直线电机进给系统轮廓误差预测控制方法及仿真研究

为提高永磁同步直线电机驱动的进给系统轮廓轨迹跟踪精度和系统的动态性能，提出了一种显式模型预测交叉耦合控制方法（Explicit model predictive cross-coupled control, EMPCCC）。该方法结合显式预测控制原理与交叉耦合控制思想，对单轴电流和速度信号进行多步预测，将轮廓误差作为反馈量来修正预测控制的给定轨迹，达到轮廓误差预测控制的目的。基于MATLAB/Simulink搭建仿真模型，结果表明，所提EMPCCC方法能快速实现不同转速波形的无超调跟踪控制，且可以实时估计并补偿轮廓误差，提升不同轨迹的轮廓精度。     

船用天然气发动机电子节气门自适应高阶滑模控制

针对船用天然气发动机电子节气门非线性控制问题以及高阶滑模控制存在的边界难以估计问题,提出了一种基于高阶 滑模理论的节气门自适应控制算法,设计了基于系统相平面轨迹收敛过程的自适应策略,为了增加控制算法的实用性,在自适 应策略的基础上设计了检测区域,通过判断系统状态与该区域的相对位置双向调节控制增益,以防止增益过大而导致控制精度 降低、控制能量浪费的问题;同时,采用鲁棒微分估计器,对不可观测量进行估计;最后,设计 3 种测试方案,将该算法与传统高 阶滑模算法进行实验对比。 实验结果表明:在阶跃信号下,该算法使系统响应速度提高 35% ,稳态误差均方根减小 37. 5% ;在正 弦信号下,系统最大稳态误差和稳态误差均方根分别减小 30% 和 22% 。     

Sliding mode control with third-order contour error estimation for free-form contour following

To reduce the contour error in contour-following tasks, the most common method is to design a contour controller based on the contour error model. Therefore, how to estimate the contour error in real-time and with high accuracy plays an important role in contour-following control. It is difficult to guarantee real-time performance, high estimation accuracy and strong robustness against arbitrary trajectories at the same time. In this paper, a contour error estimation method based on the third-order osculating helix is proposed. The osculating helix can fully consider the geometric characteristics of the interpolation trajectory and is closer to the desired interpolation trajectory. On this basis, PD-type tracking error sliding mode surface and PD-type contour error sliding mode surface are redesigned to fully take into account the regulating effect of the velocity tracking error and velocity contour error. Experimental results demonstrate the effectiveness of the proposed contour control approach.     

High accuracy motion control of linear motor drive wire-EDM machines

This paper aims to develop and investigate a permanent magnet linear-motor-driven table system for a wire-EDM machine. A dynamic model and system identification of `the linear motor system have been derived and analyzed. The linear motor drive system has nonlinear and time-varying behaviors because of the effect of irregular friction of the sliding surface and cogging force. Therefore, a conventional digital controller may not suffice to provide a high contouring accuracy as well as adequate disturbance rejection and parameter variation robustness. An indirect adaptive controller (IAC), combined with a neural network-based feedforward controller (NNBFC) is proposed to improve the contouring performance of the linear motor system. Experimental results not only indicate that the proposed control scheme can achieve a high contouring accuracy of ± 0.3 μm, they also demonstrate that the developed linear motor drive wire-EDM machine can meet the requirement for micro machining. The maximum contour error of circular trajectory at a feed-rate of 0.1 mm/min was significantly reduced from 8 μm to 0.5 μm in comparison with proportional-integral-derivative (PID) controller.     

电液振动台正弦运动控制方法

为提高正弦振动模拟试验的控制精度,针对电液振动台受不确定干扰力影响的问题,以单轴电液振动台作为控制对象,使用滑模控制抑制不确定干扰力对正弦振动控制精度的影响,同时加入最小控制综合(Minimal Control Synthesis,MCS)算法补偿系统在考虑伺服阀动态后滑模控制器的不足,结合三状态控制实现加速度控制。通过MATLAB/Simulink建立控制策略仿真模型进行仿真分析。结果表明:该复合控制策略可以有效抑制干扰力影响并且提高正弦振动控制精度。     

平面冗余驱动并联机构自适应滑模同步控制

基于Kane方程,建立了平面二自由度冗余驱动并联机构的动力学模型。基于轨迹轮廓误差,定义了机构的同步误差及滑模面,将动力学方程线性化,设计了自适应滑模同步控制器并对机构进行了稳定性分析。通过MATLAB仿真计算,并与计算力矩法进行比较发现,自适应滑模同步控制法优于计算力矩法,能够很好地实现轨迹跟踪。     

Anti-disturbance speed control of low-speed high-torque PMSM based on second-order non-singular terminal sliding mode load observer

This paper presents an anti-disturbance speed control of low-speed high-torque permanent magnet synchronous motor (PMSM) based on the second-order non-singular terminal sliding mode load observer. According to the coordinate transformation theory, the mathematical model of PMSM is established. Subsequently, the second-order non-singular terminal sliding mode observer (SNTSMO) is designed to observe the changes of load disturbance in the PMSM system. The SNTSMO combines the advantages of both high-order sliding mode and non-singular terminal sliding mode to achieve the fast convergence and no chattering. Next, the sliding mode controller (SMC) is designed to achieve speed loop control of PMSM. Then, the anti-disturbance compound speed controller is established on the basis of SMC and SNTSMO, wherein the feed-forward compensation is used to reduce the disturbance from the load. Finally, the numerical simulations and experiments are presented according to the schematic diagram of the designed compound speed controller of PMSM. The results demonstrate that the designed SNTSMO can precisely estimate the load disturbance and suppress the effects of buffeting in the traditional sliding mode observer (SMO). Additionally, the designed compound speed controller of PMSM can achieve smooth speed control in the presence of load disturbance, achieve the purpose of anti-disturbance speed control and further improve the robustness of the control system.     

基于互补滑模的起重机械电机位置伺服控制

以提升起重机械电机位置控制响应精度为目标,提出基于互补滑模的起重机械电机位置伺服控制方法。通过构建起重机械电机数学模型,分析位置伺服控制器状态和机械运动状况,以固定结构控制位置响应的加、减速过程,以互补滑模变结构控制位置响应匀速过程,确定起重机械电机的速度曲线,利用阶梯型曲线逼近指数型曲线,实现起重机械电机速度控制,并设计三阶线性扩张状态观测器( ESO )预估位置伺服控制器的各状态量,消除伺服控制的噪声及抖振,提升起重机械电机的位置互补滑模伺服控制效果。实验结果表明,低速空载、负载下电流曲线光滑、无频率波动,该方法在不同给定脉冲下均可实现位置伺服控制的快速响应,定位准确度高且无超调,位置伺服控制效果突出。     

基于矢量控制的BLDCM新型滑模控制器

针对反电动势为正弦波的直流无刷电机控制效率问题,研究了其控制方式,采用了矢量控制方法代替传统的方波控制,以提高电机运行效率,设计了一种新的指数趋近律积分型滑模控制器(sliding mode control,SMC),提高了直流无刷电机控制系统的抗干扰性及速度跟踪性。在滑模控制中引入新的趋近律可有效地抑制抖振问题,提高了滑模面的趋近速度,同时使得系统的超调得到显著的降低。采用了边界层可变的正弦饱和函数替代开关函数进一步削弱抖振,并对其进行了理论分析。最后根据所设计的控制方式通过Simulink进行了仿真验证。研究结果表明,所设计的速度控制器较传统的滑模控制器及积分型滑模控制器具有更好的抑制抖振和速度跟踪性能。     

基于负载观测器的直线开关磁阻电机滑模位置控制

基于负载观测器补偿的滑模变结构控制算法,设计了一个直线开关磁阻电机位置控制器。论文对该位置控制系统进行了仿真分析和实验验证,结果表明,采用负载观测器补偿后的滑模控制算法实现直线开关磁阻电机的位置控制比传统的PD控制和传统的滑模控制具有更好的控制性能。     

High-accuracy servo press system for the clinching joint process

This paper focuses on the quality improvements on clinching joints using a servo press with a Radial basis function neural network and a sliding mode (RBFS) control strategy. Bottom thickness, which is affected by the press punch position, is usually used to monitor clinching joint quality. Traditional clinching presses are driven by pneumatic pistons or motors that provide feedback on punch force or motor position. However, this feedback is indirectly related to the joint bottom thickness. Clinching workers who set the control parameters on these presses depend on tests and statistics. Thus, this paper presents a servo press system that utilizes punch position feedback to directly control the joint bottom thickness. Transmission errors are considered for the movement accuracy of the servo press. A mathematical model of the servo press is established for analyzing. An algorithm, which combines RBF neural network and sliding mode, is proposed and applied for press position tracking. This algorithm adopts an RBF neural network to approximate the nominal model of the press system. The update law of the algorithm is based on the Lyapunov function used to prove the stability of a closed-loop system. The sliding mode controller compensates for the neural network error and disturbance. Finally, experiments are executed on the servo press with an RBFS controller. To evaluate the performance of the proposed method, a fuzzy PID controller is also applied to the press for comparison. The results indicate that the servo clinching press system with RBFS efficiently and accurately control the clinching jointing process.

     

Robust current control-based generalized predictive control with sliding mode disturbance compensation for PMSM drives

This paper addresses the current control of permanent magnet synchronous motor (PMSM) for electric drives with model uncertainties and disturbances. A generalized predictive current control method combined with sliding mode disturbance compensation is proposed to satisfy the requirement of fast response and strong robustness. Firstly, according to the generalized predictive control (GPC) theory based on the continuous time model, a predictive current control method is presented without considering the disturbance, which is convenient to be realized in the digital controller. In fact, it's difficult to derive the exact motor model and parameters in the practical system. Thus, a sliding mode disturbance compensation controller is studied to improve the adaptiveness and robustness of the control system. The designed controller attempts to combine the merits of both predictive control and sliding mode control, meanwhile, the controller parameters are easy to be adjusted. Lastly, the proposed controller is tested on an interior PMSM by simulation and experiment, and the results indicate that it has good performance in both current tracking and disturbance rejection.     

Fuzzy sliding mode observer with dual SOGI-FLL in sensorless control of PMSM drives

To improve the performance of permanent-magnet synchronous motor (PMSM) drives, a sensorless control scheme based on a sliding mode observer (SMO) with a fuzzy logic controller (FLC) and a dual second-order generalized integrator-frequency locked loop (DSOGI-FLL) is proposed in this paper. The major drawbacks of the conventional SMO, namely chattering phenomena, high-order harmonics and external noise, are discussed. These drawbacks affect the estimated accuracy of the SMO and reduce the control reliability of the system. To eliminate these drawbacks, an FLC is designed and integrated into the SMO to adjust the observer gain in a self-adaptive manner and to reduce the chattering; an existing dual synchronous frequency extract filter-phase locked loop (DSFF-PLL) is used to filter out the main components of high-order harmonics and to calculate the rotor position and speed precisely. Furthermore, to obtain an accurate fundamental frequency for the phase locked loop (PLL) and filter out the remaining harmonics and external noise signals, DSOGI-FLL processing is developed and incorporated into the DSFF-PLL. An overall PMSM sensorless control system based on the proposed SMO is designed, and an experimental platform using the TMS320F28335 DSP controller is built. Comparative experiments using the proposed SMO and the conventional SMO are performed to validate the effectiveness of the proposed FLC and the DSFF-DSOGI-FLL-PLL structures. Performance experiments of the overall proposed SMO-based sensorless control scheme are performed to verify the robustness and control reliability of the system. The results show that the proposed SMO has satisfactory performances and can be used in practical engineering.     

区分快慢变子系统的柔性机械臂控制方法

为了提高柔性机械臂控制精度、抑制柔性机械臂末端振动,提出了区分快慢变子系统的组合控制方法。使用拉格朗日方程和假设模态法建立了柔性机械臂动力学方程,利用奇异摄动原理将柔性机械臂系统分解为快变子系统和慢变子系统;鉴于慢变子系统的强非线性和参数不确定性,将反演控制和滑膜变结构相结合,提出了基于反演滑模变结构控制方法的慢变子系统控制;鉴于快变子系统模型不准确问题,而模糊控制对模型精度没有要求,因此设计了快变子系统模糊控制器。经仿真验证可以看出,与传统PID控制相比,机械臂转角最大误差由4.1°下降为0.04°,稳定时间由10s下降为2.5s,末端振动最大值由0.081m下降为0.021m,极大地提高了柔性机械臂控制精度。     

A Linear Cross-Coupled Control System for High-Speed Machining

We present a linear cross-coupled controller to improve highspeed contouring accuracy independently of tracking accuracy in a biaxial machine tool feed drive servomechanism. Unlike conventional cross-coupled controllers, the cross-coupled controller presented here is a linear system, so it is very easy to perform the stability and steady-state error analysis, and to optimise the controller parameters. The proposed controller is evaluated experimentally on a CNC LOM machine and compared to an uncoupled controller and a conventional cross-coupled controller. Controller performance is evaluated for a circular contour at a feedrate of 30 m min _1 . The experimental results show that the proposed controller can greatly reduce the contour error at large feedrates. The linear cross-coupled controller is simple to implement and is practical.     

基于分数阶微积分的机械臂迭代滑模控制策略研究

为提高工业机械臂的控制性能,将分数阶微积分理论与迭代学习控制及滑模控制相结合,提出一种有效的分数阶迭代滑模控制策略.在控制器的设计过程中,分别采用分数阶趋近律与分数阶滑模控制律两种方法将分数阶微积分引入到迭代滑模控制中,提出分数阶迭代滑模控制策略.并使用李雅普诺夫理论分析系统的稳定性.然后以一个两关节机械臂为例,通过MATLAB仿真对所提出的控制策略进行了验证.实验表明:分数阶迭代滑模控制策略可以有效提高关节的跟踪速度和跟踪精度,减小跟踪误差,具有较强的鲁棒性,并有效地抑制了滑模控制的抖振现象.     

基于分数阶微积分的机械臂迭代滑模控制策略研究

为提高工业机械臂的控制性能,将分数阶微积分理论与迭代学习控制及滑模控制相结合,提出一种有效的分数阶迭代滑模控制策略.在控制器的设计过程中,分别采用分数阶趋近律与分数阶滑模控制律两种方法将分数阶微积分引入到迭代滑模控制中,提出分数阶迭代滑模控制策略.并使用李雅普诺夫理论分析系统的稳定性.然后以一个两关节机械臂为例,通过MATLAB仿真对所提出的控制策略进行了验证.实验表明:分数阶迭代滑模控制策略可以有效提高关节的跟踪速度和跟踪精度,减小跟踪误差,具有较强的鲁棒性,并有效地抑制了滑模控制的抖振现象.     

基于模糊切换增益调节的惯性稳定平台滑模控制

为了实现航空遥感惯性稳定平台在复杂多源扰动环境下的高精度控制,提出基于模糊滑模的惯性稳定平台高精度控制 方法,通过对总和扰动抑制实现对多源扰动抑制,从而提高稳定平台控制精度。 首先将惯性稳定平台的所有扰动视为整体,基 于滑模等效控制设计惯性稳定平台的全局快速终端滑模控制器,实现系统状态快速、精确地收敛到平衡状态并且不离开滑模 面。 其次,针对控制系统存在鲁棒性与抖振问题无法兼顾的问题,在滑模控制基础上融合模糊切换增益调节,设计模糊规则对 惯性稳定平台滑模控制中的切换增益进行实时调节,从而利用切换增益消除干扰项。 最后,对所提出方法的正确性进行仿真以 及实验验证。 结果表明,基于模糊切换增益调节的滑模控制方法扰动抑制能力强、稳定精度高,相对于 PID 控制和全局快速终 端滑模控制,稳定精度分别提高 32. 7% 和 15. 3% 。     

Active Vibration Control of SMA Actuated Structures using Fast Output Sampling Based Sliding Mode Control

Abstract

Fast Output Sampling (FOS) based discrete sliding mode control is designed for Shape Memory Alloy (SMA) actuated structures to suppress the structural vibration. For the design of discrete sliding mode control the reaching law, method proposed by W. Gao is used. The simulation results demonstrate the performance of the controller. The proposed control technique achieves good vibration suppression. This methodology is more practical and easier to implement, since the measurement or estimation of the system states is not needed for designing the controller.     

基于模糊滑模控制和两级滤波滑模观测器的PMSM改进控制策略

针对传统带有滑模观测器的永磁同步电机控制系统中转矩脉动大、抖振明显、反电动势估计精度差等问题,提出基于模糊滑模控制和两级滤波滑模观测器的PMSM改进控制策略.首先,在速度环提出基于双曲正弦函数的新型趋近率,结合模糊控制思想对趋近率参数实现自整定,设计了一种基于新型趋近率的模糊积分滑模速度环控制器,并且对新型趋近率的抖振抑制效果给出严格分析.其次,提出基于变截止频率低通滤波器和修正反电动势观测器的两级滤波结构,抑制反电动势中的高频分量和测量噪声,并对转子位置进行合理补偿,继而设计了两级滤波滑模观测器;通过Lyapunov判据对本文提出控制策略的稳定性进行了推导证明.仿真和实验结果表明,与传统滑模观测器相比,改进的控制器使电机在启动和受到外部扰动时系统响应良好,有效改善了转矩脉动、抖振、反电动势的估计精度等问题.