Dead‐Zone Model Based Adaptive Backstepping Control for a Class of Uncertain Saturated Systems

In this paper, a dead‐zone based model of saturation phenomena is proposed. This method is capable of modelling diverse kinds of saturation, including both hard‐limited and soft‐limited. Due to use of a linear parameter approach, the proposed model is consistent with the available adaptive control techniques in the literature. In addition, based on the proposed model, an adaptive controller is designed for a class of nonlinear saturated systems, where, the shape of the saturation phenomenon is assumed to be unknown. The effectiveness of the proposed method and its robustness against initial condition variation and reference signal is evaluated via simulated examples for both spring–mass–damper and ship steering autopilot systems.     

带有未建模动态的船舶减摇鳍的鲁棒自适应控制

针对船舶减摇鳍非线性数学模型,提出一种鲁棒自适应控制器,可以用于存在非线性不确定、未知有界扰动和未建模动态的情况。应用Lyapunov稳定性理论证明,所提出的鲁棒自适应控制器可保证整个非线性系统的稳定性,且通过适当选择设计参数,可使跟踪误差达到任意精度。仿真结果表明了所提方法的有效性。     

Adaptive fuzzy robust tracking controller design via small gain approach and its application

An adaptive fuzzy robust tracking control (AFRTC) algorithm is proposed for a class of nonlinear systems with the uncertain system function and uncertain gain function, which are all the unstructured (or nonrepeatable) state-dependent unknown nonlinear functions arising from modeling errors and external disturbances. The Takagi-Sugeno type fuzzy logic systems are used to approximate unknown uncertain functions and the AFRTC algorithm is designed by use of the input-to-state stability approach and small gain theorem. The algorithm is highlighted by three advantages: 1) the uniform ultimate boundedness of the closed-loop adaptive systems in the presence of nonrepeatable uncertainties can be guaranteed; 2) the possible controller singularity problem in some of the existing adaptive control schemes met with feedback linearization techniques can be removed; and 3) the adaptive mechanism with minimal learning parameterizations can be obtained. The performance and limitations of the proposed method are discussed. The uses of the AFRTC for the tracking control design of a pole-balancing robot system and a ship autopilot system to maintain the ship on a predetermined heading are demonstrated through two numerical examples. Simulation results show the effectiveness of the control scheme.     

船舶自动舵控制技术发展研究

介绍与比较了船舶操纵的各种自动舵控制方法 ,船舶自动舵可分为四个发展阶段 ,即机械舵、PID舵、自适应舵和智能舵 ,其中智能舵为目前最先进的自动舵 ,它又分为专家系统、模糊舵和神经网络舵。     

控制增益未知的船舶航向非线性自适应跟踪控制

针对参数不确定的船舶运动非线性控制系统控制方向未知的困难,将逆推算法与Nussbaum增益方法相结合,提出一种新的自适应非线性控制策略,从而实现船舶运动航向跟踪控制.首先,从理论上证明了所设计的自适应控制器保证最终的控制系数符号未知的参数不确定船舶运动非线性系统中所有信号一致有界,船舶的实际航向全局自适应地渐近跟踪期望的参考航向.对两条船舶数学模型的仿真实验结果表明,所设计的自适应非线性跟踪控制器具有良好的适应性及鲁棒性.     

Adaptive fuzzy ship autopilot for track-keeping

An adaptive fuzzy gain autopilot for ship track-keeping is developed. This autopilot is composed of Sugeno fuzzy type autopilot in an ordinary feedback loop and adjustable scaling factors mechanism in an additional feedback loop. The adjustment mechanism represents a fuzzy controller that changes scaling factors of the base fuzzy autopilot. The control system for the track-keeping is completely described. For the track-keeping problem, the maneuver of way-point turning and ship guiding through a complex path (trajectory) are presented. The influence of sea current and wave disturbances on track-keeping performance was also considered. Simulation results obtained by the Sugeno fuzzy type autopilot are first presented. Then, those results are compared with ones obtained by an adaptive fuzzy autopilot.     

波浪作用下船舶航向自抗扰控制设计及参数配置

针对具有内部参数不确定性和外部扰动的海上船舶设计了航向自抗扰控制器,并解决了舵机模型中舵角的限幅和限速问题,基于滑模控制理论提出了反馈控制带宽的计算方法.采用频域分析的方法,系统地分析了自抗扰控制器对外部波浪扰动的抑制能力、模型参数不确定时的鲁棒性;结合作者实船工作经验以及系统动态特性与控制参数的关系,提出了船舶航向控制器参数的配置规律;最后以一艘57000吨级散货船为控制对象,验证了航向控制器的鲁棒性和本文所述参数配置规律的有效性.为将自抗扰控制算法应用于船舶自动舵设计提供理论依据和实践参考.     

Study on a new and effective fuzzy PID ship autopilot

Ship autopilots are usually designed based on Proportional Differential (PD) and Proportional Integrate Differential (PID) controllers because of their simplicity, reliability, and ease of construction. However, their performance in various environmental conditions is not as good as desired. This disadvantage can be overcome by adjusting works or constructing adaptive controllers, although these methods are complex and not easy. This article presents a new method for constructing a ship autopilot based on the combination of fuzzy logic control (FLC) and linear control theory (PID control). The new ship autopilot has the advantages of both the PID and FLC control methodologies: ease of construction, and optimal control laws can be established based on ship master knowledge. Therefore, the new ship autopilot can be well adapted with parameter variations and strong environment effects. Simulation using MATLAB software for a ship with real parameters showed high effectiveness of the fuzzy PID autopilot in course-keeping and course-changing maneuvers in comparison with the ordinary PID ship autopilots.This work was presented, in part, at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003     

船舶航向模型参考模糊自适应控制器的设计

本文介绍了模型模糊自适应控制器的结构，调节机理。针对船舶航向控制，设计了参考模型模糊自适应控制器，并进行了仿真。与普通模糊控制器控制效果进行了比较，仿真表明参考模型模糊自适应控制有良好的控制性能。     

基于观测器的不确定非线性系统的自适应鲁棒模糊控制

针对单输入单输出不确定非线性系统提出了一种自适应鲁棒模糊控制算法.该算法通过设计观测器来估计系统的状态向量,因此不要求假设系统的状态向量是可测的.在这个算法中,主要的假设为最优逼近参数向量与标称参数向量之差的范数和逼近误差的界限是未知的.通过只对未知界限估计的调节,该算法减轻了在线计算量并且提高了系统的鲁棒性.所设计的自适应鲁棒模糊控制算法保证了闭环系统的所有信号是一致有界的并且跟踪误差估计收敛到一个小的零邻域内.仿真例子证实了所提方法的可行性.     

船舶航向非线性系统的多滑模自适应模糊控制

针对参数未知的船舶航向非线性控制系统数学模型,在考虑舵机伺服机构特性的情况下,船舶航向控制问题就成为一个虚拟控制系数未知的非匹配不确定非线性控制问题.基于多滑模设计方法和模糊逻辑系统的逼近能力,提出了一种多滑模自适应模糊控制算法,通过引入非连续投影算法和积分型Lyapunov函数,提高了系统在抑制参数漂移、控制器奇异等方面的能力.借助Lyapunov函数证明了所设计控制器使最终的闭环非匹配不确定船舶运动非线性系统中的所有信号有界,且跟踪误差收敛到零.仿真研究表明:该算法与传统的PID控制相比,具有较好的跟踪能力和自适应能力.     

无人机三维航路自适应跟踪控制

针对无人机自动驾驶仪参数标称值偏离实际值情况下的航迹跟踪问题,提出一种无人机三维航路自适应跟踪导引律。首先在无人机自动驾驶仪参数无偏离的条件下,推导出能够跟踪三维航路的速度指令、航迹倾斜角指令和航迹方位角指令,并使用Lyapunov稳定性理论证明了跟踪系统全局渐进稳定;之后考虑自动驾驶仪参数标称值偏离实际值的情况,设计自适应算法在线估计自动驾驶仪参数,得到无人机三维航路自适应跟踪导引律。仿真实验表明所提出的自适应跟踪导引律能够使无人机在自动驾驶仪参数偏离条件下有效跟踪三维航迹。     

基于自适应模糊滑模控制的船舶航向控制器设计

针对船舶运动系统中固有的非线性、模型不确定性和风、浪、流等的干扰.提出了自适应模糊滑模控制(AFSMC)策略解决船舶的航向控制问题.通过采用模糊逻辑系统逼近系统未知函数,将滑模控制技术与自适应模糊控制技术相结合,设计了船舶航向AFSMC控制器.在滑模边界层内应用PI (proportional-integral)控制代替滑模控制中的切换项,削弱了滑模控制带来的抖振现象.借助李亚普诺夫函数证明了船舶运动系统中的信号都一致有界并利用Barbalat引理证明了跟踪误差渐近收敛到零.在参数摄动和外界干扰情况下进行了航向保持与改变仿真试验,采用AFSMC控制器得到了与无摄动和无干扰情况下相似的输出响应.实验结果表明,所提控制器能有效地处理系统不确定性和外界干扰,控制性能良好,具有很强的鲁棒性.     

Robust Adaptive Fuzzy Control of Nonlinear Systems with Unknown and Time‐Varying Saturation

In this paper, a robust adaptive fuzzy control approach is proposed for a class of nonlinear systems in strict‐feedback form with the unknown time‐varying saturation input. To deal with the time‐varying saturation problem, a novel controller separation approach is proposed in the literature to separate the desired control signal from the practical constrained control input. Furthermore, an optimized adaptation method is applied to the dynamic surface control design to reduce the number of adaptive parameters. By utilizing the Lyapunov synthesis, the fuzzy logic system technique and the Nussbaum function technique, an adaptive fuzzy control algorithm is constructed to guarantee that all the signals in the closed‐loop control system remain semiglobally uniformly ultimately bounded, and the tracking error is driven to an adjustable neighborhood of the origin. Finally, some numerical examples are provided to validate the effectiveness of the proposed control scheme in the literature.     

非线性离散时间系统的自适应模糊补偿控制

针对一类非线性离散时间系统,提出一种自适应模糊逻辑补偿控制方案.控制律由跟踪控制律和逼近误差补偿控制律两部分组成,利用模糊逻辑系统对系统参数扰动和外界干扰进行自适应补偿,由模糊滑模控制律实现对模糊逻辑系统逼近误差的进一步补偿.所设计的控制器可保证闭环系统一致最终有界.将该控制器用于月球探测车动态转向系统中,仿真结果表明了该方法的有效性.     

单值预估离散滑模控制及其应用

提出基于单值预估离散滑模控制算法的离散交结构控制系统设计新思路．根据不确定系统的名义模型设计理想滑模面,以名义模型作为预测模型,利用当前及过去时刻的滑模信息预测未来时刻的滑模动态,并将滚动优化和反馈校正引入离散滑模控制系统的设计．该方法不仅较好地消除了抖振现象,而且能保证闭环系统的鲁棒稳定性．将该算法应用于船舶航向控制器的设计,试验结果表明了它的有效性．     

基于输入输出线性化的自适应模糊滑模航迹控制

针对船舶直线航迹控制的非线性特性,设计一种基于输入输出线性化的自适应模糊滑模控制器,并利用Lyapunov理论,证明该系统在所设计控制器作用下全局渐近稳定,Simulink仿真结果表明,所设计控制器能够有效抑制常规滑模所固有的稳态抖振现象,且在参数摄动及风浪干扰下具有强鲁棒性,较好的实现了对设定航迹的跟踪。     

基于PLC的某型气垫船空气舵控制系统的设计

某型气垫船空气舵单片机控制系统,存在稳定性差、抗干扰性不足的问题,为此提出一种以施耐德PLC M340为核心的控制方案,利用触摸屏XBT GT5330进行人机交互,采用ATmega8515单片机实现舵角信号采集、滤波.在Unity-Pro软件环境下,开发了模糊自适应PID控制程序,并现场进行了基于所设计系统的模糊自适应PID控制算法的抗干扰试验和大舵角转舵试验.试验结果表明,所设计的系统稳定性好、抗干扰性强,满足控制要求.     

船舶航向控制的多滑模鲁棒自适应设计

针对带有未知虚拟控制增益和常参数不确定的非匹配不确定船舶航向非线性控制问题,设计了一种新的多滑模鲁棒自适应控制算法.该算法利用神经网络来逼近系统模型的不确定性;应用逐步递推的多滑模控制算法降低了控制器的复杂性;尤其是采用Nussbaum函数处理系统中符号未知的问题,避免了可能存在的控制器奇异值问题;然后借助Lyapunov稳定性分析方法,理论分析证明了所得闭环系统全局一致最终有界,且跟踪误差收敛到零.仿真试验结果表明,该方法具有较好的控制效果.     

一类非线性系统综合自适应模糊滑模控制

针对一类非线性系统把模糊控制,模糊逻辑逼近及模糊滑模控制相结合,提出一种综合自适应模糊滑模控制方法、直接和间接自适应模糊控制器只能利用模糊控制规则或模糊描述信息,而综合自适应模糊控制器能利用上述两种信息。理论证明闭环系统稳定,跟踪误差收敛到零或零的一个小邻域内。仿真结果表明了算法的有效性。