A piezoelectric-actuated robot operating at running and swinging hybrid modes

Abstract

Abstract A piezoelectric robot operating at running and swinging hybrid modes was presented and tested. The robot was composed of four legs, each leg could bend along horizontal and vertical directions independently. It could run on a platform through impacting forces generated by the fast impact between the driving feet and platform. The simple square-wave exciting signals were used to excite the driving feet to move with oblique linear trajectories in the running mode. The oblique vibratory trajectory was simulated by finite element method, which was verified by experiments under no-load condition. The output performances were investigated by experiments. In the running mode, the output speeds were linearly related to the voltages, the motion along any direction in-plane could be obtained by linearly superimposing the X and Y motions; the robot achieved maximum speeds of 3.65 and 3.52 mm s −1 along axes X and Y under the voltage of 400 V p–p and frequency of 400 Hz, a carrying capacity of 19.4 kg was obtained. In the swinging mode, displacement resolution of 16 nm was achieved. The proposed piezoelectric-actuated robot can be used for nanopositioning with large load in a large planar zone through simple exciting signals.