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.

Inventor： Darya Amin-Shahidi ,  Hari Vasudevan ,  Juil Lee ,  Denis M. Chen

IPC: H01F7/18 ,  G06F3/01 ,  G06F3/041 ,  H02P25/08 ,  H02P25/092 ,  H01H47/04

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.

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.

Inventor： Darya Amin-Shahidi ,  Hari Vasudevan ,  Juil Lee ,  Denis M. Chen

IPC: H01F7/18 ,  G06F3/01 ,  G06F3/041

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.