Patent ID: 11870371
Assignee: POLIGHT ASA
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 0:
1. A method for determining and applying a voltage to a piezoelectric actuator (PEA) to achieve a given setpoint displacement, the method comprising:
determining, during an initial calibration procedure, a relation dcal(V) between a PEA displacement measure (d) and voltage (V) and a relation ttcal(V) between transition time (tt) and voltage, wherein the transition time is a charging or discharging time ΔT between two voltages VA and VB applied to the PEA, and wherein the relations are determined for both increasing and decreasing voltages to map hysteresis, and combining the determined relations to calculate a relation d(tt) between the displacement measure and transition time;
determining, after repeated biasing of the PEA, a new relation ttnew(V) between transition time and voltage, and substituting ttnew(V) in the calculated d(tt) to calculate a compensated relation dc(V);
providing a setpoint displacement measure, dsp or voltage Vs;
determining, using the compensated relation, dc(V), a voltage to be applied to the PEA to achieve dsp or a displacement measure derived from Vs; and
applying the determined voltage to the PEA.