Minimum Overshoot Research Articles

Controller Design of Higher-Order Closed-Loop Systems Based on Criterion of Minimum Integral of Time-Weighted Absolute Error

This paper focuses on analytically designing controllers or compensators for higher-order closed-loop systems based on the criterion of minimum integral of time-weighted absolute error. In light of the standardization characteristic polynomial whose coefficients are derived from the criterion of minimum integral of time-weighted absolute error, a characteristic polynomial equation is constructed. This characteristic polynomial equation includes the underdetermined parameters of designed controller or compensator whose structures are already determined. Solving this equation, the designed controller or compensator parameters are determined. Application examples indicate that the designed higher-order closed-loop systems have the minimum overshoot responses and the fastest settling times. This method provides another approach to analytically design the controllers or compensators for higher-order closed-loop systems.

Robust digital pole-placer for electric drives based on uncertain diophantine equation and interval mathematics

In this paper, a novel robust digital controller design is proposed and implemented for induction motor speed control. The objective is to design a robust output feedback controller that places the closed-loop poles in a specified region in order to achieve the desired dynamic performance for a system with variable load. The design is carried out in the frequency domain by solving the uncertain Diophantine equation using interval mathematics and non-linear optimization method. In order to capture the load variations, the characteristic equation is relaxed and enlarged from a fixed-point to an interval set. A simple model-based design methodology is adopted in this work and implemented experimentally using a Hardware-in-the-Loop environment. The proposed design is simulated and then validated using real induction drive system. The proposed controller is compared with two other controllers: the auto tuned PID and a least-square-based robust controller. Experimental results show that the designed robust controller provides a better dynamic response than conventional controllers used in the industry when the motor’s load is varied. These results validate the proposed design as the plant’s output follows the reference signal with minimal overshoot and settling time.

Three-axis gap clearance I-PD controller design based on coefficient diagram method for 4-pole hybrid electromagnet

ABSTRACT4-pole hybrid electromagnetic systems have a potential usage in many industrial areas, such as clean room design, transportation, semi-conductor manufacturing due to providing mechanical contact-free operation with considerably low energy consumption. However, the main problem of magnetic levitation process: it has highly nonlinear nature and even if it can be linearized, it has unstable pole(s), which makes the system vulnerable in terms of stability. In this paper, to overcome the instability issue and track the desired references for each degree of freedom, a modified PID controller (so called I-PD) design technique based on coefficient diagram method (CDM) has been proposed. CDM is an algebraic design applied to polynomial structure of the system on the parameter space, where a specific diagram is used to present and interpret the essential data. It is quite simple to apply with a visual support, requires basic mathematical computations for field engineers, and offers a good equilibrium in terms of simplicity, stability, minimum overshoot and robustness, which are crucial specifications for maglev applications. The effectiveness and feasibility of CDM-based I-PD controller have been compared with CDM-based classical PID controller over an experimental set-up.

Hovering Control of Quadrotor Based on Fuzzy Logic

Quadrotor is one of rotary wing UAV types which is able to perform a hover position. In order to take off, landing, and hover, it needs controllers. Conventional controllers have been widely applied in quadrotor, yet they have drawbacks namely overshoot. This paper presents attitude and altitude control algorithm in order to obtain a response as quadrotor hovered optimally within minimum overshoot, rise time, and settling time. The algorithm used is Fuzzy Logic Controller (FLC) algorithm with Mamdani method. By using the algorithm, the quadrotor is able to hover with minimum overshoot and maximum rise time. The advantage of the algorithm is that it does not require linearization model of the quadrotor.

Time varying backstepping control for trajectory tracking of mobile robot

This paper presents a time varying backstepping tracking controller TVBTC for the kinematic model of the non-holonomic wheeled mobile robot WMR that can improves the transient performances of the standard backstepping control scheme. The proposed TVBTC is derived based on the analysis of the error dynamic, as well as the stability conditions of the controlled system. The asymptotic stability of the system and the convergence of the posture errors to zero are guaranteed using the Lyapunov stability theory. In comparison with the other tracking control methods for the mobile robot, the simulation results demonstrate that the transient performance can be improved significantly using the proposed TVBTC, which is capable to track a circular path with faster settling time and minimal overshoot. In addition, the TVBTC can efficiently handle a situation with arbitrarily large initial tracking errors and it is capable to produce smooth and bounded velocity output in a finite time interval. The simulation results show the effectiveness of the proposed tracking controller at the starting time.

Adopting Setpoint Weighting Strategy for WirelessHART Networked Control Systems Characterised by Stochastic Delay

In networked control system, such as WirelessHART that is characterized by stochastic delay, the use of proportional integral and differential (PID) controllers is inadequate. This is because PID performs poorly in handling time-delay processes. The main reason for this poor performance is the limitation in the range of stable gain of the controller. Time delay causes oscillatory response of the PID with large gain. Likewise, sluggish response is experienced with small gain of the PID. Also, dead time compensators like smith predictor and internal model controller are difficult to be implemented practically since they require exact model of the process to be controlled. Therefore, this paper proposes the application of setpoint weighting strategy to be used alongside PID controller in a WirelessHART network. This method extends significantly the range of the PID gain, while providing good set point tracking and load regulation. From the simulation and experimental results obtained, the capability of the approach to load regulation and tracking can be seen in its fast recovery from effect of disturbance with minimal overshoot. Thus, a two degree of freedom control is achieved. Results also showed that the method is robust to real-time random variable network delay and model mismatches.

Comprehensive Characterization of 10-kV Silicon Carbide Half-Bridge Modules

This paper provides a comprehensive characterization of an example medium-voltage dc-based (MVDC) silicon carbide (SiC) MOSFET module of the type recently developed under Department of Defense (DoD) programs. As shown in this paper, these modules are capable of switching inductive loads very rapidly (<100 ns), with minimal overshoot and manageable parasitic-induced ringing. The transient analysis contained herein demonstrates a total per-cycle switching losses of 2.5 mJ at a bus voltage of 2 kV and a load current of 20 A. This figure is approximately two orders of magnitude lower than values recorded in the literature for commercially available silicon Insulated-Gate Bipolar Transistor modules with multikilovolt ratings at similar operating conditions (but which have lower blocking capability than the MVDC SiC module under study). These results corroborate the excellent switching performance of these MVDC SiC MOSFET modules, which has been only sparsely documented in the literature to date. In addition, this paper provides a comprehensive analysis of the static characteristics of these modules, including forward conduction, transfer characteristics, capacitance-voltage measurements, and quantization of parasitic impedances within the module housing. Technical challenges associated with making accurate and repeatable measurements with SiC modules of this scale are identified and explained, along with the details of the identified solutions. Finally, this paper includes a detailed description of the transient characterization test stand designed in support of this paper, which offers support for safely demonstrating the high-performance transient characteristics of MVDC SiC MOSFET modules at reasonable cost.

Disturbance Rejection for Quadrotor Attitude Control Based on PD and Fuzzy Logic Algorithm

Quadrotor is frequently used for photography enthusiasts to take aerial photographs. When taking aerial photographs, quadrotor moves toward destination point to obtain a good picture. When hovering in open space, quadrotor is often disturbed by wind. The paper presents control strategy for a nonlinear system to solve the problem. The main purpose of the research is to design a controller for maintaining a fixed position with a presence of horizontal wind disturbance. The control structure uses fuzzy logic controller algorithm to stabilize the xy position of the quadrotor by using Mamdani inference engine to obtain a stable quadrotor with fast rise time and settling time as well as, minimum overshoot and steady state error. The results show that the proposed control strategy is able to stabilize the quadrotor when hovering with the presence of disturbance.

Design and servo control of a leak tightness machine working based on hydrostatic pressure aging method

The leakage problem, which occurs due to the high hydrostatic pressure values of the fluid inside the pipes, is a serious issue in most of the pipeline systems. Therefore, the leak tightness test is required in different standards for verification of almost every kind of pipes used in both academic researches and industrial applications. The behavior of the hydrostatic pressure parameter in the test pipe has to be as smooth as possible during the leak tightness test. The conventional control loops of the servo mechanisms used for pumping the test fluid into the test pipe are weak to provide the minimum overshoot, the rise time and the steady-state error. In this situation, hydrostatic pressure tests are not capable of giving meaningful results. In this study, a leak tightness test machine working with a servo control loop to provide the optimum hydrostatic pressure pattern is designed. The efficacy of the designed leak tightness test machine and proposed optimized servo control loop have been shown with both simulation and experimental results.

Variable Speed Control Using Fuzzy-PID Controller for Two-phase Hybrid Stepping Motor in Robotic Grinding

In a robotic grinding process, a light-weight grinder is held by an intelligible robot arm. Material removal is carried out by the rotating grinding tool while the end effector of robot guarantees that the tool follows a programmed path in order to work on complex curved surfaces. Grinding tool is driven by Two-Phase Hybrid Stepping motor derive. This work aims to develop a controller based on fuzzy logic to improve the speed control performance of Two-Phase Hybrid Stepping motor derive in order to achieve a controller that provides grinding with higher quality. The analysis and design of PID-Fuzzy controller to improve the response of the motor speed were studied. This paper simulates six motor speed input conditions. The simullink package of the MATLAB. Comparison between the conventional PID controller and Fuzzy-PID output was done on the basis of the simulation result obtained by MATLAB. The simulation results demonstrate that the designed Fuzzy-PID controller realize a good dynamic behavior of the Two-Phase Hybrid Stepping motor, a perfect speed tracking with less rise and settling time, minimum overshoot, minimum steady state error and give better performance compared to conventional PID controller.

Some investigations on hybrid fuzzy IPD controllers for proportional and derivative kick suppression

Proportional and derivative kick i.e., a large change in control action of a proportional plus integral plus derivative (PID) controller due to a sudden change in reference set-point is generally undesired in process industry. Therefore, the structure of conventional parallel PID controller is modified to integral minus proportional derivative (I-PD) controller. In this paper, three hybrid fuzzy IPD controllers such as a fuzzy I-fuzzy PD (FI-FPD) controller and its hybrid combinations with its conventional counterpart such as fuzzy I-PD (FI-PD) and I-fuzzy PD (I-FPD) are presented in view of above industrial problem. These controllers are based upon the counterpart conventional I-PD controller and contains analytical formulae. Computer simulations are carried out to evaluate the performance of hybrid fuzzy controllers along with conventional I-PD and PID controllers for set-point tracking and disturbance rejection for an induction motor in closed loop using LabVIEW™ environment. The gains of conventional and hybrid fuzzy controllers are tuned using genetic algorithm (GA) for minimum overshoot and settling time. It has been observed that hybrid fuzzy controllers along with the conventional I-PD controller significantly remove the kick from the control action in reference set-point tracking. However, in disturbance rejection, I-PD and FI-PD controllers fail to eliminate the kick from the control signal. In contrast, FI-FPD and I-FPD controllers considerably reduced spikes from the control action in disturbance rejection. Among the conventional and hybrid fuzzy IPD controllers, FI-FPD demonstrates much better set-point tracking and disturbance rejection response with spike free control action.

Feasibility of using combined EMG and kinematic signals for prosthesis control: A simulation study using a virtual reality environment

Transhumeral amputation has a significant effect on a person’s independence and quality of life. Myoelectric prostheses have the potential to restore upper limb function, however their use is currently limited due to lack of intuitive and natural control of multiple degrees of freedom. The goal of this study was to evaluate a novel transhumeral prosthesis controller that uses a combination of kinematic and electromyographic (EMG) signals recorded from the person’s proximal humerus. Specifically, we trained a time-delayed artificial neural network to predict elbow flexion/extension and forearm pronation/supination from six proximal EMG signals, and humeral angular velocity and linear acceleration. We evaluated this scheme with ten able-bodied subjects offline, as well as in a target-reaching task presented in an immersive virtual reality environment. The offline training had a target of 4° for flexion/extension and 8° for pronation/supination, which it easily exceeded (2.7° and 5.5° respectively). During online testing, all subjects completed the target-reaching task with path efficiency of 78% and minimal overshoot (1.5%). Thus, combining kinematic and muscle activity signals from the proximal humerus can provide adequate prosthesis control, and testing in a virtual reality environment can provide meaningful data on controller performance.

Speed sensor-less induction motors drive system using particle swarm optimisation

An enhanced control system for speed sensor-less induction motors drive system using particle swarm optimisation (PSO) is developed. Vector control algorithm is introduced to control the d-q current components and speed of the induction motor. The current controllers are designed using particle swarm optimisation. They are characterised by simple design, minimum overshoot, fast rise time, fast settling time and zero steady state errors. Moreover, an enhanced PI rotor flux observer is designed to estimate the rotor flux angular speed. Dynamic performance and steady-state speed accuracy is achieved in high and low speed ranges. The obtained results show that the system performs precisely under different operating conditions.

A simple tracking maximum power points method using stator flux orientation control for DFIG

This paper presents a simple maximum power point tracking (MPPT) method using stator flux orientation control for doubly fed induction generator (DFIG). The modelling of doubly fed induction generator (DFIG) is introduced. Active and reactive power control is achieved. A control law is synthesised using PI controllers. The PI controllers are designed to guarantee minimum overshoot using particle swarm optimisation (PSO). The proposed technique is simulated by using MATLAB/Simulink package. The results given show an excellent performance of the proposed technique.

Artificial Intelligence in Performance Analysis of Load Frequency Control in Thermal-Wind-Hydro Power Systems

In this article, Load Frequency Control (LFC) of three area unequal interconnected thermal, wind and Hydro power generating units has been developed with Proportional-Integral (PI) controller under MATLAB/SIMULINK environment. Further, the PI controller gains values that optimized using trial and error method with two different objective functions, namely the Integral Time Square Error (ITSE) and the Integral Time Absolute Error (ITAE). The performance of ITAE objective function based PI controller is compared with the ITSE objective function optimized PI controller. Analysis reveals that the ITSE optimized controller gives more superior performance than ITAE based controller during one percent Step Load Perturbation (1% SLP) in area 1 (thermal area). In addition, Proportional–Integral –Derivative (PID) controller is employed to improve the same power system performance. The controller gain values are optimized using Artificial Intelligence technique based Ant Colony Optimization (ACO) algorithm. The simulation performance compares the ACO-PID controller to the conventional PI. The results proved that the proposed optimization technique based the ACO-PID controller provides a superior control performance compared to the PI controller. As the system using the ACO-PID controller yield minimum overshoot, undershoot and settling time compared to the conventional PI controlled equipped system performance.

Optimal Preview Control of a Dual-Stage Actuator System for Triangular Reference Tracking

This brief proposes an optimal preview control law for a dual-stage actuator (DSA) system to track triangular reference, which is essential in many raster scan motion control applications. The main difficulty of tracking triangular reference is to follow the waveform fast and accurately when its slope switches. For this goal, we first discuss a time-optimal controller (TOC) for the primary stage, which is a double integrator system. The TOC is then proved to achieve the minimum overshoot. This result is a new contribution to DSA control applications because it leads to a reference profile of minimum amplitude for the secondary stage to follow and thus significantly prevents the saturation of the secondary actuator. Subsequently, we propose an optimal preview control with the use of the information of the future reference to further reduce the settling time and overshoot. Finally, the secondary actuator controller is also given. Experimental results are shown to verify the effectiveness of the proposed control design.

Composite Nonlinear Feedback for Vehicle Active Front Steering

In this paper, Composite Nonlinear Feedback (CNF) is applied on Active Front Steering (AFS) system for vehicle yaw stability control in order to have an excellent transient response performance. The control method, which has linear and nonlinear parts that work concurrently capable to track reference signal very fast with minimum overshoot, fast settling time, and without exceed nature of actuator saturation limit. Beside, modelling of 7 degree of freedom for typical passenger car with magic formula to represent tyre nonlinearity behaviour is also presented to simulate controlled vehicle as close as possible with a real situation. An extensive computer simulation is performed with considering a various profile of cornering manoeuvres with external disturbance to evaluate its performance in different scenarios. The performance of the proposed controller is compared to conventional Proportional Integration and Derivative (PID) for effectiveness analysis.

Enhancing tilt range of electrostatic torsional micromirrors using robust adaptive critic-based neurofuzzy control

Electrostatic torsional micromirrors, as instances of Micro Electro Mechanical Systems (MEMS), have many optical network applications; such as optical wavelength-selective switches, optical cross-connects, etc. For all these applications, the micromirror needs to have minimal overshoot and settling time in order to minimize the time between two successive switching operations. Moreover, the controllability and stability of a torsional micromirror are major challenges due to high nonlinearities in its dynamic characteristics.In this paper, a robust adaptive critic-based neurofuzzy controller is proposed for electrostatic torsional micromirrors, which can improve the performance of the mirror tilting and enhance the robustness of the system to any stochastic perturbations. Furthermore, utilizing this adaptive neurofuzzy controller, which is based on a proportional and derivative (PD) critic, the micromirror “pull-in” phenomenon is crucially eliminated. Thus, the mirror tilting range is significantly expanded. Moreover, the stability of the closed-loop system is guaranteed via the Lyapunov theorem.The robust adaptive critic-based neurofuzzy controller is simulated for a 1-DOF electrostatic torsional micromirror and the results show the effectiveness of this approach for various tilt ranges and conditions. In addition, the robustness of this controller is examined in the presence of input noises and parameter uncertainties.

Optimal winding design of a pulse transformer considering parasitic capacitance effect to reach best rise time and overshoot

High voltage and high frequency pulses are widely used in industrial applications such as klystron modules, radar application, plasma technology, and so on. Transforming such a pulse with magnitude of thousands volt requires special transformers. Considering its frequency requirements which vary from hundreds to thousands Hertz, effects of parasitic capacitance may change the expected results. In this paper a specific method is proposed to optimize the design of both high voltage (HV) and low voltage (LV) windings, to reach the best rise time and overshoot performance. This method is based on both calculations of equivalent circuit and finite element analysis (FEA). Among the various topologies represented in the literatures, cone winding type pulse transformer is selected in which by changing its windings angle, it can be modified to parallel winding type. Initially analytical study in pulse transformer rise time equivalent circuit is performed to find the best cone angle between the windings and also the best distance between the bottom of windings to reach the optimum output parameters of pulse transformer such as fast rise time and minimum overshoot. In this analysis the lumped parameters of the equivalent circuit are calculated based on the stored energy between the windings. Afterwards sensitivity of the response to the load and source parameters variations is calculated in order to find the best distance and the angle between the windings. In the meantime, the distributed parasitic capacitances are extracted by using FEA to exert as circuit elements, in the electromagnetic model of pulse transformer. Finally a transient analysis is executed on the pulse transformer model containing distributed capacitances. The results of this analysis prove that the winding design using the distributed elements effects shows good results considering pulse shape.

Technique to Improve the Transient Response of Parallel-Connected AC/DC Converters

In this paper, a technique to improve the transient response of a parallel-connected AC/DC converter has been studied. The proposed technique is used to improve the transient response while disturbance is injected into the system. Generally, a conventional voltage loop control uses a PI controller, because of which a slow transient response is observed. In this paper, the voltage loop control is composed of a signal from the PI controller added with a peak input current and gain scheduling of change in peak input current. The performance evaluation was experimented on a three-module isolated CUK AC/DC converter, with a 500W load and-48V DC output voltage. The system achieves the following: tight output voltage regulation, good current sharing, and low harmonic distortion. Moreover, the disturbance occurs in the system by an immediate load change, and the output voltages are at minimum overshoot and undershoot with a fast settling time.