共查询到20条相似文献，搜索用时 15 毫秒
1.
Fractional calculus has been a topic of great interest for the last few decades. The applications of fractional calculus can be found in the area of viscoelastic and chaotic systems, whose dynamics is expressed in the form of fractional differential equations. The ongoing research work is based on the design of 1-Degree of Freedom (1-DOF) and 2-Degrees of Freedom (2-DOF) Fractional Order PID (FOPID) controllers for a Magnetic levitation (Maglev) plant and the performance has been compared with that of 1-DOF and 2-DOF Integer Order PID (IOPID) controllers in both simulation and real time. The Degree of Freedom (DOF) represents the number of feed-forward control loops in a closed loop system. A 2-DOF controller configuration comprises of a serial compensator and a feed-forward compensator in a closed loop structure. An FOPID controller has a structure similar to that of a conventional IOPID controller, except that its derivative and integral orders are fractional numbers. The design of such a controller requires the determination of five parameters: Kp, Ki, Kd, α and β, where α and β are the derivative and integral orders of the FOPID controller. The controller design problem has been framed as an optimization problem, in which the cost function is formulated from the characteristic equation of the closed loop system at dominant poles that are identified from the given performance specifications. The closed loop response shows that the proposed2-DOF FOPID controller exhibits superior response and robustness with respect to its integer order counterpart. 相似文献
2.
3.
In recent years, studies on real systems have revealed inherent fractional order dynamic behavior, and fractional order systems have attracted more and more attentions. It is intuitively true that these fractional order models require the corresponding fractional order controllers to achieve desired performance. In this paper, an experimental study of the fractional order proportional and derivative (FO-PD) controller systematic design is presented, to validate the control performance for the fractional order systems with generalized fractional capacitor membrane model. The performance of the designed FO-PD controller is compared with both the integer order and fractional order controllers which are designed based on the approximate integer order system. This comparison results are presented both in the simulation and the hardware-in-the-loop experiment. 相似文献
4.
This paper proposes a generalized fractional controller that covers the complete range of differintegrators of order −1 to order 1. This controller is named distributed order PID controller (DOPID) due to the fact that it broadens the structure of the conventional PID controller. Furthermore, a new method for implementation of distributed order PID controller (DOPID), as well as analysis of its properties in both time and frequency domain are proposed. As DOPID controller represents generalized classical PID controller, it is approximated by a compound fractional controller with multiple fractional differintegrators, with multiple gains, connected in parallel. Orders of these differintegrators have been equally spaced, with the first one being the first order classical integrator, and the last one being the first order classical differentiator. Noise cancellation filter is considered explicitly in the controller’s structure. 相似文献
5.
6.
设计了X模式四旋翼飞行器飞行控制系统的总体方案;在此基础上,完成了飞行控制系统的软硬件设计,包括器件选型、硬件电路设计、系统软件设计,并把互补滤波器应用于姿态解算,姿态控制部分采用PID(Proportional Integral Derivative)控制器。通过仿真验证了器互补滤波和PID控制器算法可行性。 相似文献
7.
The robotic manipulator is an extremely nonlinear, multi-input multi-output (MIMO), highly coupled, and complex system wherein the parameter uncertainties and external disturbances adversely affect the performance of this system. From this, it necessitates that the controllers designed for such system must overcome these complexities. In this paper, we develop a novel fractional order fuzzy pre-compensated fractional order PID (FOFP-FOPID) controller for 2-degree of freedom (2-DOF) manipulator dealing with trajectory tracking problem. In order to optimize the controller’s parameters while minimizing integral of time absolute error (ITAE), a metaheuristic optimization technique, viz., artificial bee colony-genetic algorithm (ABC-GA) is presented. The efficacy of our proposed controller is demonstrated by comparing it with some existing controllers, such as integer order fuzzy pre-compensated PID (IOFP-PID), fuzzy PID (FPID), and conventional PID controllers. Furthermore, the robustness analysis for proposed controllers is also investigated for parameter variations and external disturbances. The simulation results indicate that FOFP-FOPID controller can not only guarantee the best trajectory tracking but also ameliorate the system robustness for parameter variations as well as external disturbances. 相似文献
8.
In this paper, the design and implementation structures of adjustable fractional order differentiator (AFOD) are presented. First, the series expansion of ideal frequency response is used to transform the design of AFOD into the designs of log differentiators with various orders. Then, conventional FIR filter design method is applied to design log differentiators. The proposed method is flexible because the AFOD can be designed by considering the trade-off among the storage requirement of filter coefficients, implementation complexity and delay of filter. Finally, several numerical examples are shown to illustrate the effectiveness of the proposed design approach. 相似文献
9.
In this paper, we derive the impulse response of a fractional second order filter of the form (s2+as+b)−γ, where a,b?0 and γ>0. The asymptotic properties of the impulse responses are obtained. Moreover, based on the derived analytical impulse response, we show how to perform the discretization of the above fractional second order filter. Finally, a number of illustrated examples in time and frequency domains are provided as proofs of concepts. 相似文献
10.
In this paper the derivation of Kalman filter for discrete time-stochastic fractional system is investigated. Based on a novel cumulative vector form model for fractional systems, a general Kalman filter is introduced. The validity of the proposed method has been compared with a previously presented method via simulation results. It is shown that this method can be better applied for discrete time stochastic fractional systems with slower dynamics. 相似文献
11.
In this paper, a special composite hydraulic cylinder, which includes two pistons and three working chambers, is proposed for driving the insulator fatigue test device. In this force loading system, a servo valve and a proportional pressure valve are used to control the composite hydraulic cylinder to generate alternating force and fixed force respectively. Furthermore, the models of the electro-hydraulic system are built and its dynamic characteristic is analyzed based on the models. Considering the uncertainty of the model parameters, the fractional order proportional-integral-derivative controller is adopted to control the two valves. The Oustaloup method is used to discrete the fractional order controller and the iteration feedback tuning method is presented to tune the controller parameters. The tuning process which is independent on the system model can be done on the close loop system. Simulation and experimental results have shown that the fractional order controller is effective. 相似文献
12.
The fractional calculation is over 300 years old, but only in the last decades its application arisen in many areas of science and engineering. The explanation for this expansion in the scientific and tecnologic worlds is due to the good results obtained in solving different problems, which have overcome the classics. On the other hand, in the control area there was an increasing interest in the development of new strategies, which resulted in new algorithms where the use of the fractional calculus revealed an helpfull tool. In this paper we apply the fractional order concepts into two systems with time delay. Several algorithms are investigated and compared, when integrated within a Smith predictor structure and with an optimal fuzzy fractional PDβ+I controller in which the parameters are tuned by a genetic algorithm. Simulations are presented assessing the performance of the proposed fractional schemes. 相似文献
13.
14.
This paper deals with estimation of fractional order and pole locator in fractional order systems. The estimation is based on Bode diagram of the system that is obtained using input and output measurements. Here the magnitude diagram is approximated with number of straight lines depending on the level of complexity and in consequence a very good estimation of fractional order and acceptable approximations of pole locators are determined. Relying on the proposed method, complexity of fractional order system identification which is mostly due to the estimation of fractional order is substantially resolved. Some example simulation results are provided to explain the work and show its effectiveness. 相似文献
15.
16.
17.
18.
In this paper the design procedure and performance of the third order multifunction filter based on Current Differencing Buffered Amplifier (CDBA) using Fractional Elements of Different Order (FOE) is presented. Three fractional elements of different order α, β, γ are used and peak value frequencies and cut-off frequencies are computed for the multifunction filter from the fractional order transfer function. The frequency response of the filters is obtained using FOMCON toolbox of MATLAB and also with PSPICE using fractional order elements. Stability and sensitivity analysis are also examined. The Power dissipation, Total Harmonic Distortion (THD), and Noise Analysis demonstrate a very good agreement between the theoretical and simulation results. It is also observed from the simulations that the CDBA based third order multifunction filter in fractional domain is suitable for integrated circuits. 相似文献
19.
Xiong Wang Sifeu Takougang Kingni Christos Volos Duy Vo Hoang Sajad Jafari 《International Journal of Electronics》2019,106(1):109-120
By introducing fractional derivative, fractional chaotic systems were proposed. A new fractional system with chaos is presented in our work. It is interesting that the system is elegant including only five terms. By using electronic components, we realize the five-term fractional system. Experimental results show chaos of the circuit. Chaos control as well as synchronization of such a five-term fractional system has been investigated. 相似文献
20.
用波前相因子判断法,将球面波照明物体的自由空间菲涅耳衍射光场分布与分数傅里叶逆变换的标准频谱分布进行位相比较,提供了广义条件下光学分数傅里叶逆变换的无透镜模式,给出其光学实现基本单元参量选择的判定法则,计算机模拟实验证明了结论的可靠与可行。 相似文献