%0 Journal Article
%T Theory Analysis and Experiment Research of the Leg Mechanism for the Human-Carrying Walking Chair Robot
%A Lingfeng Sang
%A Hongbo Wang
%A Shuaishuai Wang
%A Na Chen
%A Yuehua Wen
%J Journal of Robotics
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/891835
%X For the high carrying capacity of the human-carrying walking chair robot, in this paper, 2-UPS+UP parallel mechanism is selected as the leg mechanism; then kinematics, workspace, control, and experiment of the leg mechanism are researched in detail. Firstly, design of the whole mechanism is described and degrees of freedom of the leg mechanism are analyzed. Second, the forward position, inverse position, and velocity of leg mechanism are studied. Third, based on the kinematics analysis and the structural constraints, the reachable workspace of 2-UPS+UP parallel mechanism is solved, and then the optimal motion workspace is searched in the reachable workspace by choosing the condition number as the evaluation index. Fourth, according to the theory analysis of the parallel leg mechanism, its control system is designed and the compound position control strategy is studied. Finally, in optimal motion workspace, the compound position control strategy is verified by using circular track with the radius 100 mm; the experiment results show that the leg mechanism moves smoothly and does not tremble obviously. Theory analysis and experiment research of the single leg mechanism provide a theoretical foundation for the control of the quadruped human-carrying walking chair robot. 1. Introduction Walking aids have been a research hot point for several years [1]. The human-carrying walking chair robot, which is one of walking aids, could help the elderly and the lower limb disabled walk freely in the outside and navigate on uneven ground. The human-carrying walking chair robot, which is different from the wheeled robot and the ordinary legged robot, not only needs to steadily walk by using leg mechanism as supporting point [2, 3], but also needs to bear weight from itself and different passengers [4]. These put forward higher requirements for performance of the leg mechanism of the walking chair robot. At present, most of human-carrying walking chair robots for the elderly and the lower limb disabled are implemented by selecting serial mechanism as leg mechanism [5¨C9], such as the I-Foot robot, the Hubo FX-1 robot, and the Hyperion4 robot. Using the serial mechanism as the leg mechanism, the whole volume and weight of the robot are bigger and the carrying capacity is smaller. For instance, the robot I-Foot is 200£¿kg in mass and can carry a person with 60£¿kg; Hubo FX-1 is 150£¿kg in mass and can bear the load of 100£¿kg. Compared with the serial mechanism, parallel mechanism (PM) can make up for the deficiencies of the serial mechanism and form the complementary
%U http://www.hindawi.com/journals/jr/2014/891835/