Good Step Response Research Articles

Design and Analysis Models with PID and PID Fuzzy Controllers for Six-Phase Drive

Due to their reliability, design and analysis models with PID and PID fuzzy controllers for six-phase drive are being applied in new areas in various industries, including transportation. First, the development of any system with multiphase motors requires an elaborate model to define the control mode and controllers. The modeling of a control system for six-phase drive is based on its conventional d-q mathematical model and indirect field-oriented control. In this study, a Simulink six-phase drive model is designed with indirect field-oriented control and simulated with two types of fuzzy controller, PID and PID fuzzy. The simulation results are presented and analyzed; these results reflect the step response and performance at the provided speed reference law while keeping the load application at a constant speed. A fuzzy controller with 49 rules is considered and applied. With field-oriented control and a well-tuned PID controller, the six-phase electric drive has good step response specifications: a short settling time when starting without a load, no overshoot in the step response, small size, and a slight decrease in speed when loaded. The system employing a PID fuzzy controller shows slightly better results in response to the application of torque: the decrease in speed is eliminated more quickly. The simulation results were tabulated with the PID and with the results of previous research that rearranged some models to only operate in the classical controller mode. The simulation results indicate the robustness to disturbance of both the systems with six-phase drive and provide high-quality transient specifications at the provided reference speed.

Design and Analysis Models With PID and PID Fuzzy Controllers for Six-Phase Drive

The multiphase motors due to their reliability find new areas of application in the industry and transportation. Developing of any system with multiphase motors at first requires elaborate model of the system, define control mode and controllers. The model of control system for the sixphase drive is based on its conventional d-q mathematical model and indirect field-oriented control. Simulink model of six-phase drive with indirect field-oriented control and simulated with two types PID and PID fuzzy controllers. The simulation results, reflecting step response and provided speed reference law as well as load application at constant speed, are presented and analyzed. Fuzzy controller with 49 rules is considered and applied. Six-phase electric drive with field-oriented control at well-tuned PID controller has good step response specifications: settling time 0.13 s at starting without load, step response has no overshoot, small about 1% short time decrease of speed at load of 5 Nm application. The system employing PID fuzzy controller shows slightly better results in response to torque application: the decrease in speed 1% is eliminated in shorter time. Simulation results indicate the robustness of both systems with six-phase drive to disturbance and provide high quality transient specifications at provided reference speed.

Game Algorithm of Intelligent Driving Vehicle Based on Left-Turn Scene of Crossroad Traffic Flow.

Vehicle networking and autonomous driving are hot areas of scientific research today, and they complement each other and play an important role in people's intelligent travel. Intelligent driving vehicle can enhance road safety, effectively reduce traffic flow and fuel consumption, and promote the overall social development. It has great application value in urban traffic system. The traffic condition of a city directly affects the economic development of the city and the improvement of people's quality of life. As the “core” of the urban traffic network, intersections are the frequent places where traffic jams occur. Game theory, as a win-win theory, mainly solves the problem of multiperson and multi-objective with contradictory objective functions and can be used to study the optimal signal control strategy. Aiming at this problem, the potential conflict behaviors of intelligent driving vehicles when turning left at urban intersections are analyzed and a decision model is established. A long-term trajectory prediction model of straight vehicles is established based on the Gaussian process regression model (GPR) considering the vehicle motion pattern. Combined with trajectory prediction, a decision-making process (model) for intelligent driving vehicles based on conflict resolution and a multifactor driving action selection method are proposed. A coordination algorithm based on game theory is designed for conflicting vehicles. The proposed algorithm is verified by the self-developed intelligent vehicle hardware simulation platform. The simulation results show that the PID method based on digital identification and positioning makes the intelligent vehicle obtain good system step response, can improve the disturbance tracking ability of intersection turning analysis, meet the requirements of turning control system, and reduce the complexity and randomness of parameter design, which is better than the traditional fuzzy control method.

Direct Drive Servovalves Actuated by Amplified Piezo-Stacks: Assessment through a Detailed Numerical Analysis

This paper presents a feasibility study using commercially available amplified piezo-stacks for the direct actuation of four-way three-position (4/3) direct drive servovalves. The prospect of using amplified piezo-stacks in place of linear force motors is very attractive by virtue of their fast response speed and low weight. Piezo-stacks equipped with mechanical amplification systems can give levels of displacement suitable for this application. A very effective amplification system has recently been produced by some manufacturers and is based on a temperature-independent diamond structure. This paper details simulations of a 4/3 servovalve directly actuated by such a piezoelectric actuator with a diamond structure. To this end, well-established equations, implemented in Simulink by means of the libraries of Simscape Fluids, are used. The proposed architecture shows simplicity of construction; in addition, very good step response speed and frequency response are predicted by the simulations.

Imperialist competitive algorithm for determining the parameters of a Sugeno fuzzy controller

Abstract We used an imperialist competitive algorithm to determine the parameters of a fuzzy controller of type Sugeno that would ensure a good unit step response of a second-order single-input and single-output automatic system.

Marine Oil Spill Control Based on Discrete Mathematical Model

Liu, Y., 2020. Marine oil spill control based on discrete mathematical model. In: Yang, Y.; Mi, C.; Zhao, L., and Lam, S.(eds.), Global Topics and New Trends in Coastal Research: Port, Coastal and Ocean Engineering. Journal of Coastal Research, Special Issue No. 103, pp. 387–391. Coconut Creek (Florida), ISSN 0749-0208.Marine oil spill has caused great environmental pollution. Therefore, the analysis of marine oil spill control based on discrete mathematics is studied. Based on the complex situation at sea, an on line monitoring and control system for offshore oil spill including an oil spill online monitoring subsystem and an oil spill integration subsystem is designed. The on-line monitoring subsystem of the oil spill establishes the land data center by the integration technology, uses the data center to monitor the pollution accidents such as oil spill and the like of the offshore oil platform, analyzes the multi-source monitoring data returned by the processing and reports the monitoring and early warning information, and expands the multi-source data receiving processing and the visual display. The main system uses the current loop discrete control model to design the PWM rectifier control module, the real-time dynamic visualization module based on the “oil particle” model, and the interactive fence distribution control based on the triangle partition algorithm to realize the oil spill control. Experiments show that the system could effectively monitor the oil spill on the sea surface, simulate the marine oil spill movement process under complex environmental conditions, and have a good step response.

Lead and lag controller design in fractional-order control systems

This paper presents a controller design method using lead and lag controllers for fractional-order control systems. In the presented method, it is aimed to minimize the error in the control system and to obtain controller parameters parametrically. The error occurring in the system can be minimized by integral performance criteria. The lead and lag controllers have three parameters that need to be calculated. These parameters can be determined by the simulation model created in the Matlab environment. In this study, the fractional-order system in the model was performed using Matsuda’s fourth-order integer approximation. In the optimization model, the error is minimized by using the integral performance criteria, and the controller parameters are obtained for the minimum error values. The results show that the presented method gives good step responses for lead and lag controllers.

Design, analysis, and testing of a flexure-based vibration-assisted polishing device

A vibration-assisted polishing device (VAPD) composed of leaf-spring and right-circular flexure hinges is proposed with the aim of realizing vibration-assisted machining along elliptical trajectories. To design the structure, energy methods and the finite-element method are used to calculate the performance of the proposed VAPD. An improved bacterial foraging optimization algorithm is used to optimize the structural parameters. In addition, the performance of the VAPD is tested experimentally. The experimental results indicate that the maximum strokes of the two directional mechanisms operating along the Z1 and Z2 directions are 29.5 μm and 29.3 μm, respectively, and the maximum motion resolutions are 10.05 nm and 10.01 nm, respectively. The maximum working bandwidth is 1,879 Hz, and the device has a good step response.

Tuning of Fractional Order PID Controllers Based on Integral Performance Criteria Using Fourier Series Method

This paper presents a time domain tuning technique for a fractional order PID controller based on optimizing an integral performance criterion. A Fourier series based method (FSM) is used to calculate accurately the step response of the closed loop control systems so as to determine the exact value of the error function performance criterion. The initial guesses for the FOPID controller parameters to be optimized are found using the analytical solution for integral squared error optimization for an integer order PID controller. The proposed method is used for two test plant transfer functions by comparing different optimal FOPID controllers. The results show that the design technique based on optimization of different integral performance criteria give good step responses for FOPID controller.

Modelling and robust control of an unmanned coaxial rotor helicopter with unstructured uncertainties

A complete methodology for an unmanned coaxial rotor helicopter with unstructured uncertainties was proposed to achieve high-accuracy tracking performance from modelling to robust control. An integrative approach was introduced to systematically construct a whole dynamic model. The key parameters were selected carefully after iteratively being checked by empirical coefficients to decrease the budget and risk of programme. Moreover, a new control scheme is proposed to simultaneously incorporate six inputs to control six states based on the investment of singularity value responses and the general rule of relative gain array. Coprime factor uncertainty model is considered to represent a class of unstructured uncertainties, such as unmolded actuator dynamics and unpredicted interferences between two rotors. Furthermore, the [Formula: see text] loop-shaping control was proposed to apply the control design of the coaxial rotor helicopter to manage complicated uncertainties and multivariable coupling. Finally, simulation results show the effectiveness of the proposed controller design in the step response of the closed loop. The stable closed-loop plant is achieved and the tolerant size of unstructured uncertainty is up to 36.09%. Good step responses and satisfied decoupling were also investigated in detail.

Performance improvement of a buck converter using Kalman filtering

This paper presents a predictive current control algorithm for a synchronous buck converter using an extended Kalman filter (EKF) algorithm. The predictive approach avoids the need of current-sensing circuitry and provides insensitivity to Gaussian noise sources at the output of the buck converter, which is the same as the control loop input. The method requires a model for the buck converter, the EKF design, and current loop tuning. All these prerequisites are described in this work along with the implementation of the algorithm in a state of the art microcontroller. Simulation and experimental results show that while maintaining a good step response, the proposed method provides better results than standard methods when Gaussian noise is present at the output voltage.

A Novel Design of Ionic Polymer-Metal Composites (IPMCs) Actuator Based on Poly(MMA-co-AA)

In this study, we report for the first time the fabrication of poly(methyl methacrylate-co- acrylic acid) (PMMAA)-based IPMCs actuator. The PMMAA membranes were prepared by a solution casting method and the carbon nanotubes (CNTs) electrodes on both sides of the membrane. The physical properties were tested in terms of ion-exchange capacity, water uptake and linear expansion. The composition of PMMAA was analyzed using Fourier transform infrared (FT-IR) spectroscopy analysis. The results showed that the PMMAA20 ionic polymer–metal composite actuator had good blocking force harmonic and step responses as an electro-active polymer.

Electric-stimuli-responsive bending actuator based on sulfonated polyetherimide

In this study, based on the ionic exchangeable membrane of biocompatible sulfonated polyetherimide (SPEI), a novel electric-stimulus-responsive bending actuator was developed. The degree of sulfonation of SPEI was controlled with chlorosulfonic acid and was analyzed by using 1H nuclear magnetic resonance spectroscopy and thermogravimetric analysis. The SPEI membrane prepared by a solution casting method shows good electro-chemical properties of ion-exchange capacity, water uptake and proton conductivity required for a high-performance ionic polymer actuator. The SPEI ionic polymer–metal composite actuator, which was prepared by coating platinum layers on both sides of the membrane by an electroless plating process, shows good harmonic and step responses as an electro-active polymer.

Iterative identification and two step control design for partially unknown unstable plants

In this paper we shall extend the applications of iterative identification and control design to partially unknown unstable plants. We show that by employong a two step approach, where an unstable plant is first stabilized by a parallel feedback stabilizer, it is possible to design systematically an overall closed-loop system that has good step responses with little overshoots by using the iterative identification and control design methodology. Furthermore, this approach easily preserves the simplicity of an IMC design through tuning the overall designed closed-loop bandwidth with a single design parameter. Specifically, similarly to situations where the plant is stable (apart from possibly including a simple integrator), we can design a system with a small initial overall designed closed-loop bandwidth (after the plant is stabilized by a known parallel feedback stabilizer) such that high frequency unmodelled dynamics of the plant are not overly excited. Through iterative applications of a control-relevant closed-loop system identification procedure and the standard IMC design method to the stabilized plant, the overall designed closed-loop bandwidth of the system can be widened progressively while maintaining good step responses with little overshoots. Two simulation examples are employed to illustrate the method. These examples show that, irrespective of the presence of adverse unstable real pole-zero structures, the expected results are achievable by the method described.

Design of Neural Network Controllers for a Two-Mass-Oscillator Using Genetic Algorithms and Implementation in a Real-Time Environment

This paper deals with the design of a neural network controller for a two-mass-oscillator. As design method for the controller, a genetic algorithm is used. This controller is implemented in a transputer network and works in real time. The combination of a neural network and a genetic algorithm (GA) leads to a controller combing fast reference value tracking and system damping. Experimental results show good step responses for the two-mass-oscillator with a neural network controller optimised by a genetic algorithm.

Active-matrix deformed-helix ferroelectric liquid crystal displays

Abstract Active-matrix DHFLC displays have potential for a better performance than can be obtained with TN AM-LCDs. Alignment of DHFLC is still difficult and the defect structure lowers the contrast. A forming voltage improves the contrast, but the defects reappear during temperature cycling in the S*C-phase. At least four different types of defects can be distinguished. Active-matrix driving of DHFLC is thoroughly investigated. The symmetric DHFLC mode is the preferred mode, for it prevents the occurence of image retention. Voltage driving and charge driving are both possible. Special measures have to be taken to improve the step response of the display. A diode-AM-DHFLC display is described which operates at video speed and shows a good step response and a wide angle of view.

Subband coding of images using asymmetrical filter banks

We address the problem of the choice of subband filters in the context of image coding. The ringing effects that occur in subband-based compression schemes are the major unpleasant distortions. A new set of two-band filter banks suitable for image coding applications is presented. The basic properties of these filters are linear phase, perfect reconstruction, asymmetric length, and maximum regularity. The better overall performances compared to the classical QMF subband filters are explained. The asymmetry of the filter lengths results in a better compaction of the energy, especially in the highpass subbands. Moreover, the quantization error is reduced due to the short lowpass synthesis filter. The undesirable ringing effect is considerably reduced due to the good step response of the synthesis lowpass filter. The proposed design takes into account the statistics of natural images and the effect of quantization errors in the reconstructed images, which explains the better coding performance.

Steady-state analysis of a three-term fuzzy controller

The steady-state response of a fuzzy logic controller that uses fuzzy addition as the basis for its decision making process is analyzed mathematically. The nature of the look-up table constructed from fuzzy addition enables the decomposition of the fuzzy controller into three one-dimensional-multilevel relays. Unlike the sinusoidal-input describing function technique, the steady-state response of the closed-loop system is analyzed. The sufficient conditions derived depend on the parameters of the controller and can be used as guidelines to achieve a good step response at steady-state, one that does not lend itself to sustained oscillations or limit cycles. >

Design of multi‐delayed control systems using a simple frequency‐domain criterion

Abstract The design of control systems with multiple delays was seldom discussed in past years. In this paper, an optimizing design method based on a frequency‐domain criterion is presented for multi‐delayed control systems to achieve good step response performance. The frequency‐domain criterion partitions the space of the controller parameters into two sets — one is undesirable and will cause unsatisfactory response; the other is desirable because it guarantees robust stability and attains satisfactory response with little overshoot and little oscillation. Over the desirable set, the final design parameters are easy to obtain by searching the set of controller parameters that lead to the maximum open‐loop gain. Examples are given to show the usefulness of this approach.

A Basic Study of Controlling a Scanner Servomechanism Used in a Plain Paper Copier.

This paper describes an investigation of the control methods for a scanner servomechanism used in a plain paper copier. Since wire and a spring are used in this servomechanism, it is not easy to obtain a step response without overshoot. Experiments with an actual scanner servomechanism used in a plain paper copier were performed, and good step responses without overshoot and with very small amounts of velocity fluctuations were successfully obtained through a design based on H∞ control theory, and the use of learning control.