Research On Ground Mobile Deformable Hexahedron Mechanisms

With the rapid development of mobile robot technology, the functional requirements of robots are facing more and more complicated tasks, such as planetary exploration, disaster rescue and so on. Complex, reconfigurable and other new conceptual design methods and techniques have been developed to enhance the mobility of robots. This paper was carried out in the view of mechanics, and integrating the innovative design of mechanism configuration and the technology of deployable robot in order to obtaining the new concept ground mobile mechanisms which can apply to complex tasks with unstructured terrain environment. The geometry of hexahedron is chosed, and the flexibility of the link mechanism improves the mobility of the mechanism as much as possible.The concept of hexahedral mobile linkage with omni-directional mobility was proposed. The essence of this method is that the complex spatial linkage mechanism with the hexahedral shape is used to form the mechanical body of the mobile robot.Based on this idea, the paper focuses on the new conceptual design and the robot deployable technology of the deployable hexahedron ground mobile mechanism, the deployable triangular hexahedral ground mobile mechanism and the deployable corrugated hexahedron ground mobile mechanism respectively. Based on the topological structure and geometry of the hexahedron, the mechanism with multi-degree of freedom is analyzed, and the gait planning is carried out by the motion analysis of large deployable, thus to develop the polyhedron mechanisms by integrating the idea of novel conceptual design and deployable robot.The specific research contents are as follows:(1) A novel deployable rolling mechanism with hexahedral geometry is proposed.The main body of the mechanism is a space link mechanism with 14 linkages and 16 joints, and the whole body is composed of two platforms and four chains, and the appearance is a pair of space orthogonal parallelogram that could realize omni-directional rolling by the control of two drives.(2) A 3-DOF deployable triangularized hexahedral mobile mechanism is proposed.Based on the 3-URU parallel mechanism, this mechanism designs a special structure of URU branch chains, so that the movement of the whole body can be realized by controlling three revolute joints. Through the kinematics analysis of the mechanism, the deployable and rolling principle of the robot are introduced.(3) A novel rolling mechanism with external geometry of truncated hexahedron is proposed. By changing the configuration of the kinematic joints, the new configurations with different deployable characteristics and multi-modes are obtained. At the same time, in the design method, the geometrical shape is taken as the basic unit to construct the new conceptual mechanism. The mechanism has the geometrical shape of hexagon,and can realize the mechanism rolling by controlling the actuators.Overall, the mechanism of hexahedron structure is studied from the aspects of mechanism configuration design, virtual prototype simulation analysis, principle prototype development and experimental study. Design and analysis methods of mapping hexahedron on geometry to deformable ground mobile mechanisms are proposed. Based on the mechanism configuration and functional requirements, a series of novel conceptual deployable mobile hexahedrons are proposed, which are based on the structural design method and the mobile robot design technology. And, revealing the movement of the mechanism, including the driving mechanism, control method,deployable ability, mobile modes and so on. The mapping process from polyhedron to mobile mechanisms is realized through the technology of kinematic pairs and actuators arrangement, and realizing the function of moving and direction switching through the technology of singular position controlling. Through this work, the design concept of novel deployable mobile mechanism is clarified, and utilization potentiality is revealed by mobility and deformability with all-posture, which provides the key technology for the subsequent and improves the mobility of the mechanism and the design of the high-passability polyhedron mobile platforms.