白一鸣 刘磊 韩新洁

摘要:为提高无人水面艇(unmanned surface vehicle, USV)对复杂海况的适应性,针对欠驱动USV的路径跟踪控制问题,设计基于改进的自适应积分视线(improved adaptive integral line-of-sight, IAILOS)制导方法和径向基神经网络(radial basis function neural network, RBFNN)的积分滑模路径跟踪控制器。在IAILOS制导方法中,引入降阶的扩张状态观测器估计未知时变洋流速度,从而使得该制导方法不仅可以估计时变漂角,而且可以补偿未知时变洋流的扰动。利用RBFNN的无限逼近特性来估计USV动力学模型中的不确定项和未知的外部环境干扰。通過稳定性分析和仿真对比实验,验证了本文所设计的控制器的准确性和鲁棒性。
关键词: 无人水面艇(USV); 路径跟踪控制; 改进的自适应积分视线(IAILOS)制导方法; 径向基神经网络(RBFNN); 滑模控制
中图分类号: U664.82 文献标志码: A
Abstract: To improve the adaptability of unmanned surface vehicles (USVs) to complex sea conditions, aiming at the path following control of underactuated USVs, an integral sliding-mode path following controller is designed based on the improved adaptive integral line-of-sight (IAILOS) guidance law and the radial basis neural network (RBFNN). The reduced-order extended state observer is introduced to estimate the unknown time-varying ocean current velocity in the IAILOS guidance law, so that the guidance law can not only estimate the time-varying drift angle, but also compensate the disturbances of unknown time-varying ocean currents. The infinite approximation property of RBFNN is used to estimate the uncertain terms in the USV dynamic model and the unknown external environment disturbances. The accuracy and robustness of the controller are verified through the stability analysis and simulation comparison experiments.
Key words: unmanned surface vehicle (USV); path following control; improved adaptive integral line-of-sight (IAILOS) guidance law; radial basis function neural network (RBFNN); sliding-mode control
0 引 言
无人水面艇(unmanned surface vehicle, USV)的路径跟踪控制目标是控制USV跟踪几何平面内的一条理想的参数化路径,并且没有时间限制[1]。针对USV的路径跟踪控制问题,国内外学者提出的主要控制方法有:比例积分微分(proportional-integral-derivative, PID)控制、反馈线性化、反步法、预测控制、滑模控制等[2-4]。在USV的控制系统中,通过将控制算法与制导方法相结合,可以大大提高USV操纵的安全性[1]。视线(line-of-sight, LOS)制导方法由于具有简单高效、易于实现等优点,被广泛应用到USV的路径跟踪控制器设计中。
LOS制导方法通过模仿熟练的操舵人员的操纵行为,利用超前视距跟踪理想路径上的前方一点,以实现路径跟踪的目的[5]。文献[6-7]提出比例LOS制导方法,并且证明了该制导方法的一致半全局指数稳定性。……