Application of Neural network PID Controller in Constant Temper-ature and Constant Liquid-level System

Guided by the principle of neural network, an intelligent PID controller based on neural network is devised and applied to control of constant temperature and constant liquidlevel system. The experiment results show that this controller has high accuracy and strong robustness and good characters.

Design of Constant-Speed Control Method for Water Medium Hydraulic Retarders Based on Neural Network PID

The water medium hydraulic retarder is the latest type of auxiliary braking device and has the characteristics of high power density,large braking torque,and compact structure.During traveling,this device can convert the kinetic energy of a vehicle to the heat energy of the cooling liquid and replace the service brake under non-emergency braking conditions.With regard to the constant-speed function of the water medium hydraulic retarder,this study designs a controller based on the neural network proportional-integral-derivative(PID)algorithm to achieve the steady traveling of the vehicle at constant velocity during a downhill course by controlling the filling ratio of the water medium hydraulic retarder.To validate the algorithm’s effectiveness,the dynamic model of the heavy-duty vehicle in the downhill process and the physical model of the water medium hydraulic retarder are developed.Three operating conditions,including a fixed slope,step-changing slope,and continuous changing slope,are set,and a simulation test is carried out in the MATLAB/Simulink environment.The neural network PID algorithm has better adaptability in controlling than the traditional PID algorithm.Thus,it controls the water medium hydraulic retarder such that the braking requirements of heavy-duty vehicles under a changing slope working condi-tion are satisfied,and it performs constant-speed control when the vehicle travels downhill.Therefore,the proposed control method can significantly improve the safety of road traffic.

基于模糊神经网络的氢液化氦气压力PID控制

为了解决氢液化装置氦气压力调节系统超调量大、响应速度慢、调节时间长、控制参数无法在线整定等问题,针对系统具有非线性和时变性的特点,设计了基于模糊神经网络的PID控制器以及基于双曲正切函数的改进型激活函数。仿真结果表明:相比传统PID控制或模糊PID控制,采用模糊神经网络PID控制的系统动态性能显著改善,使得氢液化装置的氦气压力调节更加稳定可靠。

基于反向传播神经网络PID的高功率微波炉温度控制

针对现有10 kW高功率工业微波炉,采用继电器作为控制执行器,在使用传统控制方法加热时,温度存在较大超调和明显振荡,系统温度稳定性较低,为解决上述问题将反向传播神经网络PID(BPNNPID)控制引入到该装置微波加热温度控制中,并以自来水为加热对象进行仿真对比与实验验证。首先,利用现有输入输出实验数据,建立工业微波炉温度控制模型;其次,运用MATLAB/SIMULINK搭建高功率工业微波炉温度控制系统并进行仿真对比实验;最后,实验验证BPNNPID控制方法在加热5 kg自来水时工业微波炉的温度控制性能,实验结果表明,较常规PID、模糊PID控制,该方法在微波加热过程中对媒质温度控制超调更小且未发生明显温度振荡,有效改善了高功率工业微波炉工作时的系统温度稳定性,有助于提高产品质量和安全性能。

基于RBF神经网络整定PID的电液比例系统位置控制研究

针对凿岩机械臂的电液比例系统位置控制精度问题,提出了一种基于径向基函数(RBF)神经网络整定PID的电液比例系统位置控制方法。首先,在AMESim中搭建了阀控非对称液压缸的电液比例系统简化模型,设置了各个模块的参数;然后,利用MATLAB/Simulink搭建了系统闭环控制模型,通过不断更新RBF网络模型并修正PID参数,实现了基于RBF神经网络整定PID的电液比例系统位置控制目的;结合AMESim搭建的电液比例系统模型和Simulink下搭建的控制器进行了联合仿真;最后,基于凿岩台车机械臂实验平台,进行了电液比例系统位置控制实验。仿真结果表明:在受到外部干扰的情况下,RBF神经网络整定PID控制系统能够在0.3 s内控制活塞杆重新运行至目标位置,平均响应时间为1.5 s,位置精度误差不超过5 mm。实验结果表明:与常规PID控制方法相比,RBF神经网络整定PID控制活塞杆位置精度误差降低了75%,位置精度误差在工程实际要求的10 mm范围以内,因此,RBF神经网络整定PID算法可以有效提高电液比例系统的位置控制精度,满足凿岩机械臂实际工作中对电液比例系统位置精度的控制要求。

足式机器人腿部关节改进单神经网络PID控制算法研究

为了满足液压足式机器人在复杂环境中实现精确、快速的腿部关节控制需求,把单神经网络PID能够实时调节参数的优点运用到足式机器人液压机械腿关节的控制中,在单神经网络PID的基础上增加机械腿关节的位置和速度控制算法,形成改进单神经网络PID,实现了对神经元比例参数自调整、PID参数的自整定,能够较好地适应内、外参数的变化,增强了腿部关节的快速性、精确性。在Simulink中进行建模仿真以及在设计的以STM32为中央处理芯片的控制平台上进行实验测试,结果表明:改进单神经网络PID在足式液压机器人的腿部关节控制中具有响应速度快、超调量小、控制精度高、鲁棒性强等优点。

基于PSO改进BP算法的直流电子负载PID控制仿真

针对电子负载控制灵敏度低、稳定性差等问题,提出基于PSO-BP-PID的直流电子负载控制方法。分析电子负载基本结构,构建数学模型,分析电子负载在不同工作模式下的电流变化规律;建立三层BP网络模型,分别描述每层结构的输入与输出内容;为提高BP网络的学习能力,减少控制误差,将PSO算法作为学习算法,确定粒子群规模、惯性权重等重要参数,获得所有粒子适应度值,不断更新个体的位置与速度,当满足收敛条件时,输出最优解,实现控制参数的自适应调整;根据算法特征,设计控制器整体结构,利用该控制器即可实现直流电子负载控制。仿真结果表明,所提方法的控制误差小,响应速度快,且控制过程中能够有效抑制谐波。

Decentralized PID neural network control for a quadrotor helicopter subjected to wind disturbance

A decentralized PID neural network(PIDNN) control scheme was proposed to a quadrotor helicopter subjected to wind disturbance. First, the dynamic model that considered the effect of wind disturbance was established via Newton-Euler formalism.For quadrotor helicopter flying at low altitude in actual situation, it was more susceptible to be influenced by the turbulent wind field.Therefore, the turbulent wind field was generated according to Dryden model and taken into consideration as the disturbance source of quadrotor helicopter. Then, a nested loop control approach was proposed for the stabilization and navigation problems of the quadrotor subjected to wind disturbance. A decentralized PIDNN controller was designed for the inner loop to stabilize the attitude angle. A conventional PID controller was used for the outer loop in order to generate the reference path to inner loop. Moreover, the connective weights of the PIDNN were trained on-line by error back-propagation method. Furthermore, the initial connective weights were identified according to the principle of PID control theory and the appropriate learning rate was selected by discrete Lyapunov theory in order to ensure the stability. Finally, the simulation results demonstrate that the controller can effectively resist external wind disturbances, and presents good stability, maneuverability and robustness.

基于粒子群优化BP神经网络PID的供热控制系统仿真研究

供热系统技术属于清洁技术,但其能耗非常大,因此在供热系统中能源的损耗问题就显得尤为重要。与此同时,我国供暖过程多数是用传统PID对供暖系统进行控制,由于传统PID控制响应时间长、超调量高且受外界影响较大,造成能源未充分利用、浪费现象严重。因此针对此问题,提出了在供暖系统中采用一种基于粒子群优化BP神经网络PID的控制策略,不仅可以解决供暖时水温不稳定、水温上升时间长等问题,而且可以更好地解决能源未充分利用问题。本文建立供热系统的数学模型,然后利用Matlab中的Simulink设计并仿真粒子群BP神经网络PID控制器。实验结果表明,改进后的PID控制器抗干扰能力强且具有较好的鲁棒性,对供热控制系统有更好的控制效果。

Nonlinear Decoupling PID Control Using Neural Networks and Multiple Models

For a class of complex industrial processes with strong nonlinearity, serious coupling and uncertainty, a nonlinear decoupling proportional-integral-differential （PID） controller is proposed, which consists of a traditional PID controller, a decoupling compensator and a feedforward compensator for the unmodeled dynamics. The parameters of such controller is selected based on the generalized minimum variance control law. The unmodeled dynamics is estimated and compensated by neural networks, a switching mechanism is introduced to improve tracking performance, then a nonlinear decoupling PID control algorithm is proposed. All signals in such switching system are globally bounded and the tracking error is convergent. Simulations show effectiveness of the algorithm.

薄膜复合粘接工艺的PID控制优化分析

为块状物薄膜复合粘接工艺提供精确可靠的控制方案,根据不同薄膜复合粘接工艺进行分析得到电机控制特征,并与传统的控制方法进行控制效率对比,对茶砖薄膜复合粘接的步骤加以确定并使用PLC实现粘接系统控制,通过PID策略分析和MATLAB仿真后,选择得到块状物粘接控制方案,粘接过程中的各阶段的阶跃响应曲线,下料时间有效缩短为其定重时间的80%以上,并缩短原有下料时间25%-34%。通过使用合适的PID控制方案有效地优化了原有粘接工艺,为实际应用于相关生产过程中提供科学的理论支持。

GA-BASED PID NEURAL NETWORK CONTROL FOR MAGNETIC BEARING SYSTEMS

In order to overcome the system non-linearity and uncertainty inherent in magnetic bearing systems, a GA（genetic algnrithm）-based PID neural network controller is designed and trained tO emulate the operation of a complete system （magnetic bearing, controller, and power amplifiers）. The feasibility of using a neural network to control nonlinear magnetic bearing systems with unknown dynamics is demonstrated. The key concept of the control scheme is to use GA to evaluate the candidate solutions （chromosomes）, increase the generalization ability of PID neural network and avoid suffering from the local minima problem in network learning due to the use of gradient descent learning method. The simulation results show that the proposed architecture provides well robust performance and better reinforcement learning capability in controlling magnetic bearing systems.

干涉式闭环光纤陀螺仪的PSO-PID控制优化方法

控制系统的设计会对响应速度快且应用范围较广的数字干涉式闭环光纤陀螺(ICFOG)动态性能产生影响。通过分析ICFOG的工作原理,推导出闭环离散控制系统,并利用粒子群优化算法(Particle Swarm Optimization,PSO)对传统的PID控制器参数进行优化。基于这个优化过程,设计一种新型的PSO-PID复合控制器,以取代传统的PID控制器。通过与其他BP神经网络、模糊控制等方法进行对比凸显该控制方法的优越。通过数字仿真分析显示,跟踪速度相较于BP-PID控制方法提高了1.91倍,相对于PID控制方法提高了3.5倍,相对于F-PID控制方法提高了1.75倍。同时,控制精度相对于BP-PID控制方法提高了46.03%,相对于PID控制方法提高了66.30%,相对于F-PID控制方法提高了45.27%。结果显示,采用PSO-PID控制器能够快速达到控制目标且具有较小的超调量。

飞机起落架自适应模糊神经PID控制方法的研究

针对传统PID控制与模糊PID控制的飞机起落架控制系统存在达不到理想控制精度以及控制速度的问题,提出一种基于模糊控制和神经网络的模糊神经PID控制算法。通过对起落架运动特点以及动力学相关的理论分析建立飞机起落架的运动模型,将此智能PID控制方法应用到飞机起落架的姿态控制系统中。利用MATLAB/Simulink软件进行仿真,并基于树莓派装置进行了起落架单腿实验。仿真和实验结果表明:模糊神经网络PID控制系统的响应速度和抗干扰能力相较于传统PID和模糊PID都有了较大的提升,系统稳定性更强。在飞机起落架控制系统中,应用模糊神经PID控制可进一步提升系统的响应速度,降低系统运动的惯性冲击,提高整体机构的稳定性。

四旋翼无人机预设性能自适应PID控制

针对四旋翼飞行器在轨迹跟踪过程中存在建模误差和外界干扰问题,设计了一种双闭环控制系统。内环姿态环采用自适应PID算法,用滑模算法作为自适应机制,结合梯度下降法克服传统PID需要手动调节参数的问题,并用RBF神经网络消除滑模控制过程中产生的抖振现象;外环位置环采用预设性能自适应PID算法,即在自适应PID算法的基础上加上预设性能控制,将误差用预设性能函数进行转换,使系统误差能够始终稳定在预设值,实现位置的快速跟踪;最后用Lyapunov函数证明系统的稳定性。从跟踪的快速性、稳定性和稳态性能方面,由仿真结果对比证明本文所设计的控制算法有很大的优越性,并能对不同形式的外部扰动表现出强抗干扰性。

单神经元PID控制仿真与实现研究

经典PID控制参数整定方法繁琐并且容易对设备造成损伤,此外,当系统对象存在非线性、环境变化或者其他因素时,系统的稳定性和响应速度也会受到一定的影响。为了解决这些问题,该文引入神经网络与PID控制方法相结合,控制对象选择双容水箱,对系统进行多次仿真、对比,然后提出神经网络控制仿真参数设置方法,进而将神经网络PID控制算法应用于实际控制系统中,实验证明该创新方案不仅解决了PID控制方法存在的问题,还找到了一个低成本的升级方案,为控制系统提供了重要的技术支持。

基于BP神经网络PID的中子发生器离子源阳极电流控制研究

本文将BP神经网络算法与PID控制结合,优化了中子发生器控制离子源阳极电流PID调节过程,实现了控制器自适应整定,提升了控制效果。基于离子源阳极电流控制模型改进了PID算法,通过MATLAB/Simulink软件对两种算法进行仿真并对比分析。通过LabVIEW控制并采集离子源阳极电流值,使用改进后的BP神经网络PID算法控制程序进行实验。经实验表明,BP神经网络PID对离子源阳极电流控制能够实现参数的自适应整定,相比传统PID控制器超调量更小、响应速度更快,提高了中子发生器的控制稳定性。

Research on the controller of an arc welding process based on a PID neural network

A controller based on a PID neural network （PIDNN） is proposed for an arc welding power source whose output characteristic in responding to a given value is quickly and intelligently controlled in the welding process. The new method syncretizes the PID control strategy and neural network to control the welding process intelligently, so it has the merit of PID control rules and the trait of better information disposal ability of the neural network. The results of simulation show that the controller has the properties of quick response, low overshoot, quick convergence and good stable accuracy, which meet the requirements for control of the welding process.

基于QPSO改进LSTM发动机怠速预测的FPID控制

以北京现代伊兰特G4GD发动机为试验台,将电控系统故障作为实验变量,测得规定时间内双传感器组合发生故障时的发动机怠速,并选原车ECU较难控制的6种组合怠速故障进行分析。基于量子粒子群算法(QPSO)对长短时记忆神经网络(LSTM)隐含层节点、训练次数与学习率进行寻优预测,将预测结果与多种神经网络进行对比,并通过均方根误差(RMSE)评价指标进行判断。使用Origin数据拟合将预测输出结果进行数值拟合,之后输入Matlab中使用Simulink搭建控制单元模型,由模糊常量-积分-微分(FPID)控制器对输出结果进行怠速控制。结果表明:基于量子粒子群算法改进的长短时记忆神经网络预测效果最好;模糊常量-积分-微分控制器对怠速的控制可有效缩短电子控制单元(ECU)的控制时间,无超调,且可有效调节至规定怠速。

Adaptive Server Load Balancing in SDN Using PID Neural Network Controller

Web service applications are increasing tremendously in support of high-level businesses.There must be a need of better server load balancing mechanism for improving the performance of web services in business.Though many load balancing methods exist,there is still a need for sophisticated load bal-ancing mechanism for not letting the clients to get frustrated.In this work,the ser-ver with minimum response time and the server having less traffic volume were selected for the aimed server to process the forthcoming requests.The Servers are probed with adaptive control of time with two thresholds L and U to indicate the status of server load in terms of response time difference as low,medium and high load by the load balancing application.Fetching the real time responses of entire servers in the server farm is a key component of this intelligent Load balancing system.Many Load Balancing schemes are based on the graded thresholds,because the exact information about the networkflux is difficult to obtain.Using two thresholds L and U,it is possible to indicate the load on particular server as low,medium or high depending on the Maximum response time difference of the servers present in the server farm which is below L,between L and U or above U respectively.However,the existing works of load balancing in the server farm incorporatefixed time to measure real time response time,which in general are not optimal for all traffic conditions.Therefore,an algorithm based on Propor-tional Integration and Derivative neural network controller was designed with two thresholds for tuning the timing to probe the server for near optimal perfor-mance.The emulation results has shown a significant gain in the performance by tuning the threshold time.In addition to that,tuning algorithm is implemented in conjunction with Load Balancing scheme which does not tune thefixed time slots.