毕业生知识库

自然界中，生物䲟鱼凭借搭便车行为降低运动能耗，提高觅食效率，极大增强了自身在海洋环境中的生存能力，给水下新型子母式机器人的研发带来了启示。本文围绕吸附型子母式仿生机器鱼系统设计与协同控制展开研究，旨在针对复杂的水下自主作业任务以及特殊的作业环境，为水下多机器人系统的协同作业以及其在实际场景下的应用提供重要的理论依据与技术支撑，主要内容如下：

一、针对机器鱼感知及续航能力不足的问题，以䲟鱼的吸附行为为仿生原型，提出了一种吸附型子母式仿生机器鱼系统的设计方案。首先，结合子母式系统协同作业的任务需求，建立了集感知能力、运动能力以及续航能力于一体的子母式仿生机器人系统总体架构。其次，以䲟鱼为对象，研发了一款吸附型子仿生机器鱼系统，设计了负压式仿生吸附机构和多自由度胸腹鳍机构，完成了样机的研制。再次，分析了子仿生机器鱼运动模态，基于牛顿--欧拉方程，构建了三维动力学模型。实验结果表明了子母式仿生机器鱼系统具备良好的单体运动以及协同控制的能力。

二、针对水下机器人系统算法验证困难的问题，提出了一种面向水下多机器人系统的虚拟仿真环境框架，分层实现了人机交互、协同通讯、高层控制、底层控制、运动模拟等功能，完成了从控制任务发布到决策、规划、控制的系统实现，并提供了三维可视化的仿真界面以及实物平台控制所需接口，满足了仿真与实验需求。在此基础上，针对子母式仿生机器鱼系统的任务分配问题，提出了一种集联盟组成与任务分配于一体的分配框架，构建了优化模型。同时，考虑到子母式仿生机器鱼的配合关系，构建了任务划分时的约束条件，解决了子母式仿生机器鱼系统的任务分配以及优化问题，完成了系统整体效能的优化。仿真实验验证了所提任务分配框架的有效性。

三、针对子母式仿生机器鱼系统的协同编队及围捕控制问题，提出了一种基于事件触发的分布式协同编队以及围捕控制方法。首先，设计了基于一致性的分布式控制策略，引导机器鱼编队形成预定构型，并跟随领航者实现动态编队保持。其次，根据实际任务需求，针对领航者及近邻个体状态均无法实时获取的情况，引入无迹卡尔曼滤波算法设计最优状态估计模型，并提出了一种基于模型事件触发的通讯策略，根据李雅普诺夫稳定性分析理论设计了触发函数，在保证控制性能的前提下大幅减少通讯需求。进一步地，通过分析围捕控制任务目标，提出了围捕构型的动态变换策略，实现了面向逃逸目标的动态围捕控制。编队及围捕控制的仿真和实验验证了所提方法的有效性及可靠性。

四、针对子母式仿生机器鱼系统的规划与回收任务，提出了一种多阶段的回收控制策略。首先，面向远距离的回收过程，构建了大范围三维路径跟踪控制框架，并提出了基于障碍函数的自适应导航策略，避免了仿鱼波动运动模态与不准确的速度估计对导航过程的影响。其次，提出了基于非线性扰动观测器的侧滑角补偿机制，构建了基于滑模控制与模糊映射的跟踪控制器，提高了跟踪控制精度。再次，面向近距离回收过程，搭建了吸附与回收任务场景，提出了一种基于有限状态机的子母式机器鱼系统协同回收策略，完成了多个子机器鱼相对于母机器鱼的协同回收。通过水下实验验证了所提吸附回收方案的可靠性及鲁棒性。

In nature, remora fish can reduce energy consumption and improve foraging efficiency by virtue of the ``hitchhiking" behavior, which has greatly increased their survival ability in the marine environment. This phenomenon brings enlightenment to the development of novel master-slave underwater robots. This dissertation mainly concerns on the design and cooperative control of the adhesion-based master-slave robotic fish system, aiming to 
deal with complex underwater autonomous operation tasks and special operating environment. It provides an important theoretical basis and technical support for the cooperative operation of the underwater multi-robot systems and its applications in practical scenarios. The main contents are summarized as follows.

Firstly, in view of the inadequate performance in perception and endurance of the robotic fish, a design scheme of adhesion-based master-slave robotic fish system is proposed based on the adhesion behavior of the remora. In accordance with the collaborative requirements, the architecture of a master-slave robotic fish system is established, which is integrated with perception, locomotion and endurance. Besides, inspired by the remora fish, a novel adhesion-based slave robotic fish system is developed. Comprising a negative pressure-type biomimetic adhesion mechanism and an innovative multi-degree-of-freedom pectoral-pelvic fin structure, the prototype is completed. Moreover, the locomotion of the robotic fish is discussed to construct a three-dimensional(3-D) dynamic model based on the Newton-Euler equation. Finally, the experimental results demonstrate that the master-slave robotic fish system has remarkable individual locomotion performance and cooperative control ability.

Secondly, in order to address the algorithm verification difficulties of the underwater robots, a virtual simulation environment framework for the underwater multi-robot systems is proposed. The framework realizes functions such as human-machine interaction, collaborative communication, high-level control, low-level control and locomotion simulation while completing the system implementation from task posting to decision, planning, and control. It also offers a 3-D visualization simulation interface and physical control interface to meet the simulation and experimental needs. On this basis, a framework which integrates coalition formation and task allocation is proposed for solving the task allocation problem of the master-slave robot fish system, and an optimization model is constructed. At the same time, considering the cooperation relationship of the master and slave robots, the constraint conditions are analyzed to handle the optimization problem with an optimal utility of the system. Finally, the effectiveness of the proposed task allocation framework is verified by adequate simulation.

Thirdly, an event-triggered-based distributed formation and surrounding control method is proposed for the cooperative formation and surrounding control of the master-slave robotic fish system. Based on the consistency theory, a distributed control strategy is developed to guide the configuration of the system and maintain dynamic formation following a leader. Additionally, to meet the actual requirements, several cases are analyzed where the status of the leader and neighboring robots can not be obtained in real time. On this basis, a state estimation model based on the unscented Kalman filter algorithm is introduced and a model-based event-triggered communication strategy is proposed. According to the Lyapunov stability analysis theory, the triggering function is intended to reduce the communication requirements while ensuring the control performance. Further, a dynamic transformation strategy of the encirclement configuration is proposed to achieve dynamic surrounding control for the evader. Finally, simulation and experiments verify the effectiveness and reliability of the proposed method.

Fourthly, a multi-stage recovery control strategy is proposed for the planning and recovery tasks of the master-slave robotic fish system. For the long-distance recovery process, a large-scale 3-D path-following framework is established. Then, a barrier-based adaptive line-of-sight strategy is proposed to avoid the influence of the fish-like locomotion and inaccurate speed estimation during the path-following process. Besides, a novel nonlinear disturbance observer (NDOB)-based sideslip angle compensation is put forward and the inner-loop controllers are built by sliding mode control and fuzzy mapping algorithm. By virtue of these components, the tracking performance is effectively improved. Further, for the close-range recovery process, the recovery and attach scence is planned and a finite state machine-based cooperative recovery strategy is proposed for the master-slave robotic fish system. Benefitting from the proposed method, multiple slave robotic fish can be successfully recovered to the master robot. Finally, underwater experiments are presented to verify the reliability and robustness of the proposed cooperative attach and recovery scheme.