Adaptive fuzzy terminal sliding mode control for the free-floating space manipulator with free-swinging joint failure

Space manipulator with free-swinging joint failure simultaneously contains kinematic and dynamic coupling relationships, so it belongs to a new underactuated system. To allow the manipulator to carry on tasks, an effective robust underactuated control method for the space manipulator with free-swinging joint failure is studied in this paper. Considering the effect of model uncertainty and joint torque disturbance, a robust underactuated control system based on the Terminal Sliding Mode Controller (TSMC) is designed, but two drawbacks are discussed: (A) Robustness depraves with eliminating chattering. (B) Control parameters are difficult to be determined under unknown uncertainty and disturbance. To improve the TSMC, the adaptive fuzzy controller is introduced to estimate the real effect of unknown uncertainty and disturbance according to deviations of sliding mode and its reaching law. The estimated result is directly compensated into active joints torque. In simulation, the space manipulator with free-swinging joint executes tasks based on the TSMC and the Adaptive Fuzzy Terminal Sliding Mode Controller (AFTSMC) respectively. Same tasks can be finished with smaller joints torque and stronger robustness based on the AFTSMC. Therefore, AFTSMC can serve as an effective robust control method for the space manipulator with free-swinging joint failure under unknown model uncertainty and torque disturbance.     

空天飞行器的鲁棒自适应模糊轨迹线性化控制

提出了鲁棒自适应模糊轨迹线性化控制(RAFTLC)方法并应用于空天飞行器(ASV)飞行控制系统设计.根据系统的先验知识, 设计出标称模糊系统对系统的未知干扰和不确定进行估计, 并通过鲁棒自适应控制项来克服标称模糊系统逼近误差和权值误差的影响.标称模糊系统逼近误差和权值误差的界在线调整.采用Lyapunov方法证明了闭环系统的所有信号一致最终有界.最后利用提出的控制方案设计了ASV飞行控制系统, 并在高超声速条件下进行了仿真验证.仿真结果表明了控制方案的有效性和鲁棒性.      

飞机直接力动态解耦模糊控制系统设计

将模糊控制方法与动态逆方法相结合,构成了一种动态解耦模糊控制综合方法.用该综合方法对某型飞机的侧向直接力控制模态(航向指向)进行了分析与设计,并将其与动态逆方法进行了比较.结果表明,所设计的模糊控制系统不仅能够实现动态解耦控制,获得良好的动态性能,而且对模型不够准确或系统内部参数发生变化具有较强的适应性.     

BLDCM位置伺服系统的模糊滑模控制

针对BLDCM位置伺服系统,设计了一种模糊滑模变结构控制器。滑模变结构控制具有响应速度快、控制精度高、鲁棒性强的特点,但普遍存在抖振现象。把模糊控制引入到常规滑模变结构控制中,采用模糊推理来调节开关控制的幅度,能有效的削弱滑模切换时产生的剧烈抖振,而不牺牲滑模变结构控制对系统参数摄动和外界扰动的强鲁棒性。仿真结果表明该方案在BLDCM位置伺服系统中提高了控制系统的精度和鲁棒性,使得控制性能得到了极大的改善。     

基于T-S模糊系统的空天飞行器鲁棒自适应轨迹线性化控制

 基于T-S模糊系统提出了鲁棒自适应轨迹线性化控制(RATLC)方法。利用T-S模糊系统逼近未知干扰和不确定性因素,并采用Lyapunov方法设计了鲁棒自适应控制律。不论系统状态的维数和用于逼近不确定的模糊系统规则数为多少,整个系统仅有两个参数在线调整。理论分析证明了闭环系统所有信号一致最终有界。应用提出的控制方案设计了空天飞行器(ASV)飞行控制系统,并在高超声速飞行条件下进行了仿真验证,仿真结果表明了控制方案的有效性和鲁棒性。     

Optimization Based on Convergence Velocity and Reliability for Hydraulic Servo System

This article presents an optimal hybrid fuzzy proportion integral derivative (HFPID) controller based on combination of proportion integral derivative (PID) and fuzzy controllers, by which the parameters could be evaluated by global optimization either in convergence velocity or in convergence reliability. Focusing on the nonlinear factors of hydraulic servo system, this article takes advantage of PID and fuzzy logic controller integrated with scaling factors to acquire precise tracking performances. To further improve the performances, it provides new developed optimization with rapid convergence to attain reliable approach probability. Focusing on the performance indictors of evolutionary algorithm, this article presents a new technique to predict reliability of the optimization algorithm. Statistics authenticates the effectiveness and robustness of the optimization. Further, many simulation and experimental results indicate that the optimal HFPID could acquire perfect immunity against parametric uncertainties with external disturbance.     

航空发动机多变量模糊滑模变结构模型跟踪控制

针对现代航空发动机是一个具有不确定性的强非线性系统,结合滑模变结构控制和模糊逻辑系统的优点,提出了一种模糊滑模变结构模型跟踪控制方法。采用比例积分型切换超平面设计滑模变结构控制系统,使用模糊逻辑系统自适应调节切换增益,得到某涡扇发动机的模糊滑模变结构模型跟踪控制器。数字仿真结果表明,所设计的控制器不但能使被控对象较好地跟踪参考模型,消除抖振现象,而且对系统的不确定性具有不变性,保证了被控系统在整个控制阶段都具有较强的鲁棒性。     

Attitude tracking control for variable structure near space vehicles based on switched nonlinear systems

An adaptive robust attitude tracking control law based on switched nonlinear systems is presented for a variable structure near space vehicle (VSNSV) in the presence of uncertainties and disturbances. The adaptive fuzzy systems are employed for approximating unknown functions in the flight dynamic model and their parameters are updated online. To improve the flight robust performance, robust controllers with adaptive gains are designed to compensate for the approximation errors and thus they have less design conservation. Moreover, a systematic procedure is developed for the synthesis of adaptive fuzzy dynamic surface control (DSC) approach. According to the common Lyapunov function theory, it is proved that all signals of the closed-loop system are uniformly ultimately bounded by the continuous controller. The simulation results demonstrate the effectiveness and robustness of the proposed control scheme.     

基于自适应模糊滑模退步控制的直接力/气动力复合控制导弹自动驾驶仪设计

针对直接力/气动力复合控制导弹所具有的强耦合非线性特性,提出了一种基于自适应模糊滑模退步控制的自动驾驶仪设计方法.该方法利用自适应模糊系统所具有的万能逼近特性,对大迎角飞行过程中导弹动力学方程中存在的非线性函数进行逼近,并利用变结构控制所具有对干扰的强鲁棒性,构造误差系统滑模面,克服了逼近误差和外界干扰对控制系统的影响,实现了对大机动指令的精确跟踪.仿真结果表明,所设计的自动驾驶仪对过载指令有良好的跟踪效果,对模型不确定性和外界干扰具有鲁棒性.     

Sliding-mode controller design for spacecraft attitude trackingmaneuvers

A robust sliding-mode control law that deals with spacecraft attitude tracking problems is presented. Two important natural properties related to the spacecraft model of motion are discussed. It is shown that by using these properties and the second method of Lyapunov theory, the system stability in the sliding mode can be easily achieved. The success of the sliding-mode controller and its robustness relating to uncertainties are illustrated by an example of multiaxial attitude tracking maneuvers     

直升机垂直飞行鲁棒控制系统设计与仿真

应用基于Lyapunov直接法的非线性不确定系统鲁棒控制方法，为某型直升机垂直飞行模态设计了鲁棒控制律，该控制律能保证闭环系统具有全局稳定性。为验证所设计鲁棒控制律的有效性，对直机机垂直飞行的三 机动：设定点悬停、起飞着陆机和忽上忽下机动，分别进行了闭环系统仿真。仿真结果表明，所设计的控制律对系统参数的摄动具有很强的鲁棒性。     

反馈线性化系统的非线性预测滑模控制

 对反馈线性化系统进行非线性预测滑模控制的设计，利用预测滑模的二次型代数指标的最小化来设计滑模控制律，按系统的输出相对度来设计滑动模，二次型指标中包含了控制量的代价函数项，这项是连续可调的，可以避免系统控制输入的饱和现象。证明了非线性预测滑模控制系统具有的鲁棒性，并导出了鲁棒滑模预测控制器。     

基于模糊动态逆的飞机直接升力控制

针对飞机的直接升力控制问题,设计了一种将动态逆控制器和模糊控制器结合使用的新方法,并在系统参数优化过程中对ITAE准则进行改进。在ITAE准则的基础上,引入对正向误差的积分从而约束系统响应的超调量。通过对单纯直接升力控制模态和垂直平移控制模态的仿真实验,表明文章的模糊动态逆控制器能够实现具备良好鲁棒性的直接升力控制;通过对比模糊动态逆控制器和动态逆控制器的仿真结果,表明模糊动态逆控制器的动态性能和稳态性能优于动态逆控制器。     

高效强力复合铣A轴的动力学建模与自适应滑模控制

A轴单元作为五轴数控机床的关键功能部件,其控制精度直接影响工件的加工精度和表面质量。针对系统参数摄动和不确定性切削负载对A轴伺服系统控制精度的影响,分析了A轴驱动系统的动静态性能,讨论了驱动扭矩、负载扭矩、运动方向和系统参数之间的相互关系,并建立了系统的非线性动力学模型。基于该动力学模型,设计了自适应模糊滑模控制器（AFSMC）,采用模糊系统对滑模控制律中的非线性函数项进行自适应逼近,并基于Lyapunov理论设计了模糊系统中可调参数的自适应律,同时,在滑模控制（SMC）的切换控制部分采用了指数趋近律。实验结果表明,所设计的AFSMC对不确定性负载扭矩和系统参数摄动具有较强的鲁棒性。与传统滑模控制（TSMC）相比,其在有效减小控制输入抖振的同时,使得跟踪控制精度提高了14.54%。     

Finite-time sliding mode attitude control for a reentry vehicle with blended aerodynamic surfaces and a reaction control system

This paper proposes a finite-time robust flight controller, targeting for a reentry vehicle with blended aerodynamic surfaces and a reaction control system(RCS). Firstly, a novel finite-time attitude controller is pointed out with the introduction of a nonsingular finite-time sliding mode manifold. The attitude tracking errors are mathematically proved to converge to zero within finite time which can be estimated. In order to improve the performance, a second-order finite-time sliding mode controller is further developed to effectively alleviate chattering without any deterioration of robustness and accuracy. Moreover, an optimization control allocation algorithm, using linear programming and a pulse-width pulse-frequency(PWPF) modulator, is designed to allocate torque commands for all the aerodynamic surface deflections and on–off switching-states of RCS thrusters.Simulations are provided for the reentry vehicle considering uncertain parameters and external disturbances for practical purposes, and the results demonstrate the effectiveness and robustness of the attitude control system.     

基于自适应滑模与模糊控制的导弹直接力/气动力复合控制系统优化设计

 针对导弹直接力/气动力复合控制问题,提出了一种基于自适应滑模控制(ASMC)与模糊逻辑的自动驾驶仪设计方法。该方法将整个导弹控制系统分为气动力控制子系统(ACS)和直接力控制子系统(RCS)两部分。前者采用自适应滑模控制理论进行设计,利用其所具有的强鲁棒性优点,克服了包括参数摄动与外界扰动在内的各类不确定性因素的影响。后者通过基于规则的模糊推理来确定不同条件下直接力作用的大小,以辅助提高气动力子系统的性能。在控制系统结构确定的条件下,利用遗传算法(GA)对各参数进行优化,实现了两个子系统之间的协调工作。仿真结果表明,所提出的控制方案对机动指令具有较好的跟踪效果,适用于直接力/气动力复合控制导弹的控制系统设计。     

不确定伺服系统的模糊自适应 NTSM控制

针对永磁同步电机伺服系统内因结构参数变化和末端负载变化带来的控制问题,提出了 1种结合模糊控制理论的新型自适应非奇异终端滑模控制策略。首先,在传统滑模控制理论基础上设计结构参数自适应律,消除系统结构参数变化的影响;然后,利用模糊控制理论估计负载扰动的上界,减小了滑模控制的抖动问题,进而通过构造非奇异终端滑模面,提高了伺服系统的响应能力;最后,为了缩小系统的跟踪误差,设计了基于误差积分的非奇异终端滑模面。离散化仿真结果表明,所提出控制算法对系统结构参数变化和负载变化具有良好的鲁棒性。     

Backstepping design of missile guidance and control based on adaptive fuzzy sliding mode control

This paper presents an integrated missile guidance and control law based on adaptive fuzzy sliding mode control. The integrated model is formulated as a block-strict-feedback nonlinear system, in which modeling errors, unmodeled nonlinearities, target maneuvers, etc. are viewed as unknown uncertainties. The adaptive nonlinear control law is designed based on backstepping and sliding mode control techniques. An adaptive fuzzy system is adopted to approximate the coupling nonlinear functions of the system, and for the uncertainties, we utilize an online-adaptive control law to estimate the unknown parameters. The stability analysis of the closed-loop system is also conducted. Simulation results show that, with the application of the adaptive fuzzy sliding mode control, small miss distances and smooth missile trajectories are achieved, and the system is robust against system uncertainties and external disturbances.     

Control of approach and landing phase for reentry vehicle using fuzzy logic

The reentry vehicle is affected by various disturbances such as a wind gust, atmospheric condition or aerodynamic problems in the approach and landing phase. Therefore it is necessary to design a robust control scheme. This paper presents a control scheme using Mamdani fuzzy PD controller. In this paper, the reference trajectories are generated using geometric parameters for disturbed circumstances with 4 cases: nominal, headwind and tailwind, drag increased case. Then, a Mamdani fuzzy PD controller was designed in this study. Twenty-five rules were applied in the knowledge-based system. The max–min method for a fuzzy inference system and the center-of-mass method in defuzzification were used. Finally, guidance and control simulations are performed for verification of proposed controller using generated reference trajectories. In addition, the Monte Carlo simulation is performed considering various disturbances. The results show that proposed Mamdani fuzzy PD controller has reliability and robustness for control of reentry vehicle with wind disturbance in the approach and landing phases.     

结构控制设计中具有输出反馈最小范数的极点配置方法

给出了结构控制系统输出反馈极点配置的设计方法,该方法采用鲁棒性分析设计的一些基本步骤,兼顾结构控制系统的鲁棒性和计算的简便。基于鲁棒度量建立状态向量和输出向量参数之间的协调关系,利用 QR分解技术,导出鲁棒极点配置问题的增益矩阵表达式,通过分析该表达式,可以得出本文方法的鲁棒性能够得到保证。将输出反馈极点配置问题转化为非线性最小二乘问题,用 LM方法解出具有最小范数的反馈矩阵。最后将本文方法应用一个 3层结构在正弦载荷作用下的振动控制问题,证实了本文方法的性能