基于神经网络-遗传算法的双轴运动系统PID控制

提出了一种针对双轴运动系统的基于神经网络-遗传算法的PID控制器参数寻优设计方案。离线部分用遗传算法(GA)的寻优得到一组最优的PID参数Kp^ ，Ki^ ，Kd^ ，并将其作为存线调整部分的仞始值；在线部分用神经网络的BP网络调整系统的瞬态PID响应，同时利用插补器使双轴运动系统进行圆弧插补运动。通过计算机仿真可证明，此寻优方法具有良好的控制性能。     

基于MyPSO-BP的黄酒发酵温控系统

在 Labview组态软件、西门子PLC300和温度传感器构成的温度控制系统基础上,提出一种新的黄酒发酵温度控制系统,将带交叉因子的粒子群优化(PSO)算法应用到BP神经网络(MyPSO-BP)比例积分微分(PID)控制中。改进的PSO算法初始化神经网络的权重和阈 值,可以更好地在线整定PID参数,增强系统的稳定性和鲁棒性,减小误差。对系统进行Matlab仿真实验,结果表明,该系统相较于传统的神经网络PID控制器具有更好的温度控制性能。     

基于改进模糊神经网络的PID参数自整定

针对传统PID整定控制效果差且单纯神经网络整定存在参数学习和调整困难等问题,提出了一种基于改进模糊神经网络的PID参数整定方法。在该方法中,PID控制器的控制参数采用基于Mamdani模型的模糊神经网络进行自适应整定,模糊神经网络参数采用混沌遗传算法离线粗调和BP算法在线细调的方式进行学习和调整,仿真结果表明该整定策略动态响应快、误差控制精度高且网络中各节点及参数物理意义明确。最后分别从模糊规则数的变化及适应度函数的选取两方面提出两种优化方案,仿真结果表明增加模糊规则数或采用不同的适应度函数都有利于进一步减小控制误差。     

Fuzzy neural networks for tuning PID controller for plants withunderdamped responses

In this paper, the fuzzy neural network (FNN) for tuning proportional-integral-derivative (PID) controller for plants with underdamped step responses is proposed. The underdamped systems are modeled by second-order-plus-dead-time transfer functions. For deriving the FNN, the dominant pole assignment method is applied to design the PID controllers for a batch of test plant models that represent the plants with underdamped responses. Then, a fuzzy neural modeling method is utilized to identify the relationship between the parameters that characterize the plant dynamics and the controller parameters. We then utilize the obtained FNN to tune the PID controller for plants with underdamped responses. Several simulation examples are given to demonstrate the effectiveness and robustness of the FNN obtained     

基于鲁棒迭代学习的灌浆压力自适应控制

为了提高非线性、不确定和时变性灌浆过程中压力的控制精度,在分析灌浆过程数学模型的基础上,提出了灌浆压力的PID控制器参数的自适应调节方法.由神经网络预测模型对灌浆系统进行非线性建模,然后基于神经网络学习误差迭代优化PID控制参数.为了确保控制器参数矩阵在调节时灌浆压力能收敛于灌浆设计压力,采用了李亚普洛夫误差增量迭代函数,使得对每次采样时刻系统误差PID调节向量能渐近收敛于最优值,从而使模型跟踪误差最小.通过迭代反馈调节方法的压力输出同手工控制方法对比研究,仿真结果表明,此方法有更好的自适应能力,较好地跟踪了灌浆设计压力曲线.     

Applying neural networks to on-line updated PID controllers for nonlinear process control

The inherent time-varying nonlinearity and complexity usually exist in chemical processes. The design of control structure should be properly adjusted based on the current state. In this paper, an improved conventional PID control scheme using linearization through a specified neural network is developed to control nonlinear processes. The linearization of the neural network model is used to extract the linear model for updating the controller parameters. In the scheme of the optimal tuning PID controller, the concept of general minimum variance and constrained criterias are also considered. In order to meet most of the practical application problems, several variations of the proposed method, including the momentum filter, the updating criterion and the adjustment of the step size of the control action, are presented to make the proposed algorithm more practical. To demonstrate the potential applications of the proposed strategies, two simulation problems, including a pH neutralization and a batch reactor, are applied.     

基于RBF网络自整定PID控制的改进算法

针对工业过程控制中存在的非线性,时变性以及各种不确定性,在已有的RBF网络整定PID控制的基础上,提出了一种改进的整定控制算法。先用RBF神经网络在线辨识被控对象离散模型,得到对象关于控制器输出的Jacobian信息,然后用Levenberg-Marquardt算法代替传统的梯度法对PID参数进行整定,得到改进的整定控制算法。通过对锅炉汽包水位控制系统的仿真研究,验证了算法的有效性和优越性。该控制算法提高了控制系统的快速性、鲁棒性,有一定的实用推广价值。     

线性自抗扰控制的适用性及整定

线性自抗扰控制将被控对象看成串级积分系统,把其他信息都当成不确定性.这种处理方法简单,但是对什么样的系统有效,目前还没有理论给出确定的答案.本文证明任何带有积分行为的严格正则传递函数都可以由线性自抗扰控制的反馈控制器等价实现,从而表明线性自抗扰控制具有广泛的适用性,即只要其他线性控制方法能够控制的系统,线性自抗扰控制同样可以适用.为简化线性自抗扰控制器参数整定,本文针对工业过程中广泛存在的PID控制器,提出将PID参数转化为二阶自抗扰控制参数的方法.该方法转化的线性自抗扰参数以带宽形式表示,从而保留了传统线性自抗扰简单易调的特性,为线性自抗扰控制在工业过程的应用准备了基础.     

Sugeno fuzzy PID tuning,by genetic-neutral for AVR in electrical power generation

We report a novel design method for determining the optimal proportional-integral-derivative (PID) controller parameters of an automatic voltage regulator (AVR) system, using a combined genetic algorithm (GA), radial basis function neural network (RBF-NN) and Sugeno fuzzy logic approaches. GA and a RBF-NN with a Sugeno fuzzy logic are proposed to design a PID controller for an AVR system (GNFPID). The problem for obtaining the optimal AVR and PID controller parameters is formulated as an optimization problem and RBF-NN tuned by GA is applied to solve the optimization problem. Whereas, optimal PID gains obtained by the proposed RBF tuning by genetic algorithm for various operating conditions are used to develop the rule base of the Sugeno fuzzy system and design fuzzy PID controller of the AVR system to improve the system's response (∼0.005 s). The proposed approach has superior features, including easy implementation, stable convergence characteristic, good computational efficiency and this algorithm effectively searches for a high-quality solution and improve the transient response of the AVR system (7E−06). Numerical simulation results demonstrate that this is faster and has much less computational cost as compared with the real-code genetic algorithm (RGA) and Sugeno fuzzy logic. The proposed method is indeed more efficient and robust in improving the step response of an AVR system.     

Adaptive control of a CSTR with a neural network model

An adaptive control algorithm with a neural network model, previously proposed in the literature for the control of mechanical manipulators, is applied to a CSTR (Continuous Stirred Tank Reactor). The neural network model uses either radial Gaussian or “Mexican hat” wavelets as basis functions. This work shows that the addition of linear functions to the networks significantly improves the error convergence when the CSTR is operated for long periods of time in a neighborhood of one operating point, a common scenario in chemical process control. Then, a quantitative comparative study based on output errors and control efforts is conducted where adaptive controllers using wavelets or Gaussian basis functions and PID controllers (IMC tuning with fixed parameters and self tuning PID) are compared. From this comparative study, the practicality and advantages of the adaptive controllers over fixed or adaptive PID control is assessed.     

基于模糊RBF神经网络的PID及其应用

针对传统的PID控制器参数固定而导致在控制中效果差的问题,提出一种基于模糊RBF神经网络智能PID控制器的设计方法。该方法结合了模糊控制的推理能力强与神经网络学习能力强的特点,将模糊控制与RBF神经网络相结合以在线调整PID控制器参数,整定出一组适合于控制对象的kp, ki, kd参数。将算法运用到电机控制系统的PID参数寻优中,仿真结果表明基于此算法设计的PID控制器改善了电机控制系统的动态性能和稳定性。     

神经网络PID在PLC系统控制中的应用研究

针对传统的PID算法由于难以给出精确的数学模型,使得系统参数设定困难,同时系统控制效果上存在一定的缺陷,造成系统安全性和可靠性降低,系统控制质量不高。为了解决传统的PID算法所带来的问题,提出了基于模糊神经网络的PID算法,将PID算法、模糊控制算法以及神经网络算法相结合,形成了一种智能控制算法。将算法应用在PLC控制系统中,实验表明算法有效的实现了PID参数的自整定,并且提高了控制质量,具有一定的实际应用推广价值。     

Nonlinear optimized adaptive trajectory control of helicopter

This paper attempts to develop an optimized adaptive trajectory control system for helicopters based on the dynamic inversion method. This control algorithm is implemented by three time-scale separation architectures. Pseudo control hedging (PCH) is used to protect the adaptive element from actuator saturation nonlinearities and also from the inner-outer-loop interaction. In addition, to augment the attitude control system, two online adaptive architectures that employ a neural network are used. By tuning the neural network based on the system model, a better and faster learning will be achieved, but this is a frustrating and time consuming process. Due to complexity in accurate tuning of neural network, this paper introduces a non-dominated sorting genetic algorithm II (NSGA-II) for off-line optimization of the neural network. Thus, in the proposed method, the neural network can compensate model inversion error caused by the deficiency of full knowledge of helicopter dynamics more accurately. The effectiveness of proposed method is demonstrated by numerical simulations.     

神经网络PID控制器在硬盘磁头定位系统中的应用

针对硬盘驱动器难以建立准确对象模型的特性,提出了一种采用神经网络PID控制器的方法。该方法利用神经网络的自学习能力和任意非线性表达能力,实现实时、在线地调整PID控制器的比例、积分、微分系数,从而找到PID控制参数的最佳组合,以达到某种性能指标的最优化。作为常规BP神经网络的改进型,提出以从最初时刻到当前时刻的误差的平方和最小作为性能指标函数。仿真结果表明,采用这种控制方案进行硬盘伺服控制,系统收敛速度快、调节时间短、且几乎没有超调和稳态误差,性能优于常规神经网络PID控制,适用于实际的硬盘驱动器磁头定位。     

Computational intelligence approach to PID controller design using the universal model

Despite the popularity of PID (Proportional-Integral-Derivative) controllers, their tuning aspect continues to present challenges for researches and plant operators. Various control design methodologies have been proposed in the literature, such as auto-tuning, self-tuning, and pattern recognition. The main drawback of these methodologies in the industrial environment is the number of tuning parameters to be selected. In this paper, the design of a PID controller, based on the universal model of the plant, is derived, in which there is only one parameter to be tuned. This is an attractive feature from the viewpoint of plant operators. Fuzzy and neural approaches - bio-inspired methods in the field of computational intelligence - are used to design and assess the efficiency of the PID controller design based on differential evolution optimization in nonlinear plants. The numerical results presented herein indicate that the proposed bio-inspired design is effective for the nonlinear control of nonlinear plants.     

负荷实时跟踪精细化氨法脱硫智能控制系统

传统的氨法脱硫控制系统存在延迟时间较长、无法实现实时跟踪负荷的局限性。针对该问题提出的Smith预估补偿装置,通过抵消系统中的纯滞后环节来提高控制系统的实时性。虽然该方法有效解决了长延时问题,但系统中PID参数调整采用的是试错法并依赖于调试操作经验,偶然性和因人而异导致系统波动较大。本文提出了BP（back propagation）神经网络的PID参数整定方法,该方法能实现对任意非线性函数的逼近,通过神经网络学习得到最佳的比例、微分、积分系数组合。运用该方法建模并进行长时过程控制仿真,结果验证了算法的可行性,其误差小,大幅提高了氨法脱硫系统的实时性和稳定性,实现了智能化精准控制效果。     

神经元PID控制器在两轮机器人控制中的应用

针对两轮机器人传统PID控制器参数整定困难的问题,设计了一种神经元PID控制器.该控制器利用神经元的自学习和自适应能力,在线实时调整控制器各项参数.建立了两轮机器人的非线性模型,讨论了神经元PID控制系统的结构及其控制算法和各项控制器参数的学习算法.将设计的控制器其应用于两轮机器人的平衡控制中,并且与传统PID控制器进...     

基于Hopfield网络的PID在直流伺服电机中的应用

针对直流伺服电机的非线性和时变性因素,本文结合传统PID控制器特点,介绍了一种基于Hopfield神经网络PID控制方法。该方法利用Hopfield神经网络的自学习能力,经过有限次的训练可以得到了PID控制器所需要的最优参数。采用Matlab软件对构造的系统模型进行了仿真和跟踪实验。实验表明这种方法既简化了经典控制PID参数整定,同时使系统具较好的实时性、稳定性和跟踪性,控制效果比较理想。     

PID参数整定法的仿真

PID调节器的控制品质,主要取决于调节器的参数整定.计算量大是用理论计算方法整定PID调节器参数要解决的难题之一.针对PID调节器参数整定过程中计算复杂、计算量大的问题,提出了一种基于Matlab的调节器参数衰减频率特性整定法.该方法以Matlab为工具,将理论计算与仿真分析结合起来,根据控制要求计算并绘制出控制器整定参数关系曲线,对计算结果进行仿真,分析整定参数在解平面上变化时闭环系统的响应,从而确定出最佳的调节器整定参数.结果表明,对于不同的被控对象参数或不同的整定要求,该方法都能方便地求得最佳的调节器整定参数,使得采用理论计算法整定调节器参数具有了工程实用价值.     

遗传算法优化的Fuzzy+变论域自适应Fuzzy-PID复合控制策略研究

提出了一种用遗传算法优化的Fuzzy+变论域Fuzzy-PID复合控制器的新方法。该控制器由Fuzzy控制和变论域Fuzzy-PID控制两部分组成。在系统的动态阶段,采用Fuzzy控制使其具有最优的动态性能;当系统进入稳态阶段,采用变论域自适应Fuzzy-PID控制使其具有最优的稳态性能。用遗传算法离线搜索出一组最优的PID参数作为在线调节的初始值,在在线部分,以离线搜索出的PID参数为基础,通过变论域的模糊推理在线调整系统瞬态响应的PID参数,使系统具有良好的自适应能力。 采用加权平滑切换的方式,保证两种不同控制过渡的平稳性。将提出的复合控制策略应用于变风量空调系统的室温串级控制中,计算机仿真结果表明,该方法使系统具有良好的动、稳态性能,抗干扰性和鲁棒性好。