Research On Wheel-legged Robot Based On Spatial Single-loop Mechanism

In this paper,the spatial single-loop mechanism is applied to the design of the wheel-legged robot.A variety of wheel-legged robots based on the spatial single-loop mechanism are proposed,and systematic research are carried out around the proposed robots,including scheme design,theoretical calculation,motion simulation,prototype production and experiment.Firstly,a novel spatial five-link RPRPS mechanism is proposed,and the mechanism is used as a mobile body to construct a wheel-legged robot.The degree of freedom of the robot is analyzed by the screw theory.Using Adams software to simulate the motion of the robot,the gait of the RPRPS wheel-legged robot with single degree of freedom to realize the function of straight and turning is obtained.The moving path,turning angle and the feasibility of turning motion of the robot are analyzed.A prototype is made to vertify the straight and turning motion of the robot.Secondly,a kind of transformable wheel-legged structure based on Bennett mechanism is proposed,and a biped wheel-legged robot is designed by using the wheel-legged structure.The robot kinematics,dynamics and obstacle-crossing process are analyzed.The motion simulation and theoretical verification of the robot are carried out through Adams software.A prototype is made to test the movement of the robot in straight,turning,wheel and legged mode switching and climbing stairs.Then,a kind of quadruped wheel-legged robot based on the wheel-leg structure of Bennett mechanism is proposed.In order to optimize the robot's motion,two kinds of gait,synchronous gait and diagonal gait,are planned and analyzed.The obstacle-crossing process of the robot is analyzed,and the movement ability of the robot is simulated by Adams software.A prototype is made and tested.After that,a kind of changeable wheel-legged structure based on the Myard mechanism is proposed,and its transformation process is analyzed.According to the installation relationship of the changeable wheel-legged structure on the left and right sides of the robot body,a biped wheel-legged robot capable of turning with the change of the radius of the wheel-legged is designed.The turning radius,center of mass fluctuation and ground adaptability of the robot are analyzed,and the motion ability of the robot is simulated by Adams software.Finally,a summary is given and a prospect is brought forword.A spatial 4U rolling mechanism is explored and its gait is described in detail.