| ABSTRACT:This research is in the field of robotic mechanism and it is about mobile linkage mechanism. Links are the components of legged robots, snake-like robots and some other kinds of robots without the configuration of creatures. The size and shape of a link can be designed in many ways. There are also many kinds and assembling ways of links. Therefore, the research on mobile linkage mechanism can be done deeply.The concept of mobile linkage mechanism with lattice configuration is proposed firstly in this paper. This kind of mechanism is composed of some links and the configuration is similar to lattice in the field of biology, such as the configuration of section of honeycombs. A side of a lattice means a link of a mechanism. A node of a lattice represents a joint of a mechanism.The study starts from the basic open chain linkage mechanism with three links. Then, the mobile linkage mechanisms are composed of links, with the configurations of closed loops with three sides or four sides, namely, a unit lattice with three sides or four sides. After that, based on the mechanism with the configuration of a unit lattice with four sides, that is, a parallelogram mechanism, novel mobile linkage mechanisms with lattice configuration are constructed through different ways to be studied on. The main work is listed as following:(1) According to the topology of a mobile linkage mechanism with three links, the walking or crawling mobile open chain linkages mechanisms are proposed and classified to three sub-groups. A straight walking mobile linkage mechanism with three-side lattice configuration is put forward, i. e., a walking linkage mechanism with triangle configuration. The stability, the length and height of a stride, and some other mobile characters are analyzed. From the point of view of shapes of links and kinds of joints, a modified mechanism is constructed to turn around.(2) Adding the number of sides of a unit lattice, a rolling mobile linkage mechanism with four-side lattice configuration is generated. With the knowledge of four bar linkage in mechanism and topology theory, seven kinds of mechanisms are derived after considering the directions of joints, number of actuations, position of actuations, and so on. The features of every mechanism and moving trajectories are analyzed. The turning motion of the differential system composed of two mobile linkage mechanisms with parallelogram configuration is realized. (3) Combining two parallelogram mechanisms in a plane or spatially, the planar mobile linkage mechanism with two parallelograms configuration and the mobile linkage mechanism with two spatial-crossed parallelograms configuration are produced and analyzed. The former can turn by the differential way and the latter can do omnidirectional rolling motion by itself.(4) After combining three parallelogram mechanisms in a plane, a mobile linkage mechanism with three parallelograms configuration are formed and it has symmetric structure. The relation between the vibration of its center of mass and the driving functions is studied. Aiming at minimizing the vibration, the driving functions are optimized. Its differential system can turn around.(5) Four parallelogram mechanisms are combined in a plane. The mobile linkage mechanism with four parallelograms configuration is created. Considering its ways of moving deeply, two are found. One is the rolling motion with sides support, like a tracklayer. The other is the rolling motion with two points support, like a biped. Its differential system is found out to turn and recover from side-falling.(6) Discuss and sum up the relation between the number of parallelograms and moving methods of mobile linkage mechanisms, which are generated by combining the parallelogram mechanisms with a common vertex. |
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