UUV水动力参数估计及深度自抗扰控制方法

Hydrodynamic coefficients estimation for UUV and ADRC to its diving control

在水下无人航行器(UUV)动力学模型不确定性及外部扰动下,针对常规非线性控制算法设计假设条件过多不利于实际应用的问题,提出基于自抗扰控制理论设计深度控制器以提高跟踪效果。一方面,利用非线性跟踪微分器(TD)提取微分信号以安排深度跟踪的过渡过程;设计扩张状态观测器(ESO)估计深度控制系统内、外扰动,并补偿扰动;建立非线性状态误差反馈控制律(NLSEF)来控制执行机构。另一方面,为提高自抗扰控制器参数的匹配性,利用递推最小二乘(RLS)估计UUV深度动力学模型,并进行仿真试验。最后,完成了UUV深度控制湖试试验,结果表明所提方法能够使UUV快速的到达指定深度,具有超调量小、适合工程实现等特点。

In the presence of uncertain dynamics and external disturbances, it is rather complicated to design a conventional nonlinear control algorithm for practical application in unmanned underwater vehicle(UUV) with assumptions. In order to reduce the design complexity, a depth controller was proposed to improve the diving control based on auto disturbances rejection control(ADRC) theory. On the one hand, a nonlinear tracking differentiator(TD) was brought to extract differential signal for command transition. Then an extended state observer(ESO) was introduced to estimate and compensate the internal and external disturbances. Therefore the control input could be obtained using nonlinear state error feedback(NLSEF) law. On the other hand, in order to improve the parameter matching of ADRC, the recursive least square(RLS) was used to estimate dynamics in the vertical plane for UUV. Finally, simulations and lake trials were carried out. The results from the depth tracking experiments showed that the proposed method has characteristics of fast rapidity, small overshoot and suitable for engineering realization.