Experimental Validation of a Finite Element Model of a Flexible Parallel Manipulator

Resumo

Parallel manipulators present better dynamic performance than serial robots in terms of positioning
accuracy and operating speeds. However, it is complex to develop control strategies for parallel robots due to the

difficulty of obtaining the end-effector’s pose given the position of the joints. This task can be even more com-
plicated if the robot is lightweight and the links are flexible. A model of the system’s dynamics can be used in

the design of model-based controllers and may be essential to improve the performance of flexible manipulators
subject to undesired vibration. In this paper, we developed in a multibody dynamics environment a finite element
model of the parallel manipulator 3RRR. The current setup has thin and light links connecting the revolute joints

of each one of the three kinematic chains. To validate the multibody model implemented, we performed an exper-
imental modal test with accelerometers placed on the links and a roving impact hammer. Modal parameters such

as the natural frequencies of the numerical model and experimental setup were compared for different poses of the
manipulator.