Research On The Deep-sea Pressure Adaptive Hydraulic Manipulators And Its Master-slave Compound Multi-joint Control

The demand of high-power underwater manipulator with larger operational depth and better motion-control performance has been advanced by further exploration of the deep-sea resources, which is one of the most important tools of the undersea workstations, ROVs and manned diving instruments. In this paper, a type of new deep-sea pressure adaptive hydraulic manipulators is investigated.Firstly, considering the rough condition of the special working circumstance, how to realize the pressure-resist and seal of the components is the key point for the development of deep-sea hydraulic manipulators. In order to solve the problem, a novel operation system with the whole electrical and hydraulic parts outer-inner pressure balanced technique is presented based on the known technique of the balanced compensation only directly to the hydraulic source. According to the design, the underwater circuits, sensors in the actuators on the slave arm, the electrical wires and the control valves are all immerged in the oil. And the slave controller, the valve housing cage and the tank are all connected. For the convenient assembly, the compensator unit is just equipped to the valve housing cage near the slave arm to provide hydraulic compensation to cavities within the whole electro-hydraulic control system.Secondly, in order to get better coordinated operating performances of the manipulator on the condition that the flow of oil supply is not enough when the multi-actuators of the joints on the slave arm are operated simultaneously, an electro-hydraulic digital flow distribution method based on flow feedback for multiple actuators load sensing system is put forward to distribute flows at will when multi-inertia actuators were compounded operated. Instead of the traditional structure of valve-control technique, it can effectively improve the utilization ratio of the flow output by the oil source pump. The corresponding theoretical principle is analyzed and the performances are evaluated through simulations.Thirdly, because of the limited power supply and working space, a new integrated and miniaturized research for the system is also carried out. It mainly emphasizes the design of the key operation slave arm to optimize structure of the whole manipulator's.Here are the main points of the dissertation:In Chapter 1, the domestic and oversea development and application foreground of the deep-sea underwater manipulators are summarized at first. Then, the research significance of this topic is expounded and the works need to do are also introduced in this part.In Chapter 2, it emphasizes the research on the electro-hydraulic control structure of the deep-sea pressure adaptive manipulator system. First, the necessity of the application is expatiated. Then, the principle and the structure of the pressure adaptive electro-hydraulic system are carefully analyzed and also the feasibilities of the key parts are validated by a series of experiments.In Chapter 3, the entire structure of the deep-sea underwater manipulator system is at first carefully introduced. Then, according to the demand of the integrated and miniaturized system, it emphasized the research on the structure design of the slave arm, which is the key operation part of the whole system.In Chapter 4, a real operation system is build up to have all the experiments on it. On the one hand, the design mentioned previously is validated and improved. On the other hand, according to the unsatisfied control performances when the multi-actuators of the joints on the slave arm are operated simultaneously and the flow of oil supply is not enough, an electro-hydraulic digital flow distribution method based on the flow feedback for multiple actuators load sensing system is put forward. The corresponding theoretical principle is analyzed and the performances are evaluated through simulations with the real parameters.In Chapter 5, a general summarization of the total research works in this dissertation is given here. What's more, an expectation of the further research work is also brought forward.