A new hybrid method for sensorless control of piezoelectric actuators

This paper offers a new hybrid position estimation method for the sensorless control of piezoelectric actuators. Often mathematical models which map easy to measure signals to displacement are used in this role. The proposed method is aimed at enhancing the accuracy of commonly accepted black box models. Three easy to measure signals are available to be used to estimate displacement. One, the induced voltage, is not suitable for piezoelectric stacks. Two others are more generally usable: the piezoelectric voltage and the sensing voltage. This paper proposes, then theoretically and experimentally verifies a hybrid algorithm that uses the two latter signals to produce estimates of displacement with improved accuracy.

► A new hybrid method is offered in sensorless displacement control of piezoelectric actuators.
► This method uses two ‘easy to measure’ electrical signals jointly to estimate displacement.
► This method combines a black box (fuzzy) model and a complementary algorithm.
► The fuzzy model maps the piezoelectric voltage onto displacement.
► The complementary algorithm uses the sensing voltage to enhance the accuracy of the fuzzy model.