Xiong Shen

Development of a deep ocean master-slave electric manipulator control system

Underwater vehicles and manipulators play an important role in underwater tasks such as salvage, maintenance and so on. Underwater environment, especially deep Ocean is a hazard place for human to explore for its high water pressure. It is illustrated a development course of a deep ocean Master-slave manipulator for the demand of emergency oil exploration system. This paper describes a development of master-slave manipulator feedback control system. The underwater control system is based network and consisted of three embedded PC/104 computers which are used for servo control, task plan and target sensor respectively. The sensor control system and strategy of the master-slave manipulator control system are discussed in three parts include structure, modeling and experiment. Finally; establish the two-port network mode based scaling condition and analysis the stability of the overall manipulator control system.

Position Location and Trajectory Tracking for MUWT Based Kinematics Approach

This paper describes an underwater 300m micro underwater work tool –MUWT(named huwt-3E, stands for three functions micro electric manipulator in China).The working principle and components of multi-sensors are introduced in detail. The pressure-compensated joint is compact designed and integrated of a micro permanent magnet (PM) brushless motor, a drive circuit, and an angular feedback potentiometer. The underwater control system is based network and consisted of three embedded system are used for servo control, task plan and target sensor respectively. Considering variable payload and uncertainty of model, a sliding mode control scheme is proposed to realize a MUWT with high precision. The control principle is based on the exponential approach law and a saturation function is introduced to solve the problem of chattering. A novel and simple self-adaptive regulation method is used to improve the velocity of approaching. Under the constant load and variable load, the simulation results of trajectory tracking show the effectiveness of the improved controller. The underwater test results verify the performance of controller in flow disturbance.

Modeling and Hydrodynamic Performance for A Deep Ocean Manipulator based on Numerical Approach

An accurate dynamic model is important for both controller design and mission simulation, regardless of the control strategy employed. In this paper, a dynamic model for a 3500m underwater manipulator in flow disturbance is established based on Morison method. The technique provides a direct method for incorporating external environmental forces into the model. Applying the superposition principle, the hydraulic forces are decomposed into two parts, one is in static water condition and the other is in sea current condition. Through numerical calculation of hydrodynamics, the contribution of hydraulic resistance, buoyancy, sea steady flows and unsteady flows to manipulator’s dynamic are analyzed in sort. It offers a reliable basis for this 3-DOF manipulator controller design. The model derived is a closed form solution which can be utilized in modern model-based control schemes. The underwater test results verify the performance of controller in flow disturbance.

A Depth-Setting TUV Control System Based on RS-485 Network

In order to boost the reliability of a floating TUV system, the research represents the central control system to be a Depth-setting TUV control system based RS-485 network. The paper will show the three aspect technology of this RS-485 network. According to the characteristics of the RS-485 network, the control architecture, the hardware structure and the communication protocol of this distribution system will be illustrated in the passage. Then, the passage will published the material object of the floating TUV. Given the experiment method and conclusion, it proves the distributed system is more stability, reliable, fast in response than ever in the last part.

Modeling and Simulation on Fluid Dynamic Depth-Setting TUV Based on FLUENT

The prerequisite factors for the simulation and controlling of underwater vehicles are hydrodynamic coefficients, which we must measure accurately. In this paper, we took a complex shape remotely operated vehicle as the test model, and figured out the important coefficients that can be applicable for the open-shelf depth-setting TUV through a series of hydrodynamic tests. In order to boost the reliability of a depth-setting TUV system, we carry out numerical simulation and hydrodynamics method on the body of the TUV through the Dynamic Analysis of a single rudder .Comparing with empirical equation, the method has be predicted a high accuracy in hydrodynamic characteristic prediction of depth-setting towed vehicle . After changing the experiment environment of the TUV as possible as we can, a suitability algorithm can be used on the distribute system. And then, the pre-design and later validation of TUV with the conclusion of the simulation based on FLUENT which contribute to shorter calculating period and lower economy could show better depth-setting consequent. The paper draw the Process of the Dynamic Depth-setting TUV for three parts including simulation of the rubber , algorithm experiment of the body and the experiment on TUV.

Multi-sensor based autonomous underwater manipulator grasp

As the development of mine, oil and gas resources exploitation in the ocean, the underwater manipulators become necessary tools. But operation of manipulator is tedious. To reduce its dependence on operator, autonomous manipulation is studied. With the support of the Chinese high technology develop program (the 863 program), we design an underwater 3500m electrical driven manipulator. It is equipped with a unique ultra-sonic probe array and an under-water camera. Autonomous grasping a cylinder using ultra-sonic sensor and vision is studied. The sensor system and strategy of autonomous manipulation are discussed in details. Experiments results demonstrated the manipulator autonomous work ability.