基于P-模糊自适应PID控制的无刷直流电动机调速系统

分析了无刷直流电动机的数学模型,提出了一种新型的P-模糊自适应PID控制方法,并在Matlab/Simulink环境中建立了基于P-模糊自适应PID控制的无刷直流电动机调速系统仿真模型。在该调速系统中,电流控制采用电流滞环,转速控制采用P控制和模糊自适应PID控制相结合的方式,实现了电流滞环和转速模糊控制的双闭环调速控制功能。仿真结果表明,该系统与基于常规PID控制的调速系统相比,系统响应时间缩短一半,且超调减小,具有较强的鲁棒性和自适应能力。     

Compensation of torque ripple in high performance BLDC motor drives

Brushless DC motor drives (BLDC) are finding expanded use in high performance applications where torque smoothness is essential. The nature of the square-wave current excitation waveforms in BLDC motor drives permits some important system simplifications compared to sinusoidal permanent magnet AC (PMAC) machines. However, it is the simplicity of the BLDC motor drive that is responsible for causing an additional source of ripple torque commonly known as commutation torque to develop. In this paper, a compensation technique for reducing the commutation torque ripple is proposed. With the experimental results, the proposed method demonstrates the effectiveness for a control system using the BLDC motors that requires high speed and accuracy.     

Chattering-Free Sliding Mode Altitude Control for a Quad-Rotor Aircraft: Real-Time Application

Nowadays, the chattering problem in sliding mode control is one of the most important points to consider in real-time applications. To address this problem, a real-time robust altitude control scheme is proposed for the efficient performance of a Quad-rotor aircraft system using a continuous sliding mode control. The sensing of altitude measurement sensing is performed by a pressure sensor in order to obtain a robust altitude control of the vehicle in hovering mode both indoor and outdoor. The altitude measurement has the advantage of introducing this state information directly in the closed loop control which should be very useful for achieving robust stabilization of the altitude control. Accordingly, we propose a sliding mode control strategy without chattering. The sliding mode control proposed removes the chattering phenomenon by replacing a sign function with a high-slope saturation function. The control algorithm is derived from the Lyapunov stability theorem. Moreover, we have assumed that the actuators are able to respond quickly and accurately and we have not enforced limits on the control signals for a real-time application. Finally, to verify the satisfactory performance of proposed nonlinear control law, several simulations and experimental results of the Chattering-free sliding mode control for the Quad-rotor aircraft in the presence of bounded disturbances are presented.     

Adaptive Sliding Mode Control for Re-entry Attitude of Near Space Hypersonic Vehicle Based on Backstepping Design

Combining sliding mode control method with radial basis function neural network (RBFNN), this paper proposes a robust adaptive control scheme based on backstepping design for re-entry attitude tracking control of near space hypersonic vehicle (NSHV) in the presence of parameter variations and external disturbances. In the attitude angle loop, a robust adaptive virtual control law is designed by using the adaptive method to estimate the unknown upper bound of the compound uncertainties. In the angular velocity loop, an adaptive sliding mode control law is designed to suppress the effect of parameter variations and external disturbances. The main benefit of the sliding mode control is robustness to parameter variations and external disturbances. To further improve the control performance, RBFNNs are introduced to approximate the compound uncertainties in the attitude angle loop and angular velocity loop, respectively. Based on Lyapunov stability theory, the tracking errors are shown to be asymptotically stable. Simulation results show that the proposed control system attains a satisfied control performance and is robust against parameter variations and external disturbances.      

Multivariable finite‐time output feedback trajectory tracking control of quadrotor helicopters

A continuous multivariable output feedback control scheme is developed for trajectory tracking and attitude stabilization of quadrotor helicopters. The whole closed‐loop system is composed by position loop and attitude loop. The homogeneous technique is used to design finite‐time stabilizing controller and observer in each loop. The virtual control is introduced in position loop to ensure that the real control is smooth enough such that it can be tracked by attitude loop. The finite‐time stability of the closed‐loop system is guaranteed through homogeneity and Lyapunov analysis. Finally, the efficiency of the proposed algorithm is illustrated by numerical simulations.     

Hovering Flight Improvement of a Quad-rotor Mini UAV Using Brushless DC Motors

This paper present the design of a novel embedded control system for improving attitude stabilization of a quad-rotor mini UAV. The control strategy uses low cost components and includes an extra control loop based on motor armature current feedback. This additional control loop significantly improves the performance of the quad-rotor attitude stability. This technique results in a controller that is robust with respect to external disturbances as has been observed experimentally.     

基于积分滑模的航天器有限时间姿态容错控制

针对存在执行机构故障和外部干扰的刚体航天器姿态稳定系统,本文提出了基于积分滑模的容错控制策略,实现了姿态有限时间稳定.首先,利用齐次系统相关理论,设计了一类饱和有界的基础控制律,保证了不存在执行机构故障和干扰情况下的姿态有限时间稳定.在此基础上,利用积分滑模和自适应技术设计了一种有限时间姿态鲁棒容错控制方案,对执行机构故障和干扰进行有效的补偿;该方案能够快速地实现姿态高精度稳定,并抑制系统抖振现象.最后,将本文提出的姿态容错控制方案进行数值仿真与对比,验证了方案的有效性与优越性.     

基于扩张状态观测器的四旋翼无人机快速非奇异终端滑模轨迹跟踪控制

针对受多源干扰影响的四旋翼无人机系统的轨迹跟踪控制问题进行研究,充分考虑位置回路和姿态回路动态特性,提出一种全回路复合快速非奇异终端滑模轨迹跟踪控制方案.首先,通过变换将轨迹跟踪问题转化为位置回路和姿态回路的指令跟踪控制问题;然后,将各通道之间的耦合以及多源干扰影响视作集总干扰,并基于扩张状态观测器对其进行估计;接着,基于干扰估计信息和快速非奇异终端滑模控制算法,分别在位置回路和姿态回路构造复合快速非奇异终端滑模控制器;最后,基于位置回路和姿态回路虚拟控制量解得无人机真实控制量旋翼转速.仿真结果表明,所提出控制方案显著提升了四旋翼无人机轨迹跟踪的响应速度和抗干扰性能.     

ANFIS based multi-sector space vector PWM scheme for sensorless BLDC motor drive

This paper presents a design and development of Multi Sector Space Vector Pulse Width Modulation scheme (MS-SVPWM) for the speed control of brushless direct current (BLDC) motor drive. This control scheme is developed to enhance the performance of BLDC under wide range of speed and load variation. The hardware prototype is developed for 400 W, 30 V, 3000 rpm BLDC motor. The drive consists of uncontrolled rectifier unit for providing DC source to inverterunit. The proposed drive control has been done by implementing MS-SVPWM scheme using ANFIS control. The main function of ANFIS controller is to select the suitable sector for the drive and also predict the mismatching pulses by comparing conventional SVPWM and MS-SVPWM switching patterns. This new switching control technique helps to reduce switching losses of inverter and also improves an efficiency of BLDC system. This MS-SVPWM reduces the DC voltage ripple; Total Harmonic Distortion (THD) and torque ripple to the standard level. To verify and validate the practicality of the proposed system, the simulation is first performed using MATLAB Simulink tool. The hardware system is developed for the MS-SVPWM using DSPIC30F4011controller, the simulation and experimental results are presented.     

基于SoPC的直流无刷电机加速度控制研究与实现

为了实现对直流无刷电机加速度的准确控制,在分析几种加速度控制方案的基础上,提出了在电机加速阶段,通过在速度控制回路前向通道上加一积分环节来实现加速度控制的方案。详细介绍了该方案的原理并给出了基于SoPC技术的设计思想和实现方法。     

基于Simulink的无刷直流电机自抗扰控制系统的仿真

无刷直流电机(BLDCM)作为一个多变量强耦合非线性系统,经典PID控制已难以满足日益增长的精密控制需求.本文根据无刷直流电机的特点及自抗扰控制器(ADRC)设计原则,建立了一种无刷直流电机单环自抗扰控制系统,并在MATLAB/Simulink上建立了仿真模型.仿真结果表明ADRC对外部扰动和电机参数的变化有较强的鲁棒性.     

具有执行器故障的四旋翼无人机自适应预定性能控制

针对具有执行器故障的四旋翼无人机,提出一种自适应预定性能控制方案.首先,基于内环姿态控制及外环位置控制的双闭环控制策略,将无人机系统解耦为位置子系统和姿态子系统;其次,设计自适应控制方案,对存在的执行器故障参数进行自适应估计,有效地解决了执行器故障下无人机稳定控制问题;然后,提出一种预定性能控制策略,保证系统的暂稳态性能满足预先给定的性能指标;最后,通过仿真实例验证所提出方法的有效性.     

Adaptive sensorless robust control of AC drives based on sliding mode control theory

This paper focuses in the design of a new adaptive sensorless robust control to improve the trajectory tracking performance of induction motors. The proposed design employs the so‐called vector (or field oriented) control theory for the induction motor drives, being the designed control law based on an integral sliding‐mode algorithm that overcomes the system uncertainties. This sliding‐mode control law incorporates an adaptive switching gain in order to avoid the need of calculating an upper limit for the system uncertainties. The proposed design also includes a new method in order to estimate the rotor speed. In this method, the rotor speed estimation error is presented as a first‐order simple function based on the difference between the real stator currents and the estimated stator currents. The stability analysis of the proposed controller under parameter uncertainties and load disturbances is provided using the Lyapunov stability theory. The simulated results show, on the one hand that the proposed controller with the proposed rotor speed estimator provides high‐performance dynamic characteristics, and on the other hand that this scheme is robust with respect to plant parameter variations and external load disturbances. Finally, experimental results show the performance of the proposed control scheme. Copyright © 2006 John Wiley & Sons, Ltd.     

A memristor-based architecture combining memory and image processing

Image processing is a type of memory-access-intensive application and is applied in many fields.Logic operations are very simple ones in image processing.During these operations,memory access takes a majority of the total time consumed,which puts a great pressure on memory access speed and bandwidth.However,in traditional von Neumann architecture,memory access is the inherent bottleneck of the system;that is,the speed of memory’s data supply is far lower than the data request of processor.Memristor is considered to be the fourth circuit element after resistor,capacitor and inductor.It has the capacity of both processing and memory,which supplies a new idea for solving the"memory wall"problem.In this paper,memristor is used to build an architecture combining computing and memory,where the memory has the ability to handle some simple image processing operations.This architecture can reduce readings and writings of memory effectively,which saves memory bandwidth thus improving the efficiency of the system.Logic operations of images are considered in this paper to validate the architecture.The experimental results and theoretical analysis indicate that the architecture can reduce memory access effectively.     

某履带式全方位平台的电机控制器设计

针对某履带全方位平台实际工况要求,介绍了平台总体方案,选取一款1000W无刷直流电机（BLDC）作为平台驱动电机,阐述了BLDC控制原理及其控制方案,基于DSP28335设计了电机控制器,搭建了硬件电路,编写并调试了软件程序,采用速度、电流双闭环控制方案,设定电机转速为3000rpm,测定了电机相电压、电流等数据,进行了实物实验,结果表明该控制器性能稳定,响应迅速,具有较高的实际应用价值,且为后续控制策略研究奠定了基础。     

Real-Time Stabilization of an Eight-Rotor UAV Using Optical Flow

An original configuration of a small aerial vehicle having eight rotors is presented. Four rotors are devoted to the stabilization of the orientation of the helicopter, and the other four are used to drive the lateral displacements. A precompensation on the roll and pitch angles has been introduced so that the attitude dynamics is practically independent of the translational dynamics. This compensation is directly related to the velocity of the lateral motors. The dynamical model is obtained using the Euler–Lagrange approach. The proposed configuration is particularly useful for image processing since the the camera orientation is held constant. The eight-rotor rotorcraft is simpler to pilot than other rotorcrafts. A control strategy is proposed that uses the optical flow measurements to achieve a hover flight that is robust with respect to perturbations like wind. The new aerial configuration and control strategy have been tested in real-time experiments.      

A Quasi‐Sliding Mode Observer‐based Controller for PMSM Drives

In this paper a quasi‐sliding mode control for a permanent magnet synchronous motor (PMSM) is proposed where a cascade control scheme based on a properly designed state observer provides accurate speed tracking performance. The ultimate boundedness of both the observation error and the speed tracking error is proven. The controller performance has been validated using hardware in the loop (HIL) tests on a simulator based on the model of a commercial PMSM drive. Tests show that the proposed observer‐based controller produces good speed trajectory tracking performance and it is robust in the presence of disturbances affecting the system.     

ON STABILITY AND PERFORMANCE OF INDUCTION MOTOR SPEED DRIVES WITH SLIDING MODE CURRENT CONTROL

A novel inner loop sliding mode current control scheme for induction motor speed drives is proposed in this paper. The controller design is based on the nonlinear mathematical model of an induction motor in a coordinate system oriented along the rotor flux. The parameters of the PI speed controller are taken into consideration in the inner loop sliding mode current control. Rigorous stability verification for the overall system is provided in this paper. The chattering in sliding mode control is attenuated using the reaching law design method. The experimental results show that the proposed approach exhibits robust tracking performance in the presence of motor parameter variations and load disturbances.     

A new robust speed-sensorless control strategy for high-performance brushless DC motor drives with reduced torque ripple

This paper presents an analysis, design, and strategy of a high-performance speed-sensorless control scheme for estimating the phase-to-phase trapezoidal back-EMF of BLDC motor drive by means of a novel stochastic deconvolution technique in the H_∞ setting, named robust stochastic H_∞ deconvolution filter. In the proposed method, unlike the conventional observer-based approaches, the back-EMF is considered as an unknown input, and no need is felt for the constancy assumption of the rotor position and speed of machine within a short period of the time in the modeling of the BLDC motor which leads to ignoring the back-EMF dynamic at high and variable speed. In addition, since high-speed operation is vital for the motor, an improved approach has also been proposed to reduce the commutation-torque-ripple at high-speed for direct torque control (DTC) strategy of three-phase BLDC motor with 120° conduction mode in parallel with the proposed method due to the fact that drive performance intensely downgrades in this mode.     

PI velocity control of brushless DC motors using the extended dq transformation

This paper is concerned with velocity control in brushless direct current (BLDC) motors. Our control scheme is composed of a classical proportional–integral velocity controller and a proportional electric current controller computed in the extended dq coordinate system. We employ a finite time estimator that has been previously proposed in the literature intended to estimate the unknown back electromotive forces. This estimator has been proven previously to converge locally to the true values. This control strategy is proposed to eliminate torque ripple produced by the fact that back electromotive forces in BLDC motors are nonsinusoidal. We present, for the first time, a formal stability result for this control scheme: (a) the state has an ultimate bound provided that the estimate of the back electromotive forces is close to the true values, and (b) this ultimate bound can be rendered arbitrarily small when the estimate of the back electromotive forces converges to the true values. This result stands when starting from any initial condition such that the finite time estimator is ensured to converge to the true values. We verify our findings through simulations.