Adaptive on-line flux estimation in field-oriented control of an IM

An adaptive technique for the online estimation of the rotor field vector to use as a feedback for the field-oriented control of an induction machine (IM) is described. This method makes use of the stator voltage and rotor speed measurements. It uses the least square estimation technique for identifying the machine parameters to be used in the estimation of the field vector. The position and magnitude of the flux vector are identified during the normal operation of the machine by applying some special constraints to the forcing function. This constraint is applied only for a short duration to make some measurements, and the machine performance is not affected. Extensive simulation of the system has been carried out, and the results are presented     

基于RVM回归误差补偿的航空发动机分布式控制系统多步预测控制

针对具有随机有界双侧时延的航空发动机分布式控制系统,提出了一种基于多步预测和关联向量机(RVM)回归误差补偿的控制方案.首先建立航空发动机分布式控制系统(DCS)的神经网络非线性自回归滑动平均(NARMA)模型,利用当前的系统输出和控制量对N步之后的系统输出进行预测;其次用改进的RVM回归多步预测算法估计NARMA模型的的预测误差,并对预测结果进行误差补偿;最后利用补偿之后的预测值和设定值对控制参数进行滚动优化,设计系统的神经网络逆控制器实现系统的自适应控制.仿真结果证明该控制策略能够避免随机有界双侧时延对控制系统的影响,实现对设定值的稳定跟踪,且控制器具有较好的实时性和鲁棒性.低压转子转速阶跃响应的稳态绝对误差小于0.04%,响应时间小于0.3s.      

Adaptive control for a sensorless permanent-magnet synchronousmotor drive

An adaptive velocity controller for a permanent-magnet synchronous motor without using shaft sensor is presented. Two line-to-line voltages and two stator currents are sensed to produce the flux position. The design part is concerned with the formulation of control algorithm for current-regulated pulsewidth modulated inverter and vector control strategy for speed loop. Under the vector control framework, self-tuning, model following, and model referencing adaptive control are applied to design for the speed-loop controllers. The implementational part integrates the control of current and speed loop using microprocessor-based controllers. Experimental case studies that correlate simulation and measurement results are provided. The experimental results validate the theoretical development. A new approach for designing advanced adaptive controller for a sensorless ac drive is provided     

直升机结构响应自适应控制研究

研究了基于自适应滤波技术、采用伺服惯性力发生器（SIFG）的直升机结构响应主动控制;比较了被动动力吸振器和SIFG的减振效果。研究表明,SIFG在直升机前飞速度和旋翼转速及前飞速度改变的情况下均能保持良好的减振效果。     

Adaptive recurrent-neural-network control for linear inductionmotor

In this study an adaptive recurrent-neural-network controller (ARNNC) is proposed to control a linear induction motor (LIM) servo drive. First, the secondary flux of the LIM is estimated with an adaptive flux observer on the stationary reference frame and the feedback linearization theory is used to decouple the thrust force and the flux amplitude of the LIM. Then, an ARNNC is proposed to control the mover of the LIM for periodic motion. In the proposed controller, the LIM servo drive system is identified by a recurrent-neural-network identifier (RNNI) to provide the sensitivity information of the drive system to an adaptive controller. The backpropagation algorithm is used to train the RNNI on line. Moreover, to guarantee the convergence of identification and tracking errors, analytical methods based on a discrete-type Lyapunov function are proposed to determine the varied learning rates of the RNNI and the optimal learning rate of the adaptive controller. The effectiveness of the proposed control scheme is verified by both the simulated and experimental results. Furthermore, the advantages of the proposed control system are indicated in comparison with the sliding mode control system     

Experimental study in adaptive tracking control

The authors describe an experimental study of adaptive pointing and tracking control for flexible spacecraft conducted on a complex ground experiment facility. The algorithm used is based on a multivariable direct model reference adaptive control law. Several experimental validation studies performed using this algorithm for vibration damping and robust regulation are extended by addressing the pointing and tracking problem. As is consistent with an adaptive control framework, the plant is assumed to be poorly known to the extent that only system level knowledge of its dynamics is available. Explicit bounds on the steady-state pointing error are derived as functions of the adaptive controller design parameters. It is shown that good tracking performance can be achieved in an experimental setting by adjusting adaptive controller design weightings according to the guidelines indicated by the analytical expressions for the error     

Robust variable structure speed control for induction motor drive

In order to eliminate the effect of parameter variation on field-oriented control for induction motor drive, an adaptation algorithm for tuning the rotor time-constant is proposed. Based on the adaptive observation of the rotor flux linkages, the rotor time-constant is adapted to obtain an exact indirect-field-oriented control (IFOC). In this proposed algorithm, a related function to the variation of the rotor time-constant is designed, then the accurate slip frequency needed for IFOC is obtained from this error function through a PI-type (proportional-integral) filter. Furthermore, a novel variable structure speed control with integral sliding surface is proposed under the adaptive field-oriented operation. By means of the variable structure speed control, the dynamics of motor speed have the property of an exponentially convergent rate. Using the proposed adaptive field-oriented control and the variable structure speed control, the IFOC is robust to the variation of the rotor time-constant and the speed control is insensitive to parameter uncertainty and load disturbance. Finally, some simulation and experimental results are presented to validate the effectiveness     

基于数据驱动的变循环发动机多变量自适应控制算法研究

本文针对变循环发动机包线范围大,自适应控制需求高的问题,在增广线性二次型调节器(ALQR)基础上,提出一种基于数据驱动的自适应ALQR(DA-ALQR)控制算法。构建了多变量系统自适应控制准则函数,以梯度下降法对控制器参数进行调整,借助基于数据驱动的动态线性化建模方法,递推进行输出对输入梯度的近似计算,实现了对ALQR控制参数的自适应调整。仿真结果表明,所设计的DA-ALQR控制器参数随发动机状态变化得到了有效调整,相较于ALQR控制算法,闭环系统动态性能得到了大幅度提升,推力在单外涵模式表现出较快的响应速度,在双外涵模式表现出更小的超调,转速同样表现出了超调减小和响应速度加快特性,验证了所提出方法的有效性。     

基于模糊逻辑系统的转子振动控制方法研究

电流变液作为一种智能材料在振动控制工程领域有着广泛的应用。由于电流变效应具有非线性特性,使得难以设计基于常规控制理论的控制律。本文利用模糊逻辑系统能够逼近非线性函数的特性,设计了电流变阻尼器-转子振动系统自适应模糊控制方案。针对该转子系统的仿真计算表明,转子系统的振幅能够得到有效的抑制,自适应模糊控制器性能良好。      

基于预测扭矩前馈的涡轴发动机内模控制方法

基于内模原理设计了涡轴发动机功率涡轮转速控制器.针对主旋翼扭矩变化对功率涡轮转速的干扰,提出了一种基于极端学习机的扭矩预测方法.极端学习机训练基于动态仿真数据,其输入通过相关分析获得.基于内模原理的功率涡轮转速控制器采用极点配置的设计方法,将输入信号的内模直接加入控制器,实现鲁棒跟踪.扭矩前馈采用比例微分(PD)控制策略,实现对发动机负载变化干扰的有效补偿.数字仿真结果表明:极端学习机扭矩预测精度高,扭矩相对误差小于1.5‰,与不加前馈控制相比,所提出的控制方法减小了机动飞行过程中功率涡轮转速的超调或下垂30%以上.      

Fuzzy adaptive robust control for space robot considering the effect of the gravity

Space robot is assembled and tested in gravity environment, and completes on-orbit service（OOS） in microgravity environment. The kinematic and dynamic characteristic of the robot will change with the variations of gravity in different working condition. Fully considering the change of kinematic and dynamic models caused by the change of gravity environment, a fuzzy adaptive robust control（FARC） strategy which is adaptive to these model variations is put forward for trajectory tracking control of space robot. A fuzzy algorithm is employed to approximate the nonlinear uncertainties in the model, adaptive laws of the parameters are constructed, and the approximation error is compensated by using a robust control algorithm. The stability of the control system is guaranteed based on the Lyapunov theory and the trajectory tracking control simulation is performed. The simulation results are compared with the proportional plus derivative（PD） controller, and the effectiveness to achieve better trajectory tracking performance under different gravity environment without changing the control parameters and the advantage of the proposed controller are verified.     

A novel intelligent adaptive control of laser-based ground thermal test

Laser heating technology is a type of potential and attractive space heat flux simulation technology, which is characterized by high heating rate, controlled spatial intensity distribution and rapid response. However, the controlled plant is nonlinear, time-varying and uncertainty when implementing the laser-based heat flux simulation. In this paper, a novel intelligent adaptive controller based on proportion–integration–differentiation(PID) type fuzzy logic is proposed to improve the performance of laser-based ground thermal test. The temperature range of thermal cycles is more than 200 K in many instances. In order to improve the adaptability of controller,output scaling factors are real time adjusted while the thermal test is underway. The initial values of scaling factors are optimized using a stochastic hybrid particle swarm optimization(H-PSO)algorithm. A validating system has been established in the laboratory. The performance of the proposed controller is evaluated through extensive experiments under different operating conditions(reference and load disturbance). The results show that the proposed adaptive controller performs remarkably better compared to the conventional PID(PID) controller and the conventional PID type fuzzy(F-PID) controller considering performance indicators of overshoot, settling time and steady state error for laser-based ground thermal test. It is a reliable tool for effective temperature control of laser-based ground thermal test.     

航空发动机的支持向量机自适应PID控制

首先介绍了支持向量机(SVM)的原理, 建立了支持向量机回归(SVMR)模型.将SVMR与基于支持向量机的控制器相结合, 组成自适应PID支持向量机控制(SVMC)系统.最后用于某型航空发动机, 通过在选定的设计点处进行控制系统的设计, 利用支持向量机强大非线性映射能力、网络结构的自动最优化特性, 使控制系统在发动机偏离设计点工作时控制系统仍保持很好的性能.为通用非线性控制提供了一种新的控制思路.      

涡轴发动机自适应非线性预测控制

为了实现当直升机旋翼负载变化时,尽量保持功率涡轮转速恒定,并提高系统动态品质,研究了一种针对涡轴发动机的自适应非线性预测控制(ANMPC)算法.基于涡轴发动机稳态数据和动态特性,采用递归最小二乘法(RLS)进行模型参数辨识,建立了具有在线自适应能力的涡轴发动机数值-ARX(auto regressive with external input)并联预测模型.在此基础上,通过多步输出预测和反馈校正,利用序列二次型优化(SQP)算法,进行在线滚动优化,从而获得了涡轴发动机ANMPC控制器.仿真结果表明:当旋翼负载变化时,相比于传统的串联PID(比例-积分-控制)控制器,ANMPC控制器能够使得功率涡轮转速收敛更快,超调量/下垂量更小.      

混合励磁轴向磁场磁通切换型永磁电机特性分析与试验研究

提出了一种适用于电动汽车驱动系统的E型铁心混合励磁轴向磁场磁通切换型永磁(HEAFFSPM)电机。以一台三相6/10极电机为例,基于三维有限元方法全面研究该电机静态特性,包括气隙磁密、空载永磁磁链、空载反电动势、电磁转矩、转矩-电流特性、绕组电感和磁场调节能力等；研究转子齿扇形角度和转子斜极对电机反电动势和齿槽转矩的影响,分析表明转子齿扇形和转子斜极可以改善反电动势和齿槽转矩波形。制造了一台2 kW样机并对其进行测试,验证了有限元分析结果的准确性,结果表明HEAFFSPM电机的磁链和反电动势均为正弦分布,带载能力和磁场调节能力均较强。     

电动汽车用永磁同步电机模型预测MRAS无速度传感器控制

针对电动汽车机械式传感器在复杂工作环境下易失效的问题,将基于模型参考自适应(MRAS)的无速度传感器技术应用于电动汽车中。针对传统MRAS无速度传感器控制存在的转子位置估计相位延迟较大、转速估计误差较大等问题,将模型预测控制算法应用到MRAS中。参考模型选用永磁同步电机(PMSM)电流磁链方程,可调模型选取电压磁链方程,代价函数是磁链的差值,待估计参数选择转子位置。与传统MRAS无速度传感器控制算法相比,转速、转子位置估计结果更加精确,估计误差较小,动态性能和稳态性能优良。通过仿真和试验验证了算法的可行性和有效性。     

Start-up current adaptive control for sensorless high-speed brushless DC motors based on inverse system method and internal mode controller

The start-up current control of the high-speed brushless DC (HS-BLDC) motor is a chal-lenging research topic. To effectively control the start-up current of the sensorless HS-BLDC motor, an adaptive control method is proposed based on the adaptive neural network (ANN) inverse system and the two degrees of freedom (2-DOF) internal model controller (IMC). The HS-BLDC motor is identified by the online least squares support vector machine (OLS-SVM) algo-rithm to regulate the ANN inverse controller parameters in real time. A pseudo linear system is developed by introducing the constructed real-time inverse system into the original HS-BLDC motor system. Based on the characteristics of the pseudo linear system, an extra closed-loop feed-back control strategy based on the 2-DOF IMC is proposed to improve the transient response per-formance and enhance the stability of the control system. The simulation and experimental results show that the proposed control method is effective and perfect start-up current tracking perfor-mance is achieved.     

Predictor-based model reference adaptive roll and yaw control of a quad-tiltrotor UAV

An attempt is made to apply modern control technology to the roll and yaw control of a rudderless quad-tiltrotor Unmanned Aerial Vehicle (UAV) in the latter part of the flight mode transition, where aerodynamic forces on the tiltrotor’s wings start to take effect. A predictor-based adaptive roll and yaw controller is designed to compensate for system uncertainties and parameter changes. A dynamics model of the tiltrotor is built. A Radial-Basis Function (RBF) neural network and offline adaptation method are used to reduce flight controller workload and cope with the nonlinearities in the controls. Simulations are conducted to verify the reference model response tracking and yaw-roll control decoupling ability of the adaptive controller, as well as the validity of the offline adaptation method. Flight tests are conducted to confirm the ability of the adaptive controller to track different roll and yaw reference model responses. The decoupling of roll and yaw controls is also tested in flight via coordinated turn maneuvers with different rotor tilt angles.     

Simple adaptive control for aircraft control surface failures

This work extends the so-called simple adaptive control approach to direct model reference adaptive control of multi-input multi-output systems to include loss of control effectiveness failures. It is proven that all signals are bounded for loss of control effectiveness failures during a bounded input disturbance. A state space approach is introduced for computing the feedforward compensator that is required by the stability result. The adaptive algorithm is applied to a three input model of the linearized lateral dynamics of the F/A-18 aircraft. Simulation results are obtained with single, double, and triple control effectiveness failures of 88% during the occurrence of a lateral gust. These results show that the adaptive controller exhibits improved model following as compared with a fixed gain eigenstructure assignment controller.     

升降舵辅助操纵的自转旋翼机自适应姿态控制

针对常规自转旋翼机俯仰操纵方式存在的问题,提出了一种升降舵辅助操纵的自转旋翼机布局。采用解析叶素积分方法建立了自转旋翼气动模型,通过与风洞试验数据及数值叶素积分法的对比验证了其合理性。提出了基于神经网络动态逆的自转旋翼机姿态控制方法,采用动态逆技术设计了基本控制器,采用在线神经网络自适应补偿建模误差、外界干扰和设计模型误差导致的不确定逆误差。提出了基于动态控制分配技术的升降舵-旋翼纵向周期变距分配方法,以协调二者在控制效率和带宽方面的差异。仿真结果表明,提出的升降舵辅助操纵方式可以有效地降低旋翼机桨盘的调整频率和幅值;提出的姿态控制方法具有良好的控制性能和鲁棒性;动态控制分配器能够合理地协调升降舵和旋翼纵向周期变距。