水下滑翔机垂直面运动的模糊滑模控制方法

Fuzzy sliding mode control method for vertical motion of autonomous underwater gliders

[目的]针对执行器输出能力受限的水下滑翔机(AUG)垂直面运动控制问题,提出一种基于T-S模糊逻辑的模糊滑模控制器。[方法]该模糊滑模控制器使用模糊切换率代替固定时间控制器中的切换率,用来有效抑制滑模控制器中存在的抖振,其中模糊切换率通过T-S模糊规则拟合固定时间控制器中的切换率得到。基于水下滑翔机执行器能力有限的问题,设计一种饱和辅助系统,以改善执行器饱和带来的影响。最后,通过Lyapunov稳定性分析和数值仿真对系统性能进行验证。[结果]结果显示,在使用模糊滑模控制器和饱和辅助系统的情况下,水下滑翔机系统能够在有限的时间内收敛,模糊滑模控制器和饱和辅助系统是有效的。[结论]研究表明,所提出的模糊滑模控制器在与固定时间控制器控制性能接近,同时模糊滑模控制器的抖振更小。

[Objective]This paper proposes a fuzzy sliding mode controller based on T-S fuzzy logic for the vertical plane motion control of an autonomous underwater glider(AUG) with limited actuator capability.[Methods]In the fuzzy sliding mode controller, the fuzzy switching rate is used to replace the switching rate in the fixed time controller to effectively suppress buffeting. The fuzzy switching rate is obtained by fitting the switching rate of the fixed time controller with T-S fuzzy rules. Based on the limited capabilities of AUG actuators, a saturation auxiliary system is designed to improve the actuator saturation effect. Finally, the performance of the system is verified by Lyapunov stability analysis and numerical simulation.[Results]The results show that the AUG under the fuzzy sliding mode controller and the saturation auxiliary system can converge in finite time. The effectiveness of the fuzzy sliding mode controller and the saturation auxiliary system are verified by numerical simulation. [Conclusions]By making comparisons with the fixed-time controller, it is verified that the two controllers have similar control performance, and the buffeting of the fuzzy sliding mode controller is lesser.