Performance recovery output voltage control algorithm for AC/DC converter

This article proposes a proportional-type cascade output voltage control algorithm equipped with disturbance observers for a three-phase AC/DC converter considering a model-plant mismatch. The advantages of the proposed method are grouped into two. First, a simple first-order disturbance observer is devised for both inner and outer-loops, not only to recover the target closed-loop performance, but also to eliminate steady-state offset errors. Second, it is thoroughly verified that the entire closed-loop system driven by the proposed proportional-type cascade controller is stable. The efficacy of the proposed method is experimentally investigated using a 3 ? kW AC/DC converter.     

Optimal control of non-minimum phase integrating processes with time delay using disturbance observer-based control scheme

A systematical design method of optimal control for non-minimum phase integrating processes with time delay using disturbance observer-based (DOB) control scheme is presented. All stabilising controllers and the filter of DOBs for integrating plants are developed. Then the optimal set-point tracking controller and the optimal filter of DOB are systematically derived by minimising the H₂ norm performance specifications. The proposed design method has three main advantages. First, the design procedure is systematical and simple. Specified weight functions are chosen for step inputs and inputs similar to steps. The designed set-point tracking controller and the filter of DOB are given in analytical forms. Second, the designed set-point tracking controller and the filter of the DOB are optimal. They are derived from minimising the performance indexes of set-point tracking and input load disturbance rejection (ILDR). Finally, the set-point tracking performance specification and ILDR specification can be quantitatively achieved by conveniently tuning the adjustable parameters. Numerical simulations are given to illustrate the effectiveness of the proposed method.     

参数不确定机器人分散鲁棒跟踪控制

提出了一种新的参数不确定机器人分散控制器设计方法．首先将关节子系统的动力学模型分解为人工标称模型和非线性时变不确定模型两部分；然后分别设计相应的标称控制器和鲁棒补偿器．标称控制器使得标称闭环系统具有理想的跟踪性能；鲁棒补偿器可以抑制参数不确定和关节间非线性耦合等因素的影响，实现鲁棒跟踪．所设计的控制器只需要局部关节的位置反馈，具有易于实现和可在线调整的优点．仿真结果说明了该方法的有效性．     

Disturbance observer based backstepping for position control of electro-hydraulic systems

We propose a disturbance observer (DOB) based backstepping control which improves the position tracking performance in the presence of both friction and load force in an electro-hydraulic systems. The DOB is designed to estimate the disturbance including friction and load force, while avoiding amplification of the measurement noise. We use an auxiliary state variable to avoid the use of the derivative of the measured signal. This results in the avoidance of the amplification of the measurement noise. For position tracking with compensation of disturbances, a backstepping controller is design. The backstepping controller guarantees the ultimate boundedness of the tracking error in the presence of both friction and load force. The closed-loop stability is proven using Lyapunov’s theory.

     

基于动态递归模糊神经网络的自适应电液位置跟踪系统

提出了动态递归模糊神经网络(DRFNN)以在线估计电液位置跟踪系统中包括非线性、参数不确定性、负载干扰等在内的未知动态非线性函数,基于lyapunov稳定性理论推导出DRFNN可调参数和估计误差的界的自适应律,并构造出稳定的自适应控制器.实验结果表明:基于DRFNN的自适应控制器可使电液位置跟踪系统具有较强的鲁棒性和满意的跟踪性能.     

基于自适应模糊控制器和非线性扰动观测器的永磁直线同步电机反馈线性化控制

由于永磁直线同步电机(PMLSM)伺服系统应用于一些高精密场合,因此克服系统存在的负载扰动、参数变化等不确定性影响是提高系统性能的关键.针对不确定性问题,采用一种基于自适应模糊控制器(AFC)和非线性扰动观测器(NDO)的反馈线性化控制方法.首先设计反馈线性化控制器(FLC)实现系统的线性化,便于位置跟踪;其次采用NDO估计并补偿系统的不确定性,提高跟踪精度.但在实际运行过程中观测器增益较难选取,极易产生较大的观测误差,为此,采用AFC方法逼近NDO的观测误差,通过自适应律动态调整模糊规则,改善模糊控制器的学习能力,增强系统的鲁棒性,并用李雅普诺夫定理保证系统闭环稳定性.实验结果表明,与基于DOB和NDO的反馈线性化位置控制相比,该方法能够明显提高系统的跟踪性和鲁棒性.     

Multivariable sliding mode backstepping controller design for quadrotor UAV based on disturbance observer

This paper deals with the tracking control problem of quadrotor unmanned aerial vehicles (QUAVs) with external disturbances. First, because the QUAV model contains two non-integrity constraints, the dynamic model of the QUAV is decomposed into two subsystems which are independently controlled, so as to reduce controller design complexity. Secondly, the nonlinear disturbance observer (DOB) technique is integrated into a backstepping control method to design the controller for the first subsystem, in which a DOB is applied to estimate the lumped uncertainty. Based on the double power reaching law and the DOB, a multivariable sliding mode control (MSMC) scheme is developed for the second subsystem. Thirdly, based on Lyapunov theory, the closed-loop system is proved to be asymptotically stable. Finally, our comparative simulation results demonstrate that the presented control scheme behaves better in terms of tracking performance than the adaptive backstepping control (ABC) approach.     

Linear Model‐based Feedforward Control for Improving Tracking‐performance of Linear Motors

The main purpose of this article is to propose a linear model‐based approach for improving the tracking performance of linear motors. In particular, P‐ and PI‐controllers, augmented with a linear‐model‐based feedforward controller and disturbance observer (DOB), were utilized in this research. Experimental results show that the feedforward controller can substantially reduce the phase‐delay problem resulting from the limitation of closed‐loop bandwidth. In addition, the DOB can reject nonlinear behaviors to keep a motor‐system close to our nominal linear model. Compared with the results of using P‐ and PI‐controllers only, tracking errors were reduced from 4.44% to 0.67% of the desired trajectory. Therefore, the proposed method provides a solution for improving the tracking performance of linear motors.     

具有不确定参数永磁同步电动机的自适应反步控制

针对永磁同步电动机系统的非线性耦合特性以及参数的不确定性,采用自适应反步控制实现永磁同步电动机的非线性控制,在补偿参数不确定性影响,提高系统的抗干扰能力的同时,实现了永磁同步电动机的高性能全局渐近稳定速度跟踪控制．采用二阶滤波环节平滑速度指令,实现了理想无超调的快速速度跟踪控制．仿真结果证明了所提出方法的有效性．     

Analysis and design of single-phase power factor corrector with genetic algorithm and adaptive neuro-fuzzy-based sliding mode controller using DC–DC SEPIC

This paper proposes a methodology for single-phase power factor correction with DC–DC single-ended primary inductance converter (SEPIC) using cascade control strategy which comprises of genetic algorithm-based outer PI controller and an inner current controller which uses an adaptive neuro-fuzzy inference system-based sliding mode controller. DC–DC SEPIC is a fourth-order converter, and in order to reduce the complexity in controller design, reduced-order model of the original higher-order system is obtained by using Type-I Hankel matrix method. The performance of the proposed system is analysed using MATLAB/Simulink-based simulation studies. In order to ensure the robustness of the proposed controller, the performance parameters such as percentage total harmonic distortion, power factor, % voltage regulation, and % efficiency are analysed. From the simulation results, it is inferred that the proposed method provides efficient tracking of output voltage and effective source current shaping for load, line, and set point variations.

     

Position Control of a Flexible Manipulator Using a New Nonlinear Self-Tuning PID Controller

In this paper, a new nonlinear self-tuning PID controller(NSPIDC) is proposed to control the joint position and link deflection of a flexible-link manipulator(FLM) while it is subjected to carry different payloads. Since, payload is a critical parameter of the FLM whose variation greatly influences the controller performance. The proposed controller guarantees stability under change in payload by attenuating the non-modeled higher order dynamics using a new nonlinear autoregressive moving average with exogenous-input(NARMAX) model of the FLM. The parameters of the FLM are identified on-line using recursive least square(RLS) algorithm and using minimum variance control(MVC) laws the control parameters are updated in real-time. This proposed NSPID controller has been implemented in real-time on an experimental set-up. The joint tracking and link deflection performances of the proposed adaptive controller are compared with that of a popular direct adaptive controller(DAC). From the obtained results, it is confirmed that the proposed controller exhibits improved performance over the DAC both in terms of accurate position tracking and quick damping of link deflections when subjected to variable payloads.     

方波型无刷直流电机的电压跟踪控制策略

针对方波型无刷直流电机控制系统的电压跟踪控制问题,利用非线性系统理论获得一种关于角速度的非线性降阶观测器,以及一种简单、易于应用的非线性位置反馈控制器.理论上,论证了在所设计的控制器作用下,该受控系统能实现全局一致毕竟有界.数值实验显示该控制器具有很好的普适性,以及此系统能快速跟踪额定电压范围内的参考电压,转矩脉动能被有效抑制.     

Switched adaptive tracking control of robot manipulators with friction and changing loads

A switched adaptive controller is designed for robot manipulators with friction and changing loads. The nonlinear friction is depicted by a nonlinear friction model, and a switched nonlinear system is used to model the parameter jump caused by load change. Hyperstability theory is used in the designing procedure, which provides more options for adaptive laws than Lyapunov theory. In the presence of friction and changing loads, asymptotic tracking is achieved under arbitrary switching, which is not able to accomplish by a non-switched adaptive controller. The proposed method is validated by a simulation of a 2 degree of freedom manipulator.     

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.     

基于滑模干扰观测器的直流电机系统复合控制

随着直流电机设备在农林业、制造工业和航空航天领域应用得越来越广泛,实际工程对其性能的要求也越来越高。针对直流电机系统控制中面临的建模误差、参数摄动以及摩擦力矩干扰问题,提出一种滑模干扰观测器(SMDOB,sliding mode disturbance observer),其输出可作为控制系统中干扰补偿的设计依据。基于所设计的内环SMDOB,并利用不变性原理,提出一种外环复合控制方案,从而实现直流电机系统的位置跟踪能力。仿真结果表明,相比传统的控制方案,该控制方案下电机系统的跟踪性能更好,对建模误差、参数摄动以及摩擦力矩干扰的鲁棒性更高。而且,该控制方案的结构较为简单,易于工程实现。     

基于微分观测器的飞行模拟转台伺服系统非线性控制

飞行模拟器转台伺服系统是导弹飞行的重要模拟设备,用于获取实验数据。针对飞行模拟转台伺服系统在跟踪控制过程中存在参数不确定性、非线性摩擦等不确定性问题,提出了一种基于微分观测器的飞行模拟转台伺服系统非线性控制方法;考虑系统在跟踪控制过程中存在不确定性问题,设计了微分观测器来估计复合不确定扰动;设计非线性控制器来控制飞行模拟转台伺服系统,使得系统可以收敛到期望位置转角信号;通过李雅普洛夫稳定性证明控制器作用在系统条件下的鲁棒性;通过MATLAB/Simulink仿真试验平台验证了文中提出的控制策略能够使系统有效跟踪期望位置转角,具有一定工程应用价值;     

基于三阶干扰观测器的三轴MEMS陀螺稳定控制

微机电系统(Micro-Electro-Mechanic System,MEMS)陀螺仪是一种新兴的惯性传感器,然而在加工制造和现场应用过程中,MEMS陀螺不可避免地会受到外界干扰的影响,降低角速率检测精度。针对无法等效到输入通道且频率成分复杂的不匹配干扰,提出一种基于三阶干扰观测器的全局滑模控制方法。利用三阶干扰观测器估计频率成分复杂的不匹配干扰,在此基础上提出一种新的非线性滑模面实现滑动模态的全局鲁棒性,滑模面的可达性由指数趋近律保证。仿真结果表明了该基于干扰观测器的全局滑模控制器能够有效抑制不匹配成分,干扰估计误差由0.58降至0.18,且陀螺三轴位置响应呈现更小的超调。     

基于扩张状态观测器的 连铸结晶器振动位移系统自适应滑模控制

针对伺服电机驱动的连铸结晶器振动位移系统中存在时变负载转矩、参数不确定性等问题,本文提出了一种基于扩张状态观测器(extended state observer, ESO)的自适应非奇异终端滑模(nonsingular terminal sliding mode,NTSM)控制方法.首先,设计ESO对系统存在的综合扰动和不可测状态进行估计.然后,采用分层设计的方法,分别对位移跟踪子系统和电流环子系统设计基于ESO的自适应NTSM控制器和滑模控制器.为削弱ESO估计误差对跟踪精度的影响,在NTSM控制器中引入了自适应增益.可以证明,所设计的控制器能够保证闭环系统所有信号有界,系统状态可渐近收敛到原点附近的小邻域内.最后,仿真结果验证了所提出控制方法的有效性.     

Dynamic evolution control for synchronous buck DC–DC converter: Theory,model and simulation

This paper proposes a new control technique for synchronous buck DC–DC converter. Theory, design and implementation of the proposed control technique are provided. A new approach for converter controller synthesis based on dynamic evolution control theory is presented. In order to synthesize the converter controller, this method uses a simple analysis of nonlinear equation models of the converter. The synthesis process is simple and requires a quite low bandwidth for the controller. Therefore, this control method is suitable for digital control implementation. As an illustrative example, the synthesis of synchronous buck DC–DC converter controller is discussed in detail. The model of the synchronous buck DC–DC converter system was implemented using SimPowerSystems toolbox of MATLAB-SIMULINK. Performance of the proposed dynamic evolution control under step load change and step input voltage condition was investigated. Simulation results confirm that the proposed control method is superior to traditional PI based controller because of fast transient response and good disturbance rejection.     

基于单个神经元的机器人自适应控制

本文提出了针对多关节机器人采用单个神经元的独立关节控制方案，控制器由ＰＩＤ反馈和ＰＤＤ＾２前馈补偿构成，关节之间的静态和动态耦合通过单个神经元控制器前馈补偿，对一个二自由度机器人采用这种控制策略进行仿真，仿真结果表明该控制器在有非线性耦合，非线性摩擦，负载变化，模型参数变化时仍能跟踪期望轨迹。