Apparatus for controlling a piezoelectric assembly of a piezo actuator coupled with a driven member

A controller for controlling at least one piezoelectric assembly of a piezo actuator coupled with a driven member and with the piezo actuator having a piezoelectric element coupled frictionally with the driven member at an end of the piezoelectric element which reciprocates during expansion and contraction of the piezoelectric element responsive to analog waveforms;

• and the controller comprising:
• a memory for storing data corresponding with at least one digitized pulse, and the at least one digitized pulse with a rising edge and a falling edge, asymmetrical with respect to one another;
• a processor with an output and an input and with the input coupled to the memory and the processor responsive to instructions to move the driven member in a selected one of two linear and or rotary directions of movement to generate at the output digitized pulses utilizing the stored data stored in the memory, and with asymmetry between rising and falling edges of the digitized pulses varying depending on the direction of movement selected and with the processor responsive to instructions to increase a speed of movement of the driven member to decrease an interval between each of the digitized pulses while substantially maintaining the duration of each of the digitized pulses, thereby decreasing a period of the asymmetrical analog waveforms;
• and
• a digital-to-analog converter (DAC) with an input coupled to the output of the processor and an output coupled to the piezoelectric element and the DAC converting the digitized pulses from the processor to the asymmetrical analog waveforms at the output of the DAC to move the driven member in the selected direction of movement.

A means for controlling at least one piezoelectric assembly of a piezo actuator coupled with a driven member and with the piezo actuator having a piezoelectric element coupled frictionally with the driven member at an end of the piezoelectric element which reciprocates during expansion and contraction of the piezoelectric element responsive to analog waveforms;

• and the means for controlling comprising:
• means for storing data corresponding with at least one digitized pulse, and the at least one digitized pulse with a rising edge and a falling edge, asymmetrical with respect to one another;
• means for processing coupled to the means for storing data, and the means for processing responsive to instructions to move the driven member in a selected one of two linear and or rotary directions of movement to utilize the stored data stored in the means for storing to generate the digitized pulses with an absolute value for the average slope of the rising edge which exceeds the absolute value for the average slope of the falling edge responsive to instructions to move the driven member in a first of the two directions of movement;
• and with the absolute value for the average slope of the falling edge which exceeds the absolute value for the average slope of the rising edge responsive to instructions to move the driven member in a second of the two directions of movement, and with an asymmetry between rising and falling edges the digitized pulses varying depending on the direction of movement selected;
• and
• means for digital-to-analog conversion (DAC) with an input coupled to the means for processing and an output coupled to the piezoelectric element to convert the digitized pulses to the asymmetrical analog waveforms to move the driven member in the selected direction of movement.