: Application
    Filed: September 24, 2019
    Publication date: March 25, 2021
    Inventors: Darya Amin-Shahidi, Hari Vasudevan, Juil Lee, Denis M. Chen
  • Publication number: 20210067023
    Abstract: A haptic actuator may include a spool having an opening therein and at least one coil wound on the spool. The haptic actuator may also include a tubular shaft bearing within the opening and a shaft slidable within the tubular shaft bearing. The haptic actuator may further include a field member coupled to the shaft and that includes a frame and at least one permanent magnet carried by the frame and surrounding the at least one coil.
    Type: Application
    Filed: August 10, 2020
    Publication date: March 4, 2021
    Inventors: Kathryn K. WOPAT, Hari VASUDEVAN
  • Publication number: 20210064137
    Abstract: An electronic device may include a haptic actuator that includes a field member including at least one permanent magnet, and at least one coil configured to cause relative movement with the field member. The electronic device may also include at least one inductance sensor configured to sense relative movement between the at least one coil and field member and a processor configured to drive the at least one coil based upon the at least one inductance sensor.
    Type: Application
    Filed: August 10, 2020
    Publication date: March 4, 2021
    Inventors: Kathryn K. WOPAT, Hari Vasudevan
  • Publication number: 20210067022
    Abstract: 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.
    Type: Application
    Filed: August 10, 2020
    Publication date: March 4, 2021
    Inventors: Kathryn K. WOPAT, Fu-Ying HUANG, Hari VASUDEVAN, Xin Alice WU, Shingo YONEOKA
  • Patent number: 10746570
    Abstract: 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.
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: August 18, 2020
    Assignee: Apple Inc.
    Inventors: Denis G. Chen, Hari Vasudevan
  • Patent number: 10601355
    Abstract: 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.
    Type: Grant
    Filed: September 28, 2018
    Date of Patent: March 24, 2020
    Assignee: Apple Inc.
    Inventors: Hari Vasudevan, Eileen A. Mazzochette, Arman Hajati, Shingo Yoneoka
  • Publication number: 20200081536
    Abstract: 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.
    Type: Application
    Filed: September 10, 2018
    Publication date: March 12, 2020
    Applicant: Apple Inc.
    Inventor: Hari Vasudevan
  • Patent number: 10564728
    Abstract: 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.
    Type: Grant
    Filed: September 10, 2018
    Date of Patent: February 18, 2020
    Assignee: Apple Inc.
    Inventor: Hari Vasudevan
  • Patent number: 10496209
    Abstract: 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.
    Type: Grant
    Filed: November 14, 2017
    Date of Patent: December 3, 2019
    Assignee: Apple Inc.
    Inventors: Krishna Prasad Vummidi Murali, Hari Vasudevan, Michael A. Lehr, Wesley S. Smith
  • Patent number: 10277154
    Abstract: 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.
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: April 30, 2019
    Assignee: Apple Inc.
    Inventors: Arman Hajati, Hari Vasudevan
  • Publication number: 20190103829
    Abstract: 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.
    Type: Application
    Filed: September 28, 2018
    Publication date: April 4, 2019
    Applicant: Apple Inc.
    Inventors: Hari Vasudevan, Eileen A. Mazzochette, Arman Hajati, Shingo Yoneoka
  • Publication number: 20180316296
    Abstract: 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.
    Type: Application
    Filed: September 7, 2017
    Publication date: November 1, 2018
    Applicant: Apple Inc.
    Inventors: Arman Hajati, Hari Vasudevan
  • Publication number: 20180284936
    Abstract: 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.
    Type: Application
    Filed: November 14, 2017
    Publication date: October 4, 2018
    Inventors: Krishna Prasad Vummidi Murali, Hari Vasudevan, Michael A. Lehr, Wesley S. Smith
  • Publication number: 20180266849
    Abstract: 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.
    Type: Application
    Filed: September 7, 2017
    Publication date: September 20, 2018
    Applicant: Apple Inc.
    Inventors: Denis G. Chen, Hari Vasudevan