Integrated Tracking Control of an Underwater Bionic Robot Based on Multimodal Motions
针对水下仿生机器人在狭窄空间中的精确跟踪控制难题，提出一个集成框架，包含顶层规划、中层跟踪和底层控制分配，并通过仿真和水池实验验证了有效性。
As a key technology for autonomous underwater operations, precise tracking control in tight space environments is a great challenge. With the aid of high maneuverability of the underwater bionic robot, this article proposes an integrated tracking control framework for a robotic dolphin to move through narrow areas, including top-level planning, middle-level tracking, and bottom-level control allocation. First, a nonlinear model predictive control-based planning method is presented with full consideration of tracking accuracy and obstacle avoidance safety. Second, in order to improve the anti-interference ability, we derive a nonlinear path tracking control law by combining the backstepping technique with a nonlinear disturbance observer. More importantly, through hydrodynamic analysis of the bionic multimodal motions under flippers and flukes, a fuzzy-based nonlinear control allocation system is particularly adopted to convert calculated control forces into bionic motion parameters. Finally, extensive simulations and aquatic experiments are conducted, and the obtained results validate the effectiveness of proposed methods, providing a new idea to further ocean exploration.