Novel piezoelectric crawling robot with multiple degrees of freedom

Traditional ultrasonic motors can usually produce either linear or rotational motion. Piezoelectrically driven structures with multiple degrees of freedom require two or more ultrasonic motors, and the manufacturing process is associated with some problems related to their complex structure and difficult control. This study proposes a new structure of a multi-degree-of-freedom piezoelectric crawling robot. Four modes are selected as the working modes, and mode superposition is used to produce the linear and rotational motion of the robot. This structure is designed based on a combination of size and topological optimization to adjust the frequency response consistency of the motor. The performance of the motor was tested on surfaces with different roughnesses. Its performance on the desk surface was the best. Its maximum linear speed is 37 mm/s, and its maximum rotational speed is 6.28 rad/s. The performance tests were performed under different loads. The linear motion speed of the motor reached its maximum value at 29.2 kHz, and the rotational motion speed reached its maximum value at 32.1 kHz.