Research On The Control Technology Of Emergency Navigation In The Three Gorges Reach

Emergency navigation refers to the process of improving the trafficability and reducing the influence of water traffic via taking reasonable technical method,organization,or control strategy under abnormal or emergency situation caused by unfavorable factors.Adverse factors including bad hydrological and meteorological conditions,the anomaly traffic,traffic control,channel restrictions which cause abnormal or emergency.Several typical hydrologic meteorological factors are taken into considertation to conduct research on key technology for emergency navigation and control strategy in the Three Gorges reach.Since the freight volume of the Three Gorges ship lock is growing rapidly,the backlog of ship in the Three Gorges reservoir area has been a normal state.In special conditions such as fog or wind weather,massive flow of the flood season and lock repair,the ship stock is more serious in the Three Gorges water area.Currently,navigation management measures for poor visibility,high winds and heavy water flow are mainly temporary and local restrictions,while the visibility,wind scale and flow reach the set value,navigation in the Three Gorges area is prohibited.Therefore,carry out research on emergency ship navigation technology and management control strategy and explore the feasibility of improve the the traffic restrinctions,and put forward methods and technique to enhance the navigational capacity and alleviate ship backlog,thus further supplement and perfect the emergency navigation system of the Three Gorges area.Firstly,based on the analysis of the adverse meteorological and hydrological conditions of the Three Gorges dam waters,the concept of navigation backlog rate and calculation formula are put forwarded.And the quantitative analysis of the influence brought by three typical conditions are conducted.Secondly,the technical scheme of visual auxiliary driving system is put forward in the Three gorges reach.3D environment visual model,3D channel model(including the segment above the water surface and below),three dimensional flow numerical model and ship motion model are established based on virtual reality technology.Then the visualization auxiliary driving system is set up based on multi-source information fusion of multi-sensors.Thirdly,through the analysis of the influential law of winds on navigation and maneuverability of ship,and wind loading of all kinds of ships are determined via the ship maneuvering model calculation and simulation test.Anti-wind navigation technique with tug aided is put forwarded and the original restricted condition for wind navigation is optimized.Fourthly,in this paper,the towing method and load shedding technique is proposed for emergency navigation under super flow.The demand for towing ability of each typical ship type under different grade of water flow is confirmed through simulation.Combined with the navigation condition of the Three Gorges reaches,the tug species selection and the outfit scheme are put forwarded.On the other hand,according to the dynamic control model the ship,the relationship between power and weight of each ship type while navigation under various conditions of water velocity is figured out and the lightening scheme of ship navigation is established on the premise of shipping efficiency and safety.The theoretical calculation method and results of the study is deduced and verified through prototype testing.Fifthly,based on the research results of navigation technology under the three typical conditions,the emergency control strategy is studied of the three gorges reach.Hierarchical navigation management strategy is put forwarded and the backlog rate after the application the scheme is quantized.The main innovative achievements of this paper includes(1)Navigation improving technology under typical conditionOn account of the typical meteorological and hydrological conditions,a solution to improve the navigation ability is put forwarded for the first time.And the feasibility of the solution is proved through theoretical model,numerical calculation,laboratory simulation and prototype testing.Based on 3D visualization aided ship driving technology in poor visibility,tug aided navigation technology in winds and the emergency tug assistance and load-shedding technology,systemic solutions of improving navigation ability under abnormal conditions is constructed.(2)Optimization of ship navigation restrictionsEmergency navigation control strategy is put forwarded under typical meteorological and hydrological adverse conditions,the control standards for ship navigation in the Three gorges reach is optimized.(3)Dynamic compensation model and calculation method of ship in floodCompensation model is established based on ship resistance,ship power and tug horsepower,combined with the feature of force of ship navigation in mountain river,two methods of dynamic compensation that are tug assistance and load shedding are proposed.