孵化机温度模糊控制器设计与仿真

温度控制的精度和稳定性是孵化机系统急需解决的关键技术,系统中的被控对象不能建立精确的数学模型。为了提高温度控制精度和稳定性,采用模糊控制方法设计模糊控制器并通过Matlab进行仿真。对模糊规则的仿真说明规则较合理,对系统的仿真表明模糊控制器超调量较小,调节时间大约为20秒,系统稳定。     

深度确定性策略梯度与模糊PID的协同温度控制

针对现有温度控制系统控温时间长、误差大的问题, 本文提出了一种基于深度确定性策略梯度(DDPG)和模糊自整定PID的协同温度控制. 首先, 模糊PID在控制大滞后系统时, 控制器不能立刻对产生的干扰起抑制作用, 且无法保证大滞后系统的稳定性等问题, 本文建立了模糊PID和DDPG算法相结合的温度控制模型, 该模型将模糊PID作为主控制器, DDPG算法作为辅助控制, 利用双控制器模型实现温度协同控制. 接着, 利用遗传算法对模糊PID的隶属函数和模糊规则进行寻优, 获得模型参数最优解. 最后, 在仿真实验中验证所提方法的有效性. 仿真实验结果表明, 本文提出的算法可有效减少噪声干扰, 减小控制系统的响应时间、误差和超调量.     

基于模糊规则切换的变水量空调温度Fuzzy-PID控制器设计

针对变水量空调温度控制的Fuzzy-PID复合控制器存在切换点选择困难和切换扰动的问题,设计了基于模糊规则切换的Fuzzy-PID复合控制器;在控制误差大时,采用模糊控制提高系统动态特性;在控制误差小时,采用PID控制提高系统的控制精度;为使控制器切换平滑,采用模糊规则进行切换,并对模糊规则的选取原则进行了分析,在Matlab/Simulink软件上进行了仿真;仿真结果表明,该控制器实现了平滑切换,且具有一定的抗干扰性。     

PCR温度模糊PID控制器的设计及仿真

根据PCR对温度控制的要求设计出一种模糊PID控制器,采用误差和误差变化率作为模糊PID控制器的输入,PID参数作为模糊PID控制器的输出,并使用一组模糊规则实现对PID参数的在线优化调节.通过使用Simulink图形化工具平台对模糊PID控制器和传统的PID控制器进行建模和仿真.结果表明,与传统PID控制器相比,模糊PID控制器性能优良,使系统响应速度加快,超调减小.     

温度控制系统模糊自适应PID控制器仿真研究

研究电机绝缘处理的过程中,针对烘干炉的温度控制具有非线性和大滞后的特点,常规的PID控制器和模糊控制器很难达到理想的控制效果,为保证温度系统的稳定性,把模糊控制和常规的PID控制结合起来,提出了模糊自适应PID控制器.首先建立了烘干炉温度控制系统的数学模型,确定了系统的输入输出量,建立了模糊控制规则,进行模糊推理,计算PID控制器的参数,可由PID控制器控制烘干炉的温度,采用计算机仿真结果表明,模糊自适应PID控制器与常规PID控制器相比较,提高了烘干炉温度控制系统的自适应能力和鲁棒性,改善了系统的动态性能和静态性能,能使非线性、大滞后等特殊的系统达到良好的控制效果.     

蒸汽过热炉温度模糊自适应PID控制

针对乙苯脱氢制苯乙烯生产过程中蒸汽过热炉温度控制非线性、大滞后的问题,提出了一种模糊自适应PID控制器用于改善蒸汽过热炉的温度控制效果。首先建立了蒸汽过热炉的数学模型,确定了系统的输入输出量;其次,在构建模糊控制器结构的基础上设计了模糊控制规则,实现了PID控制器的参数自适应调节;最后对所设计的蒸汽过热炉温度模糊自适应PID控制器进行了仿真分析。结果表明,模糊自适应PID控制器与常规PID控制器相比较,提高了蒸汽过热炉温度控制系统的自适应能力和鲁棒性,改善了系统的动态性能和静态性能,对非线性时滞系统控制效果更好。     

三级倒立摆的加权变量模糊神经网络控制

为了提高三级倒立摆系统控制的响应速度和稳定性,在设计Mamdani型摸糊推理规则控制器控制倒立摆系统稳定的基础上,设计了一种更有效率的基于Sugeno型模糊推理规则的模糊神经网络控制器。该控制器使用BP神经网络和最小二乘法的混合算法进行参数训练,能够准确归纳输入输出量的模糊隶属度函数和模糊逻辑规则。通过与Mamdani型控制器的仿真对比,表明该Sugeno型模糊神经网络控制器对三级倒立摆系统的控制具有良好的稳定性和快速性,以及较高的控制精度。     

二级倒立摆的Sugeno型模糊神经网络控制

为了提高二级倒立摆系统实时控制的响应速度和稳定性,在设计Mamdani型模糊推理规则控制器控制倒立摆系统稳定的基础上,设计了一种更有效率的基于Sugeno型模糊推理规则的模糊神经网络控制器。该控制器使用BP神经网络和最小二乘法的混合算法进行参数训练,能够准确归纳输入输出量的模糊隶属度函数和模糊逻辑规则。通过与Mamdani型控制器的仿真对比及实际控制实验结果,表明该Sugeno型模糊神经网络控制器对二级倒立摆实验装置的控制具有良好的稳定性、快速性和较高的控制精度。     

基于自适应模糊PID控制器的温度控制系统

针对温度控制系统非线性、大滞后、时变性等特征和对温度控制的要求,采用了自适应模糊PID控制器来实现温度控制,给出了C8051F020 Soc单片机控制实现的具体方案.仿真和实验结果表明了该系统的控制效果优于常规PID控制器,满足温度控制系统实时性和精度的要求.     

二级倒立摆的Sugeno型模糊神经网络控制

为了提高二级倒立摆系统实时控制的响应速度和稳定性,在设计Mamdani型模糊推理规则控制器控制倒立摆系统稳定的基础上,设计了一种更有效率的基于Sugeno型模糊推理规则的模糊神经网络控制器.该控制器使用BP神经网络和最小二乘法的混合算法进行参数训练.能够准确归纳输入输出量的模糊隶属度函数和模糊逻辑规则.通过与Mamdani型控制器的仿真对比及实际控制实验结果,表明该Sugeno型模糊神经网络控制器时二级倒立摆实验装置的控制具有良好的稳定性、快速性和较高的控制精度.     

Structure and stability analysis of a Takagi–Sugeno fuzzy PI controller with application to tissue hyperthermia therapy

 In this paper, we first reveal the analytical structure of a simple Takagi–Sugeno (TS) fuzzy PI controller relative to the linear PI controller. The fuzzy controller consists of two linear input fuzzy sets, four TS fuzzy rules with linear consequent, Zadeh fuzzy logic AND and the centroid defuzzifier. We prove that the fuzzy controller is actually a nonlinear PI controller with the gains changing with process output. Utilizing the well-known small Gain Theorem in control theory, we then derive sufficient conditions for global stability of the fuzzy control systems involving the TS fuzzy PI controller. Finally, as an application demonstration, we apply the fuzzy PI controller to control issue temperature, in computer simulation, during hyperthermia therapy. The relationship between heat energy and tissue temperature is represented by a linear time-varying model with a time delay. The sufficient conditions for global stability are used to design a stable fuzzy control system. Our simulation results show that the fuzzy PI control system achieves satisfactory temperature control performance. The control system is robust and stable even when the model parameters are changed suddenly and significantly.     

Stable adaptive fuzzy control of nonlinear systems

A direct adaptive fuzzy controller that does not require an accurate mathematical model of the system under control, is capable of incorporating fuzzy if-then control rules directly into the controllers, and guarantees the global stability of the resulting closed-loop system in the sense that all signals involved are uniformly bounded is developed. The specific formula for the bounds is provided, so that controller designers can determine the bounds based on their requirements. The direct adaptive fuzzy controller is used to regulate an unstable system to the origin and to control the Duffing chaotic system to track a trajectory. The simulation results show that the controller worked without using any fuzzy control rules, and that after fuzzy control rules were incorporated the adaptation speed became much faster. It is shown explicitly how the supervisory control forces the state to remain within the constraint set and how the adaptive fuzzy controller learns to regain control     

液压混合动力履带车辆联合制动模糊控制

针对液压混合动力履带车辆联合制动系统,为了实现制动过程平稳性,提出了基于制动力分配原则的模糊控制策略.首先在MATLAB中建立了能量再生制动系统和机械制动系统以及车辆动力学仿真模型,然后设计了以制动力分配系数为控制变量的联合制动模糊控制器,给出了模糊控制规则,建立了控制系统仿真模型,并在不同制动强度条件下对车辆制动过程进行仿真.仿真结果表明,联合制动模糊控制系统能够有效回收制动能量,同时与PID控制相比明显改善和提高了履带车辆制动过程稳定性.     

Stability Analysis and Controller Design of Discrete Interval Type‐2 Fuzzy Systems

This paper is concerned with trajectory stabilization of a computer simulated model car with uncertain velocity via type‐2 fuzzy control systems. First, stability conditions of discrete interval type‐2 fuzzy control systems are given in accordance with the definition of stability in the sense of Lyapunov. Then, we approximate a computer simulated model car, whose dynamics are nonlinear and velocity is uncertain. A type‐2 Takagi–Sugeno TS fuzzy controller is designed to handle system uncertainty. The control rules, which guarantee stability of the system, are derived from the approximated model. The simulation results show that the type‐2 fuzzy control rules can effectively stabilize the car model.     

基于RBF网络的参数自学习模糊控制的研究

模糊控制以其自适应性、鲁棒性和易于实现等优点得到广泛应用。然而模糊控制规则的获得通常由专家经验给出,这就存在诸如控制规则不够客观、专家经验难以获得等问题。在模糊控制系统中,模糊规则库的构建是至关重要的,因此研究模糊规则的自动生成有着重要的理论和应用价值。本文首先以模糊控制理论和RBF神经网络理论为基础,提出了一种能够有效表达模糊系统可解释性的RBF网络结构;然后详细讨论在此网络结构下提取模糊规则的学习算法;最后依据上述方法进行仿真实验,实验结果表明,这种根据测量数据自动提取模糊规则的方法是有效的。     

质子交换膜燃料电池动态建模及其双模控制

由于已提出的质子交换膜燃料电池(PEMFC)模型难于控制, 提出利用MATLAB/SIMULINK仿真工具进行PEMFC系统动态建模, 同时为实现对PEMFC系统输出电压的控制, 采用了基于模糊规则切换的模糊逻辑控制器(FLC)和比例积分微分控制器(PID)相结合的双模控制方式. 仿真结果证明该动态模型易于控制, 能够反映出PEMFC系统的动态输出特性, 而且验证了基于模糊规则切换的双模控制能够有效抑制扰动, 改善PEMFC系统的动态输出特性, 保证系统的稳定运行, 有助于对PEMFC系统的输出性能分析以及实时控制系统的设计.     

基于变论域的铝电解模糊控制研究

针对铝电解控制中的不确定性、非线性等因素给系统带来的影响,基于常规模糊控制,分析研究了该系统基于变论域的模糊控制机理。选定电解槽中的电解质温度为论域伸缩因子,利用变论域的思想,通过论域的膨胀或压缩使模糊控制规则可派生出任意多条,实时提高在线控制精度。分析仿真结果可知,该算法使铝电解温度控制具有比用常规控制更高的温度控制精度和系统性能,验证了该设计的有效性和实用价值。     

An Adaptive Fuzzy Control Model for Multi-Joint Manipulators

Multi-joint manipulator systems are subject to nonlinear influences such as frictional characteristics, random disturbances and load variations. To account for uncertain disturbances in the operation of manipulators, we propose an adaptive manipulator control method based on a multi-joint fuzzy system, in which the upper bound information of the fuzzy system is constant and the state variables of the manipulator control system are measurable. The control algorithm of the system is a MIMO (multi-input-multi-output) fuzzy system that can approximate system error by using a robust adaptive control law to eliminate the shadow caused by approximation error. It can ensure the stability of complex manipulator control systems and reduce the number of fuzzy rules required. Comparison of experimental and simulation data shows that the controller designed using this algorithm has highly-precise trajectory-tracking control and can control robotic systems with complex characteristics of non-linearity, coupling and uncertainty. Therefore, the proposed algorithm has good practical application prospects and promotes the development of complex control systems.     

On stability of fuzzy systems expressed by fuzzy rules withsingleton consequents

Addresses the issue of stability of a fuzzy system described by fuzzy rules with singleton consequents. It first presents two canonical forms of a fuzzy system: a parametric expression and a state-space expression. A fuzzy system with singleton consequents is found to be a piecewise-polytopic-affine system. Then the paper gives stability theorems for a discrete-time system as well as for a continuous time system. It also gives a brief survey on the stability issues of fuzzy control systems