Multi-degree of freedom platform based on spherical wheels

Abstract

A multi-degree of freedom (DOF) motion platform has been developed for various applications such as motion simulators and game industry. Existed motion platforms have some limits in motion realization which is caused by mechanical linkages and their actuating mechanism. Numerous mechanisms to increase a range of motion as well as the number of DOF have been developed but still controlled motion is limited. In this paper, a new concept of motion platform has been designed to increase a range of motion as well as six DOFs. The platform is based on spherical wheels for orientation and linear guided actuator for translation so that two motions are decoupled to each other, capable of control independently. Kinematic and dynamic analysis of the motion platform have been analyzed to prove no singularity of motion control. The prototype of the platform has been fabricated and experimental results of orientation motion in open loop control has been demonstrated. The experiments with two different spherical wheel positions have been conducted to demonstrate translation motion as well as orientation. The results show the capability of orientation along three orthogonal axes without limit of motion range and translation motion.