| Mobile manipulator was a complex robot system which integrated the functions of walking and operation, now it is a hot subject in the robot research area. This mechanism had better operation flexibility and expands mobile robots working space. Compared with individual system, it has a relatively wide application prospect. Meanwhile it is very important for theory studies. However, there were some shortages: such as imprecise position, unable to set up accurate dynamics analysis model, efficient method to identify mobile manipulator and dynamic coupling, the difficulty in getting a motion planning method of redundant robot. In order to solve the problems which the mobile manipulator faced at present the subject group has developed omni-directional mobile manipulator(ODMM) and ultrasonic absolute positioning(UAP) system and developed the research of some key technology such as ODMM kinematics and dynamics analysis, omni-directional mobile platform and manipulator coordination motion plan, obstacle avoidance navigation, path planning. In summary, the goal of this thesis is to solve the following problems.First, combining omni-directional mobile part with manipulator, and developing ODMM to make ODMM have omni-directional mobile ability, since the turning radius of ODMM was zero, ODMM was able to move freely and flexibly when it work at narrow or crowded places; to solve the problem of position, the fusion method for information was used according to the spreading feature of ultrasound, and the UAP method based on the fusion method for redundancy ultrasonic information was suggested, accuracy of UAP was developed. At the same time, ultrasonic obstacles avoidance module and digital compass information added reliability to navigation. Obstacle avoidance navigation was the key technique in ODMM research. Two obstacle avoidance navigation algorithms were offered in the paper. One was ODMM navigation algorithm based on UAP, whick had two tactics avoiding obstacles and heading for the object. The other was fuzzy obstacle avoidance navigation algorithm based on UAP. Fuzzy rules set up according to one's driving experience. The obstacle avoidance navigation algorithm improves the adoption and obstacle avoidance ability of the omni-directional mobile manipulator. The simulation and experiment has proved the validity and feasibility of obstacle avoidance algorithm.Next, the ODMM kinematics was studied. The forward and inverse kinematics were analyzed. The unique solution of the inverse kinematics for mobile manipulator could not be obtained due to ODMM was a 7-DOF redundant robot, thus only constraint relationships to some variables could be given, and not unique solution. To get effective solution, some constraint equations and optimization parameters were added based on these constraint relationships and the working conditions, then the satisfactory solution was obtained. The study results described above offer important technique foundations for the following motion planning designs. Meanwhile, ODMM modeling dynamics was set up with Lagrange approach, and research was done on dynamic coupling between omni-directional-motion model. The relationship for rate, acceleration and coupling was achieved via many simulation experiments under different conditions, the dynamics based on the relationship for ADAMS moving along elliptical track and sinusoid track were simulated.Then, different motion modules of omni-directional mobile platform were analyzed. To realize the function of motion coordination between omni-directional mobile platform and manipulator of ODMM, two motion planning methods were given in this paper: one was timing motion planning and control based on absolute position with an additive constraint equation to get control parameter in ODMM inverse value of the kinematics. The other was the improving Genetic Algorithm to optimize coordination motion planning of the change of ODMM joint angle. This method well solves the problem of redundant robot inverse kinematics, and makes full use of the motion flexibility of redundant robot to do motion optimization.The efficiency of improving Genetic Algorithm in ODMM joint angle change optimization was higher than traditional Genetic Algorithm. Simulation experiment proved the correctness and rationality of this coordination motion planning method. At the same time, trajectory tracking and control was analyzed based on improving Genetic Algorithm optimization ODMM joint angle change coordination motion planning. In trajectory tracking planning, the improving Genetic algorithm was used in order to optimize ODMM joint angle change coordination motion planning. The trajectory of 3D circle tracking and control were simulated. The simulation results proved that the coordination motion planning of optimizing ODMM joint angle change based on the improving Genetic Algorithm was correct and efficient.ODMM path planning was the key technique of this subject. It included complete path planning and partial path planning. Understanding the shortage of artificial potential field in partial path planning, the improving artificial potential field path planning method based on Genetic Algorithm optimization in complex environment was set up in the paper. This method was more accurate and rational than traditional artificial potential field path planning. The results of the following simulation experiments have proved the efficiency and rationality of this path planning method.Finally, hardware experiment system of ODMM was set up to do the coordination motion planning between omni-directional-mobile platform and manipulator experiment, ODMM fuzzy obstacle avoidance navigation experiment and ODMM path planning experiment which was based on improving artificial potential field. The result of the experiment had proved the efficiency of motion mobile manipulator absolute positioning, rationality of motion planning, and the efficiency of obstacle avoidance navigation algorithm and route planning algorithm. The shortage of this research is pointed out at the end of the article and the article looks into the follow-up work.This article had studied ODMM and ultrasonic absolute positioning system, set up ODMM kinematics dynamics analysis model, and developed the technology of ODMM positioning, navigation, motion planning and route planning, which has laid the foundation for further research on ODMM and ODMM entry into practical application.
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