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US 11,056,985 B2Granted
Microelectromechanical system and control method to control a piezoelectric drive based on an admittance or impedance of the piezoelectric drive
AssigneeRobert Bosch GmbH
InventorMichael Curcic
Life of this patent
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Abstract
A microelectromechanical system includes a piezoelectric drive and a control unit coupled to the piezoelectric drive and designed to control the piezoelectric drive based on a change of the admittance and/or the impedance of the piezoelectric drive.
Claims14
A microelectromechanical system comprising:
- a piezoelectric drive;
- and
- a control unit coupled to the piezoelectric drive, wherein the control unit is configured to control the piezoelectric drive based on a change of at least one of an admittance and an impedance of the piezoelectric drive, including by, in a normal operation:
- providing a control voltage, which includes a DC voltage component and an AC voltage component overlaid on the DC voltage component, to vibrate the piezoelectric drive;
- receiving, from a current measuring device, a current flowing through the piezoelectric drive while the piezoelectric drive is vibrated via the control voltage;
- determining an amplitude of the vibration based on a first impedance and the detected current;
- and
- regulating an amplitude of the vibration by adjusting the control voltage based on the determined amplitude and a predefined setpoint amplitude.
5 more elements
A control method for a microelectromechanical system, the method comprising:
- detecting a change of at least one of an admittance and an impedance of a piezoelectric drive of the microelectromechanical system;
- and
- controlling, by a control unit, the piezoelectric drive based on the detected change, including by, in a normal operation:
- providing a control voltage, which includes a DC voltage component and an AC voltage component overlaid on the DC voltage component, to vibrate the piezoelectric drive;
- receiving from a current measuring device a current flowing through the piezoelectric drive while the piezoelectric drive is vibrated via the control voltage;
- determining an amplitude of the vibration based on a first impedance and the detected current;
- and
- regulating an amplitude of the vibration by adjusting the control voltage based on the determined amplitude and a predefined setpoint amplitude.
5 more elements
Dependencies are inferred from the claim text.