核电站水池水下机器人设计及其运动控制研究

The increasing number of the nuclear power plants has brought about the great needs for underwater robots with the abilities of detecting and repairing the spent fuel pools in nuclear power plants. To meet these needs, the project on underwater robot system design and its locomotion control is deeply carried out. Firstly, a small robot with multi-propellers, which can cruise omnibearingly, roll over to a position freely. Directional navigation and attach stably to stainless steel pool bottom and its side wall by propulsive force, is proposed to deal with robot abilities of detecting and repairing in the limiting underwater space and the irregular surfaces around the nuclear power plant pools. With the establishment of the parametric design model influenced by the coupling effects of the gravity and flow field, optimizations on the system topology and the layout of propellers in 3d space are carried out, and then the design method of underwater robot based on load bearing optimization is formed. Secondly, with the mathematical model and fluid-structure simulation, research on hydrodynamic behaviours of the umbilical cable and robot body and the coupling effects between the two is carried out. The dynamic behavior test and the dynamic parameter identification method are established before the formation of the system dynamic model with all parameters. Thirdly, based on the methods to decoupling the dynamic models, the control strategy of the system is put forward to realize the accurate dynamic positioning of the system, and the adaptive control system for the robot is designed. Finally, an underwater robot prototype with multi-propellers for detecting and repairing the nuclear power plant pools is developed, then the experiments to verify the theoretical researching results are carried out by the prototyp. The achievements of the project will provide theoretical and technical support to the design and application of the robot used in nuclear power plants.

针对核电站对水池检测与修复作业水下机器人的迫切需求，本项目深入开展了水下可变姿附着作业机器人系统的设计方法和运动控制研究。1.针对空间受限、不锈钢池底与侧壁形貌复杂难以附着的问题，提出可在水下全方位定向巡游和翻转变姿、并利用合成推力实现稳定附着的多推进器小型机器人解决方案；通过建立流-固耦合作用下复杂系统参数化设计模型，进行多推进器三维布局优化，并进行系统结构拓扑优化，形成机器人平台机构优化设计方法。2.通过数学求解和流-固耦合仿真，揭示脐带线缆系统和机器人本体翻转变姿和定向巡游的水动力行为规律及其耦合效应，并提出动力学参数辨识与测试方法，建立系统全参数动力学模型。3.基于解耦的动力学模型，提出实现系统准确动力定位的控制策略，完成自适应控制系统设计。4.研制水下机器人原理样机并开展功能与性能测试，验证理论研究结果。本项目研究成果将促进我国核电站水池水下机器人设计理论与应用技术的发展。

核电站燃料水池的不锈钢池底和池壁可能会由于内应力、作业事故、灾害等造成局部破坏和泄露，需要及时发现和修复。以往用专业人员检测和焊接修补，成本高、效率低，并对人员健康有影响甚至伤害。本项目针对该方面水下作业机器人的迫切需求，开展了以下几方面研究：. 1）针对不锈钢池底与侧壁形貌复杂难以附着的问题，提出有效的机器人解决方案，开展系统布局和结构优化设计研究；2）通过数学求解和动态仿真，研究机器人运动时本体及脐带线缆的水动力特性，提出动力学参数辨识与测试方法；3）考虑作业特点和水动力特性影响，建立机器人系统动力学模型，提出系统准确动力定位和运动控制策略，完成自适应控制系统设计；4）研制水下机器人原理样机，进行机器人功能、性能和水动力特性试验研究。. 本项目取得了以下成果：1）面向核电水池焊接修复和日常巡查需求，提出了水下全方位巡游、翻转变姿和推力附着作业的多推进器机器人解决方案，能够实现在不锈钢池底、池壁的稳定附着作业，形成了机器人本体设计方法；2）建立了机器人水动力模型，通过CFD计算，获得了机器人全方位及近壁运动时的水动力特性规律；建模分析了线缆的稳态、动态水力学特性，获得了线缆对机体的扰动影响规律；3）揭示了水下推进器近水面工作的类空化效应机理，提出了基于高斯过程的类空化推进力准确预测方法；提出了LS-QP-Switch冗余推力分配算法，实现了满足实时性和饱和约束的能耗最优推力分配；4）提出了融合多区域划分、数据校正、变置信度滤波的定位算法和基于视觉的抗扰路径跟踪算法，实现了受限结构化水域的高精度水下定位和路径跟踪；5）建立了全系统动力学模型和变质心特征模型，基于模型设计了自适应滑模控制器，实现了水下机器人附着作业时的变质心稳定性与全方位高精度运动控制；6）研制了机器人原理样机，试验验证了理论研究结果的正确性。. 本项目研究成果将有力促进核电站水池水下机器人设计理论与应用技术的发展。