Piezoelectrically Actuated Robotic End-Effector with Strain Amplification Mechanisms

Abstract

AbstractThis chapter describes a nested rhombus multilayer mechanism for large effective-strain piezoelectric actuators. This hierarchical nested architecture encloses smaller flextensional actuators with larger amplifying structures so that a large amplification gain on the order of several hundreds can be obtained. A prototype nested PZT cellular actuator that weighs only 15 g produces 21% effective strain (2.53 mm displacement from 12 mm actuator length and 30 mm width) and 1.69 N blocking force. A lumped parameter model is proposed to represent the mechanical compliance of the nested strain amplifier. This chapter also describes the minimum switching discrete switching vibration suppression (MSDSVS) approach for flexible robotic systems with redundancy in actuation. The MSDSVS method reduces the amplitude of oscillation when applied to the redundant, flexible actuator units. A tweezer-style end-effector is developed based on the rhombus multilayer mechanism. The dimensions of the end-effector are determined by taking the structural compliance into account. The assembled robotic end-effector produces 1.0 N of force and 8.8 mm of displacement at the tip.KeywordsEffective StrainPiezoelectric ActuatorLump Parameter ModelStructural ComplianceAmplification MechanismThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.