Performance Comparison Of Controllers Research Articles

Performance and Stability Margins Comparison of Pole Placement and Optimal Controllers using Cart-Inverted Pendulum System

In this paper, pole placement and two optimal control techniques which are the linear quadratic regulator and linear quadratic Gaussian are compared. A cart and inverted pendulum which is an inherently unstable dynamical system is used as a case study to analyze their performance and stability margins. Lagrangian equations defining the system dynamics are converted to linear state-space representation. The objective is to keep the pendulum in an upright position as the cart on which it is mounted moves from one position to another. MATLAB is used to solve the optimization problem and simulate the step response of the system. The robustness of both controllers is measured by giving uncertain model parameters to the system and observing the level of uncertainty these controllers can handle. The simulation results justify the relative advantages of these control schemes.

Performance Comparison of Various controllers on Semi-Active Vehicle Suspension System

The value of a self-tuning adaptive semi-active control scheme for automotive suspension systems is discussed in this paper. The current vehicle suspension system uses fixed-coeffcient springs and dampers. The ability of vehicle suspension systems to provide good road handling and improve passenger comfort is usually valued. Passive suspension allows you to choose between these two options. Semi-Active suspension(SAS), on the other hand, can provide both road handling and comfort by manipulating the suspension force actuators directly. The semi-active suspension system for a quarter car model is compared to passive and various controllers such as Proportional-Integral, Proportional-Integral-Derivative, Internal model control (IMC)-PID, IMC-PID with filter, FUZZY, and Adaptive-network-based fuzzy inference system(ANFIS) in this analysis. This research could be relevant in the future for designing better car suspension adjustments to eliminate vertical jerks and rolling motion experienced by the vehicle body on bumps and humps.

Control Performances of Friction Pendulum and Sloped Rolling-Type Bearings Designed with Single Parameters

Owing to quite different features and hysteretic behavior of friction pendulum bearings (FPBs) and sloped rolling-type bearings (SRBs), their control performances might not be readily compared without some rules. In this study, first, on the premise of retaining the same horizontal acceleration control performance, the effects arising from different sloping angles and damping forces on the horizontal maximum and residual displacement responses of SRBs are numerically examined. For objective comparison of passive control performances of FPBs and SRBs, then, some criteria are considered to design FPBs with the same horizontal acceleration control performance by referring to the designed damping force and the maximum horizontal displacement response of SRBs under a given seismic demand. Based on the considered criteria, the passive control performances of FPBs and SRBs under a large number of far-field and pulse-like near-fault ground motions are quantitatively compared. The numerical comparison results indicate that the FPB models might potentially have better horizontal acceleration and isolation displacement control performances than the SRB models regardless of whether they are subjected to far-field or near-fault ground motions, while the opposite tendency is observed for their self-centering performances, especially when the SRB model designed with a larger sloping angle or a smaller damping force.

Optimal guidance against active defense ballistic missiles via differential game strategies

The optimal guidance problem for an interceptor against a ballistic missile with active defense is investigated in this paper. A class of optimal guidance schemes are proposed based on linear quadratic differential game method and numerical solution of Riccati differential equation. By choosing proper parameters, the proposed guidance schemes are able to drive the interceptor to the target and away from the defender simultaneously. Additionally, fuel cost, control saturation, chattering phenomenon and parameters selection were taken into account. Satisfaction of the proposed guidance schemes of the saddle point condition is proven theoretically. Finally, nonlinear numerical examples are included to demonstrate the effectiveness and performance of the developed guidance approaches. Comparison of control performance between different guidance schemes are presented and analysis.

Nonlinear Robust Optimal Control via Adaptive Dynamic Programming of Permanent-Magnet Linear Synchronous Motor Drive for Uncertain Two-Axis Motion Control System

In this article, a nonlinear robust optimal control (NROC) scheme for uncertain two-axis motion control system via adaptive dynamic programming (ADP) and neural networks (NNs) is proposed. The two-axis motion control system is an X-Y table actuated by permanent-magnet linear synchronous motor servo drives. First, the motions of the tracking contour in X-axis and Y-axis of the X-Y table are stabilized through feedback linearization control (FLC) laws. However, the control performance may be destroyed due to parameter uncertainties and compounded disturbances. Therefore, to improve the robustness of the control system, an NROC is designed to achieve this purpose. The tracking control problem of the X-Y table with uncertainties is transformed to a regulation problem. Then, it is solved by an infinite horizon optimal control using a critic NN. Consequently, the NN is developed via ADP learning algorithm to facilitate the online solution of the Hamilton-Jacobi-Bellman equation corresponding to the nominal system for approximating the optimal control law. The uniform ultimate boundedness of the closed-loop system is proved utilizing the Lyapunov approach and the tracking error asymptotically converges to a residual set. The validation of the proposed control schemes are carried out through experimental analysis. The control algorithms have been implemented using a DSP control board. A comparison of control performances using FLC, adaptive FLC, and FLC-based NROC is investigated. From the experimental results, the dynamic behaviors of the two-axis control system using the proposed FLC-based NROC can achieve robust optimal control performance against parameter uncertainties and compounded disturbances.

Comparative Analysis of Different Model-Based Controllers Using Active Vehicle Suspension System

This paper deals with the active vibration control of a quarter-vehicle suspension system. Damping control methods investigated in this paper are: higher-order sliding mode control (HOSMC) based on super twisting algorithm (STA), first-order sliding mode control (FOSMC), integral sliding mode control (ISMC), proportional integral derivative (PID), linear quadratic regulator (LQR) and passive suspension system. Performance comparison of different active controllers are analyzed in terms of vertical displacement, suspension travel and wheel deflection. The theoretical, quantitative and qualitative analysis verify that the STA-based HOSMC exhibits better performance as well as negate the undesired disturbances with respect to FOSMC, ISMC, PID, LQR and passive suspension system. Furthermore, it is also robust to intrinsic bounded uncertain dynamics of the model.

Control performance comparison between tuned liquid damper and tuned liquid column damper using real-time hybrid simulation

Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is employed to investigate the difference in control performance between TLD and TLCD. A series of RTHSs is presented with the premise of the same liquid length, mass ratio, and structural parameters. Herein, TLD and TLCD are physically experimented, and controlled structures are numerically simulated. Then, parametric studies are performed to further evaluate the different performance between TLD and TLCD. Experimental results demonstrate that TLD is more effective than TLCD under different amplitude excitations.

Tracking-error control via the relaxing port-Hamiltonian formulation: Application to level control and batch polymerization reactor

In this paper, a tracking-error-based control design without feedback passivation stage is developed for the stabilization of physical and chemical nonlinear processes. To achieve control objectives, the system dynamics is first formulated under appropriate conditions as a relaxing (pseudo) port-Hamiltonian (PH) representation with some quadratic storage function, in which the positive semi-definite property of damping matrix may not be taken necessarily into account. Then, a reference trajectory expressed by a certain structure passing through a desired set-point (or containing an optimal profile) is suitably chosen. By adding a relevant damping injection, asymptotic and global convergence of error dynamics is guaranteed. Two case studies including the level control of a four-tank process of continuous time type and the optimal tracking of a batch polymerization reactor of discontinuous time type due to the nature of the process operation are used to illustrate the application and the effectiveness of the approach. Besides the control performance comparison with the conventional passivity-based control method and the robustness evaluation against disturbance and/or noise are included.

Performance enhancement of pressure-swing distillation process by the combined use of vapor recompression and thermal integration

The intensified pressure-swing distillation (PSD) process is explored by applying vapor recompression and thermal integration. The evaluation indicators of second-law efficiency and CO2 emissions are adopted to rank different pressure swing-top vapor recompressed (PSDVRC) configurations. Compared to the conventional PSD process, the economically optimum flowsheet is the thermal integrated PSDVRC process with overhead vapor splitting since it can reduce 67.05% in energy consumption, 72.66% in CO2 emissions and 34.14% in total annual cost (TAC) as well as enhance 159.06% in thermodynamic efficiency. Besides, PSDVRC processes with overhead vapor splitting (PSDVRC-VS) are also superior to other PSDVRC configurations where economic-efficient process is PSD process (PSDSVRC) with single vapor recompression. Dynamic controllability for the highly integrated and interacting economic-efficient process is also investigated. An effective control structure is developed that only handles small (5%) disturbances in throughput and feed composition. The modified process is further developed to achieve robust control performance in terms of peak dynamic transients, settling time, oscillation and steady-state offsets. Meanwhile, control performance comparisons for PSDVRC-VS and PSDSVRC processes are also studied and showed that there is conflict between the steady-state economics and dynamic controllability.

Performance comparison of DC and AC controllers for a two-stage power converter in energy storage application

This paper presents a procedure for modelling and controlling a single-phase, two-stage, bidirectional DC–AC converter for application of energy storage system (ESS) in autonomous microgrids, in addition to experimental verification of its uninterruptible power supply (UPS) functionality. Average theory and frequency analysis are utilized to model the power converters and design the controllers in a generic fashion. Performance comparison of different controllers (type-2 and type-3 Venable compensators, Proportional Integral, Resonant-PI and multiple-RPI) is realised through simulations and tests. To tune the controllers, parameter values of crossover frequency and phase margin are adjusted by comparing simulation responses of the converters. A 5-kW ESS is evaluated through simulations during normal operation (grid-connected or stand-alone mode), as well as under transition events such as disconnection and recovery of the main grid. Besides that, a 100-W system was implemented, in which grid-connected mode was evaluated by measuring the power factor (about 0.998 in simulation and 0.993 in test at rated power), while stand-alone mode was evaluated by the total harmonic distortion of the output voltage (about 1.57% in simulation and 2.35% in test at rated power). The presented procedure can also be used to design higher power systems.

Experimental study on control performance comparison between model predictive control and proportion-integral-derivative control for radiant ceiling cooling integrated with underfloor ventilation system

Radiant ceiling cooling integrated with underfloor ventilation (RCCUV) system has energy-saving potential in buildings. However, control problem results in its energy-saving effect lower than expected and restricts its application. Conventional control is inadequate due to its poor performance, control lag and low economy, etc. The objectives of this study are to: (1) develop advanced model predictive control (MPC) controller of RCCUV system; and (2) experimentally discuss MPC controller performance compared with conventional proportional-integral-derivative (PID) controller performance. The experimental results indicated that under experimental step setpoint variations, the adjusting time of controlled variables using MPC controller was less than that of using PID controller. The time to reach recommended thermal comfort range using MPC controller was 3 min, and was 13 min using PID controller under experimental step setpoint variations. Meanwhile, MPC controller reduced energy consumption of RCCUV system by 13.2% compared with PID controller during 2 h of experimental period. Thus, control performance of MPC controller is superior to that of PID controller in every aspect. The study provides an advanced superior MPC controller for RCCUV system.

Dynamic Decoupling Control Optimization for a Small-Scale Unmanned Helicopter

This article presents design and optimization results from an implementation of a novel disturbance decoupling control strategy for a small-scale unmanned helicopter. Such a strategy is based on the active disturbance rejection control (ADRC) method. It offers an appealing alternative to existing control approaches for helicopters by combining decoupling and disturbance rejection without a detailed plant dynamics. The tuning of the control system is formulated as a function optimization problem to capture various design considerations. In comparison with several different iterative search algorithms, an artificial bee colony (ABC) algorithm is selected to obtain the optimal control parameters. For a fair comparison of control performance, a well-designed LQG controller is also optimized by the proposed method. Comparison results from an attitude tracking simulation against wind disturbance show the significant advantages of the proposed optimization control for this control application.

Performance Comparison and Evaluation of Different Software Defined Networks Controllers

Performance Comparison and Evaluation of Different Software Defined Networks Controllers

Performance Comparison of Controllers for Suppressing the Structural Building Vibration

<span lang="EN-US">This paper presents the modelling and simulation of controllers for controlling the position of two degree of freedom (2 DOF) mass spring damper system. Proportional integral (PI), fuzzy logic controller (FLC) and sliding mode controller (SMC) are design to minimize the vibration of the system that represent as building structure towards earthquake. A structural building is simulate based on real earthquake occur in El Centro on May 1940. The algorithm for building structure, actuator and controller is derived. Matlab/Simulink is used to analyze the performance of controllers towards the vibration building structure. At the end of the study the time response for two story building for uncontrolled and controlled system is present. Besides, the result for limitation voltage for each controller is also analyse to determine the maximum voltage consume for the system. The simulation results show the comparison of the controllers’ performance in suppressing the building vibration. From performance analysis, SMC provides better performance compared to PI and FLC based on structural vibration reduction.</span>

PSO-based PID Speed Control of Traveling Wave Ultrasonic Motor under Temperature Disturbance

Traveling wave ultrasonic motors (TWUSMs) have a time varying dynamics characteristics. Temperature rise in TWUSMs remains a problem particularly in sustaining optimum speed performance. In this study, a PID controller is used to control the speed of TWUSM under temperature disturbance. Prior to developing the controller, a linear approximation model which relates the speed to the temperature is developed based on the experimental data. Two tuning methods are used to determine PID parameters: conventional Ziegler-Nichols(ZN) and particle swarm optimization (PSO). The comparison of speed control performance between PSO-PID and ZN-PID is presented. Modelling, simulation and experimental work is carried out utilizing Fukoku-Shinsei USR60 as the chosen TWUSM. The results of the analyses and experimental work reveal that PID tuning using PSO-based optimization has the advantage over the conventional Ziegler-Nichols method.

Robust Gain-Scheduled Flight Controller via A New Formulation for Over-Bounding Scheduling Parameter Errors

Abstract This note addresses Gain-Scheduled (GS) flight controller design for the lateral-directional motions of an In-Flight Simulator (IFS) in a certain speed range. The design requirements for the GS flight controller are twofold: Model-matching and gust alleviation under some plant uncertainties as well as bounded errors in the provided scheduling parameters. We design a GS Output Feedback (GSOF) controller which meets the afore-mentioned design requirements via a new formulation for over-bounding the errors between actual scheduling parameters and inexactly provided ones. Control performance comparison between our new controller and the controller designed with an existing method in literature confirms that the former has less conservatism than the latter in synthesis as well as a posteriori analysis.

Performance comparison of FACTS controllers for transmission pricing diminution

The deregulated electric power industry creates a scope for the private companies to enter and compete in different activities of electric power system market. The electricity transmission and the ...

Comparison of Output Power Control Performance of Wind Turbine using PI, Fuzzy Logic and Model Predictive Controllers

In the variable speed wind energy conversion system, one of the operational problems is to handle the speed uncertainty and discontinuity of wind, that influence the power generation from a wind energy conversion systems (WECS). In order achieve a stable power output from a WECS despite variations in the wind speed, a number of control algorithms were devised in the literature over the past few years. Pitch angle control is widely used for regulation of output power fluctuations in a WECS. The control objective is to maintain stable power generation against wind speed variation, which can be achieved by regulating the pitch angle and/or generator torque. In view of handling the uncertainties owing to wind speed variations, this paper pursued a comparative assessment of three controllers, namely Proportional-Integral control, Fuzzy logic control (FLC) and Model predictive control (MPC) schemes. To evaluate their performance a simulation setup for implementing these three controllers applied to a WECS is prepared in MATLAB/Simulink. From the obtained results, it is envisaged that the proposed MPC exhibits excellent response and robustness of the WECS in face of uncertainties owing to intermittency and discontinuity of the wind speed.

Performance Comparison of PI and Fuzzy Logic Controllers of DTC for Torque Ripple Reduction

Performance Comparison of PI and Fuzzy Logic Controllers of DTC for Torque Ripple Reduction

Performance Analysis of SDN/OpenFlow Controllers: POX Versus Floodlight

Software-Defined Networking (SDN) is an emerging network architecture that is adaptable, dynamic, cost-effective, and manageable. The SDN architecture is a form of network virtualization where the network controlling functions and forwarding functions are decoupled. A setup and configuration task of a control plane to work as an SDN controller is explained in this paper. This paper includes a brief survey of different SDN based OpenFlow-enabled controllers available in various programmable languages. This paper mainly focuses on two OpenFlow-enabled controllers, namely, POX--a Python-based controller and Floodlight--a Java-based controller. A performance comparison of both controllers is tested over different network topologies by analyzing network throughput and round-trip delay using an efficient network simulator called Mininet. A single, linear, tree and custom (user-defined) topologies are designed in Mininet by enabling external controllers. It is obtained that, a percentage improvement in round-trip time for Floodlight over POX is 11.5, 13.9, 19.6 and 14.4% for single, linear, tree and custom topology respectively. Similarly, a percentage improvement in throughput for Floodlight over POX is 5.4, 8.9, 3.8 and 4.9% for single, linear, tree and custom topology respectively.