Development of a 3-DOF Planar Parallel Robot (RRR Type) for Omni-directional Locomotion Interface

Abstract This paper describes the design and control of the 3dof planar parallel robot for omni-directional locomotion interface, which can generate infinite floor on planar surfaces. The interface is composed of three limbs, each of which has three serial revolute joints with the actuated first joint. To simulate natural human walking, the locomotion interface design specifications are acquired based on gait analysis and each mechanism is optimally designed and manufactured to satisfy the given requirements. The designed locomotion interface allows natural walking (step: 0.8m, foot angle: 10deg). To provide continuous walking in a confined area, a controller is implemented hierarchically to low-level for joint position control, mid-level for platform position control, and high-level control for generation of walking trajectory. At high-level control, a walking control algorithm is suggested to satisfy continues walking on an infinite floor for planar surfaces. From experimental results of walking simulations at level ground, it is proven that with the proposed walking interface, a general person can walk naturally without any considerable disturbances and with safety.