Design and Analysis of a Novel Adjustable Closed-chain Multi-legged Robot

doi:10.3901/JME.2020.19.191

Abstract

Abstract: The single foot trajectory of the single-degree-of-freedom close-chain leg mechanism leads to insufficient ground adaptability. Addressing this, a novel closed chain adjustable leg mechanism is proposed. Based on the six-bar Klann mechanism, one degree of freedom is added to realize the adjustment of the frame hinge position. By this way, the continuous change of foot trajectory can be obtained. The height of the legs can be increased longitudinally to enhance the obstacle crossing ability, and the stride distance can be changed in the transverse direction to achieve the plan of approaching the target point, and the slope-climbing impact can be reduced during the transition section as well. This kind of leg mechanism is driven by an electric motor while walking, which maintains its single-degree-of-freedom characteristics with fewer actuators, high structural stiffness and large carrying capacity. The configuration design, kinematics analysis and parameter optimization of the leg mechanism are carried out. Further the eight-legged robot is constructed. The foot trajectory cluster is established. The trajectory parameters and the walking strategies are analyzed and studied. The feasibility of the design is verified by fabricating a prototype and carrying out adaptability experiments in typical ground environment.

Key words: walking robot, adjustable mechanism, foot trajectory, walking strategy, mechanism analysis

CLC Number:

TH122
TP242

WANG Sen, YAO Yanan, WU Jianxu. Design and Analysis of a Novel Adjustable Closed-chain Multi-legged Robot[J]. Journal of Mechanical Engineering, 2020, 56(19): 191-199.

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