積層型圧電素子で駆動されるソフトハンドリング・グリッパ : 第1報, 解析モデル並びに微小把持力制御

This paper is a study on the development a soft handling two-fingered miniature gripper driven by a piezoceramic stack. The system is essensially a magnifying mechanism cut out of a monolith. It is composed of a piezoelectric actuator, a flecxible-hinged two-stage linkage and a force sensor attached at the tip of one of the fingers. A linkage that effectively transforms longitudinal expansion/contraction of the actuator into lateral fingertip motion is designed. Furthermore, a highly efficient compact force sensor is developed for measuring a minute force at the fingertip. The mathematical model of the electromechanical system is developed and applied to the study of a PID control problem where the gripper holds the object with a time-constant force 0.036 N.