A 3-DOF inertial impact locomotion robot constructed on four piezoelectric bimorph actuators

An inertial impact locomotion robot(IILR), consisting of a base, three supporting feet and four vertically distributed piezoelectric bimorph actuators(PBAs), was developed in this work. The IILR could complete plane locomotion with three degrees of freedom(DOFs), including translation along X-axis, translation along Y-axis and rotation around Z-axis. The inertial impact force driving the IILR was generated by the PBAs through vibration. A simplified dynamic model of the IILR was established to predict its locomotion characteristics. Then, a prototype was fabricated, whose size was φ114 × 14 mm3 and weight was 160.5 g. Then the locomotion performances and carrying capability of the IILR were tested, the results indicated that the maximum linear velocity was 76.66 μm s-1 and the maximum rotary velocity was 161.19 μrad s-1 under voltage of 600 Vp-p and frequency of 9 Hz, respectively. In addition, the maximum carrying load was 1600 g(about 9.97 times of self-weight). The experiment results were also in good agreement with the dynamics simulation results. Overall, the IILR held the characteristics of multiple DOFs, large carrying capability, simple structure and no electromagnetic interference; therefore, it could be suitable for precision positioning and carrying applications such as wafer inspection, microscopic observation and operation.