Implementation of a motion planning technique for a low-frequency piezo-actuated inchworm drive

Abstract

A novel piezoelectric inchworm drive capable of long-range motion has been designed, fabricated, and tested in this research work. To control the motion of the inchworm drive, trajectory planning has been proposed. The trajectory planning ensures that the inchworm drive achieves smooth and continuous motion with high accuracy. Two trajectory planning methods were incorporated for the developed inchworm drive: a linear function with a parabolic blend trajectory and a cubic polynomial trajectory. Simulations for both the cubic polynomial and trapezoidal trajectories were conducted, with the estimated displacement results closely verified through experimental validation. The fabricated inchworm drive is tested for varying input voltages and frequencies. The experimental findings demonstrate that the proposed piezoactuated Inchworm drive can achieve substantial displacement, constrained only by the linear slides length. When an input signal of 150 V peak to peak and frequency of 10 Hz is applied the inchworm drive, it was capable of moving at a speed of 1425 µm/s. When incorporating trajectory planning for the Inchworm drive the experimental results show that the maximum percentage error for the trapezoidal motion profile is 1.56% and the cubic polynomial profile trajectory is within 1% for the corresponding target position for a travel range of 25 mm of the inchworm drive.