Experimental Study Of The 3-RRR Planar Flexible Parallel Robot

The parallel robot is a kind of closed-loop robot that has many advantages such as low inertia and high accuracy. It is a complement to the serial robot in the structure and performance, and expands the application field of robotics. On the command of high-speed and lightness, the elastic deformations that have impacted on the performances of parallel robot can not be neglected. Therefore, the flexible parallel robot has become a new hotspot. At present, most of the studies are focused on theory, and experimental study is seldom. We carried a series of experimental studies toward flexible parallel robot.This article is based on a 3-RRR flexible robot system. Experimental studies including terminal trajectory measurement and vibration suppression are carried out. The content of this paper is as follows:Firstly, A experimental system including 3-RRR flexible parallel robot, dynamic strain instrument, magnifying circuit, data collecting box and PZT driving power is build up. The control system for the experiment is programmed by Visual C++ which is composed of several function blocks, such as digital display, voltage deduction for PZT, the data transmission interface, data recording and the data preservation. The drive voltage of PZT is core of the software.Secondly, trajectory of the moving platform is measured in two methods, a linear wire encoder kinematics data acquiring system and 3D measuring instrument Optotrak, and comparison is made to analyze the reliability and validity of the system. It can provide the support for the kinematics control feedback on the planar 3-RRR flexible parallel robot.Thirdly, a fuzzy controller is designed based on fuzzy theory technology. It doesn't rely on the model of the system, and most of the operation is done off-line, it is convenience and real-time.Finally, based on the experimental system and the fuzzy controller, vibration suppression experiments are carried out. The effectiveness of the fuzzy controller is validated, and the effect of vibration suppression is relatively revealed. The experimental data shows that the PZT can suppress the elastic vibration to a certain extent.