| Summary: | 将水下机器人用于极地科考，可以通过其携带的多种传感器和设备进行大范围、长时间的冰下观测作业，并取得重要的极地科考资料，如冰下水纹，海冰厚度等。而这些观测数据必须与准确的浮冰位置信息相结合才有实用价值，但北极高纬度特性和长期覆盖的大范围海冰使得一些传统水下机器人导航技术难以有效实施，所以需要研究一种能在北极冰下具有良好性能和高可靠性的导航系统。同时，对北极海冰进行的一系列科学考察，需要载体能够沿着浮冰上预定轨迹航行，但由于海流等外界影响的存在，浮冰处于实时运动中，所以要顺利完成科考任务，必须有相应的轨迹跟踪算法作为支撑。 本文正是针对以上这两点需求，在充分考虑环境特殊性的情况下，研究了水下机器人在北极冰下的导航与轨迹跟踪问题，提出了基于GPS测向仪冰面修正的水下机器人自主导航技术和基于制导控制器的浮冰轨迹跟踪方法，并进行了仿真和实物测试，试验结果表明本文所研究的导航设计方案和浮冰轨迹跟踪方法合理，可以达到北极冰下科考的定位精度和作业要求。 主要工作包括：（1）ARV导航系统设计。详细研究了各导航传感器的输出信息；坐标系定义、坐标变换、相对于浮冰的航位推算以及绝对坐标的求解；最后详细研究了整个冰下导航系统。（2）ARV导航系统误差分析。首先对各传感器的误差进行了详细分析；接着通过分析整个导航算法，建立了浮冰坐标系下ARV位置误差传递方程；最后通过引入具体传感器的参数指标，数值计算了整个导航系统的精度。（3）浮冰轨迹跟踪系统设计。首先对水下机器人在冰下的航迹进行了描述；接着分析了两种冰下制导控制器，视线法制导和横向轨迹误差法制导；最后详细研究了整个ARV航迹控制系统。（4）浮冰轨迹跟踪算法仿真。详细讨论了北极“ARV”的水平面动力学模型。并结合模型对浮冰轨迹跟踪算法进行了Matlab和视景仿真，验证了算法的合理性。（5）湖试和海试结果分析。通过对ARV棋盘山湖试和北极冰下海试数据分析，定量说明了导航误差和轨迹跟踪性能。 We can apply underwater vehicle into the polar scientific expedition, it can carry multiple sensors and equipments to carry out large scale and long time scientific observation under the ice, and obtain important information for polar research, such as hydrological data under the sea ice and the thickness of the ice. But these observational data must be combined with accurate location information relative to floating ice, then it will become useful. But Arctic high-latitude features and a wide range of sea ice covering the polar region don’t make some traditional navigation technology be well achieved. So we need research a navigation system under ice with good performance and high reliability. Meanwhile, it is necessary that the ARV can navigate along the prescribed trajectory on the floating ice when exploring in the Arctic Ocean. However, due to the existence of outside force, such as ocean current, the floating ice moves all the time, in order to complete the scientific expedition task, tracing algorithm is required. This thesis aims at these two problems, and researches the ARV under-ice navigation and trajectory tracing problem with the special circumstances fully considered. Then an ARV autonomous navigation technology based on GPS direction indicator on the ice surface and a floating-ice trajectory tracking method based on guidance controller are proposed. At last, the simulation and experiment have been conducted, the result shows these methods proposed are reasonable and meet the locating accuracy and task demand. The main research work are as follows: (1) The design of ARV navigation system under ice. It includes the researches of output information from the navigation sensor, reference frame definition, coordinate transformation, Dead Reckoning in ice reference frame, solution of ARV longitude and latitude and the whole under-ice navigation system. (2) The error analysis of under-ice navigation system. Firstly, analysis is made on the error from the sensors. Secondly, transfer function of error is established by the analysis of navigation algorithm. Finally, through introducing the parametric value of sensor, the precision of under-ice navigation system is calculated. (3) The design of floating ice tracking system. At first, the prescribed track of ARV is described, then two kinds of guidance control algorithm, Line of Sight and Cross Track Error, are analysed. At last, the whole ARV under-ice trajectory tracking system is studied. (4) The simulation of floating ice trajectory tracking algorithm. ARV horizontal dynamic model is discussed, and the trajectory tracking algorithm is simulated in Matlab and three-dimensional simulating software based OpenGL, the result prove it to be reasonable. (5) The analysis of data obtained from experiment on lake and Arctic sea. Through the analysis of data, the error of navigation and the performance of trajectory tracking are explained quantificationally.
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