Tracking Control Technique Research Articles

THD Analysis for PV Based Cascaded Multilevel Inverters with MPPT Technique

Due to the shortage of fossil fuels and environmental reasons caused by conventional power generation, photovoltaic energy integrated with multilevel inverters has gained popularity. This work presents a comparative analysis of a 5-level and 7-level cascaded H-bridge multi level inverter (CHB-MLI) integrated with photovoltaic (PV) system. The voltage output of a PV array varies with changes in atmospheric temperature and irradiation. Therefore, (Perturb and Observe) P&O maximum power point tracking (MPPT) control technique with boost converter is used in this work to extract the maximum voltage from PV array. To improve the performance quality in term of total harmonic distortion (THD) and switching losses, genetic algorithm (GA) based selected harmonic elimination pulse width modulation SHE-PWM technique is used to control the firing angles of PV based 5-level and 7-level CHB-MLI. The comparative results are obtained using MATLAB/ SIMULINK software.

Study of Grid Connected Wind Energy System with Fuzzy Logic Based MPPT Controller

<p>Renewable energy sources (RESs) are gaining more importance due to depleting fossil fuel sources in few decades. When compared to other RESs wind energy system is widely available and user friendly in nature. This paper presents modelling and simulation of grid connected PMSG based wind energy conversion system with P&O maximum power point tracking (MPPT) control technique. The PQ controller is used for grid tied inverter to exchange real and reactive power with DC bus voltage regulation. The fuzzy logic controller (FLC) is used for MPPT implementation as it provides better performance as compared to the traditional PID controllers. The various case studies are considered for power management between wind system and the utility grid and the results are evaluated in MATLAB/ Simulink platform.</p>

Real-Time Implementation of Continuous Model Based Sliding Mode Control Technique for Trajectory Tracking Control of Mobile Robot

In this study, real-time trajectory tracking control of an autonomous mobile robot, actuated by two DC motors, has been designed, analyzed and studied. Two different control approaches such as model based sliding mode (SMC) and the classical proportional–integral–derivative (PID) control are employed to increase the tracking performance of the mobile robot. A model based SMC technique has been presented in order to consider the complete dynamic model of the robot and in order to increase trajectory tracking performance of the system. The experimental outcomes strongly verified that the proposed controller gives a quite well trajectory tracking response and smaller magnitude overshot compared with the classical PID controller.

Control of transformerless grid-connected PV system using average models of power electronics converters with MATLAB/Simulink

This paper presents the analysis, modeling and control of a grid connected photovoltaic (PV) system supplying two local loads. For this purpose, the average models of both boost converter and three-phase voltage source inverter (3-ph VSI) are used. Their advantage in term of computational speed allows simplifying and accelerating the simulation in order to develop their control laws. A Fractional Open Circuit Voltage (FOCV) algorithm based Maximum Power Point Tracking (MPPT) control technique is modified and combined with a DC-DC boost converter. The Watt-Var control approach is presented for the 3-ph VSI control. The Both proposed control algorithms are thereafter validated in detailed (switching) models. The proposed model is implemented in the MATLAB/Simulink software and simulation studies are presented. The simulation results show the advantage of using Power Electronics Converters (PEC) in their average versions. They also demonstrate the high performance and feasibility of the proposed system with its control strategy.

Standalone Photovoltaic Water Pumping System Using Induction Motor Drive With Reduced Sensors

A simple and efficient solar photovoltaic (PV) water pumping system utilizing an induction motor drive (IMD) is presented in this paper. This solar PV water pumping system comprises two stages of power conversion. The first stage extracts the maximum power from a solar PV array by controlling the duty ratio of a dc–dc boost converter. The dc bus voltage is maintained by the controlling the motor speed. This regulation helps in the reduction of motor losses by reducing motor currents at higher voltage for the same power injection. To control the duty ratio, an incremental conductance based maximum power point tracking (MPPT) control technique is utilized. A scalar-controlled voltage source inverter serves the purpose of operating an IMD. The stator frequency reference of IMD is generated by the proposed control scheme. The proposed system is modeled, and its performance is simulated in detail. The scalar control eliminates the requirement of a speed sensor/encoder. Consequently, the need of motor current sensor is also eliminated. Moreover, the dynamics are improved by an additional speed feedforward term in the control scheme. The proposed control scheme makes the system inherently immune to the variation in the pump constant. The prototype of PV-powered IMD emulating the pump characteristics is developed in the laboratory to examine the performance under different operating conditions.

Sliding Mode Controller for Trajectory Tracking Control of Autonomous Mobile Robot

Trajectory tracking control is an important issue in the field of autonomous mobile robot. In high speed and heavy load applications, the dynamic of autonomous mobile robot plays an important factor in allowing the robot to follow the desired trajectory path. However, the parameters attribute to robot dynamic are difficult to model and highly uncertain. One of the uncertainty factors is the load variation which changes the dynamic parameters of autonomous mobile robot. Meanwhile, Sliding Mode Control (SMC) is well known for its robustness against model uncertainties and disturbances. This paper is about design of dynamic controller based on SMC technique for trajectory tracking control of autonomous mobile robot system. The model of mobile robot is developed based on Pioneer 3-DX mobile robot. The trajectory tracking controller is divided into two parts, kinematic controller and dynamic controller. Stability of both dynamic and kinematic controller is verified using Lyapunov stability theory. The performance of trajectory tracking control for proposed dynamic controller based on SMC technique is compared against dynamic controller based on Proportional-Integral-Derivative (PID) technique with and without the presence of dynamic uncertainties. Simulation results show proposed dynamic controller based on SMC technique give better performance in trajectory tracking control in comparison to PID.

Sliding Mode Control Based on Disturbance Observer for Greenhouse Climate Systems

Greenhouses are closed environments that require careful climatic control, which can benefit from a system control method to cope with the high nonlinearity, complex coupling, and robustness of unknown disturbances. This paper presents a general framework for an integral sliding mode controller based on a disturbance observer combined with feedback linearization for a greenhouse temperature and humidity system. The first-principle greenhouse climate model is described as a standard affine nonlinear system. The feedback linearization control law is used to achieve a system consisting of two separate integrator channels for temperature and humidity. System compound disturbances are estimated by applying a sliding mode disturbance observer. Based on the observer, an integral sliding mode control is incorporated to enhance the robustness against uncertainties and guarantee satisfactory tracking performance even when there are unknown estimation errors. The validity and efficacy of the proposed control technique for greenhouse climate tracking were verified by comparison with simulation results obtained using the common sliding mode control method using feedback linearization without the disturbance observer. Based on this comparison, the developed controller shows a faster system response speed, higher control precision, and stronger anti-interference ability. This method can be applied to improve greenhouse climate control systems.

Feasibility Study on UAV-assisted Construction Surplus Soil Tracking Control and Management Technique

Construction surplus soil tracking management has been the key management issue in Taiwan since 1991. This is mainly due to the construction surplus soils were often regarded as disposable waste and were disposed openly without any supervision, leading to environmental pollution. Even though the surplus soils were gradually being viewed as reusable resources, some unscrupulous enterprises still dump them freely for their own convenience. In order to dispose these surplus soils, site offices are required to confirm with the soil treatment plant regarding the approximate soil volume for hauling vehicle dispatch. However, the excavated soil volume will transform from bank volume to loose volume upon excavation, which may differ by a certain speculative coefficient (1.3), depending on the excavation site and geological condition. For managing and tracking the construction surplus soils, local government authorities frequently performed on-site spot check, but the lack of rapid assessment tools for soil volume estimation increased the evaluation difficulty for on-site inspectors. This study adopted unmanned aerial vehicle (UAV) in construction surplus soil tracking and rapidly acquired site photography and point cloud data, the excavated soil volume can be determined promptly after post-processing and interpretation, providing references to future surplus soil tracking management.

Sensored and sensorless scalar-control strategy of a wind-driven BDFRG for maximum wind-power extraction

This paper presents a scalar volt per hertz (V/f) control technique for maximum power tracking of a grid-connected wind-driven brushless doubly fed reluctance generator (BDFRG). The proposed generator has two stator windings namely; power winding, directly connected to the grid and control winding, connected to the grid through a bi-directional converter. In order to enhance the performance of the proposed scalar-control strategy, a soft starting method is suggested to avoid the over-current of the bi-directional converter. Moreover, the capability of generator speed estimation for sensorless control is also studied. The capability of the proposed scalar-control technique is validated using a sample of simulation results. In addition, the presented simulation results ensure the effectiveness of the proposed control strategy for maximum wind-power extraction under wind-speed variations. Furthermore, the results show that the estimated generator speed is in a good accordance with the actual generator speed which supports sensorless control capability.

Linear vs Nonlinear MPC for Trajectory Tracking Applied to Rotary Wing Micro Aerial Vehicles

Precise trajectory tracking is a crucial property for Micro Air Vehicles (MAVs) to operate in cluttered environment or under disturbances. In this paper we present a detailed comparison between two state-of-the-art model-based control techniques for MAV trajectory tracking. A classical Linear Model Predictive Controller (LMPC) is presented and compared against a more advanced Nonlinear Model Predictive Controller (NMPC) that considers the full system model. In a careful analysis we show the advantages and disadvantages of the two implementations in terms of speed and tracking performance. This is achieved by evaluating hovering performance, step response, and aggressive trajectory tracking under nominal conditions and under external wind disturbances.

A novel robust adaptive second-order sliding mode tracking control technique for uncertain dynamical systems with matched and unmatched disturbances

This paper investigates a robust adaptive second-order sliding mode control method for tracking problem of a class of uncertain linear systems with matched and unmatched disturbances. The fundamental idea of the suggested control method is that the discontinuous sign function is used for the time-derivative of the control signal and hence the smooth control input achieved after an integration process is continuous and removes the chattering problem. Using a PID sliding surface, the finite-time convergence of output tracking errors is obtained. The adaptive gain-tuning control law removes the necessity of gaining information about the upper bounds of the external disturbances. The control system is in the sliding mode and then, tracking errors converge to the origin in a finite time under the presence of the external disturbances. Simulation results on an uncertain numerical system and a turntable servo-system are presented to indicate the effectiveness and feasibility of the proposed scheme.

Payload oscillation reduction in load-handling machines: A frequency-based approach

This article presents an innovative pressure feedback method to address undesired payload oscillations in hydraulic load-handling machines, which have a negative impact on both machine productivity and safety. Tracking control techniques in these machines are often not applicable due to the difficulty or the cost associated with the installation of the feedback sensors on the payload. In this work, by means of pressure sensors installed on the hydraulic system, the payload oscillation frequency is first detected by analyzing the frequency content of the measured pressure and then counteracted through a sinusoidal-based excitation command on the machine actuator. The work particularly addresses the challenges related to the use of the same actuator for detecting and quantifying the oscillation (in both frequency and amplitude) and for reducing the payload oscillations. In fact, interference on the feedback pressure signal due to the control action is present. Experimental results on a truck-mounted hydraulic crane show how the proposed technique permits to reduce payload oscillation in order of 50%, which is comparable to other less-practical tracking control techniques.

Implementation of Wind Powered Switched Reluctance Generator System

This paper reports implementation of Battery Energy Storage System (BESS) for Switched Reluctance Generator (SRG) based wind power generation system supplying stand alone load. MATLAB/Simulink model of the SRG machine is developed using the characteristics acquired by solving the Finite Element Analysis (FEA) model of the machine used for implementation. Wind turbine is incorporated with Maximum Power Point Tracking (MPPT) control technique and to mitigate the problem of wind power fluctuation a BESS for a wind powered SRG with Isolated Bi-directional DC-DC Converter (IBDC) is proposed. The response of BESS is evaluated using MATLAB/Simulink computing tool and the results are reported. For experimental purpose, the wind turbine is emulated by a 12V DC motor. The BESS for wind powered SRG is analyzed and implemented using microcontroller to validate the simulation results.

Dual‐mode LQR‐feedforward optimal control for non‐minimum phase boost converter

A digital dual-mode linear quadratic regulator (LQR) with feedforward optimal controller is presented, which allows voltage control of a boost converter for wide-load-range condition, whether in continuous conduction mode (CCM) or in discontinuous conduction mode (DCM). Based on the conventional LQR method, the proposed controller is designed and makes the following two improvements. First, in order to eliminate the phase error caused by right-half-phase zero emerged in non-minimum phase boost converter, a feedforward controller is implemented by zero phase error tracking control technique because the inverse of non-minimum phase system is unstable. Second, since the models of DC-DC converter in CCM or DCM are different, the proposed control strategy allows boost converter to autonomously operate in CCM or DCM controller by utilising a mode detector. The proposed mode detector greatly enhances the control performance in both operating modes. Finally, the proposed controller has been implemented for voltage control of a boost converter. The simulation and experimental results show the proposed controller offers better performance in both transient response and frequency response than the conventional LQR controller.

Adaptive Fault-Tolerant Tracking Control for MIMO Discrete-Time Systems via Reinforcement Learning Algorithm With Less Learning Parameters

This paper is concerned with a reinforcement learning-based adaptive tracking control technique to tolerate faults for a class of unknown multiple-input multiple-output nonlinear discrete-time systems with less learning parameters. Not only abrupt faults are considered, but also incipient faults are taken into account. Based on the approximation ability of neural networks, action network and critic network are proposed to approximate the optimal signal and to generate the novel cost function, respectively. The remarkable feature of the proposed method is that it can reduce the cost in the procedure of tolerating fault and can decrease the number of learning parameters and thus reduce the computational burden. Stability analysis is given to ensure the uniform boundedness of adaptive control signals and tracking errors. Finally, three simulations are used to show the effectiveness of the present strategy.

An adaptive technique for trajectory tracking control of a wheeled mobile robots without velocity measurements

This paper addresses an adaptive method for designing a sensorless trajectory tracking control scheme for a wheeled mobile robot. In order to reduce the cost of the robot, a new Nonlinear Observer (NOB) is used to leave out velocity sensors in the robot. Also, an adaptive model reference technique is used for designing the dynamic controller. In order to ensure the implementability of proposed controller, dynamic controller and nonlinear observer are designed in the presence of uncertainties. In addition, the Observer-based Kinematic Controller (OKC) is designed in the presence of sliding velocity. In order to improve the performance of the kinematic controller, sliding velocity is estimated and used for modification of kinematic controller. Finally, the effectiveness of the proposed method is demonstrated by simulations.

On fractional-order hyperchaotic complex systems and their generalized function projective combination synchronization

Some fractional-order hyperchaotic complex systems are introduced in this paper. These hyperchaotic systems appear in several fields of applied sciences, e.g., secure communication and laser physics. The values of the fractional-order and the parameters at which these systems have hyperchaotic attractors are calculated based on the sign of their Lyapunov exponents. The fractional Lyapunov dimension is computed for these hyperchaotic attractors. On the other hand, we introduced the new definition of what is called generalized function projective combination synchronization (GFPCS). This new kind of synchronization may be considered as a generalization of many kinds of synchronization in the literature. To study this kind of synchronization we state a scheme based on the tracking control technique. An example is considered for the scaling functions which is the nonlinear one. The active control method cannot be used in this scheme since its error is large.

Real-time optimal control of tracking running for high-speed electric multiple unit

High-speed electric multiple unit (HSEMU) is an advanced transportation system, which share some special characteristics such as nonlinear dynamics, complex working environment and time-varying operational conditions. To achieve a safe, punctual and automatic running of HSEMU, effective modeling methods of HSEMU and real-time optimal control schemes are useful to further improve the running performances. This paper aims to develop intelligent control techniques for speed tracking control of HSEMU. The well-known adaptive neuro-fuzzy inference system (ANFIS) is employed to model the dynamics, and an ANFIS-based generalized predictive controller is proposed with a stability analysis of the closed-loop system. Experimental results with comparisons on real-world running data demonstrate that our proposed techniques in this work can perform favorably in terms of both safety and punctuality.

Disturbance observer and finite-time tracker design of disturbed third-order nonholonomic systems using terminal sliding mode

This paper proposes a novel recursive terminal sliding mode structure for tracking control of third-order chained–form nonholonomic systems in the presence of the unknown external disturbances. Finite-time convergence of the disturbance approximation error is guaranteed using the designed disturbance observer. Under the proposed terminal sliding model tracking control technique, the finite-time convergence of the states of the closed-loop system is guaranteed via Lyapunov analysis. A new reaching control law is proposed to guarantee the existence of the sliding mode around the recursive TSM surface in a finite-time. Simulation results are illustrated on a benchmark example of third-order chained-form nonholonomic systems: a wheeled mobile robot. The results demonstrate that the proposed control technique achieves promising tracking performance for nonholonomic systems.

Adaptive fuzzy fault tolerant tracking control for a class of uncertain switched nonlinear systems with output constraints

This paper studies the adaptive fuzzy fault tolerant tracking control problem for a class of switched multi-input multi-output (MIMO) nonlinear systems with output constraints under arbitrary switchings. The actuator faults under study consist of unknown stuck and loss of effectiveness. In the design procedure, the unknown control signals are approximated directly by fuzzy logic systems. To prevent constraints violation, a tan-type barrier Lyapunov function is incorporated into the Lyapunov function design. Based on the idea of estimating the bound on switching parameters, a novel adaptive fuzzy fault tolerant tracking control technique for the problem studied is set up by exploiting the common Lyapunov function method and backstepping. It is shown that under the proposed control law and adaption rules, all the signals remain bounded and the system output tracking error can be guaranteed to exponentially converge to a neighborhood of origin, while the constraints on the system output will not be violated during operation. Finally, simulation results are presented to show the effectiveness of the proposed approaches.