GAIT PATTERN INVESTIGATIONS OF BIONIC PIEZOELECTRIC ROBOT

Abstract

The development of micro-robots based on bionic motion has garnered increasing attention with the advancement of bionic technology. These micro-robots can be employed in various tasks, such as military applications, disaster search and rescue, in vivo drug delivery, minimally invasive surgery, and tumor treatment. Robot joint motion is commonly achieved through actuators, which encompass motor, hydraulic, or pneumatic components that often carry excessive weight. To achieve the goal of miniaturizing robotic mechanisms, innovative actuators need to be developed. This study focuses on designing a four-limbed micro-robot that utilizes piezoelectric actuators. Automatic Dynamic Analysis of the Mechanical System is employed to investigate the kinematic aspects of the micro-robot's motion, and finite element analysis is also used to obtain the resonant characteristics of the limbs actuated by piezoelectric bimorphs. The results indicate that the gait pattern of a piezoelectric robot changes according to the walking strategy and the robot dimension. The forward travel speed varies depending on the gait pattern, and adjustments in gait design can reduce the up/down oscillation and right/left offset. The robot's travel speed increases with both trunk and limb length, although longer thigh and leg lengths might lead to greater offset and vertical oscillation. The resonant frequency and mode shapes change with the limb structure and affect the limb motion style. By adjusting the driving frequency of the bimorph actuators, the gait pattern can be manipulated. The information presented in this study contributes to a deeper understanding of micro-robot design.