Active Vibration Control and Coupled Vibration Analysis of a Parallel Manipulator with Multiple Flexible Links

Quan Zhang,Chaodong Li,Jiamei Jin,Jiantao Zhang

doi:10.1155/2016/7474085

Abstract

This paper addresses the active vibration control and coupled vibration analysis of a planar parallel manipulator (PPM) with three flexible links. Multiple piezoelectric ceramic transducers are integrated with the flexible links to constitute the smart beam structures, and hence the vibration of the flexible link can be self-sensed and self-controlled. To prevent the spillover phenomena and improve the vibration control efficiency, the independent modal space control combined with an input shaper is developed to suppress both the structural and the residual vibration of the flexible links. The coupled vibration features between rigid and elastic motions and the interaction effects among three flexible links are theoretically analyzed based on the one-pass rigid-flexible dynamic models. Numerical simulation and experiment results show that the vibration of the three flexible links is coupled through the moving platform and the vibration suppression efficiency is getting improved with the number of controlled flexible links increased.

Highlights

With the increasing demands for productivity in many industrial fields, such as semiconductor manufacturing, medical application, and automatic microassembly, parallel robots with light components are designed to fulfill the requirements of high speed and high accuracy
The symbols are defined as follows: the layout angle of the three linear guides and the angle between the x-axis of the static frame and ith links are defined as variable αi and βi (i = 1, 2, 3), respectively; the length of the linkage is represented by Li; ρi is the prismatic motion of the LUSM; the position of the end-effector in the static coordinates is stated as a vector of Xp =T; wi(xi) is the elastic deformation at xi (0 ≤ xi ≤ Li) of the ith flexible linkage
For the two-pass method, the rigid-flexible manipulators are first modeled as fully rigid body in order to calculate the inertial and joint forces, and the prescribed rigid motion can be applied to the elastic model as excitation forces

Summary

Introduction

With the increasing demands for productivity in many industrial fields, such as semiconductor manufacturing, medical application, and automatic microassembly, parallel robots with light components are designed to fulfill the requirements of high speed and high accuracy. For the task of fast trace tracking and positioning which require high acceleration and deceleration, the unwanted vibrations are introduced to the manipulator due to the use of light components In this situation, the settling times get longer and the positioning accuracy is decreased due to the residual vibration after the motion stop, which is countered to our initial goal. For the two-pass method, the rigid-flexible manipulators are first modeled as fully rigid body in order to calculate the inertial and joint forces, and the prescribed rigid motion can be applied to the elastic model as excitation forces In such method, for example, the KinetoElasto-Dynamics (KED) approach, only the effect of the rigid body motion on flexible body motion is considered. The one-pass method which considered the fully coupled dynamics characteristics between the rigid and elastic motions is adopted

Methods

Results

Conclusion