Theory, simulation, experimentation: an integrated approach toteaching digital control systems

This paper discusses the approach adopted by the authors for teaching an undergraduate course (lecture and laboratory) in digital controls. Theoretical material is developed in the lecture concerning the application of direct digital control (DDC) to an analog bench-scale system consisting of a DC motor and tachometer. A simulation of the closed-loop control system with embedded digital controller is developed and run by the students using the TUTSIM dynamic simulation language. Finally, students perform a laboratory experiment in which they write a program to control the actual system using a personal computer and inexpensive interface card. The combination of hands-on experience and computer simulation with the more traditional, theoretical lecture material provides a well-rounded learning experience that better prepares the students to implement digital control systems in the real world     

Digital hardware implementation of a current controller for IMvariable-speed drives

This paper presents the design of an induction machine current controller that is entirely implemented in digital hardware. A hardware current controller allows high switching frequencies with only modest processing power, as well as simplified controller hardware and software. The paper briefly presents the concepts of the algorithm implemented, and then outlines the changes that are made to make the digital implementation even more efficient. It then discusses the architecture used for the hardware design. Experimental results are presented to demonstrate the algorithm's performance     

An integrated environment for modeling, simulation, digital signalprocessing, and control

An integrated laboratory for system modeling, simulation, real-time digital signal processing, and control is being developed at Bucknell University for undergraduate electrical engineering education. The laboratory bridges the gap between software simulation and testing of actual systems through a common visual programming interface. Students can explore the iterative process of developing a model and then refining the model until computer simulation results agree with experimental measurements. A liquid level control system is presented to illustrate the features of the laboratory environment. The key components of the laboratory are networked digital signal processing (DSP) hardware units and a simulation software package. The simulation software runs on workstations, and all of the laboratory equipment (including the DSP hardware) is connected to the Internet     

Using TACS functions within EMTP to teach protective relayingfundamentals

The purpose of this discussion is to provide an educational tool for investigating relaying concepts by modeling digital relays using TACS functions within EMTP in a closed-loop manner. Various elements of digital protection systems are identified and organized to generate an systematic approach to modeling the actual hardware of relay systems. Discussion is limited to conventional relaying systems that monitor the vitality of the 60 fit voltages and/or currents. TACS functions for transport delay and pulse generators are used to model dynamics associated with analog to digital conversion and sampling systems. DSP algorithms convert a sequence of sampled data into a sequence of values for magnitude and phase components. A simple example of a time overcurrent relay is developed to demonstrate the techniques to implement relay control in EMTP with TACS and illustrates the kinds of phenomena that can be studied using these techniques     

一种智能型控制器的电路设计

提供了智能控制器的简要硬件框图、控制器放大电路的设计、控制器各个功能的介绍.控制器以DSPIC30F6014单片机为核心,由数字信号处理器、放大电路、LCD显示、控制接口电路、区域联锁、键盘、模拟电源模块、通信接口电路、开关电源等模块组成.控制器能够实时监控并及时、有效地控制执行机构的动作.     

Microcomputer Control of Switched Reluctance Motor

A microcomputer-based four-quadrant control system of a switched reluctance motor is described. The control was implemented with a speed feedback loop, a torque feedback loop, and both the torque and speed feedback loops combined. In addition the controller incorporates a startup operation, sequencing, and synchronized angle steering control. The angle controller was designed using dedicated digital hardware, whereas the other functions were implemented using an Intel 8751 single-chip microcomputer. The complete control system was tested in the laboratory with a 5-hp drive, and the test results were found to be excellent.     

DSP-Based Real-Time Implementation of a Hybrid H ∞ Adaptive Fuzzy Tracking Controller for Servo-Motor Drives

An embedded hybrid Hinfin adaptive fuzzy control structure is implemented for trajectory tracking control of a brushless servo drive system. The control structure employs a fuzzy logic controller incorporating an Hinfin tracking controller via an acceleration feedback signal. The fuzzy logic controller is equipped with an adaptive-law-based Lyapunov synthesis approach to compensate for system uncertainty and random changes in the external load acting on the drive system. The proposed control structure is experimentally verified on a state-of-the-art dSPACE DS1104 digital signal processor (DSP)-based data acquisition and control system in a laboratory 1-hp brushless drive system. The controllers are first designed in Simulink. Then, the Real-Time Workshop is used to automatically generate optimized C code for real-time applications. Afterward, the interface between MATLAB/Simulink and the dSPACE DS 1104 allows the control algorithm to run on the hardware processor of the DSP. The result is a powerful testbed for the rapid design and implementation of the hybrid tracking controllers for a wide variety of operating conditions. Experimental results are provided to verify the effectiveness of the proposed controller. Considerable improvement in the performance generated by the hybrid controller is compared with the traditional Hinfin controller     

基于Lyapunov函数的全数字锁相环的优化设计

对三相输入电压畸变条件下的矢量型数字锁相环工作原理及其非线性动态模型进行了研究,给出了一种基于Lyapunov函数的具有高稳定性和相位跟踪能力的三相数字PLL的设计方法。对环路滤波控制器和具有自动复位功能的压控振荡器分别进行离散化,解决了数字化过程中处理器有限字长的问题。对三相输入相不平衡、谐波、偏移等畸变条件下的PLL误差进行了计算和分析,采用PI控制器取代传统的环路滤波器,提高了三相数字锁相环抑制畸变的能力和跟踪响应的速度。采用DSP实现三相数字锁相环技术,并用于6kW逆变器功率因数的控制中,仿真和实验均验证了理论分析的正确性。     

APF控制器的动静态性能分析

讨论了基于可编程逻辑门阵列（Field Programmable Gate Arrays,FPGA）实现的全数字控制器对并联型有源电力滤波器（Shunt Active Power Filter,SAPF）的动静态性能的影响,着重分析了数字控制器的运算延时和响应时间。最后,给出了控制器对SAPF动静态性能影响的实验结果。实验结果与理论分析一致。     

基于模糊逻辑的磁悬浮混合悬浮磁极控制方案

电磁永磁混合悬浮是电磁型(EMS)高速磁悬浮列车悬浮系统的发展方向之一,由于系统具有强非线性和慢时变的特点,传统的状态反馈控制在系统参数变化较大时有可能使系统失稳.本文在简要分析系统数学模型的基础上首先给出了传统的状态反馈控制器的设计方法,并在此基础上,提出了一种非线性模糊PD控制器结合线性加速度阻尼环节和线性积分环节的混合控制器.由于模糊控制器的设计过程综合了专家经验,从而使得整个系统更具有鲁棒性,并且动态特性也得到了改善,系统响应速度更快,超调量也更小.试验结果证明了该方案是正确的.     

Purdue's Junior-Level Control Laboratory with Microprocessors

A microprocessor-based direct digital control system laboratory developed at Purdue University is discussed. The microprocessor controller interfaces directly to an analog computer for simulation control or to control components such as motors, heaters, etc. Available resident processor routines (A/D, D/A, arithmetic, timing, etc.) can be easily configured into a digital control system program allowing strategies to be quickly developed and tested. Al operations are performed directly at the control station via a terminal keyboard, and the system has the potential for stand-alone operation with a graphics output terminal A typical digital control system example-servo position control-has been developed for use in the Junior Control Laboratory. In addition to unlimited possibilities for software strategies, patchable features such as comparators, logic circuitry, timing functions, etc., are available on the front panel, allowing quick, efficient development of a complete digital control system.     

用于电力系统控制的计算机辅助工程(CAE)平台的设计

介绍了用于电力系统仿真及控制器设计的计算机辅助工程平台的开发。给出了该平台的软、硬件设计方法,描述了该平台的功能和应用。利用该系统,可以使控制算法设计人员方便地将在平台上仿真后认为满意的算法直接提取出来,经平台提供的编译连接程序处理后直接下载到ＤＳＰ硬件中,从而显著提高了控制器设计的效率。文中还介绍了该平台在ＳＴＡＴＣＯＭ 控制方面的动模实验结果     

Implementation of an intelligent-position-controller-based matrix formulation using adaptive self-tuning tracking control

This paper proposes an intelligent position controller for brushless motor drives and motion controls. The controller is based on theory of the self-tuning tracking control. It integrates the principles of fuzzy logic with learning functions of neural networks into intelligent control architecture. A matrix formulation of a fuzzy-rule-based system is introduced. Consequently, a training-algorithm-based error function is also expressed in a matrix form. The resulting controller is significantly simple in structure and learning capability, and robust, and has high tracking performance (with respect to reference and measured data). With the proposed controller the rotor position can trace any arbitrary selected trajectory without overshooting or overstressing the hardware system. The entire system is designed and implemented in the laboratory using a hardware setup. The results of the laboratory testing are described in the paper. Compared to the proportional-plus-integral controller, the proposed controller yields a better dynamic performance with shorter settling time, without overshoot. Experimental results have shown that the proposed controller adaptively and robustly responds to a wide range of operating conditions.     

基于FPGA的飞行校验多模信号采集与处理设计

针对仪表着陆系统(ILS)、甚高频全向信标(VOR)等的飞行校验需求,设计了一种基于FPGA的多模信号采集与处理系统。选用普通导航接收机接收信号,以FPGA作为逻辑和时序控制核心。系统包含了模拟信号调理和A/D转换、无线电系统总线(RSB)接口、ARINC 429总线接口、USB总线接口等的相应软硬件设计,首次在国内提出RSB软硬件实现方案。根据ILS与VOR的信号特点,并且分析了FPGA有限字长的影响,设计了数字滤波器,实现了在FPGA上的校验信号处理。经过验证,设计能够为飞行校验平台提供有效的数据,并且具备较强的可移植性,符合要求。     

Demonstration of the internal model principle by digital repetitive control of an educational laboratory plant

A key topic in classical control theory is the Internal Model Principle (IMP). A particular case of the IMP for tracking periodic references or attenuating periodic disturbances in closed-loop control systems is a technique called repetitive control. This work proposes and describes an educational laboratory plant to show the students the advantages of repetitive controllers in systems with periodic references or disturbances. The plant has been designed to be low cost, easy to build, and subject to periodic disturbances with a clear physical explanation. More specifically, it consists of a pulsewidth modulation (PWM) electronic amplifier, a small dc motor, and a magnetic setup that generates a periodic load torque under constant mechanical speed operation. The control objective for the closed-loop control system is to regulate the mechanical speed to a constant value in spite of the periodic load torque disturbance. In order to accomplish this performance specification, a detailed design of a digital repetitive controller is presented, and some basic experimental results are provided to prove its good behavior. The paper also includes some repetitive control concepts and facts that teaching experience shows as essential to understand the design process.     

A new control strategy for voltage-type PWM rectifiers to realizezero steady-state control error in input current

In this paper, a new simple control strategy for AC input current of voltage-type pulsewidth modulation (PWM) rectifiers which can eliminate the steady-state control error completely is proposed. This control method requires neither the instantaneous value of the supply voltage nor any accurate circuit parameters on the AC side of the rectifier. Thus, a robust operation against the variation of the circuit parameters can be achieved. In the proposed control system, a digital resonant element implemented by a digital signal processor (DSP) is introduced as a feedback controller. The digital resonant element exhibits a function similar to an integrator for the fundamental frequency components. Thus, it can eliminate the steady-state control error of the input current completely, The principle of the proposed control method is discussed, and its effectiveness is shown theoretically. The detailed method of the implementation of the lossless digital resonant element is explained. The effects of the harmonics in the supply voltage on the AC input current waveform are clarified. To confirm the effectiveness of the proposed control method, some experimental results from two laboratory test systems are shown     

基于ASIC的高速开关磁阻电机数字控制器

为了提高高速开关磁阻电机(SRM)控制器的系统性能,简化控制电路,设计了一种具有角度控制功能的专用集成电路(ASIC)SR3P10K07A.基于ASIC,开发了一套高速SRM数字控制器.其转子位置信号处理、角度解算等功能由SR3P10K07A完成,执行效率高、抗干扰能力强.而微处理器(MCU)仅负责控制算法实现和状态检测等功能,对MCU的资源需求大幅减少,因此可选用单片机(SCM)来实现高速SRM的实时控制.最后,该控制器在一台高速SRM样机上进行了实验,样机最高转速达到130 000 r/min.试验结果表明,所设计的数字控制器可有效满足高速SRM的控制要求.     

A new hardware-efficient digital sinusoidal oscillator with low- and uniform-frequency spacing

In this paper, a new low-frequency digital sinusoidal oscillator with uniform-frequency spacing is proposed, and its performance is evaluated. The proposed oscillator structure, P, requires a single, short word-length multiplier for its hardware implementation. For the same frequency range, the single multiplier utilized can be implemented using an 8-bit word length, assuming that the multipliers in the previously reported oscillators, such as the multiple-output direct form digital oscillator and its modified versions, are implemented using 16 bits. The saving in multiplier word length results in a reduction in the silicon area and power dissipation. The proposed oscillator structure utilizes a multiple-output direct form digital oscillator with a single, short word-length multiplier in addition to a very simple switching and sign changing operation. The proposed oscillator structure is capable of generating sinusoidal signals with a large number of samples per cycle. The phase of the generated sinusoids is continuous at the switching points, and the difference between any two adjacent generated frequencies is approximately constant. Simulation results are presented to verify the analysis and demonstrate the performance as measured in terms of total harmonic distortion. It is evident from the simulation results that the performance of the proposed oscillator is essentially the same as those of the previously reported oscillators with less hardware complexity.     

嵌入CBAM结构的改进YOLOV3超宽带雷达生命信号检测算法

为了提高超宽带雷达生命信号检测准确率,提出了一种改进型YOLOV3检测算法。考虑到超宽带雷达探测的人体呼吸信号成像后宽高相差较大,采用多尺度训练时网络对宽高的敏感程度不一样,因此在设计损失函数时,对宽高损失给予不同的权重系数。为了提高网络通道以及空间特征表达能力,使得网络能够扩大对目标特征区域的感知范围,因此将通道注意力与空间注意力结构(CBAM)嵌入到YOLOV3基础网络Darknet53的每个shortcut层,得到CBAM-YOLOV3网络结构。对比改进前后的算法。实验结果表明,改进后的算法在IoU阈值为0.5时,mAP为98.09%,提升3.90%,在阈值为0.75时,mAP为76.49%,提升16.48%。