Abstract
The present paper presents a method to improve motion accuracy of a precision feed device driven with open loop control by means of 'Walking Drive', which has been developed by the present authors. Displacements of the contact block and voltages applied to the piezoelectric actuators are measured at the same time, and it is clarified that the motion error is caused mainly by the nonlinearity between the displacements and the voltages. Thus, the repeated learning control is applied to compensate the voltages, and a feed motion error of 300 nm under the open loop control is reduced to 58 nm by the compensation.
