Delay-dependent guaranteed cost control for state-delayed system with disturbance and its application to engine idle speed control

This paper proposes a delay-dependent guaranteed cost control scheme for engine idle speed control （ISC） with induction-to-torque delay and external load disturbance. An augmented linearization model of engine at idle speed operating mode was developed based on physical principle and experiment data. To provide a compromise between disturbance rejection and other performance requirements of ISC, a multi-objective cost function upper bound was given, which can help us to take into account the fuel economy and disturbance rejection performance together in ISC. Poles constraint was added to the closed-loop system to guarantee convergence rates of state. The whole optimization solution to ISC can be solved under the framework of LMI. A commercial engine model was utilized to assess the performance of the controller. Simulation results on this model show us that designed controller can achieve desired performance.     

大功率天然气发动机怠速控制策略研究

为提高大功率天然气发动机怠速时的稳态和动态效果,以V模式为研究手段,基于一款六缸天然气多点电喷发动机,实现了发动机怠速控制策。首先针对不同的怠速工况设计了不同的目标怠速转速值的计算,并根据发动机特性确定了PI控制模式。利用目标怠速转速和瞬时转速的差值确定不同PI控制参数,通过PI控制调节电子节气门的开度,从而实现对发动机怠速转速的控制。然后根据实际发动机参数搭建了发动机MATLAB/SIMULINK仿真模型,用于对怠速控制策略进行软件在环仿真测试以及PI控制参数预标定。最后在天然气发动机试验台架上对控制策略进行了进一步的试验和标定。试验结果表明：该怠速控制策略,可让发动机转速响应时间控制在1秒左右,转速稳定时间在2秒左右,发动机转速稳态误差控制在±5rpm范围之内,实现了对怠速的良好稳定控制。     

A QFT-type design methodology for a parallel plant structure and its application in idle speed control

Developed in this paper is a frequency domain design methodology for disturbance rejection in a MISO plant which has a special parallel structure. Shown in this paper is that it is not necessary to close all the parallel loops in order to achieve the hard time domain constraints. The proposed methodology is applied to the idle speed control of a fuel-injected engine.     

新型幅值最优及抗干扰的PI设计方法

针对传统幅值最优及其抗干扰技术存在的问题,基于新的幅值最优模型,提出了PI求解方案。与传统的幅值最优及抗干扰PI整定公式相比,新的PI整定公式,减少了所需特征参数的个数,新的抗干扰幅值最优PI整定公式也大大简化。改进后的幅值最优求解方法,扩大了幅值最优技术的应用范围;改进后的抗干扰设计比原有方法有更好的抗干扰性能。通过被控对象的仿真比较实验,证明了改进方法的有效性。     

Active disturbance rejection control for high pointing accuracy and rotation speed

This paper presents a design method proposed to design an active disturbance rejection control for the antenna pointing control of a large flexible satellite system. A simplified dynamics model is established using Euler-Lagrange and used to analyze the dynamic stability of the antenna system. The capturing strategy of the antenna is configured and the inner and outer loops of the active disturbance rejection control are then designed to improve pointing accuracy and rotation speed. The design of the active disturbance rejection control is verified through numerical simulation. Simulation results indicate that the proposed method can be used to achieve high pointing accuracy and rotation speed.     

快速刀具伺服系统自抗扰控制的研究与实践

快速刀具伺服系统(fast tool servo, FTS)是实现非圆截面和非轴对称表面零件加工的关键部件. 加工过程中,FTS应克服时变切削力负载和自身参数的非线性, 驱动刀具完成高频高精度跟踪运动. 为了解决FTS的快速精密跟踪控制问题, 根据刀具运动参考轨迹已知的特点, 应用自抗扰控制原理和前馈控制策略, 针对基于剪应力和正应力电磁驱动的两种直线执行机构, 分别设计了采用线性和非线性扩张状态观测器的自抗扰控制器, 并利用传递函数和描述函数方法, 分析了线性控制器的跟踪精度和动态刚度特性, 探讨了非线性控制系统的极限环问题. 两种基于自抗扰控制的快速刀具伺服系统已应用于发动机椭圆截面活塞的精密车削和二维正弦微结构表面的超精密车削,满足了加工需求. 研究与应用结果表明: 自抗扰控制思想独特、算法易于工程实现, 具有很好的工程应用价值.     

改进型预测函数控制在感应电机功率优化中的应用

在对感应电机效率优化问题进行研究的基础上,考虑到传统方法在电机动态时无法同时兼顾响应性能和效率优化的缺陷,设计了一种新型分数阶PI(FOPI)预测函数控制策略.该控制策略将预测函数控制和分数阶PI两种算法相结合,构建具有分数阶比例、积分性质的多变量预测函数控制器,兼顾了感应电机动态效率与转速响应速度的优点.应用于电动机效率优化的最大转矩电流比控制方面,采用前馈补偿解耦设计的思路,将系统分解成两个具有可测扰动的子系统.仿真实验表明新型控制策略具有在线识别模型识别模型参数,跟踪效果好,抗干扰能力强,无超调,稳态误差小,取得了良好的控制效果.     

有源电力滤波器的自抗扰控制研究

针对采用PI控制器控制有源电力滤波器时存在谐波或基波电流指令而无法实现无静差调节,且数字化后会进一步增大稳态误差,使有源电力滤波器的补偿性能降低的问题,提出一种有源电力滤波器的自抗扰控制策略。该策略利用自抗扰控制器的非线性跟踪-微分器和扩张状态观测器分别处理参考输入和输出,并选择适当的状态误差,实现了对滤波的自动、精确补偿。仿真和实验结果表明,有源电力滤波器采用自抗扰控制策略后具有很强的鲁棒性、稳定性和适应性,控制性能有较大改善。     

连铸过程结晶器液面控制的模糊控制方法

对连铸过程结晶器液面控制提出一种新的模糊控制方法。该方法采用一种简化的模糊 PID结构 ,结合了传统模糊 PI与模糊 PD控制方法的优点。仿真结果表明 ,该方法对周期性扰动具有良好的抑制效果 ,对过程参数的变化具有很强的鲁棒性     

基于定量反馈理论的时滞系统自抗扰控制参数整定

工业过程对象普遍存在时滞、模型参数不确定性和外部扰动多等特点,传统Smith预估控制方法难以设计出满足期望性能的鲁棒控制器.针对模型参数不确定性和外部扰动,本文采用自抗扰控制技术进行估计和补偿.针对系统存在时滞的特点,本文提出改进Smith预估器结构,提升扩张状态观测器对于扰动估计的实时性.在此基础上,本文以一阶时滞系统为例提出了控制器参数整定方法.首先根据最优参数选取准则确定预估器模型,然后在等效模型框架下采用定量反馈理论整定自抗扰控制器参数,确保控制系统达到预期性能指标.在仿真实验中,将所提出方法与几种常见时滞系统控制方法进行比较,通过设定值跟踪、抗扰及蒙特卡罗实验验证了所提出方法具有良好抗扰能力与鲁棒性.     

NARMAX modelling and robust control of internal combustion engines

Detailed in this paper is a SISO non-linear modelling and robust controller design methodology experimentally verified on an internal combustion engine. The methodology begins with the identification of a NARMAX model that captures the non-linear dynamics relating the input to the output of a system. This model is converted to a describing function representation for the purpose of robust feedback controller design. The ideology for the describing function recovery is developed in the form of an algorithm which can be extended to other NARMAX model structures not considered here. The controller design is executed in the frequency domain where the output performance specification is |y(t)|≤β?t>0 and the actuator saturation constraint is |u(t)|≤K?t>0. For the engine idle speed control application of this study, a SISO NARMAX model of the engine is developed between the by-pass idle air valve (BPAV) and engine speed. The performance objective for the controller design is the time domain tolerance of |Δ rpm| ≤ 100 rpm on idle speed perturbations despite a non-measurable 20 N m external torque disturbance. The controller is validated through numerical simulations as well as experimental verification.     

Robust digital control approach for high performance tunneling current measurement system

This paper is devoted to the digital control system design for high performance measurement of tunneling current. A common approach for such applications is to use a conventional Proportional Integral (PI) control. In this paper, a robust digital design method is instead considered, based on combined pole placement with sensitivity function shaping, and allowing for better performance tuning in terms of precision, robustness and disturbance rejection. The resulting control scheme looks like some enhanced PID controller, and is validated over an experimental setup, developed in GIPSA-lab (Grenoble Image Parole Signal Automatique) research center. The corresponding simulation and experimental results show improved performances with respect to those obtained with the more conventional PI control technique.     

Fractional order and BICO disturbance observers for a run-of-mine ore milling circuit

Grinding mill circuits are hard to control due to poor plant models, large external disturbances, uncertainties from internal couplings, and process variables that are difficult to measure. This paper proposes a novel fractional order disturbance observer (FO-DOB) for a run-of-mine (ROM) ore milling circuit. A fractional order low pass filter (Q-filer) is used in the DOB to offer an additional degree of freedom in tuning for set-point tracking performance and disturbance rejection performance. Another disturbance observer is introduced in which a Bode ideal cut-off (BICO) filter is used for the Q-filter. A full non-linear plant model is used for evaluation of the performance gained over the ubiquitous PI controller. The simulation results show that the FO-DOB and BICO-DOB schemes are useful additional tools for ROM ore milling circuit control implementations.     

永磁同步电机自抗扰反步控制

为实现永磁同步电机的高性能控制,提出一种复合控制策略。在永磁同步电机矢量控制基础上,设计反步控制器用于电流环控制,得到同步旋转坐标系下定子电压,并能保证系统全局稳定。设计结构优化的线性自抗扰控制器用于速度环控制,提高系统抗干扰能力。采用二阶环节平滑速度指令,实现转速无超调。仿真结果表明该控制策略较传统PI控制具有转速适应范围广、无超调、抗扰动性能强等优点。     

Neural network model-based automotive engine air/fuel ratio control and robustness evaluation

Automotive engines are multivariable system with severe non-linear dynamics, and their modelling and control are challenging tasks for control engineers. Current control of engine used look-up table combined with proportional and integral (PI) control and is not robust to system uncertainty and time varying effects. In this paper the model predictive control strategy is applied to engine air/fuel ratio control using neural network model. The neural network model uses information from multivariables and considers engine dynamics to do multi-step ahead prediction. The model is adapted in on-line mode to cope with system uncertainty and time varying effects. Thus, the control performance is more accurate and robust compared with non-adaptive model based methods. To speed up algorithm calculation, different optimisation algorithms are investigated and performance compared. Finally, the developed method is evaluated on a well-known engine benchmark, a simulated mean value engine model (MVEM). The simulation results demonstrate the effectiveness of the developed method.     

Modeling and speed control design of an ethanol engine for variable speed gensets

This paper presents the development of a discrete dynamic mean value engine model (MVEM) suitable for the design of speed controllers of ethanol fueled internal combustion engines (ICE), to be used in variable speed gensets. Two MVEMs are developed for the ICE: the Time Based model and the Crank Based model. The speed controller design is held through the discretization and linearization of the Crank Based MVEM. This model is used due to the advantages over the time based MVEM especially with respect to the transport delay which becomes constant. Two approaches for the ICE speed control are investigated: (i) a single loop gain-scheduled proportional integral (PI) controller and (ii) a dual loop control based on an internal gain-scheduled Manifold Absolute Pressure (MAP) feedback loop and an outer loop composed of a gain-scheduled PI controller. The control design is developed in the frequency domain and its stability is ensured by the phase and gain margins. In addition, an integral anti-windup and a feed forward action are also proposed to improve the behavior during control law saturation, improve transient responses and disturbance rejection capability. Experimental results on a 50 kW generator set are provided to validate the controllers and to demonstrate the performance of the system.     

采煤机牵引系统双电机功率平衡控制策略

随着采煤机装机功率和开采能力的提升,牵引系统控制效果及动态性能已成为影响采煤机工作稳定性的重要因素.目前,采煤机电牵引系统双电机控制策略多采用传统的主从控制,其同步性能存在滞后问题,容易导致牵引电机偏载.此外,系统在控制算法方面多采用传统PI控制,对于容易发生参数摄动及负载变化频繁的牵引系统而言,传统PI控制的控制性能不佳.为提高采煤机牵引系统驱动性能并实现牵引电机功率平衡,根据采煤机牵引系统结构,本文提出了一种基于自抗扰控制的转速主从、转矩交叉耦合控制的双电机控制策略,并对控制策略进行了仿真分析和实验研究.结果表明,本文所提出控制策略实现了牵引系统功率平衡并提升了系统的控制性能.     

基于扩张状态观测器的磁通切换永磁电机的无传感器控制

将线性自抗扰控制应用于磁通切换永磁电机（FSPMM）的无速度传感器控制中,采用线性扩张状态观测器（LESO）构造FSPMM的转速观测器,实现对转速准确而快速的实时估计;设计线性自抗扰控制器（LADRC）作为转速环调节器,系统的鲁棒性被提高了.仿真结果验证了所设计的基于LESO的无传感器LADRC控制策略能够使FSPMM可靠稳定运行,LESO提升了系统的观测精度和响应速度,克服了滑模观测器（SMO）带来的高频抖振和滞后现象;与基于SMO的无传感器PI控制策略相比,所提的控制策略在负载扰动和参数摄动时具有更强的鲁棒性.     

Speed Tracking Control of Permanent Magnet Synchronous Motor by a Novel Two-step Internal Model Control Approach

The control problem of permanent magnet (PM) synchronous motor has attracted extensive attentions in both control society and industrial applications. Much recently, a local speed tracking and nonlinear disturbance rejection problem of PM synchronous motor was investigated by nonlinear internal model design. In this paper, we propose a novel two-step controller design strategy to achieve speed tracking and nonlinear disturbance rejection of PM synchronous motor with wide speed range, which combines the advantages of classical double-loop control and nonlinear internal model control. It is worth mentioning that the proposed two-step controller design strategy can not only guarantee exact speed tracking with wide speed range, but also reject small nonlinear external disturbances in the load torque, generated by a so-called nonlinear exosystem. Simulation results demonstrate the effectiveness of our design.     

无刷直流电机换相转矩脉动抑制的研究

针对无刷直流电机换相时产生的转矩脉动,采用自抗扰控制技术设计出一种自抗扰控制器来消除转速响应的超调,同时通过自身的扩张状态观测器检测系统的相电流脉动和自身的非线性状态反馈控制律对检测到的电流脉动误差值进行补偿抵消,以达到抑制相电流脉动的效果,从而抑制电机的转矩脉动.仿真结果表明,自抗扰控制比PI控制能更好地抑制转矩脉动,提高电机转速的稳定性和系统的可靠性.