Patent ID: 11870371

Abstract:
The invention relates to a method and an actuator system for determining and applying a voltage to a piezoelectric actuator (PEA) to achieve a given setpoint displacement. The method involves determining a relation dcal(V) between a PEA displacement measure (d) and voltage (V) and a relation ttcal(V) between transition time (tt) and voltage and combining the determined relations to calculate a relation d(tt) between the displacement measure and transition time during an initial calibration procedure. This relation is characteristic for the PEA, and by determining a new relation ttnew(V) after repeated biasing of the PEA, a compensated relation dc(V) can be calculated by substituting ttnew(V) in the calculated d(tt). The compensated relation dc(V) compensates for piezo creep effects due to the wear and can be used to determine the voltage to be applied directly, or be used in other compensation algorithms.