一种智能PID控制在中央空调冷冻水系统中的仿真研究

中央空调冷冻水系统属于典型的复杂非线性系统,常规PID控制难以达到满意的控制效果。本文在研究模糊控制及粒子群优化算法的基础上,结合模糊控制技术、PID控制技术、粒子群优化算法各自的优势,提出了一种新的模糊自适应PID控制策略。最后运用MATLAB软件对控制系统进行仿真。仿真研究表明,这种方法调节精度较高,调节迅速,超调小,具有很好的控制效果。     

Sugeno模糊推理实现PID的分层控制及仿真研究

结合普通PID控制扣模糊控制理论，在普通PID控制原理的基础上，提出了利用模糊控制理论中的Sugeno模糊推理实现模糊PID分层控制。此算法既结合了普通PID控制算法中所具有的结构简单、易实现、易使用的特点；同时又加入了专家经验等模糊智能控制的思想，使整个控制算法在控制过程中能根据实际所处的控制阶段及控制要求来动态地调整PID各参数。针对不同的仿真对象进行了仿真实验，仿真结果表明：使用此算法，整个控制过程性能参数有了很大的提高，超调明显减小，调节时间缩短，反应速度加快。由于此算法实现方便，原理简单，而且控制效果好，在实际的工业控制过程中具有非常广泛的应用范围，值得推广和借鉴。     

基于量子粒子群算法的PID参数自整定方法

PID控制在工业生产中应用非常广泛.以直流电机模型为被控对象,提出了基于量子粒子群算法的PID参数自动整定方法.应用经典的Ziegler-Nichols方法整定PID参数,被控对象性超调大往往难以满足要求.粒子群算法是通过模拟鸟群觅食过程中的迁徙和群聚行为而提出的一种基于群体智能的全局随机搜索算法.将量子粒子群算法用于优化PID参数,并与Z-N法整定的PID控制器性能进行对比.仿真结果发现,与Z-N法相比,基于粒子群算法优化的PID控制器,系统超调明显减小.除QPSO-PID(ITSE)对应的系统具有较长调节时间外,虽然应用不同优化目标优化后的PID参数不同,控制对象的响应性能却非常相似.     

基于动态神经网络在线辨识的PID控制

针对工业控制领域中复杂非线性时变系统和传统RBF神经网络辨识PID控制的不足,提出了一种基于聚类结合算法的动态RBF神经网络在线辨识PID自适应控制方法.通过优化的动态RBF辨识神经网络更好地描述了控制对象的动态行为,获得PID参数在线调整信息,实现系统的智能控制.仿真结果表明,与常规RBF神经网络辨识的PID控制方法相比该方法具有较高的控制精度,较快的系统响应,较强的适应性和鲁棒性.     

基于Hopfield网络的PID模型参考自适应控制的研究与仿真

为了得到较好的PID模型的控制效果,提出一种有效的控制方案.阐述PID控制技术的定义与Hopfield网络的基本原理.结合PID控制的特点,构造了基于Hopfield网络的PID模型参考自适应控制算法.利用Hopfield网络对控制器进行优化,得出优化后系统的相应参数.通过Matlab软件对构造的系统模型进行仿真.仿真结果表明,该算法实现简便,具有较好的实时性、稳定性和鲁棒性,对被控对象的控制效果比较理想.     

基于MFO优化RBF神经网络的舵机控制与仿真

针对某型号火箭发动机摆动机构舵机系统在非线性时变复杂条件下传统的PID控制精度低、适应能力差的缺点,通过对RBF神经网络算法和MFO算法的研究,并结合传统PID控制器,设计了MFO-RBF神经网络控制器。通过对系统仿真可以看出,同传统PID相比舵机最大偏角反馈值从22.2°优化到19.78°相移滞后减小了9°,系统的频率响应大大提高,阶跃响应超调量明显减少,上升时间从27 ms减小到11 ms,并且大大减小了稳态误差。研究表明,和传统的PID相比,MFO优化的RBF神经网络PID在位置环的控制效果上有明显提升。     

机载光电跟踪系统的模糊PID控制

为了提高机载光电跟踪系统的控制性能,提出了一种模糊自适应PID控制算法。首先,针对机载光电跟踪控制系统的特点,建立了被控对象的模型。接着,对机载光电跟踪系统模糊PID控制器的设计进行了详细介绍。最后,利用经典PID控制、模糊控制、模糊PID控制3种算法对机载光电稳定跟踪系统进行仿真比较。仿真结果表明模糊PID控制算法较之前两种算法具有响应快、超调量小、抗干扰能力强、稳态性能好等优点,对机载光电跟踪系统具有较好的控制能力。     

基于Toeplitz方程的改进广义预测PID控制

针对具有较大时滞的复杂被控对象,研究了改进的广义预测(GPC)PID控制算法。在保证经典PID控制性能的前提下,用滚动预测优化原理,自整定PID控制参数,同时解决系统时滞引起控制问题。通过最后对仿真结果的分析来看,运用Toeplitz方程的改进算法能有效提高系统的稳定性和求解计算的快速性。     

基于LabVIEW的炉温灰色预测PID控制仿真研究

文中以干燥箱为被控对象,以灰色系统理论为基础,应用GM(0,N)灰色建模方法,进行了其灰色PID控制算法研究,并在LabVIEW平台上,利用Matlab Script节点实现了其控制算法仿真。仿真结果表明:灰色预测PID控制的系统超调量较少、调节时间较短、动态品质较好和抗干扰能力强,控制效果明显优于传统PID控制。     

四旋翼飞行器MAC-PID位置控制研究

针对四旋翼飞行器传统PID控制系统存在的响应慢、抗干扰能力差、超调较大等问题,将模型算法控制(MAC)引入传统PID控制系统,以改善控制系统的动静态性能。将不完全微分PID控制器与MAC控制器相结合,构成串级闭环控制系统:将不完全微分PID控制器作为内环控制,实现对横滚角和俯仰角的姿态控制;将MAC作为外环控制,实现对位置以及偏航角的控制。仿真结果表明该方法与传统PID控制相比,其超调量小、响应速度快、响应曲线平滑。     

模糊PID控制在锅炉燃烧系统中的应用

针对目前锅炉存在的能耗高、燃烧不完全、污染环境、热效率低的缺点,设计了一种新型锅炉燃烧系统.该系统采用PID串级和Vague集分时控制,有效地提高了锅炉控制质量.     

Suboptimal digital control systems with bounded control inputs

Bounds on the control inputs to a linear system are dealt with in a manner suitable for online computer control. The method guarantees that for r control inputs the constrained optimum will be located in, at most, r steps.     

水泥配料控制中控制算法的研究

配料是水泥生产过程的重要环节,在一些连续称量配料工艺过程中,以往大多通过控制每种物料的瞬时流量来满足工艺要求,但往往误差较大,给生产带来不良影响。为提高控制精度,提出了一种偏差加权累积量控制PID算法,并在水泥生料配料控制中进行了实施,实验结果表明该算法能有效地抑制和消除系统过量超调和不停振荡,且对于某些不要求每个瞬时值都控制给定值的量,该算法可以避免调节阀的频繁动作并大大提高调节品质。偏差加权累积的PID控制算法具有简单、方便、易于实现的特点,且在水泥生料配料控制中取得了理想的效果,有很好的推广前景。     

Adaptive ABR congestion control with active buffer control

ATM Forum has defined that the ABR service is designed mainly for data traffic. The design of a simple and efficient congestion control scheme is a problem that network managers have to face. In this paper, we propose a control scheme for ABR service for better scalability and response. The scheme uses both the load level and an increase in queue length to detect the presence of congestion. Continuous control functions are designed for the bandwidth allocation. A better buffer control is achieved by incorporating the percentage of buffer occupancy into the control function. All of the control functions are designed in such a way that they are sensitive to the change of the system states when they are far from the optimal level to get a fast response, but insensitive and change slowly when the states are close to the optimal level to keep the system around the steady state. Our simulation results show that the algorithm is fair to all the connections and it converges fast when the network's condition changes. Copyright © 2001 John Wiley & Sons, Ltd.     

Content-based deep communication control for networked control system

In smart cities, the networked control system plays a significant role in transportation systems, power stations or other critical infrastructures, and it is facing many security issues. From this point, this paper proposes a content-based deep communication control approach to guarantee its security. Based on the layer architecture, this approach analyzes the interactive content in depth according to different industrial communication protocols, and implements the access control between two distinct enclaves. For OPC Classic, we acquire the dynamic port provided by OPC server, and open a new connection belonging to this port; for Modbus/TCP, we not only analyze the ordinary function codes and addresses, but also check the register or coil values by using the multi-bit Trie-tree matching algorithm. Besides, the white-listing strategy is introduced to satisfy the special requirements of industrial communication. Our experiment results show that, on the one hand the proposed approach provides OPC and Modbus/TCP defenses in depth; on the other hand it has less than 1 ms forwarding latency and 0 packet loss rate when the rule number reaches 200, and all these meet the availability requirements in the networked control system. In particular, this approach has been successfully applied in several real-world petrochemical control systems.     

基于TRICON控制系统防喘振控制算法

喘振是造成压缩机损坏的重要原因,在此针对某厂70万吨/年烯烃项目,根据丙烯工艺流程,设计了一套压缩机的防喘振控制系统。该控制系统以TRIEW软件为人机界面,利用TRICON独有的防喘振控制软件包,将喘振PID控制、喘振超驰、手动控制算法相结合,通过喘振PID参数的在线优化,有效地实现了压缩机的防喘振控制,现场实际运行结果表明了该系统的稳定性和可靠性,同时,验证了该喘振控制算法的有效性。     

Modeling and control for smart Mesoflap aeroelastic control

This paper introduces a novel concept termed Smart Mesoflaps for Aeroelastic Recirculation Transpiration (SMART) to render mass and momentum transfer for controlling shock/boundary-layer interactions in supersonic jet inlets. The SMART concept consists of a matrix of small flaps designed to undergo local aeroelastic deflection to achieve proper mass bleed or injection when subjected to shock loads. To optimize the performance of this system, NiTi shape memory alloy is used as an actuator for the flaps to control the amount of recirculation. The focus of this paper will be the subsystem modeling and control of a single flap. After a relatively detailed model is developed, a simpler model is generated, and it is experimentally shown that this approximation is adequate for control purposes. Next, the control strategy for this subsystem, subject to hysteresis and actuator saturation, is presented. A basic proportional integral derivative (PID) controller is enhanced using a hysteresis compensator (HC) and an error governor (EG). A generalized error governing scheme for PID controllers to compensate for actuator saturations is also developed. This EG method is generalizable to any stable process controlled by a PID. Finally, the PID with HC and the error governing method is experimentally applied to a benchtop SMART subsystem.     

Throttle actuator control system for vehicle traction control

Accurate and quick positioning of the throttle valve in a gasoline engine is required to implement various systems such as traction control systems (TCS), cruise control systems and drive-by-wire systems. In this research, the throttle actuator system for TCS application was developed. Unlike other systems, this system consists of only one throttle body to obtain small volume and low manufacturing cost, and uses a DC servo motor for quick and accurate responses. In order to drive the DC motor, a PWM signal generator and PWM amplifier were built and interfaced to the motor and controller. This paper also presents the position control logic of the throttle actuator with the TDC (time delay control) scheme with a variable reference model. By varying the reference model based on the size of the step changes in the target throttle angle, the TDC scheme yields good transient response characteristics in that both overshoot prevention and a quick response time are achieved. Actual vehicle tests with this developed system incorporated with the TCS system show that it satisfies all the conditions required for the TCS operation.     

基于自适应模糊理论的某型无人机起飞控制方法

基于合理简化的无人机纵向模型,设计了一种自适应模糊控制器,该控制器将Takagi-Sugeno模糊系统与等效控制器相结合,以增强系统的鲁棒性.只要求预先知道系统的相对阶以及未知函数的上下界即可,不需要精确的数学模型.Lyapunov合成方法证明了跟踪误差能趋近于零且其余的控制信号均有界.最后,结合优先级按比例分配的控制分配器,给出了存在扰动情况下飞行控制系统的仿真结果,表明即使在模型部分未知的情况下,该系统仍然能够达到飞行控制的指标性能和品质要求,验证了该方法的有效性.