Design And Research Of Wheel-arm Hybrid Reconfigurable Robot

In planetary exploration, military reconnaissance and disaster search and other poorworking environment, monomer robot system remains a great risk. Applying the concept ofmodular, reconfiguration and multi robot cooperation, can change the mechanical design andmotion control mode to adapt the unknown complex work environment. Reconfigurable robot iscomposed of some isomorphic or non-isomorphic robot modules which can connect with eachother and has a relatively simple structure. Multiple modules also can be combined into aconfiguration which would be adaptable to a task or environment to the utmost. Reconfigurablerobot system can not only simplify structure design, reduce manufacturing costs and increase therobot functional and structural diversity, but also can improve the robustness andinterchangeability.According to the expected system function and module characteristics of the wheel-armhybrid reconfigurable robot, the overall scheme design of the monomer reconfigurable robot canbe established. Based on the configuration synthesis, structure transformation, mechanismsuperposition and graph theory, the variable topology repeated foldable wheel is presented withthe characteristics of real-time adjusting radial size according to different terrains. Consideringthe function of manipulator, the configuration synthesis and optimization of the manipulatorconfiguration, the degree of freedom and optimal configuration are determined.In accordance to the requirements on the design of the wheel-arm hybrid reconfigurablerobot, its main body structure is designed, and the critical dimensions of the variable topologyrepeated foldable wheel are settled. In terms of functional demands on the manipulator, structuraldesigns of the manipulator, end effectors and training wheels are completed. Afterwards, everydimension related to the mechanical arm is determined. Eventually,3D models and engineeringdrawings of the wheel-arm hybrid reconfigurable robot are accomplished. Meanwhile, theprototype is produced.Based on monomer structure of the wheel-arm hybrid reconfigurable robot, D-H coordinatemethod is adopted to construct forward and inverse kinematics models of the monomer robot.Then, configuration state matrix is applied to express topology information of the robot, and the hierarchy description method is utilized to describe group configuration of the reconfigurablerobot system. Hence, connections between different monomer robots, as well as positions of endeffectors, are achieved. And each joint rotation angle is evaluated by solving the inversekinematics model. Consequently, mapping relations between the configuration of thereconfigurable robot system and joint angle of every module are presented. In the end, dynamicsimulations of the unfolding function of the wheels, group configuration transformation,operating modes and locomotion mode are respectively conducted.With regard to the requirements of the wheel-arm hybrid reconfigurable robot controlsystem, the overall control scheme and hardware are designed. Besides, some function tests arecompleted, such as unfolding movement of its driving wheel, motion control of the monomerrobot and the manipulator.