Design And Implementation Of A Test Platform Of Unmanned Ship

In recent years,with the promotion of maritime strategy of our country,there is a growing demand for multifunctional and intelligent unmanned ship.Research institutes and enterprises also pay more and more attention to the R&D of unmanned ship.At present,we are comparable to the advanced countries in terms of theoretical research,however,we are far behind them in the breadth and depth of application research.Therefore,developing a real unmanned ship will not only help verify the current theoretical achievements,but also contribute to the application.Toward this demand,this thesis designs and implements a unmanned ship test platform.Based on the platform,we studied the path planning and dynamic positioning of ship.The details are as follows:(1)Developed a highly usable,scalable,full-featured unmanned ship test platform.We discussed the features it should have in detail,and gave the software and hardware solution in an architectural perspective.Our platform have both under-actuated and full-actuated ship,we applied some special design according to the characteristics and applications of each type of ship.To reduce the development task and enhance the mantainability,we reuse the master-side despite the slave-side of the two ship are different.(2)Implement the parallel fast sweeping method,and use it in path planning of our platform.Focusing on the convergency and efficiency,we compared the fast marching method and fast sweeping method.And choose the fast sweeping method as the basic algorithm for path planning.Then,we introduced fast sweeping squared method to solve the problem that the path is too close to obstacles.Further more,we take the dynamic constraints of under-actuated ship into consideration to obtain a more feasible path.To accelerate the computation,we continue to explore the potential of fast sweeping method.By applying a novel iteration order,we make it possible for fast sweeping method to be calculated in a parallel way.This improvement can exploit the advantage of modern multi-core computer,enable the path planning to be more real-time.(3)Designed automated zigzag test for the under-actuated ship,compared to traditional manual way,it has quicker response,better precision,and it's stable and repeatable.By a lake test we verified the feature,and obtained the first-order Nomoto model of the ship.(4)Designed dynamic positioning system for the full-actuated ship.This feature is a combination of filtering,control and allocation algorithms.We applied Unscented Kalman filter to eliminate the high-frequency motion and noise,also to estimate the velocity for the ship.Based on the hull and dynamic characteristics of the ship,control and thruster allocation algorithms are designed.Finally,we conducted a experiment on a lake to demonstrate the stability of platform and feasibility of our algorithms.