| The modular self-reconfigurable (SR) robot system is composed of the standard modules, each of which can connect with or disconnect to the adjacent modules, communicate with each other and capable of locomotion and communication. Usually, a single module is not flexible enough to do too much by itself, but a collection of modules can remarkably strength the function of the system, as they can be organized as the most suitable geometric structure under the local environmental conditions to perform variety of tasks through changing the connection position and locative relations. Compared with the traditional robots, the modular self-reconfigurable robots can move in many kinds of ways and have a lot of advantages, such as: modularization, self-deformation, self-replication, self-repairing. The SR robots can perform outstanding advantages in the unstructured environment, and have broad application prospects especially in the uncontrolled environment with variety of complicated tasks, such as: space exploration, emergency search and rescue, nuclear power plant maintenance. As the self-reconfigurable robots have great abilities in deformation and environmental adaptability, they have interested researchers all over the world. Therefore, researching in the SR robots system in time should play an important part both in theoretic and practicality, as the research can raise the level of the SR robot research of our country and make applying the SR robots in rescuing and space exploration early.The SR robots can perform outstanding advantages in the unstructured environment, and have broad application prospects especially in the uncontrolled environment with variety of complicated tasks, such as: space exploration, emergency search and rescue, nuclear power plant maintenance. As the self-reconfigurable robots have great abilities in deformation and environmental adaptability, they have interested researchers all over the world. Therefore, researching in the SR robots system in time should play an important part in advancingThe module is the elementary unit of the SR robot system. The function of the module directly determines the locomotion and reconfiguration abilities of the SR robots, and then influences the control system, reconfigurable algorithm and the motional complexity of the modular robot system. From the characteristics of the SR robots, a new design method has been proposed. Through analysis and comparison of the modules with different degrees of freedom configuration, we determined a new combination program of the shape and the DOF configuration. A new SR robot system, namely UBot, has been proposed, each of which is based on universal joint and has two rotational degrees of freedom. The UBot system can perform as both lattice-type and chain-type SR robot system. The UBot module has regular cubic shape and is composed of two L-type parts connected by a right angle shaft. Each module has two independent joints around the right angle shaft and four connecting surfaces. The active and passive hook-type connecting systems have been proposed, which can connect to or disconnect from the adjacent modules quickly and reliably. The mechanism has the function of self-lock and energy-saving, and mutually opposite polarity of the permanent magnets located on the surface of each connecting surface make pre-position for the connecting. The battery is embedded inside the module, and wireless communication technology has been employed. To solve the problem of the cable wound, the wires go through the center of the right angle shaft between two parts. The connecting mechanism and the module substrate have been connected with full contact connection, so the maintenance of the modules is more convenient.Through the deep analysis of the UBot module'characteristic, a topological description method based on correlation matrix has been proposed. The method fully describes the joint angles'states, the connecting relations and the location information of the modules. The configuration recognition method has been proposed based on the graph theory. The automatic matching of the new configuration and the configuration from database has been implemented through analysis and computation of the adjacency matrix and the connection orientation matrix of the configuration. Consequently, all the possible moving gaits can be mapped to the new configuration. The restrictions in the process of reconfiguration and deformation of the UBot self-reconfiguration system have been analysed. The hypothetical conditions of the reconfiguration and deformation have been proposed. According to the characteristic of the UBot module, a necessity criterion which can judge whether the configurations can be reconstructed between each other has been proposed. The criterion can remove a portion of configurations which can't be deformed to each other, and avoid the meaningless operation of the deformation. This criterion can also be applied to other SR robot system the modules of which are cubic and only have rotational degrees of freedom. For the reconfiguration and deformation between the fixed configurations, a deformation planning method that makes the degree of the configuration similarity as the search-driven function has been proposed. The method can find a deformation path which needs a relatively less steps within a reasonable time. The method has been used in the deformation from the quadruped configuration to the worm-like configuration and has been verified through the simulation. The locomotion of some typical configurations composed of UBot modules has been researched. The linear motion and rotary motion of the Omni-directional mobile cross configuration have been controlled in static gait planning, respectively. The motion control method of the static rolling locomotion and the dynamic rolling locomotion of the ring configuration has been proposed based on the theory of the floating four-bar linkage. The control method can be extended to control the locomotion of any ring configuration made of arbitrary modules. The dynamic rolling gait has been optimized and simulated. Through optimizing and simulating the dynamic rolling gait, the best combination of the ring angle and the deformation rate has been determined. Crawling gait and in-situ rotation gait of the quadruped configuration have been planned and have been verified through the result of simulation. Finally, the general motion planning function of the worm-configuration and the snake-like configuration composed of arbitrary number of modules has been proposed.The self-reconfigurable robot experiment has been established. The deformation experiment from three-limbed configuration to worm-like configuration and the coordinated movement experiment of cross configuration, ring configuration, quadruped configuration and single chain series-connection configuration have been completed. The results have proved that the UBot system has strong capabilities of reconfiguration and coordinated movement, and also verified the correctness of the proposed reconfiguration and coordinated motion planning.
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