Multidegree-of-Freedom Motion Platform Based on Spherical Wheels

This paper presents a new concept and design of a multidegree-of-freedom (DOF) motion platform capable of controlling three DOFs rotation and three DOFs translation to provide unlimited rotational range of motion for virtual reality (VR) based on spherical wheels. Multi-DOF motion platforms have been developed for various applications such as motion simulators and game industry. In addition, motion recognition is one of main features for VR with visual display. However, existing motion platforms have critical limits of range of motion in motion realization due to mechanical linkages and their actuating mechanisms. In addition, unnatural motion control causes mismatch in the VR environment. The motion platform developed in this paper can provide six DOFs motion, and in particular, unlimited range of rotation without motion singularity. The design is compact and lightweight offering fast speed of response. Kinematic and dynamic analysis of the platform are investigated to provide a basis of motion control in an open loop. Performance of motion control is demonstrated in real scale size (ride on platform). The experimental results show that the platform is successfully capable of multi-DOF motion control and can be utilized for various applications in future demands.