一类不确定线性切换系统的鲁棒H∞滑模控制

对一类含有非匹配不确定性且有外部干扰的线性切换系统,研究了H∞滑模变结构控制问题.利用LMI技术和单Lyapunov函数方法,设计单H∞滑模面,切换律以及子系统的变结构控制器,确保了切换系统的闭环系统为鲁棒稳定,且具有H∞扰动衰减度γ.系统状态到达滑模面后,该滑模面成为切换系统的全局鲁棒滑模面,可提高系统的暂态性能和鲁棒性.仿真例子说明所提出设计方法的有效性.     

不确定切换系统的鲁棒H∞控制:滑模控制设计

研究了一类不确定切换系统的鲁棒H∞控制问题, 提出一个新的鲁棒H∞滑模变结构控制方法. 该方法分为二个步骤. 首先是构造单鲁棒H∞滑模面, 使得降阶等效滑动模态在所设计的滞后切换律下是鲁棒镇定的且具有H∞扰动衰减度γ. 其次是设计变结构控制, 以确保切换系统的状态在有限时间内到达这个单鲁棒H∞滑模面. 仿真例子说明提出设计方法的有效性.     

不确定多时滞系统的输出滑模控制

本文研究了带有不匹配参量不确定性和匹配外扰的多时滞系统的鲁棒滑模控制。当状态不可量测时,利用系统输出设计滑模面,通过线性矩阵不等式给出了滑模面存在的一个时滞无关充分性条件,在此基础上设计变结构控制律,实现滑模控制。最后通过仿真说明该控制策略的有效性。     

基于线性化反馈的径向神经滑模控制器设计

针对非线性系统,采用径向神经网络逼近及自适应控制方法,利用线性化反馈技术,设计一种自适应神经滑模控制器。滑模变结构控制具有独特的鲁棒性能以及对匹配不确定性和外干扰的完全自适应等特点,但容易出现系统抖振问题,将神经网络应用于滑模变结构控制系统的设计中,系统抖振得到抑制。仿真结果也表明将神经网络与滑模控制相结合的方法是行之有效的。     

不确定性系统的非因果鲁棒学习控制

针对不确定性系统提出一种非因果鲁棒学习控制方法。该学习控制律的非因果学习部分通过标称系统的优化指标得到,鲁棒部分通过设计鲁棒加权来实现。首先,不考虑鲁棒部分的具体形式,推导出标称系统描述的学习控制律的鲁棒收敛性条件;然后,设计与系统不确定性相关的鲁棒加权,由鲁棒收敛性条件得到鲁棒加权的设计原则;最后,通过仿真实验验证了所提出方法的有效性,并分析了不同形式不确定性系统鲁棒设计的保守性。     

不确定线性系统的鲁棒切换函数变结构控制

针对工程领域中常见的一类不匹配不确定系统,即不确定性不是发生在控制通道中的系统,如工程中具有执行器的控制系统,提出了一种建立鲁棒切换函数的方法,进面设计滑模变结构鲁棒控制策略,该策略可确保整个闭环系统的轨迹是一致最终有界并具有稳定性,最后以船舶减摇鳍控制系统为例,进行了变结构鲁棒控制器设计。     

不确定系统鲁棒自适应离散变结构控制

研究不确定系统的离散变结构控制设计问题.对离散趋近律方法进行分析, 提出一种基于鲁棒趋近律的自适应切换增益算法,能根据不确定因素对系统影响的强弱自动调整增益大小. 给出了闭环系统的鲁棒稳定性证明,并对其准滑模运动进行分析.理论分析与仿真研究结果均表明, 所提方法能有效减弱抖振,较好地改善离散变结构控制器的性能, 并解除了传统上确界方法要求不确定因素上确界可知的限制.     

空间系绳系统展开的滑模变结构控制

为了增强空间系绳系统展开过程的抗干扰性,本文提出了空间系绳系统展开运动轨迹跟踪的滑模变结构控制方法.考虑大气摄动和无模型摄动建立了空间系绳系统展开运动动力学模型.基于遗传算法,针对两阶段展开方式,采用最优振荡阻尼张力控制律和等分时张力控制律设计了展开运动标称轨迹.为了实现轨迹的鲁棒跟踪,采用考虑展开长度的等效控制和连续函数幂次趋近律切换控制设计了滑模变结构控制器.仿真结果表明,所提出的控制方法有效增强了空间系绳系统展开运动的动态性能及鲁棒性.     

不确定离散切换系统的滑模控制

研究一类不确定离散切换系统的鲁棒滑模控制问题.针对传统变结构控制应用于离散系统时易失去其鲁棒性的问题,提出一种采用带调整参数递归式滑模函数的离散滑模控制策略,改进了离散时间滑模控制系统的趋近律方法,并针对不确定因素的影响设计了无须知道扰动上界的估计器.应用Lyapunov函数给出了离散切换系统的滑动模态可达条件,并设计了离散切换规则.仿真结果表明了所提出设计方法的有效性.     

电液伺服系统的多滑模鲁棒自适应控制

针对一类参数与外负载非匹配不确定的非线性高阶系统,提出了一种基于逐步递推方法的多滑模鲁棒自适应控制策略.应用逐步递推的多滑模控制方法简化了高阶系统的控制问题,同时在自适应控制中加入鲁棒控制的方法,以消除不确定性对控制性能的影响.首先利用逐步递推方法与状态反馈精确线性化理论,得出确定系统的多滑模控制器设计方法;然后基于Lyapunov稳定性分析方法,给出不确定系统的参数自适应律,及鲁棒自适应控制器的设计方法.本文把该控制策略应用到电液伺服系统的位置跟踪控制中,仿真结果显示,该控制方法具有较强的鲁棒性及良好的跟踪效果.     

不确定非线性系统的自适应反推高阶终端滑模控制

针对一类非匹配不确定非线性系统,提出一种神经网络自适应反推高阶终端滑模控制方案.反推设计的前1步利用神经网络逼近未知非线性函数,结合动态面控制设计虚拟控制律,避免传统反推设计存在的计算复杂性问题,并抑制非匹配不确定性的影响;第步结合非奇异终端滑模设计高阶滑模控制律,去除控制抖振,使系统对于匹配和非匹配不确定性均具有鲁棒性.理论分析证明了闭环系统状态半全局一致终结有界,仿真结果表明了所提出方法的有效性.     

非匹配不确定系统的自适应反步非奇异快速终端滑模控制

针对一类n阶非匹配不确定系统,提出一种自适应反步非奇异快速终端滑模控制方法.控制的前n-1步采用自适应反步控制策略,消除非匹配不确定性的影响;最后一步利用误差的积分构造非奇异快速终端滑模面,设计控制律使系统第n个状态有限时间收敛.该方法对系统中匹配和非匹配不确定项均具有鲁棒性,比自适应反步终端滑模方法具有更快的收敛速度.理论分析证明了闭环系统的稳定性,仿真结果验证了该方法的有效性.     

A Terminal Sliding Mode Observer Based Robust Backstepping Sensorless Speed Control for Interior Permanent Magnet Synchronous Motor

To achieve high-performance sensorless speed control for the interior permanent magnet synchronous motor (IPMSM) drive system, a terminal sliding mode observer based robust backstepping control is proposed in this paper. Firstly, an integral-type terminal sliding mode observer is designed to replace the real mechanical sensor to obtain the rotor position and speed information. Stability of the observer is guaranteed. Then, a robust backstepping controller with integral and sliding mode actions is designed to achieve speed regulation despite uncertainties and disturbances. The convergence for the backstepping control system is ensured. Finally, the sufficient conditions for input-to-state stability (ISS) property of the observer-controller closed-loop system are also analyzed. Simulation and comparison results have demonstrated the effectiveness of the proposed sensorless control scheme.     

一种基于反步法的鲁棒自适应终端滑模控制

针对不确定严格反馈块控非线性系统, 提出了一种基于反步法的鲁棒自适应终端滑模变结构控制方法. 系统的未知不确定及外界干扰由模糊系统在线逼近, 利用反步法设计了变结构控制的终端滑模面, 并由此得到了鲁棒自适应终端滑模控制器, 使系统的跟踪误差在有限时间内趋于给定轨迹的任意小的邻域内. 通过Lyapunov定理证明了闭环系统所有信号最终有界. 对某战斗机6自由度机动仿真结果表明, 该方法具有强鲁棒性.     

Data‐driven robust backstepping control of unmanned surface vehicles

In this article, a novel data‐driven robust backstepping control (DRBC) approach for tracking of unmanned surface vehicles (USVs) with uncertainties and unknown parametric dynamics has been developed. Main contributions are fourfold: (a) Unlike previous approaches, within the DRBC scheme, backstepping decoupled technique and data‐driven sliding‐mode control (DSMC) can be effectively cohered. (b) Using backstepping philosophy, a new data‐driven PI‐type sliding‐mode surface is devised, such that strong robustness with simple structure can be ensured. (c) Complex unknowns including couplings, uncertainties and parametric dynamics are sufficiently lumped, and are totally compensated by the extended state observer. (d) The entire DRBC scheme eventually achieves accurate tracking of USVs with strong couplings, uncertainties and unknown parametric dynamics. The efficacy and superiority of the proposed DRBC approach is validated on a prototype USV.     

A Robust Backstepping Sensorless Control for Interior Permanent Magnet Synchronous Motor Using a Super‐Twisting Based Torque Observer

In order to achieve high‐performance speed regulation for sensorless interior permanent magnet synchronous motors (IPMSMS), a robust backstepping sensorless control is presented in this paper. Firstly, instead of a real mechanical sensor, a robust terminal sliding mode observer is used to provide the rotor position. Then, a new super‐twisting algorithm (STA) based observer is designed to obtain estimates of load torque and speed. The proposed observer ensures finite‐time convergence, maintains robust to uncertainties, and eliminates the common assumption of constant or piece‐wise constant load torque. Finally, a sensorless scheme is designed to realize speed control despite parameter uncertainties, by combining the robust backstepping control with sliding mode actions and the presented sliding mode observers. The stability of the observer and controller are verified by using Lyapunov's second method to determine the design gains. Simulation results show the effectiveness of the proposed approach.     

Backstepping sliding mode control with functional tuning based on an instantaneous power approach applied to an underwater vehicle

In this paper, we present a modified backstepping sliding mode control to deal with Euler–Lagrange systems. The controller is applied in an underwater vehicle in order to show the effectiveness of the approach proposed. Instantaneous power data provided by the propulsion system are used to tune the controller in order to guarantee robust performance and energy saving. Thanks to the combination of an internal Proportional Integral and Derivative (PID) controller, it is possible implement high gains to deal with the influence of disturbances and uncertainties. A comparative study among this backstepping sliding mode controller and standard sliding mode controls is presented.     

Robust adaptive controller with disturbance observer for vehicular radar servo system

In vehicular radar servo system, parameter variations of the executive motor and external disturbance uncertainties have great effects on the position tracking precision of the system. In this paper, a robust adaptive controller with disturbance observer is designed for vehicular radar servo system, which combines the merits of disturbance observer, adaptive backstepping method and sliding mode control. The system is modeled, and a disturbance observer is employed to observe and compensate for the unknown uncertainties. Adaptive backstepping method is used to design the sliding model controller to guarantee the global stability of the overall system. Simulation results show that the proposed robust adaptive controller has good performance in position tracking and enhances the robustness of vehicular radar servo system while observing the uncertainties precisely and quickly.     

Adaptive Sliding Mode Control for Re-entry Attitude of Near Space Hypersonic Vehicle Based on Backstepping Design

Combining sliding mode control method with radial basis function neural network (RBFNN), this paper proposes a robust adaptive control scheme based on backstepping design for re-entry attitude tracking control of near space hypersonic vehicle (NSHV) in the presence of parameter variations and external disturbances. In the attitude angle loop, a robust adaptive virtual control law is designed by using the adaptive method to estimate the unknown upper bound of the compound uncertainties. In the angular velocity loop, an adaptive sliding mode control law is designed to suppress the effect of parameter variations and external disturbances. The main benefit of the sliding mode control is robustness to parameter variations and external disturbances. To further improve the control performance, RBFNNs are introduced to approximate the compound uncertainties in the attitude angle loop and angular velocity loop, respectively. Based on Lyapunov stability theory, the tracking errors are shown to be asymptotically stable. Simulation results show that the proposed control system attains a satisfied control performance and is robust against parameter variations and external disturbances.      

Robust control of a hydraulically driven flexible arm

A new robust controller is proposed to regulate both flexural vibrations and rigid body motion of a hydraulically driven flexible ann. The controller combines backsteppmg control and sliding mode to arrive at a controller capable of dealing with a nonlinear system with uncertainties. The sliding mode technique is used to achieve an asymptotic joint angle and vibration regulation in the presence of payload uncertainty by providing a virtual torque input at the joint while the backstepping technique is used to regtthte the spool position of a hydraulic valve to provide the required torque. It is shown that there is no chatter in the hydraulic valve, which results in smoother operation of the system.