Application And Research Of Constant Tension Winch On Ocean Buoys Cast And Recovery System

Ocean buoy is one of important tools for monitoring, exploration and developmentof marine resources. Ocean buoys can play its important functions with the premise thatit can cast facilities into the sea accurately and safely；So it comes out technology ofocean buoys cast. At the same time there is lifetime of ocean buoys, which requiresregular or unscheduled maintain and recovery. During the Ocean buoys cast andrecovery operations, the complex sea conditions cause the hull to roll, pitch and heave;so the tension cable is easy be mutation. If the cable tension is too large, it easily leadsrope to break off; while if cable tension is too small, it easy leads the buoy hull tocollided, resulting in equipment damage. To ensure smooth and safe operation, theoperating equipment should be provided with the function of accurate measurement,setting and automatic constant of tension. Current domestic research on constant tensionwinch is still at an initial stage, so the research of the topic is of great importance.To solve the above problems, the paper focused on the research and analysis for therecovery of marine buoys cast constant tension winch. Ocean buoy cast recoverytechnology at home and abroad are still with poor security and tedious work. This papercombines with the current type of ocean buoys and mooring system features to optimizeocean buoys cast recycling programs. At the same time the water dynamics analysis ofstreamer and towed body in ocean buoys towed system is to provide an importanttheoretical support for the Constant tension control system of recovery ocean buoyoperations. Then based on the hydrodynamic analysis, it designed electro-hydrauliccontrol system to meet the universal buoys cast and recovery of constant tension winchunder the program. To achieve the precise tension control, first the PDF(pseudo-differential feedback control) control algorithm was introduced in constanttension electro-hydraulic control system. Using Matlab/Simulink modeling andsimulation, Simulation results show that the designed PDF controller has fast dynamicresponse, small overshoot, high stability, strong anti-interference ability and otheradvantages to effectively meet the complex sea conditions under constant tension winchcontrol requirements. This paper further demonstrated the reliability and stability ofelectro-hydraulic control system and the control algorithm of PDF by experiments usingcompression ratio method. It provides an important basis for further sea trials ofconstant tension winch and it has important academic significance and applicationvalue.The main content of each chapter are as follows:Introduction section outlines the state of the technical of ocean buoys cast recovery at home and abroad by analyzing the development and application of constant tensionwinch at home and abroad, and then puts forward the research significance and the mainresearch content.Design ocean buoys cast recovery program. Summary the advantages,disadvantages and the facing difficulties of ocean buoys cast recovery technology, Startfrom the constant tension winch and optimize design for ocean buoys cast recoveryprograms by combing with the characteristics of ocean buoys. Make analysis of oceanbuoys cast recovery operations considerations.Design of constant tension winch overall program. Analyze operating conditionsand control requirements of winch and design constant tension winch structure andcalculated parameter by combing with control principle of constant tension winch.Analyze cable tension measurement techniques and propose a "three-point bending" oncable tension dynamic measurement and feedback loop based on the characteristics ofthe buoy cast recycling operations. Through analysis and learning underwater dragoperation models，construct hydrodynamic equations of ocean buoys drag operation.Through analysis of the water dynamics of streamers and drag body, provide importanttheoretical basis for design of buoy cast recycling drag constant tension control system.Then design electro-hydraulic control system of constant tension winch, focus onanalysis and principle works according to ocean buoys cast recovery operationsrequirements.Design and simulation of PDF Controller in constant tension control system.Summarize the development situation and characteristics of engineering control theory,first proposed to apply PDF algorithm to the constant tension electro-hydraulic controlsystem. Establish mathematical model between cable tension of constant tensionwinch and pressure ratio of the two oil mouth of hydraulic motor, while optimize designthe system parameters by analyzing the principle of PDF control algorithm. Simulatedynamic feedback of models when it is under complex sea conditions such as sine wavesignal, step signal, the variable loads by using Matlab/Simulink modeling andsimulation of PDF systems. Simulations results show that the control system isreasonable and PDF control algorithm has the advantages of fast dynamic response,small overshoot, anti-interference ability and high stability. It’s good for cast andrecovery operations under the complex sea conditions.Experimental verification of the constant tension winch control system. AdoptSiemens S7-200series PLC as an experimental platform and design the field of PLCcontrol program based on the principle of electro-hydraulic control. Select models andanalyze the main technical parameters of component parts involved in the PLC controlprogram. Use discrete method to analyze PDF control algorithm achieved by PLCplatform principle. On the basis of PLC control scheme, calibrate proportional reliefrelationship between cable tension and voltage input of electro-hydraulic by using thescaled experimental method. Use mutation load to analyze the cable of control systemsability to maintain constant tension through experimental simulation of complex seaconditions. Experimental results show that the design of electro-hydraulic controlsystem and PDF controller is with high reliability, fast dynamic response, strong anti-interference and it meets the operational requirements of the complex seaconditions.Finally, summary and prospect the full text. This paper designed a new constanttension winch used for ocean buoys cast and recovery. It proposed programs used forgeneral-purpose buoy cast and recovery operations. By analyzing the hydrodynamiccharacteristics of the buoy drag operation, it designed precisely controlledelectro-hydraulic control system. Firstly the PDF (pseudo-differential feedback control)control algorithm was introduced in electro-hydraulic control system. Using Matlab/Simulink modeling and simulation analysis, simulation results show that theelectro-hydraulic control system is stable, reliable, and fast response to meet thecomplex sea conditions ocean buoys cast recovery operations requirements. Reductionratio method experiments further demonstrate the feasibility of the design ofelectro-hydraulic control system and lay the foundation for carrying out the actual seatrial tests.The subject although got some progress in the constant tension winch on thestructure and control systems etc, some further research work still needs to be done dueto the conditions. Specifically consider the following aspects:(1) Improve the cable tension loop control experiment platform. Currently buildingexperiment platform for cable tension closed-loop control simulation is still insufficient.How hydraulic system and PLC platforms communicate smoothly needs to be improvedand the control of the precision of experimental platform needs to be progressed.(2) Improve dynamics analysis of ocean buoys drag operation. For ocean buoysdrag system of hydrodynamic model by underwater drag systems, it needs to take thetest validation. There are some differences between buoy drag and underwater drag, sosystems theory needs further study.(3) Carry out the sea experiment. This stage is limited to the theoretical analysisand model simulation. We should product prototypes based on the design and carry outoperations in the sea for ocean buoys cast and recovery operation, to test the machine’sperformance. Further validate and analyze reliability and superiority of designedConstant tension winch electro-hydraulic control system and PDF control algorithms.(4) Improve machine performance. Considering that the object of cast recoveryoperation in this topic is ocean buoys, we can strengthen the research of drag recyclingoperations in other Marine structures or floaters. Do some further optimization designfor constant tension winch through the experiment analysis and comparison, making itan ocean engineering constant tension control device for cast recovery operations.