Posture Balancing Adjustment Technology Of Underwater Vehicle-Manipulator System

With the non-renewable resources on earth is being consumed up, the ocean,which contains all sorts of resources, becomes more and more important for human being. The underwater vehicles and the robotic manipulators are seem as the most important tools in the underwater world, in which only the advanced equipment and technique could be used. The Underwater Vehicle-Manipulator System (UVMS), which usually contains a autonomous underwater vehicle (AUV) and one or several robotic manipulators which are mounted in th AUV,is the main direction of the underwater vehicles' development. A stable and dependable UVMS system ensures perfect tasks such as underwater exploration,cable lying and mine detection.The character of the UVMS is nonlinear, coupled, time-varying and high-dimension. The implementation of the self-manipulation under water depends on various kinds of pivotal technology. The important one of them is the posture balance of the AUV in operation. It is presented the posture balancing strategy of UVMS in this dissertation.This dissertation develops a regulation system of pitch posture balancing system and roll posture balancing system, which bases on removing the effect of moving the manipulator in operation. According to the request of the task,this dissertation develops the posture balancing system's structure. Because of the restriction of the mass and volume of AUV, this dissertation develops a box body structure that consists of polyethylene,and it also designs a synchronization teeth-shape belt transmission mechanism in order to use the space efficiently.This dissertation also constructs the overall structure of the regulation system of posture balance on the basic of master-slave controlling mode, and designs the hardware circuit of the slave computer, which features are detailed in the dissertation.This dissertation focus on the regulation control technology of posture balance. With the establishment of the space coordinates system and the derivation of the dynamic equation, this dissertation establishes the mathematical model of UVMS and the pitch posture balancing equation and roll posture balancing equation in steady environment, which would provide the theory foundation for simulation. Considering the character of UVMS and the complicated working environment,this dissertation develops a fuzzy-PID controller to the regulation system of posture balance by using fuzzy input and the establishment of fuzzy control rules which would be used to calculate fuzzy relation matrix and defuzzification. This dissertation analyses the control performance between regular PID controller and fuzzy-PID controller through simulation. The result demonstrates that fuzzy-PID controller is better than regular PID controller when adjusting the posture.This dissertation builds a UVMS experiment platform that could be moved easily and carried through it in tank. This dissertation built a manipulator with 2 DOF and designed a control system with host-slave structure. This could promoted the convenience of the system because it used Lab View to construct the control program of the host computer and its interface. This dissertation carried out pitch posture balancing experiments, roll posture balancing experiments and the combination experiments of these two situations. By analyzing many groups of experiments' results, the regulation system of posture balance has excellent dynamic characteristics and high steady-state accuracy.