匹配和不匹配干扰共存时电液伺服系统预设性能渐近跟踪控制

针对电液伺服系统匹配和不匹配干扰共存的特点,兼顾瞬态性能和稳态性能需求,提出一种新型高精度跟踪控制策略。以阀控电液位置伺服系统为例,建立了包含匹配和不匹配干扰的系统非线性数学模型,定义预设性能函数规划控制误差,基于规划后的转换误差设计反步控制器,并融合采用干扰上界估计的连续渐近控制技术处理匹配和不匹配干扰,获得了可预设的瞬态性能和渐近稳态性能,通过Lyapunov分析证明了稳定性。两种位置指令跟踪试验的结果表明,相比PID控制和反馈线性化控制,初始阶段跟踪精度提高超22.9%,相比仅引入预设性能函数的控制器,稳态跟踪精度提高超42.9%。     

基于反步法和分层滑模控制的轮式移动机器人轨迹跟踪

结合了反步法和分层滑模控制方案提出了一种轮式移动机器人轨迹跟踪控制算法。首先,针对一类轮式移动机器人系统将其分解成两个子系统,分别设计子系统的控制率。针对第一个子系统,利用分反步法通过构造Lyapunov函数设计系统的控制率。针对第二个子系统,将其进一步分解为两个子系统,利用分层滑模技术设计出最终的控制器。基于反步法和分层滑模控制方案设计的系统控制器,不仅可以保证了闭环系统是渐进稳定的且系统的跟踪误差能够收敛到任意小的邻域内。最后通过一个数值模拟结果表明了所提出控制方法的有效性。     

磁悬浮系统的积分滑模自抗扰控制

针对磁悬浮系统存在着非线性、时滞和易受到其它不确定性因素干扰的问题，首先建立了单自由度的磁悬浮系统模型，提出一种基于积分滑模自抗扰的位置控制算法。算法利用扩张状态观测器对悬浮球的位置和未知干扰进行估计，再将估计的位置信息和干扰项用于控制的反馈和控制量的补偿。将积分滑模控制引入到非线性状态误差反馈控制律中，设计了积分滑模自抗扰控制器，并根据Lyapunov理论对控制系统的稳定性进行了证明。仿真结果表明，所设计的积分滑模ADRC控制器实现了对磁悬浮球的位置控制，对系统存在的内外扰动和不确定性具有较强的鲁棒性，同时能对设定位置信息进行跟踪，并有较好的动态特性。     

双框架磁悬浮控制力矩陀螺框架系统的扰动抑制

内外框架之间的耦合力矩和谐波减速器的非线性传输力矩是影响双框架磁悬浮控制力矩陀螺(DGMSCMG)框架系统精确角速度控制的主要因素,为了解决以上干扰问题,实现框架系统高精度角速率伺服控制提出了一种基于扰动观测器和自适应反步的框架系统复合解耦控制方法。通过扰动观测器来估计框架系统中的扰动,并结合自适应反步法获得控制律,其间将扰动估计误差当作未知参数设计了其自适应律,对扰动的两次处理使得框架系统干扰估计更加精确,同时可以保证估计参数的收敛性和整个框架系统的稳定性。仿真和实验结果表明,采用此复合控制方法,DGMSCMG框架系统扰动估计误差不超过框架系统实际扰动的3%,实际框架角速率跟踪参考指令角速率的精度达到99.2%。此复合解耦控制方法可以满足DGMSCMG框架系统抗干扰能力强、高精度角速率伺服控制的要求。     

四旋翼飞行器非线性轨迹跟踪控制

针对四旋翼飞行器在复杂飞行条件下速度不可测的轨迹跟踪控制问题,考虑系统存在外界未知干扰和模型参数不确定的情况,提出了一种基于扩张观测器的轨迹跟踪控制方法。该方法设计了积分型反步法跟踪控制器,以降低系统的稳态误差,并引入了状态扩张观测器,来估计系统未知速度信息,同时对干扰和模型参数不确定因素进行实时估计并给予补偿;最后,选取李雅普诺夫函数证明了该控制系统的稳定性。以Quanser公司的Qball2四旋翼飞行器为研究对象和飞行实验平台,对所设计的控制器进行验证。实验结果表明,本文所设计的基于扩张观测器的轨迹跟踪控制器,能够有效地估计轨迹跟踪控制过程中的未知速度信息,解决外界未知干扰和模型参数不确定的问题,增强对环境的适应能力,有效提高了飞行器对未知干扰的鲁棒性和轨迹跟踪控制的精确性。     

永磁同步电机调速系统的自抗扰控制

提出了一种利用反双曲正弦函数的一阶自抗扰控制器,以提高永磁同步电机正弦波脉宽调制(SPWM)调速系统的跟踪精度。研究了永磁同步电机转速环的数学模型;分别设计了一阶跟踪微分器和二阶扩张状态观测器,利用李雅普诺夫函数分析了它们的收敛性;构造了转速环的一阶自抗扰控制器,同时证明了一阶自抗扰控制误差系统的渐近稳定性。最后,将该新型一阶自抗扰控制器作为永磁同步电机的转速调节器,分析了自抗扰控制永磁同步电机的SPWM调速系统。仿真实验表明:自抗扰控制调速系统速度阶跃跟踪的调整时间约为0.15 s,稳态误差小于0.28 r/min;同一调速系统正弦响应的最大跟踪误差约为17 r/min。与PI控制调速系统相比,自抗扰控制永磁同步电机调速系统阶跃响应快速而平稳,无超调,稳态误差小;另外,系统正弦响应的跟踪性能好,跟踪误差小。     

线性自抗扰气缸位置伺服控制研究

针对气动伺服系统复杂的非线性问题,提出了一种线性自抗扰控制策略对气动伺服系统进行位置控制。利用线性自抗扰控制器不依赖于被控对象精确数学模型的特点,解决被控气动系统内外各种不确定性,设计了线性扩张状态观测器来估计和补偿系统的全部干扰,同时给出了线性状态误差反馈控制器来保证系统的闭环响应性能。证明了线性扩张状态观测器的收敛性和闭环系统的镇定性。应用线性自抗扰控制策略与PID控制策略在气缸伺服系统中进行实验、比较,实验结果表明所设计的线性自抗扰控制器具有良好的控制效果。     

采用滑模观测器的机械臂故障检测与控制优化

针对复合干扰影响下机械臂的故障检测和控制精度问题,提出了一种基于滑模观测器的故障检测和控制优化方法。首先建立了带有电机故障、模型误差和机械摩擦等复合干扰的机械臂系统故障模型,然后设计了滑模观测器来实现在复合干扰下对电机故障的准确检测,最后引入滑模观测器对电机故障程度进行估计,并设计了反步容错控制方法,从而实现了对机械臂系统的精确控制。仿真结果表明,基于滑模观测器的故障检测和控制优化方法能够快速、准确检测和估计电机故障,确保机械臂系统准确跟踪指令信号,角度跟踪误差范围仅为-0.2°～0.2°,能够准确估计出复合干扰的大小,估计误差范围仅为-0.1～0.1 (°)/s²,大大改善了对机械臂的控制效果。     

基于状态估计和干扰重构的磁悬浮系统控制设计

针对一类实际的磁悬浮系统,讨论了基于状态观测器和干扰估计的控制问题。首先基于线性化的磁悬浮系统,结合实际工程问题,分析干扰特征。其次,设计未知输入全维观测器,估计系统的内部状态并重构外部干扰。然后,基于观测器,针对实际控制需求提出反馈控制策略。最后对实际的模型系统进行仿真,验证控制率的有效性和正确性。     

基于压电智能结构状态估计误差补偿的自抗扰振动控制

压电智能结构的模型难以精确建立,且存在外界环境激励干扰和内部参数不确定等问题,从而影响闭环结构的振动控制性能。基于此,将结构的内部干扰和外界激励的影响归结为系统的集总干扰,并利用扩张状态观测器(Extended state observer,ESO)设计不依赖于模型的自抗扰振动控制器。然而当外界扰动激励变化时,扩张状态观测器对扰动和各阶状态的估计不可避免存在偏差,难以保证振动控制的效果。为克服二阶自抗扰策略在振动主动控制中的不足,提出一种基于压电智能板结构的状态估计误差补偿自抗扰振动控制方案。利用状态观测误差信息,对二阶自抗扰控制器进行补偿,从而减小ESO对扰动和各阶状态估计的压力,提高振动控制效果。利用dSPACE实时仿真系统,搭建四面固支压电智能板结构的振动主动试验平台。四种干扰激励的试验结果验证该方法的有效性、实用性和强抗干扰能力。     

永磁同步电机位置伺服系统改进变结构自抗扰控制

为进一步提高传统变结构自抗扰控制器的控制精度,增强永磁伺服驱动系统的抗干扰能力,提出一种改进变结构自抗扰控制策略。该方法在基于变结构原理设计的扩张状态观测器中引入位置、速度的观测误差以实现状态变量的无差估计,采用基于指数趋近律设计的非线性状态误差反馈控制律实现线性控制与非线性控制的平滑过渡,并在此基础上引入位置跟踪误差,提高伺服系统的跟踪性能。通过实验分析比较了改进变结构自抗扰控制与传统变结构自抗扰控制两种控制策略,结果显示改进控制策略较传统控制策略的位置跟踪误差减少了约30%。当负载突变时,传统控制策略的跟踪误差约为负载突变前最大跟踪误差的3.4倍,而改进变结构自抗扰控制策略仍能准确跟踪给定信号。     

四辊卷板机侧辊位移线性自抗扰控制

侧辊位移的精确控制对实现四辊卷板机高效加工至关重要,其核心问题是提高阀控非对称缸电液伺服系统的抗扰能力。由于电液伺服系统具有高度非线性和时变不确定性,传统非线性控制方法很难有效处理包含未知动态、外部扰动以及参数变化等的多源不确定扰动。提出一种四辊卷板机侧辊位移线性自抗扰控制方法。综合考虑各种不确定扰动因素的影响,设计了线性扩张状态观测器进行实时估计,采用状态误差反馈控制律给予主动补偿,并消除跟踪误差,证明了线性扩张状态观测器状态观测误差的收敛性和电液伺服系统的闭环稳定性。试验结果表明,所设计的线性自抗扰控制器能有效抑制电液伺服系统中多源不确定性扰动,实现侧辊位移的快速、精确轨迹跟踪。     

Disturbance observer-based backstepping sliding mode fault-tolerant control for the hydro-turbine governing system with dead-zone input

This paper investigates a backstepping sliding mode fault-tolerant tracking control problem for a hydro-turbine governing system with consideration of external disturbances, actuator faults and dead-zone input. To reduce the effects of the unknown random disturbances, the nonlinear disturbance observer is designed to identify and estimate the disturbance term. To drastically decrease the complexity of stability functions selection and controller design, the recursive processes of the backstepping technique are employed. Additionally, based on the nonlinear disturbance observer and the backstepping technique, the sliding mode fault-tolerant tracking control approach is developed for the hydro-turbine governing system (HTGS). The stability of HTGS is rigorously demonstrated through Lyapunov analysis which is capable to satisfy a tracking control performance. Finally, comprehensive simulation results are presented to illustrate the effectiveness and superiority of the proposed control scheme.     

Sliding mode output feedback control based on tracking error observer with disturbance estimator

For a class of systems who suffers from disturbances, an original output feedback sliding mode control method is presented based on a novel tracking error observer with disturbance estimator. The mathematical models of the systems are not required to be with high accuracy, and the disturbances can be vanishing or nonvanishing, while the bounds of disturbances are unknown. By constructing a differential sliding surface and employing reaching law approach, a sliding mode controller is obtained. On the basis of an extended disturbance estimator, a creative tracking error observer is produced. By using the observation of tracking error and the estimation of disturbance, the sliding mode controller is implementable. It is proved that the disturbance estimation error and tracking observation error are bounded, the sliding surface is reachable and the closed-loop system is robustly stable. The simulations on a servomotor positioning system and a five-degree-of-freedom active magnetic bearings system verify the effect of the proposed method.     

Anti-disturbance backstepping control for air-breathing hypersonic vehicles based on extended state observer

In this paper, we propose an anti-disturbance backstepping control approach with extended state observer (ESO) for tracking control of air-breathing hypersonic vehicles. Considering the large uncertainties, the external disturbances, and especially the lack of aerodynamic knowledge, several ESOs are introduced in the backstepping controller. With the total disturbance estimation ability of ESOs, almost no aerodynamic knowledge is needed for the controller design. Meanwhile, ESOs are also used to estimate the derivatives of the virtual control signals. The problem of “explosion of terms” is avoided. A key strategy of the controller is that each step of backstepping is activated successively. Consequently, the closed-loop system has time-scale structure. Rigorous stability proof can be obtained. At last, compared simulation results verify the superior tracking performance of the proposed controller.     

Robust adaptive integral backstepping control for opto-electronic tracking system based on modified LuGre friction model

This paper presents a robust adaptive integral backstepping control strategy with friction compensation for realizing accurate and stable control of opto-electronic tracking system in the presence of nonlinear friction and external disturbance. With the help of integral control term to decrease the steady-state error of the system and combining robust adaptive control approach with the backstepping design method, a novel control method is constructed. Nonlinear modified LuGre observer is designed to estimate friction behavior. Robust adaptive integral backstepping control strategy is developed to compensate the changes in friction behavior and external disturbance of the servo system. The stability of the opto-electronic tracking system is proved by Lyapunov criterion. The performance of robust adaptive integral backstepping controller is verified by the opto-electronic tracking system with modified LuGre model in simulation and practical experiments. Compared to the adaptive integral backstepping sliding mode control method, the root mean square of angle error is reduced by 26.6% when the proposed control method is used. The experiment results demonstrate the effectiveness and robustness of the proposed strategy.     

导引头稳定平台的扰动补偿及改进滑模控制

为提高导引头稳定平台抗扰性,提出了一种导引头稳定平台的扰动补偿及改进滑模控制策略。首先根据扰动特点将扰动分为摩擦力矩和"剩余扰动"两部分,基于Stribeck摩擦模型辨识摩擦参数,并进行摩擦力矩补偿;采用扩张高增益观测器对"剩余扰动"进行估计,并给出了扩张高增益观测器的收敛条件。然后设计了改进滑模控制器作为稳定回路的控制器实现伺服控制,采用Lyapunov函数证明其稳定性。最后,搭建测试系统分别进行了稳定平台性能测试和导引头性能测试,用于验证跟踪和抗扰效果。实验结果表明,跟踪1(°)/s的梯形波时,提出的控制器有效地补偿了摩擦,同时稳态精度提高了0.032 8(°)/s;给定三轴转台典型幅值和频率扰动下,采用提出的控制器时系统隔离度至少提高了0.57%。表明提出的控制器改善了系统抗扰性。     

Improved adaptive integral line-of-sight guidance law and adaptive fuzzy path following control for underactuated MSV

This paper presents an adaptive fuzzy path following control law based on an improved adaptive integral line-of-sight (IAILOS) guidance law for the underactuated marine surface vessel (MSV) exposed to the time-varying ocean currents and time-varying sideslip angle. Initially, the IAILOS guidance law is proposed which can not only calculate the desired yaw angle but also estimate the time-varying ocean currents and time-varying sideslip angle simultaneously. Furthermore, the adaptive fuzzy path following control law is established by combining with the estimator to cope with the MSV’s attitude tracking control and velocity tracing control problem via backstepping technique. Specifically, the dynamic uncertainties and unknown environment disturbances are compensated by the fuzzy logic system with fuzzy updating law based on estimation error rather than tracking error. Additionally, two high-order tracking differentiators (TDs) are designed to construct derivatives of virtual control vector and reduce computational complexity inherent in backstepping method. It is proved that the proposed adaptive fuzzy path following control law can drive the vessel to track the desired path and tracking error can converge to an arbitrarily small compact set, while guaranteeing all signals in the closed-loop control system are uniformly ultimately bounded. Finally, simulation results and comparisons are carried out to demonstrate the effectiveness of the proposed control approach.     

基于遗传算法的可控励磁直线磁悬浮同步电动机自抗扰控制

对可控励磁直线磁悬浮电动机控制系统提出基于遗传算法的自抗扰控制策略。根据可控励磁直线磁悬浮电动机的运行机理,建立其数学模型。设计反馈跟踪微分器、扩张状态观测器、非线性反馈控制律,对传统函数fal进行改进,应用到控制器中。实现对给定信号的跟踪,并将系统耦合量和外界扰动作为系统的“总扰动”,并对总扰动进行观测与补偿。针对控制器中存在多个参数难以整定的问题,采用遗传算法对控制器参数进行寻优。对控制系统进行仿真研究,结果表明,基于遗传算法的自抗扰控制系统具有对参考信号良好的跟踪性能,以及对干扰信号的抑制能力。