Fractional Order Proportional Integral Derivative Controller Design and Simulation for Bioengineering Systems

This paper deals with the study of fractional order system tuning method based on Factional Order Proportional Integral Derivative( FOPID) controller in allusion to the nonlinear characteristics and fractional order mathematical model of bioengineering systems. The main contents include the design of FOPID controller and the simulation for bioengineering systems. The simulation results show that the tuning method of fractional order system based on the FOPID controller outperforms the fractional order system based on Fractional Order Proportional Integral( FOPI) controller. As it can enhance control character and improve the robustness of the system.

Robust Fractional-Order Proportional-Integral Observer for Synchronization of Chaotic Fractional-Order Systems

In this paper, we propose a robust fractional-order proportional-integral(FOPI) observer for the synchronization of nonlinear fractional-order chaotic systems. The convergence of the observer is proved, and sufficient conditions are derived in terms of linear matrix inequalities(LMIs) approach by using an indirect Lyapunov method. The proposed FOPI observer is robust against Lipschitz additive nonlinear uncertainty. It is also compared to the fractional-order proportional(FOP) observer and its performance is illustrated through simulations done on the fractional-order chaotic Lorenz system.

Improved quantum bacterial foraging algorithm for tuning parameters of fractional-order PID controller

The quantum bacterial foraging optimization(QBFO)algorithm has the characteristics of strong robustness and global searching ability. In the classical QBFO algorithm, the rotation angle updated by the rotation gate is discrete and constant,which cannot affect the situation of the solution space and limit the diversity of bacterial population. In this paper, an improved QBFO(IQBFO) algorithm is proposed, which can adaptively make the quantum rotation angle continuously updated and enhance the global search ability. In the initialization process, the modified probability of the optimal rotation angle is introduced to avoid the existence of invariant solutions. The modified operator of probability amplitude is adopted to further increase the population diversity.The tests based on benchmark functions verify the effectiveness of the proposed algorithm. Moreover, compared with the integerorder PID controller, the fractional-order proportion integration differentiation(PID) controller increases the complexity of the system with better flexibility and robustness. Thus the fractional-order PID controller is applied to the servo system. The tuning results of PID parameters of the fractional-order servo system show that the proposed algorithm has a good performance in tuning the PID parameters of the fractional-order servo system.

Design of Smith Predictor Based Fractional Controller for Higher Order Time Delay Process

Normally all real world process in a process industry will have time delay.For those processes with time delays,obtaining satisfactory closed loop performances becomes very difficult.In this work,three interacting cylindrical tank process is considered for study and the objective of the work is to compensate for time delays using smith predictor structure and to maintain the level in the third tank.Input/Output data is generated for the three interacting tank process.It is approximated as Integer First Order Plus Dead Time system(IFOPDT)and Fractional First Order Plus Dead Time system(FFOPDT).Smith predictor based fractional order Proportional Integral controller and Integer order Proportional Integral controller is designed for the IFOPDT and FFOPDT model using frequency response technique and their closed loop performance indices are compared and tabulated.The servo and regulatory responses are simulated using Matlab/Simulink.

分数阶移相全桥变换器的建模与优化控制

基于电路中的分抗元件具有非整数阶特性,利用分数阶微积分理论和状态空间平均法,对分数阶移相全桥变换器进行建模与优化控制分析。建立了移相全桥变换器的分数阶状态平均方程,研究电感和电容的分数阶特性对移相全桥变换器频域特性的影响。结合遗传算法的优点,得到满足误差绝对值积分的最优分数阶比例积分(PIλ)控制器参数与最优整数阶比例积分(PI)控制器参数,并搭建了分数阶移相全桥变换器的电路仿真模型与不同控制器的仿真模型,进行了不同控制器、不同工况和负载变化下电路仿真结果的比较。结果表明:相较于整数阶PI控制器,分数阶PIλ控制器能够提供更优的控制性能,使分数阶移相全桥变换器具有更快的响应速度、更好的稳态性能和更强的鲁棒性。

基于改进麻雀搜索算法分数阶PI的PMSM调速策略

永磁同步电机调速系统采用传统比例积分双闭环控制结构存在抗扰性能差与响应速度慢的问题。为此,文中在建立PMSM数学模型和分析传统PI参数设计方法的基础上,提出一种基于改进麻雀搜索算法分数阶比例积分的PMSM调速优化策略,通过在常规SSA中引入佳点集初始化策略和黄金正弦更新策略,解决了SSA易陷入局部最优的问题,提高了收敛速度和精度,以进一步改善PMSM调速系统的响应性能。最后通过MATLAB仿真对比结果可知,所述ISSA-FOPI调速改进策略在4种工况下具有最短的调节时间分别为1.2、0.9、9.9与12.1 ms,和最小的超调量分别为0.16%、0.16%、0.05%与0.6%,这充分体现了所述策略的有效性与优越性。

动态拓扑结构混合粒子群算法及其应用

针对传统粒子群算法面对较高维度参数整定问题时所表现出的寻优速度慢、易陷入局部最优解的问题,提出一种动态环形拓扑结构混合粒子群算法(DynRing-hfpso)。该算法以粒子群算法为基底,融合萤火虫算法的优点,通过定义选择逻辑使粒子在迭代过程中各自独立地交替进行全局搜索与局部探索,并以自适应的粒子速度与位置约束方法提高算法在迭代过程中信息的利用率。对粒子群拓扑结构进行改进,以动态多邻域环形拓扑结构提高搜索空间覆盖能力,均衡收敛速度。设置动态性能分析以及消融实验,验证算法中粒子分布质量与改进措施的有效性。采用分数阶比例-积分-微分(FOPIλDμ)控制下的速度伺服系统作为应用场景,将该算法与其他四种算法进行对比。结果表明,DynRing-hfpso算法较已有的元启发式优化算法有更快的收敛速度与更优的收敛精度,且在多次实验中展现出更强的鲁棒性。

基于FOPI~λ的复合控制在CVCF逆变电源中的应用

提出一种基于分数阶比例积分(FOPI~λ)的复合控制策略。介绍了三相逆变电源的系统结构,分析了d,q坐标系下的传递函数,研究了FOPI~λ控制和重复控制的基本理论和实现方法,并设计FOPI~λ控制器和重复控制器,对两种控制策略使用可变加权因子有机结合形成复合控制器。针对该分数阶控制器待整定参数较多的问题,提出基于粒子群优化(PSO)算法对参数进行整定优化的方法。与传统复合控制相比,仿真验证所提方案可保证系统有较高稳压精度和较快动态响应,输出电压总谐波畸变率(THD)更小;实验结果表明该方案有效、可行。

基于矩阵解耦的精馏塔VOFFLC温控系统

针对复杂的精馏塔MIMO温控系统的多变量、非线性、强耦合的特点和自适应需求,设计了基于矩阵解耦精馏塔的VOFFLC系统。首先,对温控系统的多变量控制模型进行改进,利用矩阵解耦理论实现对角解耦,以此改变控制通道的特性;然后,设计基于矩阵解耦的精馏塔VOFFLC温控系统,实现精馏塔的塔顶和塔底的自适应温控;最后,采用仿真实验,对所设计的多种温控系统进行性能比较。实验结果表明,VOFFLC系统可以实现控制参数的自适应,具有更强的论域容错性和鲁棒性。

三相并网逆变器的分数阶PCI控制技术

针对比例谐振和比例复数积分控制器都存在谐振项带宽偏低的问题,提出一种更具普遍形式的分数阶比例复数积分控制器。首先,论证比例积分、比例谐振和比例复数积分等控制器均是分数阶比例复数积分的特殊形式,给出分数阶比例复数积分的谐振项带宽与阶次的关系,并合理选取控制器阶次;其次,构建三相并网逆变器在分数阶比例复数积分控制下的数学模型,证明系统的输出不存在稳态误差,并利用开环截止频率和主导极点确定相关参数;最后,进行对比仿真测试,结果验证了所提控制算法的有效性和优越性。

基于ESO和分数阶PID的改进P&O控制策略

为了提高光伏电池转换效率、降低能量损失,有必要研究最大功率点跟踪(maximum power point tracking,MPPT)方法。针对传统扰动观察法(perturbation observation method,P&O)存在无法兼顾跟踪速度与稳态精度、在光照度发生较大变化时会产生误判现象的问题,文中提出一种能适应环境变化的变步长P&O控制策略。首先,利用光伏电池刚启动时类似恒流源的特性获取当前光照度下的短路电流,通过固定电流法推导出最大功率点(maximum power point,MPP)的参考电压;其次,当光照度突变时,提出功率修正方法,并给出突变时的变步长调整策略;最后,设计基于线性扩张状态观测器(linear extended state observer,LESO)的分数阶比例积分微分(fractional order proportion integration differentiation,FOPID)控制器,可以对算法输出的参考电压进一步进行跟踪补偿。仿真结果表明,所提控制策略可以提高稳态精度和跟踪速度,有效提高光伏电池的输出功率。

基于麻雀搜索优化算法分数阶PI的PMSM矢量控制

永磁同步电机(Permanent Magnet Synchronous Motor,PMSM)矢量控制系统转速环采用PI控制器难以满足系统动态响应速度快、鲁棒性强等要求,采用分数阶比例积分(Fractional Order Proportional Integral,FOPI)控制器,并利用麻雀搜索算法(Sparrow Search Algorithm,SSA)优化FOPI控制器参数.通过搜索最优适应度的麻雀所在位置,得到控制器最优组合参数,选择时间乘以误差绝对值积分作为其目标适应度函数.对SSA整定FOPI、粒子群算法(Particle Swarm Optimization,PSO)整定PI参数的电机调速性能进行试验对比.结果表明,SSA优化的FOPI具有增强鲁棒性和减小超调量的优势.

Research on Stick-Slip Vibration Suppression Method of Drill String Based on Machine Learning Optimization

During the drilling process,stick-slip vibration of the drill string is mainly caused by the nonlinear friction gen-erated by the contact between the drill bit and the rock.To eliminate the fatigue wear of downhole drilling tools caused by stick-slip vibrations,the Fractional-Order Proportional-Integral-Derivative(FOPID)controller is used to suppress stick-slip vibrations in the drill string.Although the FOPID controller can effectively suppress the drill string stick-slip vibration,its structure isflexible and parameter setting is complicated,so it needs to use the cor-responding machine learning algorithm for parameter optimization.Based on the principle of torsional vibration,a simplified model of multi-degree-of-freedom drill string is established and its block diagram is designed.The continuous nonlinear friction generated by cutting rock is described by the LuGre friction model.The adaptive learning strategy of genetic algorithm(GA),particle swarm optimization(PSO)and particle swarm optimization improved(IPSO)by arithmetic optimization(AOA)is used to optimize and adjust the controller parameters,and the drill string stick-slip vibration is suppressed to the greatest extent.The results show that:When slight drill string stick-slip vibration occurs,the FOPID controller optimized by machine learning algorithm has a good effect on suppressing drill string stick-slip vibration.However,the FOPID controller cannot get the drill string system which has fallen into serious stick-slip vibration(stuck pipe)out of trouble,and the machine learning algorithm is required to mark a large amount of data on adjacent Wells to train the model.Set a reasonable range of drilling parameters(weight on bit/drive torque)in advance to avoid severe stick-slip vibration(stuck pipe)in the drill string system.

基于分数阶微积分的模糊分数阶控制器研究

在分析分数阶微积分的基础上,提出了一种新型模糊分数阶比例积分微分控制器.分数阶微积分将传统控制器中的积分和微分的阶数扩展到任意实数,为控制器的设计提供了比传统整数阶更好的性能扩展.结合分数阶比例积分微分控制器和模糊控制逻辑,用分数阶比例积分微分单元代替传统的模糊比例积分微分控制器中的比例积分微分单元,构建了模糊分数阶比例积分微分控制器的结构,采用模糊逻辑推理和Tus-tin离散方法实现了模糊分数阶比例积分微分控制器的计算.最后,用数字仿真方法和不同条件下的对比分析验证了新型模糊分数阶比例积分微分控制器的优良控制特性.研究结果表明,设计的新型模糊分数阶比例积分微分控制器对非线性和参数不确定性具有较强的鲁棒性.

分数阶PID控制器参数的自适应设计

分数阶比例-积分-微分(proportional-integral-derivative,PID)控制器是整数阶PID控制器在复数域的推广,通过引入两个可调参数λ和μ使得控制器参数整定范围变大,但使得参数设计变得更加复杂。针对分数阶PID控制器的特点,提出了一种参数自适应的改进型差分进化算法整定方法,在目标函数的选取上,针对传统时间与绝对误差乘积准则对超调量控制不足,引入误差与控制信号加权,分别对整数阶和分数阶被控模型进行理论分析和数值仿真,仿真结果证明了该控制器参数设计方法的有效性和准确性。

制导弹箭分数阶控制系统

针对制导弹箭控制系统中系统参数出现较大的非线性和时变性等问题,整数阶PID控制难以获得满意的控制效果。根据分数阶微积分的定义和性质,构造了分数阶控制器的结构,分析了其控制器参数对系统性能的影响,将分数阶控制器应用到制导弹箭的控制系统设计中,并对制导弹箭的分数阶控制系统进行了研究。结果表明,分数阶控制器较PID控制器有更强的鲁棒性和抗干扰能力,可以应用于制导弹箭的控制系统中,设计的分数阶控制器的频域和时域响应特性较PID控制器要好。研究结果为分数阶控制器在制导弹箭控制系统中的应用提供了理论基础。

基于分数阶PI速度控制器的永磁同步电动机控制

将分数阶比例积分控制器应用于交流永磁同步电动机的速度控制,来达到实现系统高性能控制的目的。本文重点研究了应用分数阶比例积分控制器作为速度控制器的交流永磁同步电动机速度控制系统的跟随性能。在相同条件下,对采用按照最优化设计的整数阶比例积分控制器的系统与采用分数阶比例积分控制器的系统,分别采用阶跃输入、三角波输入和正弦输入信号进行了仿真和实验研究。研究结果表明:采用分数阶比例积分控制器的系统响应速度和跟随性能均优于采用整数阶比例积分控制器的系统。

基于粒子群优化算法的分数阶PID控制器设计

分数阶PID控制器具有可变的微分和积分阶次,通过调整控制器参数可以获得更好的控制性能。本文基于粒子群优化算法设计分数阶PID控制器。首先介绍分数阶PID和粒子群优化算法,然后给出分数阶PID控制系统结构、分数阶微积分算子的近似算法和分数阶PID控制器设计的仿真流程,最后通过MATLAB/Simulink对算例进行控制器设计仿真。仿真结果表明,通过粒子群寻优能够获得满意的分数阶PID控制器参数,满足对控制性能的要求。

混合粒子群算法优化分数阶PID控制参数研究

分数阶比例—积分—微分(PID)控制器是一种把PID控制器的整数阶次推广到分数的比例、积分、微分控制器,它比传统的PID控制器更能精确地控制复杂的被控系统。而参数的取值对控制效果的好坏起着决定性作用,为此提出了一种混合粒子群算法BFA-TPO优化参数值。该算法将具有趋化、繁殖和驱散特点的细菌觅食算法和参数少,易于优化的粒子群算法相结合来计算出精确的分数阶PID控制器的参数值。通过对传统PID控制器和分数阶PID控制器参数优化的实验仿真,结果表明基于该算法的分数阶PID控制不仅无超调量、收敛速度快,而且鲁棒性强、收敛精度高,可用于控制不同的对象和过程。