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

    公开(公告)号:US11380470B2

    公开(公告)日:2022-07-05

    申请号:US16581686

    申请日:2019-09-24

    Applicant: Apple Inc.

    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.

    Methods to Control Force in Reluctance Actuators Based on Flux Related Parameters

    公开(公告)号:US20210090773A1

    公开(公告)日:2021-03-25

    申请号:US16581686

    申请日:2019-09-24

    Applicant: Apple Inc.

    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.

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