Chunyang Wang

Fractional order proportional integral (FOPI) and [proportional integral] (FO[PI]) controller designs for first order plus time delay (FOPTD) systems

In this paper, systematic design schemes of fractional order proportional integral (FOPI) controller and fractional order [proportional integral] (FO[PI]) controller for the first order plus time delay (FOPTD) system are presented, respectively. For comparison between the fractional order and the integer order controllers, the integer order proportional integral derivative (IOPID) controller is also designed following the same proposed tuning specifications to achieve the robustness requirement. It is found that the three controllers designed by the proposed tuning methods not only make the system stable, but also improve the performance and robustness for the first order plus time delay (FOPTD) systems. Simulation results are presented to validate the proposed tuning schemes. Furthermore, from the simulation results, it can be seen that the FOPI controller outperforms the other two controllers.

An analytical design of Fractional Order Proportional Integral and [Proportional Integral] controllers for robust velocity servo

In this paper, two tuning methods of Fractional Order Proportional Integral (FOPI) controller and Fractional Order [Proportional Integral] (FO[PI]) controller for the typical first-order velocity servo system are discussed. Using the Integer Order Proportional, Integral and Derivative (IOPID) controller, the controller can not be designed to follow the proposed tuning idea to achieve the robustness requirement. However, the FOPI and FO[PI] controllers designed by the proposed tuning methods can improve the performance and robustness of the first order velocity servo system. Furthermore, following the proposed systematic and analytical design schemes, the FO[PI] controller outperforms the FOPI controller. Simulation results are presented to validate the proposed tuning methods.

Tuning fractional order proportional integral controllers for fractional order systems

In this paper, two fractional order proportional integral controllers are designed to improve the performance and robustness for a class of fractional order systems which can better model many real systems such as bioengineering systems. For comparison between the fractional order proportional integral controllers and the traditional integer order PID (IOPID) controller, the IOPID controller is also designed following the same proposed tuning specifications. Unfortunately, the designed IOPID controller can not meet the required spcification. However, the designed fractional order proportional integral (FOPI) and fractional order [proportional integral] (FO[PI]) controllers both can satisfy all the three specifications proposed. From the simulation results presented, it can be seen that both the FOPI and FO[PI] controllers designed work efficiently. Furthermore, we can observe that the FO[PI] controller outperforms the FOPI controller following the proposed design schemes for the fractional order systems considered.

Auto-tuning of FOPI and FO[PI] controllers with iso-damping property

A systematical design method for robust integer order proportional-integral-derivative(IOPID) controller with an iso-damping property was suggested in [3]. In this paper, two auto-tuning methods of Fractional Order Proportional Integral(FOPI) and Fractional Order [Proportional Integral] (FO[PI]) controllers with iso-damping property for a class of unknown, stable and minimum phase plants are designed and summarized. The FOPI and FO[PI] controllers designed by the two methods ensure that the phase Bode plot is flat, i.e., the phase derivative w.r.t. the frequency is zero at a given frequency called the “tangential frequency”, so that the closed-loop system is robust to gain variations and the unit step responses exhibit iso-damping property. During the process of the FOPI and FO[PI] controllers design and simulation, no plant models are assumed. Several relay feedback tests are used to identify the plant gain and phase at the tangential frequency in an iterative way. Simulation results are presented to validate the proposed auto-tuning methods for robust FOPI and FO[PI] controllers with iso-damping property.

LabVIEW based experimental validation of fractional order motion controllers

Fractional calculus has been more and more frequently used in the control domain in recent years. But the fractional order controllers are not widely implemented on the real-time experiments because of the complexity of realization. In this paper, for the first time on the LabVIEW hardware-in-the-loop platform which is a fast prototyping experimental setup, we made an experimental study of the fractional order proportional derivative (FO-PD) and [proportional derivative] (FO-[PD]) controllers which are designed following systematic schemes. The experimental results validated the advantages of the FO-PD and FO-[PD] controllers over the traditional integer order PID controllers designed under the same design specifications. Furthermore, the future work of the cooperative motion control system with multi-LabVIEW platforms for fractional order control is introduced briefly.

FRACTIONAL ORDER PROPORTIONAL DERIVATIVE (FOPD) AND FO(PD) CONTROLLER DESIGN FOR NETWORKED POSITION SERVO SYSTEMS

This paper considers the fractional order proportional derivative (FOPD) controller and fractional order [propor tional derivative] (FO[PD]) controller for networked position se rvo systems. The systematic design schemes of the networked position servo system with a time delay are presented. It follo ws from the Bode plot of the FOPD system and the FO[PD] that the given gain crossover frequency and phase margin are fulfille d. Moreover, the phase derivative w.r.t. the frequency is zero , which means that the closed-loop system is robust to gain variatio ns at the given gain crossover frequency. However, sometimes w e can not get the controller parameters to meet our robustnessrequirement. In this paper, we have studied on this situation a nd presented the requirement of the gain cross frequency, and p hase margin in the designing process. For the comparison of fractional order controllers with traditional integer order co ntroller, the integer order proportional integral differential (IOP ID) was also designed by using the same proposed method. The simulation results have verified that FOPD and FO[PD] are effective for networked position servo. The simulation results also r eveal

Design and simulation of inverted pendulum system based on the fractional PID controller

This paper implements fractional order controller to the compound control, taking the first-order inverted pendulum system as the plant, In which, using direct compensator to reach steady. Then we give the design method of fractional order PID controller (PIλDμ controller), fractional order (PDμ controller controller), integer order PID controller and optimize parameters based on genetic algorithm. The simulation results prove that the proposed method can achieve high performance comparing the PID controller.

Parameter calibration and simulation of fractional PID controller for hydraulic servo system

This thesis proposed the integer order, fractional orderPID controller parameter tuning scheme for the hydraulic servo position system controlled object. The controller parameters are given by the geometric meaning of the controller parameter vector, based on the improved Ziegler-Nichols algorithm. The simulation results show that the system achieves the expected control index, and obtains a high steady-state accuracy, fast dynamic response and good robustness.

Tuning fractional order proportional integral controllers based on vector in the complex plane for first order systems

In this paper, an improved fractional order proportional integral controller parameter tuning method has been proposed. This method is to map the controller to get a set of vectors in the complex plane. Following the method of vector and geometric in the complex plane, the complicated derivation and calculation can be simplified in the process of the controller design. In addition, the established geometric relationship equations not only can still be used when the plant is different, but also can be programmed in MATLAB. Therefore, the repetitive process of formula derivation can be omitted. Because of the triangle constraints in the complex plane, we can solve the problem that using MATLAB to calculate the controller parameters has multiple solutions.

Method and verification for measuring surface roughness of components by angle resolved scattering method

This paper introduces the automatic measurement system of laser scattering method based on angular resolution. Discuss the principle of laser in optical element surface scattering, propose the method which use angle resolved scattering (ARS) method to measure surface roughness, at the same time the measurement principle experimental platform is built based on the experimental results after verifying the correctness of the angle resolved scattering method.