Koksal Erenturk

Trajectory Tracking Control for a 3-DOF Parallel Manipulator Using Fractional-Order

In this paper, a 3-degrees-of-freedom parallel manipulator developed by Tsai and Stamper known as the Maryland manipulator is considered. In order to provide dynamic analysis, three different sequential trajectories are taken into account. Two different control approaches such as the classical proportional-integral-derivative (PID) and fractional-order PID control are used to improve the tracking performance of the examined manipulator. Parameters of the controllers are determined by using pattern search algorithm and mathematical methods for the classical PID and fractional-order PID controllers, respectively. Design procedures for both controllers are given in detail. Finally, the corresponding results are compared. Performance analysis for both of the proposed controllers is confirmed by simulation results. It is observed that not only transient but also steady-state error values have been reduced with the aid of the PIλDμ controller for tracking control purpose. According to the obtained results, the fractional-order PIλDμ controller is more powerful than the optimally tuned PID for the Maryland manipulator tracking control. The main contribution of this paper is to determine the control action with the aid of the fractional-order PI λDμ controller different from previously defined controller structures. The determination of correct and accurate control action has great importance when high speed, high acceleration, and high accuracy needed for the trajectory tracking control of parallel mechanisms present unique challenges.

\hbox{PI}^{\lambda}\hbox{D}^{\mu}

This paper proposes an efficient compensation algorithm based on an adaptive network-based fuzzy inference system capable of converting a sampled current waveform that is distorted by current-transformer (CT) saturation to a compensated current waveform. Quick response time, no cumulative estimation error, desired sample-by-sample output, no dependency of CT parameters/characteristics and secondary burdens, and simplicity are some attractive features of the proposed method. The accuracy and robustness of the introduced compensation algorithm are demonstrated through extensive test cases reflecting a wide range of variations in fault conditions and CT parameters. The proposed algorithm has also been implemented and tested on a digital signal processor board.

Control

This paper presents a method of fuzzy control combined with grey system modeling approach of a mechatronic system to be used in driving a four-bar mechanism by a dc motor through a buck converter. The main contribution of this paper is that it predicts the future error values in terms of the previous error values using a grey estimator and determines the control action for the following step that depends on the predicted error value before it occurs. Despite the basic assumption that the angular velocity of the crank is constant in most of the mechanism analysis, this may not be valid when the mechanism is connected to an electric motor. In this paper, a complete state-space mathematical model of each part of the converter-motor-mechanism system is first developed and numerically simulated to demonstrate the crank angular speed fluctuations for the case of a constant voltage supply. Then, a fuzzy logic controller combined with grey system modeling approach is designed to regulate the crank angular speed of the mechanism and compared with a fuzzy controller used alone. Finally, results are obtained for each part of the system separately, then related parts are connected as cascade, and complete system control is tested for the proposed control approach. The connection between dc motor and four-bar mechanism has been considered as a dynamic load for the converter. Comparatively better results are obtained when the fuzzy controller is used together with grey system modeling approach. The results obtained from the proposed controller are not only superior in the rise time, speed fluctuations, and percent overshoot, but also much better in the controller output signal structure.

ANFIS-Based Compensation Algorithm for Current-Transformer Saturation Effects

An attractive and instructive approach for teaching basis of fuzzy logic‐based controller design steps and effects of properties of the controller to control system by using MATLAB environment is presented in this paper. All design stages are developed in MATLABs graphical user interface (GUI). Source codes used for both controller and to define systems to be controlled are written in separated script files using MATLAB language. Maximum and minimum values of the parameters that belong to membership functions (MFs) and rule base table are determined by using step responses and error graphics of the systems. Two different examples are given to demonstrate the usefulness of the developed tool and to visualize effect of changes of fuzzy logic‐based controller parameters.

Hybrid Control of a Mechatronic System: Fuzzy Logic and Grey System Modeling Approach

Dynamic modeling of an ultraviolet (UV) fluorescent lamp has been addressed in this paper. Based on a recently developed lamp model, a semiempirical modeling technique has been applied for dynamic modeling of a UV fluorescent lamp. In the modeling stage, simple electrical measurements have been used. In the proposed mathematical model, model parameters have been determined from electrical voltage and current measurements of the lamp under AC operation at operating frequency. In order to calculate the model constants, the lamp data from lamp manufacturers have not been required. Once the model constants have been determined at 50-Hz main fundamental operating frequency, with the same set of parameters, the model can predict the lamp terminal characteristics accurately under different operating conditions. Different operating frequencies, such as low-, medium-, and high-frequency operations, have been considered, and good simulation results have been achieved when the lamp power has been reduced to different operating levels. The simulation results are confirmed by laboratory experiments.

MATLAB-Based GUIs for Fuzzy Logic Controller Design and Applications to PMDC Motor and AVR Control

A three-axes portal-type computer numerical control (CNC) manipulator is analyzed, in this study. In order to improve the trajectory tracking ability of the manipulator for both linear and circular trajectories different controllers are examined. To compare the effectiveness of different control approaches on the improvement of tracking and contouring performance of the examined three-axes portal-type CNC, proportional-integral-derivative (PID), observer-based PID, and feedforward computed torque (FFCT) control approaches are applied. It is observed that not only overshoot in tracking and contour errors but also transient and steady-state errors are reduced using the proposed FFCT controller. Although computing time increases, the FFCT control method is found as the best solution for the considered cases to improve the trajectory tracking ability of the manipulator for both linear and circular trajectories.

Dynamic Characterization of a UV Fluorescent Lamp

In this study, kinematic analysis of 6-DOF RSS parallel manipulator using Denavit Hartenbeng (D-H) method is investigated. In addition, in order to improve the proposed method, determination of all the active and passive angles, required to obtain Jacobian and complete dynamic model of manipulator, is also achieved. The effects of dynamic models of 6-DOF RSS parallel manipulator with its actuators on trajectory tracking control are studied in detail. Feedback dynamic compensation terms of motor-mechanism coupling system that is needed to compute torque control are obtained through both a single link approximation model and a complete dynamic model. The complete model is derived by taking account of the interaction between the input links and coupler links of the manipulator. Simulations showed that obtaining complete model of manipulator by means of D-H method and using computed control law could improve the quality of trajectory tracking control of parallel manipulator.

Trajectory Tracking Control and Contouring Performance of Three-Dimensional CNC

Robotic manipulators on a moving base are used in many industrial and transportation applications. In this study, the modelling of a RRP SCARA-type serial manipulator on a moving base is presented. A Lagrange-Euler approach is used to obtain the complete dynamic model of the moving-base manipulator. Hence, the dynamic model of the manipulator and the mobile base are expressed separately. In addition, Virtual Instrumentation (VI) is developed for kinematics, dynamics simulation and animation of the manipulator combined with the moving-base system. Using the designed VI in LabView, the relationship between frequency of disturbances of the moving base and joint torques is investigated. The obtained results are presented in graphs.

Modeling and trajectory tracking control of 6-DOF RSS type parallel manipulator

Abstract This paper presents application of adaptive network based fuzzy inference system (ANFIS) to estimate critical flashover voltage on polluted insulators. Diameter, height, creepage distance, form factor and equivalent salt deposit density were used as input variables for ANFIS, and critical flashover voltage was estimated. In order to train the network and to test its performance, the data sets are derived from experimental results obtained from the literature and a mathematical model. Obtained results were given in both tabulated and graphical form for various cases studies, separately. Satisfactory and more accurate results obtained by using ANFIS to estimate the critical flashover voltage for the considered conditions compared with the previous works. Both test and validation stages were explained in detail and it is observed that estimated results rather close to experimental results.

Detailed Analysis of SCARA-Type Serial Manipulator on a Moving Base with LabView

Abstract In this study, fuzzy logic is used to identify faults that may occur in a radial power system. In addition to the design concept of fuzzy logic based on protective relay, its architecture and application of the developed prototype system are discussed. A digital relay is designed and tested in a laboratory environment using a developed prototype. In order to constitute a new approach to digital protection purpose, fuzzy logic is used instead of conventional protection approaches. The relay proposed here is developed using conventional relay characteristics by adding some abilities, i.e., to distinguish whether the fault is sub‐transient, transient, or permanent, to determine whether the fault is one of the types known as phase‐to‐phase, phase‐to‐neutral, double phase‐to‐neutral, or balanced three phase. Performance analysis is performed and the results obtained are given using graphical illustration to show validity of the proposed relay.