基于自抗扰控制器的柴油机转速控制

当柴油机作为转速控制系统的被控对象时,是一个多变量强耦合非线性系统,采用经典PID控制难以得到满意的控制效果,但是自抗扰控制理论设计的控制器,能够提高调速系统的精度、准确度和柴油机的抗扰动能力。本文主要介绍了自抗扰控制技术(Active Disturbance Rejection Control Technique,ADRC),并且根据自抗扰控制技术设计了切实可行的自抗扰控制器,通过与PID控制的仿真比较,显示出自抗扰控制器对转速控制的较小超调量和较短调节时间,反应出良好的动态性能和稳态特性。     

MPPT控制器的线性自抗扰控制

光伏并网发电系统极易受到外部环境的影响,并且抗干扰能力较差。环境改变、电网不稳定或参数难以确定等原因都会对电能输出效率和其工作效率造成很大影响。针对光伏系统的这些特性,提出一种线性自抗扰控制器对电流进行控制。采用扩张状态观测器对扰动进行补偿,从而快速消除扰动,达到平和状态,使系统对扰动有着很好的适应能力。为了验证该算法的有效性,通过Matlab/Simulink仿真表明,加入自抗扰控制器能够明显提高光伏并网系统的跟踪速度和控制性能,降低了功率震荡,在外界环境突变的情况下,也能够达到很好的效果。     

Robust disturbance rejection for improved dynamic stiffness of a magnetic suspension stage

Magnetic suspension is an attractive approach in realizing ultraprecision multiple-degree-of-freedom actuation for precision engineering. However, improving the dynamic stiffness of magnetic-suspension systems is an engineering challenge due to their noncontact nature. Two disturbance rejection algorithms that improve the dynamic stiffness of a magnetic-suspension stage (MSS) are presented in this paper. For rejection of narrow-band disturbances with unknown frequencies, an internal model principle-based control together with a frequency estimation algorithm based on adaptive-notch filtering is proposed. A chattering-free sliding mode (CFSM) disturbance rejection algorithm is developed in order to reject wide-band disturbances. The CFSM disturbance rejection scheme includes a continuous approximation of the switching function to avoid chattering, an integral control term to reduce the switching magnitude, and a derivative control term to elevate the bandwidth of disturbance rejection. Experimental results verified that the disturbances can be effectively rejected with the two developed algorithms. Consequently, the dynamic stiffness of the MSS is greatly improved.     

采用自抗扰控制的三电机同步协调系统

自抗扰控制器自问世以来被用于多种应用场合,但其有着参数多,难整定的弊端,文中依据RBF神经网络结构简单、逼近能力强的优势提出了基于RBF神经网络的复合自抗扰参数调节器,利用RBF神经网络获得自抗扰参数的在线调整信息,且将其应用于三电机同步系统,经过实验验证,该调节器能实时调节自抗扰参数且能改善控制性能,具有实用性。     

基于蚁群算法优化自抗扰控制器的机器人控制

研究基于线性自抗扰控制器的机器人无标定手眼协调控制,搭建了控制系统的Simulink模型,为解决控制器的参数整定问题,选择并编写了蚁群算法的MATLAB程序,通过代码与模型相结合的仿真实验,实现了六自由度机器人对运动目标的跟踪控制,仿真结果验证了算法的可行性和有效性。     

基于自抗扰控制器的电动缸载荷系统研究

针对航空飞行器关键部件疲劳性能评价试验系统准确模拟极端条件下载荷谱的要求,在电动缸载荷系统中通过设计自抗扰控制器(ADRC)估计系统的状态信息和扰动信息,解决在极端条件、无扰动数学模型条件下对规定载荷谱的精确控制问题;解决因极端条件变化带来的扰动和系统不确定性导致的系统稳定性问题。通过仿真试验,电动缸加载三阶系统的力闭环自抗扰控制系统在外部条件相同的条件下,自抗扰控制器的控制效果优于PID控制,响应速度更快,抗系统扰动能力更强,满足伺服电动缸加载控制系统加载精度高、试验评价系统载荷谱重复及一致性精度高的要求。     

基于PSODE混合算法优化的自抗扰控制器设计

自抗扰控制器在强干扰系统和大时滞条件下的控制效果不好,主要影响因素是静态参数机制,为此设计了一种基于差分进化算法和粒子群算法联合优化的自抗扰控制器。使用粒子群算法对自抗扰控制器中抗扩张状态观测器的动量估计系数进行在线优化,使用误差阈值触发启动的伺服机制提高动态优化的计算速度,并使用差分进化算法的变异、交叉和选择算子提高粒子群算法的多样性,防止陷入局部最优值以提高算法的收敛精度。在热工时滞系统中的实验结果表明,改进后的算法在强干扰系统和大时滞条件下的控制效果得到提高,抗干扰性能和鲁棒性得到提高。     

弹性体导弹鲁棒控制器设计

基于欧拉-自由梁模型理论得出弹性体导弹横向振动模型,用模态分析方法对模型进行求解。结合弹性导弹的刚体运动方程,得到包括横向振动和刚体运动的增广模型,对该模型进行鲁棒控制器设计,仿真结果表明,所设计的鲁棒控制器能够在保证弹体运动姿态控制的同时抑制横向振动。     

基于自抗扰控制器和坐标变换的BSRM转子不平衡振动补偿控制

磁悬浮开关磁阻电机(BSRM)在运行时由于转子的不平衡振动会使系统的稳定性和安全性受到严重影响,在介绍了BSRM转子悬浮力产生原理的基础上,推导出转子的动力学方程。给出BSRM悬浮力解耦控制模型,利用自抗扰控制器中TD滤波器优越的低通滤波特性,基于坐标变换的思想,设计了BSRM转子的不平衡振动补偿策略,对BSRM转子的不平衡振动进行实时动态补偿。仿真结果验证了该策略的有效性,设计的基于自抗扰控制器和坐标变换的方法成功实现了对BSRM转子不平衡振动的补偿,而且基本消除了转子的不平衡振动对BSRM系统的影响,控制系统性能优良。     

Robust speed control algorithm with disturbance observer for uncertain PMSM

This article suggests a robust cascade speed control algorithm for a permanent magnet synchronous motor (PMSM) combining the classical feedback linearising (FL) method and the disturbance observers (DOBs) without the integrators. The contributions of this method are twofold. The first one is to provide the simple DOBs for not only guaranteeing the closed-loop performance recovery property but also removing the steady-state errors without the integrators with respect to the tracking errors. The second one is to prove that the inner and outer loops are stabilised by the proposed cascade-type controller, simultaneously. The simulation and experimental results reveal that the proposed method maintains the speed tracking performance to be satisfactory for a wide operating region with the fixed control gain despite a plant-model mismatch where a 3-kW interior PMSM is utilised.     

Sliding-mode motion controller with adaptive fuzzy disturbance estimation

This paper proposes a motion control scheme which belongs to the class of the control schemes known as sliding-mode control with disturbance estimation. A novel adaptive fuzzy disturbance estimator works as an estimator of a major part of robot dynamics. The adaptation algorithm is derived by using the Lyapunov stability theory and provides global asymptotic stability of the state errors, resulting in the sliding-mode regime. The structure of the disturbance estimator is optimized by the introduction of three fuzzy logic subsystems, based on the physical properties of the robot mechanism. This also significantly lowers the computational burden and enables real-time implementation. Performance of the proposed controller scheme, as well as some practical design aspects, are demonstrated by the control of a direct-drive robot.     

Robust motion controller design for high-accuracy positioningsystems

This paper presents a controller structure for robust high speed and accuracy motion control systems. The overall control system consists of four elements: a friction compensator; a disturbance observer for the velocity loop; a position loop feedback controller; and a feedforward controller acting on the desired output. A parameter estimation technique coupled with friction compensation is used as the first step in the design process. The friction compensator is based on the experimental friction model and it compensates for unmodeled nonlinear friction. Stability of the closed-loop is provided by the feedback controller. The robust feedback controller based on the disturbance observer compensates for external disturbances and plant uncertainties. Precise tracking is achieved by the zero phase error tracking controller. Experimental results are presented to demonstrate performance improvement obtained by each element in the proposed robust control structure     

基于最小二乘法惯量辨识的永磁同步电机速度环自抗扰控制器设计

在永磁同步电机速度环线性自抗扰控制器中,扩张状态观测器是保证调速系统抗干扰能力的核心模块。因此扩张观测器对存在调速系统中的内外部扰动的观测性能,直接决定了系统的调速性能。针对在受到变惯量转矩干扰时,扩张状态观测器对扰动观测的动态性能下降而导致的调速系统控制性能恶化的问题,提出采用带遗忘因子的递推最小二乘法对调速系统的转动惯量在线辨识,以保证扩张观测器对系统扰动的动态观测性能。     

An adaptive fuzzy sliding-mode controller for servomechanismdisturbance rejection

A two-level spring-lumped mass servomechanism system was constructed for disturbance rejection control investigation. This dynamic absorber is similar to a model of the serial-type vehicle suspension system. The lower level is actuated by two DC servo motors, to provide the specified internal and external disturbances to the vibration control system. The upper level has another DC servo motor to control the main body balancing position. In order to tackle the system's nonlinear and time-varying characteristics, an adaptive fuzzy sliding-mode controller is proposed to suppress the main mass position variation due to external disturbance. This intelligent control strategy combines an adaptive rule with fuzzy and sliding-mode control technologies. It has online learning ability for responding to the system's time-varying and nonlinear uncertainty behaviors, and for adjusting the control rules and parameters. Only seven rules are required for this control system, and its control rules can be established and modified continuously by online learning. The experimental results show that this intelligent control approach effectively suppresses the vibration amplitude of the body, with respect to the external disturbance     

Robust independent joint controller design for industrial robotmanipulators

A novel approach is presented for the design of simple robust independent joint controllers for industrial robot manipulators. In this approach, each joint actuator is treated as a simple inertial system plus a disturbance torque representing all the unmodeled dynamics. By a very simple algorithm, the disturbance is instantly estimated and rejected, thus allowing a simple proportional-derivative (PD) control scheme to be used. The stability of the proposed control law is analyzed. Experimental evaluations of the controller on a microcomputer-controlled PUMA 560 arm were performed. It is shown that the control scheme is simple and practical and that it can be easily implemented on an industrial manipulator presently in use     

Robust current controller for three-phase inverter usingfinite-state automaton

A novel feedback current controller for a three-phase load driven by a power inverter is proposed. The main design specifications are robustness to load electrical parameters, fast dynamical response, reduced switching frequency, and simple hardware implementation. To meet previous specifications a multi-variable hysteresis type controller is proposed, designed as a finite-state automaton and implemented with a programmable logic device. After a general introduction, system analysis is performed, control targets are specified, and the proposed control strategy is presented and discussed. Further, actual controller architecture, based on simple analog-logic hardware, is shown and experimental results are presented using an induction motor as the inverter load. However, this does not limit the wider applicability of the proposed controller that is suitable for different types of three-phase AC loads     

Soft eigenvalue assignment with limited disturbance feedforward and state controller norm

The method of softly assigning eigenvalues is attractive for design problems where constraining the control effort and disturbance feedforward is more important than following the exact pole location.     

Robust controller design for a series resonant converter viaduty-cycle control

Robust controller design for a series resonant power converter is presented when load variation and unregulated input line voltage perturbation are taken into consideration. The perturbation of unregulated line voltage is treated as an exogenous disturbance and the load variation as a structured uncertainty of the converter. An averaged model, including disturbance and model uncertainty, is then derived. Two kinds of μ synthesis-D-K and μ-K iteration schemes-are applied to design robust controllers to diminish the susceptibility of the regulated voltage to perturbations of load variation and unregulated line voltage. In addition, a classical controller is also designed for performance comparison. Finally, simulations and experimental results are presented to verify the feasibility of the robust control theory     

Robust cerebellar model articulation controller design for unknown nonlinear systems

In this study, a robust cerebellar model articulation controller (RCMAC) is designed for unknown nonlinear systems. The RCMAC is comprised of a cerebellar model articulation controller (CMAC) and a robust controller. The CMAC is utilized to approximate an ideal controller, and the weights of the CMAC are on-line tuned by the derived adaptive law based on the Lyapunov sense. The robust controller is designed to guarantee a specified H/sup /spl infin// robust tracking performance. In the RCMAC design, the sliding-mode control method is utilized to derive the control law, so that the developed control scheme has more robustness against the uncertainty and approximation error. Finally, the proposed RCMAC is applied to control a chaotic circuit. Simulation results demonstrate that the proposed control scheme can achieve favorable tracking performance with unknown the controlled system dynamics.     

Robust controller design for a parallel resonant converter usingμ-synthesis

DC-to-DC resonant power converters have been the subject of much attention recently. These power converters have the potential to provide high-performance conversion without some of the problems associated with classical pulse-width modulation (PWM)-based converters, thus allowing for smaller, lighter power supplies. However, in order to achieve this, a suitable control circuit, capable of maintaining the desired output voltage under different operating conditions, is required. In the past, small-signal models obtained around the nominal operating points were used to design controllers that attempted to keep the output voltage constant in the presence of input perturbations. However, these controllers did not take into account either load or components variations, and thus could lead to instability in the face of component or load changes. Moreover, the prediction of the frequency range for stability was done a posteriori, either experimentally or by a trial-and-error approach. In this paper, the authors use μ-synthesis to design a robust controller for a conventional parallel resonant power converter. In addition to guaranteeing stability for a wide range of load conditions, the proposed controller rejects disturbances at the power converter input while keeping the control input and the settling time within values compatible with a practical implementation. These results are validated by means of detailed nonlinear circuit simulations obtained using PSpice