US 11,539,308 B2 · Virtual resistive load in feedback loop driving a piezoelectric actuator

Abstract

A virtual resistive load feedback circuit for driving a piezoelectric actuator is provided that accounts for a hysteresis error and drift within the movement of the actuator. The circuit may include a voltage divider and charge divider. A voltage monitor signal corresponding to a voltage of a driver signal and a current monitor signal corresponding to a current provided to the amplifier are combined by an operational amplifier and include electrical characteristics of the actuator such that the circuit approximates a virtual load across the actuator. A feedback portion of the operational amplifier may include a resistor and capacitor connected in parallel to provide the voltage and charge divide functions. The use of the virtual resistive circuit allows for the piezoelectric actuator to be ground referenced, with no external components connected directly to the actuator while gaining the feedback effect to counter the hysteresis and drifts errors of the actuator.

Claims13

Dependent claims

A piezoelectric power amplifier comprising:

an amplifier comprising a first input and a second input, the first input receiving a control input signal and the amplifier transmitting, based on the control input signal, a power driving signal to a piezoelectric actuator device;
and
a hysteresis compensation circuit comprising:
a summing circuit comprising a first input receiving a voltage monitor signal comprising a first voltage value corresponding to a voltage of the power driving signal and a current monitor signal comprising a second voltage value corresponding to a current of the power driving signal, the output comprising the sum of the voltage monitor signal and the current monitor signal;
and
a dividing circuit, coupled between the output of the summing circuit and the first input of the summing circuit, wherein the output of the summing circuit is coupled to the second input of the amplifier for hysteresis compensation of the piezoelectric actuator device based at least on the voltage monitor output signal and the current monitor output signal.

3 more elements

A system for hysteresis compensation of a piezoelectric actuator, the system comprising:

an operational amplifier comprising:
a first input receiving a voltage monitor signal of a power amplifier and a current monitor signal of the power amplifier, the power amplifier receiving a control input signal and providing a power driving signal to a load, the voltage monitor signal comprising a first voltage value corresponding to a voltage of the power driving signal and the current monitor signal comprising a second voltage value corresponding to a current of the power driving signal;
a second input coupled to a common value;
and
an output coupled to a feedback input of the power amplifier, the output comprising a summation of the voltage monitor signal and the current monitor signal;
and
a feedback circuit, coupled between the output of the operational amplifier and the first input, comprising a first resistor connected in parallel with a capacitor, the feedback circuit dividing the voltage and the current of the power driving signal.

4 more elements

Dependencies are inferred from the claim text.

Virtual resistive load in feedback loop driving a piezoelectric actuator

Life of this patent

Virtual resistive load in feedback loop driving a piezoelectric actuator

Life of this patent

Abstract

Claims13