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Minimizing electric losses is critical to the success of battery-powered small unmanned aerial systems (SUASs) that weigh less than 25 kgf (55 lb). Losses increase energy and battery weight requirements which hinder the vehicle's range and endurance. However, engineers do not have appropriate models to estimate the losses of a motor, motor controller, or battery. The aerospace literature often assumes an ideal electrical efficiency or describes modeling approaches that are more suitable for controls engineers. The electrical literature describes detailed design tools that target the motor designer. We developed SUAS powertrain models targeted for vehicle designers and systems engineers. The analytical models predict each component's losses using high-level specifications readily published in SUAS component datasheets. We validated the models against parametric experimental studies involving novel powertrain flight data from a specially instrumented quadcopter. Given propeller torque and speed, our integrated models predicted a quadcopter's battery voltage within 5% of experimental data for a 5+ min mission despite motor and controller efficiency errors up to 10%. The models can reduce development costs and timelines for different stakeholders. Users can evaluate notional or existing powertrain configurations over entire missions without testing any physical hardware. [ABSTRACT FROM AUTHOR]

Here, a new method for solving the H∞ control problem for a class of affine nonlinear singular systems is presented. The main idea is to restrict the control inputs and initial states to the sets of admissible inputs and consistent initial values, respectively. Consequently, the impulse‐freeness of the system response is guaranteed. In this regard, a novel concept of "distance from the admissible inputs set" is introduced. Based on this concept, a set of sufficient conditions for the H∞ control problem's solvability and the corresponding H∞ controller is provided. The adopted approach can also be employed to solve the H∞ control problem for indefinite nonlinear singular systems as well as non‐singular nonlinear systems with a restricted inputs set. Sufficient conditions for the solvability of and corresponding solution to these problems are also presented. Finally, the practicality of this method is illustrated using a numerical example. [ABSTRACT FROM AUTHOR]

This paper presents the development of a microcontroller-based process monitoring system that is capable of being embedded within high speed automated assembly systems. A generic architecture is presented to fully utilise the communication, data acquisition and signal processing attributes of a current generation microcontroller. The efficacy of this approach is illustrated by the development of an autonomous method in which the system acquires and analyses transient data related to the operation of a linear actuator. The performance of this system clearly identifies the potential of microcontroller based solutions as very powerful yet affordable real-time quality management tools. The low costs associated with the implementation offer the prospect of affordable integrated quality management to a wide range of industries. [ABSTRACT FROM AUTHOR]

This article, titled "Retracted: Electronic Controller Automatic Test System Based on Intelligent Control Algorithm," has been retracted by the publisher, Hindawi, due to evidence of systematic manipulation of the publication process. The investigation revealed discrepancies in scope, description of the research, availability of data, inappropriate citations, incoherent content, and manipulated peer review. The publisher cannot vouch for the reliability of the article's content. Wiley and Hindawi have implemented additional measures to safeguard research integrity. The corresponding author has been given the opportunity to respond to the retraction. [Extracted from the article]

In this article, a novel fuzzy proportional integral derivative (PID) controller with filtered derivative action and fractional order integrator (fuzzy PIλDF controller) is proposed to solve automatic generation control (AGC) problem in power system. The optimization task for fine-tuning parameters of the proposed controller structure is accomplished by cuckoo optimization algorithm (COA). To appraise the usefulness and practicability of proposed COA optimized fuzzy PIλDF controller, four extensively used interconnected test systems, that is, two-area non-reheat thermal, two-area multi-source, three-area thermal and three-area hydro-thermal power plants, are considered. Different nonlinearity such as generation rate constraint (GRC) and governor dead band (GDB) as a source of physical constraints are taken into account in the model of the three-area power systems to examine the ability of the proposed technique to handle practical challenges. The acceptability and novelty of COA-based fuzzy PIλDF controller to solve aforesaid test systems are evaluated in comparison with some recently reported approaches. The consequences of time domain simulation reveal that designed secondary controllers provide a desirable level of performance and stability compared with other existing strategies. Additionally, to explore the robustness of the proposed technique, sensitivity analysis is conducted by varying the operating loading conditions and system parameters within a specific tolerable range. [ABSTRACT FROM AUTHOR]

Automation based on pneumatic soft actuators (PSAs) offers extensive benefits for operation in strong magnetic fields, at ultrahigh electric potentials and in underwater environments. However, due to the lack of automated pneumatic control systems, most of the PSAs require external electronic controls, such as programmable logic controllers (PLCs), pumps, and solenoid valves. Recently, researchers have investigated the use of microfluidic logic gates as a promising alternative for the control of submillimeter-scale fluidic components. In this letter, we demonstrate the use of microfluidic logic gates for addition operations. Based on functionally integrated fluidic components with local and global physical characteristics, we examine a fundamental class of the basic NOT gate. In addition, an adder application is described in this letter. We also introduce a calculation signal into a flip latch that is then connected to a microfluidic decoder. The system can avoid the need for cumbersome and fragile external electronic controllers. [ABSTRACT FROM AUTHOR]

Abstract In this paper, an assessment tool for stator-current predictive control of multi-phase induction machines is presented. The tool stems from a parameter analysis of the class of predictive controllers. This analysis exposes the underlying trade-offs among variables of interest. A reduced set of performance criteria is proposed for the parameter analysis. It is shown how the locus of the performance measures can be used to compare different types of predictive controllers. As application examples, some of the most common predictive strategies are reviewed. It is shown that the proposed assessment tool allows ranking the types of controllers under comparison. Additionally, the proposed tool can be used in control design and parameter tuning. The simulation results are backed by real experimentation using a six-phase motor. [ABSTRACT FROM AUTHOR]

Railways in this modern era, offer important contribution for building a nation by exchange of modern and progressive ideas which perpetuates social resonance and economic productivity. Rail applications adapt technological advancements to improve railway network "Engine" plays the important part and plays the important unit of the system. The engine can be differentiated on the basis of the fuel system and its combustion. Cummins India Limited provides the engines for various applications like railway, defense, marine, pump, etc. This paper is basically for rail application which describes the new concept for rail engine introduced for Parel Central railway. This paper proposes to integrate the engines for railway application by controlling the mechanical engine with the electronic controller. This will provide automated control to the mechanical system. The integration of engines to railway basically providing the safety features to engines, the protection to the engine as well as controlling two engines with the electronic controller. Hence, the modified architecture system for rail engine which will interface both the engines so that it will work properly and covering all safety features and sensor data for a smooth functioning of rail engine. The synchronization of two engines for same train to work simultaneously where also proposed using the GAC electronics governor controller. [ABSTRACT FROM AUTHOR]

In Distributed Control System (DCS), multitasking management has been important issues continuously researched and developed. In this paper, DCS was applied in global temperature control system by coordinating three Local Control Units (LCUs). To design LCU's controller parameters, both analytical and experimental method were employed. In analytical method, the plants were firstly identified to get their transfer functions which were then used to derive control parameters based on desired response qualities. The experimental method (Ziegler-Nichols) was also applied due to practicable reason in real industrial plant (less mathematical analysis). To manage set-points distributed to all LCUs, master controller was subsequently designed based on zone of both error and set-point of global temperature controller. Confirmation experiments showed that when using control parameters from analytical method, the global temperature response could successfully follow the distributed set-points with 0% overshoot, 193.92 second rise time, and 266.88 second settling time. While using control parameters from experimental method, it could also follow the distributed set-points with presence of overshoot (16.9%), but has less rise time and settling time (111.36 and 138.72 second). In this research, the overshoot could be successfully decreased from 16.9 to 9.39 % by changing master control rule. This proposed method can be potentially applied in real industrial plant due to its simplicity in master control algorithm and presence of PID controller which has been generally included in today industrial equipments. [ABSTRACT FROM AUTHOR]

This paper proposed a finite time convergence global sliding mode control scheme for the second-order multiple models control system. Firstly, the global sliding surface without reaching law for a single model control system is designed and the tracking error finite time convergence and global stability are proved. Secondly, we generalize the above scheme to the second-order multimodel control system and obtain the global sliding mode control law. Then, the convergent and stable performances of the closed-loop control system with multimodel controllers are proved. Finally, a simulation example shows that the proposed control scheme is more effective and useful compared with the traditional sliding mode control scheme. [ABSTRACT FROM AUTHOR]

The present work deals with the design problem of a robust observer-based controller for a motorcycle system using LPV approach. The designed model is specifically uncertain and disturbed one, whose uncertainties are related to variations of both the cornering stiffness and the longitudinal velocity. The nonlinear motorcycle model is firstly transformed on an uncertain LPV model with two vertices; then an observer-based H∞ robust controller is designed. Both the controller and observer gain matrices are computed by solving a unified convex optimization problem under LMI constraints using YALMIP solver. Numerical simulation results are given to illustrate the effectiveness of the designed method. [ABSTRACT FROM AUTHOR]

Reliable cooperative adaptive cruise control on highways requires the lead vehicle of a vehicle convoy to be capable of resisting disturbances outside the convoy. This paper proposes a controller synthesis approach adopting behavior classification to improve the lead vehicle’s ability to deal with outer disturbances. First, a behavior classifier is developed based on hidden Markov models to detect dangerous driver behaviors of surrounding traffic participants. The classification results with corresponding predicted trajectories are then imported to a model predictive controller for the lead vehicle. A behavior-guided cost function of the controller is carefully designed to react to behavior differences and to contribute to convoy string stability. The impact of the lead vehicle’s state deviation on the convoy is studied based on leader-to-formation stability properties. Furthermore, a nonlinear bound is also given to state the performance of the proposed controller. Simulations of a cut-in scenario are conducted using the CarSim simulation environment to show the effectiveness of the proposed controller. [ABSTRACT FROM AUTHOR]

In this paper, the potential improvement in performance of an NCS (Networked Control System) subject to variable delays controlled by means of an adaptive system is analyzed. An adaptive Smith Predictor has been used to compensate the effects of varying delays measured on the network. The NCS, closed over the Internet, has been implemented using a platform called NCS-CMUF, composed of local and remote stations. The plant used to carry out the experimental tests is consisted of an optical oven in which the luminosity loop is the main controlled variable whose time constant lies in the range of milliseconds. This paper highlights the importance of synchronization between the clocks of the local and remote stations to perform consistent measurements of network delays, in order to provide an active compensation of the effects of delays. The results show the effectiveness of adaptive Smith Predictor in coping with different delays and the performance improvements achieved with the proposed scheme. [ABSTRACT FROM AUTHOR]

Cascaded controllers have been shown in recent literature to significantly reduce hunting behavior and improve the performance of a variety of HVAC systems. The cascaded architecture uses multiple proportional-integral-derivative loops, standard in industry and building automation controls, to minimize the effects of load dependent nonlinearities. This article builds on previous work by defining and demonstrating the properties of two nonlinear gap metrics that quantify the closed-loop linearization of the cascaded control structure and enable proper tuning of the inner-loop proportional gain. This is followed by the development of a linear quadratic framework that enables simultaneous tuning of inner- and outer-loop control gains. The proposed gap metrics and tuning procedures are demonstrated with two case studies. A simple single input, two output example plant is used to demonstrate the benefits of the proposed tuning method compared to standard proportional-integral-derivative control and successive loop closure tuning techniques. The tuning approach is also applied to the control of a two-ton, residential heat pump system. The proposed metrics and tuning techniques showed significant improvement in control over standard proportional-integral-derivative control tuning methods in both simulation and experiment. [ABSTRACT FROM PUBLISHER]

An autonomous switched controller is proposed for a robot manipulator to ensure asymptotical tracking performance in the presence of shifting loads. Since the manipulator parameter jumps along with the load shift, the manipulator is modeled as a switched system whose switching signal depicts the load change. When the load change is not detectable, the switching signal of the switched system is unavailable. In this case, another “autonomous” switching law is designed for the given subcontrollers using a switched reset supervisory variable. Asymptotic tracking is ensured for slow load shifting. The effectiveness of the proposed method is verified by both simulations of a 2-DOF robot manipulator and experiments of a closed-chain five-bar robot. [ABSTRACT FROM PUBLISHER]

This paper presents the design and application of fractional single-input–single-output (SISO) controllers to a grinding mill circuit, which is a multiple-input–multiple-output (MIMO) process. Two kinds of controllers are presented: fractional order proportional-integral (FOPI) controllers, and a combination of FOPI and fractional order model reference adaptive controllers (FOMRAC). The parameters of the controller are tuned using off-line particle swarm optimization. In the presence of disturbances and process noise, the SISO fractional controllers achieve similar or better performance compared to linear model predictive control (LMPC). [ABSTRACT FROM AUTHOR]

In this paper a review of the Smith predictor and its modifications oriented to improve its performance is developed. The historic progress of Smith predictor is shown. Finally, some challenges of the international scientific community to continue improve the performance of the Smith predictor in control of plants characterized by dominant time delay are offered. [ABSTRACT FROM AUTHOR]

Model predictive controller (MPC) has demonstrated its competency in controlling autonomous vehicles. But to apply the current MPC-based schemes, it has to be formulated into certain formats and meet all prerequisites in order to fit the optimization solvers. To eliminate the gaps, in this paper, we propose a nonlinear MPC controller which controls the vehicle velocity and steering simultaneously. The optimization solver is based on genetic algorithms (GA). As compared to other solvers, using GA in the optimization enables a more flexible structure for MPC formulation. The cost function and constraints can be designed in a more accurate, meaningful, and direct way. Both simulation and on-field test results showed that the vehicle under the control of the proposed nonlinear MPC is able to follow the road center line accurately and consistently, even at sharp corners. Moreover, the results also showed that passengers’ safety and comfort can be well taken care of under the proposed MPC scheme as both the vehicle movement acceleration and steering acceleration are well confined within a safety range. The promising results indicate that the proposed GA-based nonlinear MPC can be a suitable solution to autonomous vehicle control. [ABSTRACT FROM AUTHOR]

This paper focuses on the $H_\infty$ state feedback control method for networked control systems and its application to the discrete-time direct-drive linear motion control system over a communication network with external disturbances and network-induced random time delay. The unavoidable network-induced random delay is modeled by a Markov chain with the uncertain transition probability. In this paper, the experimental linear motion control system is a double-sided linear switched reluctance machine (DLSRM). To tackle the external disturbances in the DLSRM, an $H_\infty$ control strategy is designed by using Lyapunov stability theory and linear matrix inequalities technique. A mode-dependent state feedback $H_\infty$ controller is designed for the closed-loop discrete-time direct-drive linear motion control system over a network to achieve a high-precision position control performance with antidisturbance capability. The experimental tests on the networked DLSRM system are presented to verify the effectiveness and practicability of the proposed $H_\infty$ control method for industrial applications of networked control systems. [ABSTRACT FROM PUBLISHER]

Software-defined networking offers several benefits for networking by separating the control plane from the data plane. However, networks’ scalability, reliability, and availability remain as a big issue. Accordingly, multicontroller architectures are important for SDN-enabled networks. This paper gives a comprehensive overview of SDN multicontroller architectures. It presents SDN and its main instantiation OpenFlow. Then, it explains in detail the differences between multiple types of multicontroller architectures, like the distribution method and the communication system. Furthermore, it provides already implemented and under research examples of multicontroller architectures by describing their design, their communication process, and their performance results. [ABSTRACT FROM AUTHOR]

FTA is a top down, deductive failure analysis method in which an undesired state of a system is analyzed using Boolean logic to combine a series of lower-level events. It is widely used in the aerospace, automotive and other safety-critical intensive systems. This work addresses the use of FTA by using an experiment for safety-critical ball position control system. The work presented here provides a general example illustrating how FTA can be effectively applied to an 8-bit microcontroller (Chip 89S52) based computer control system having little or no hardware protection. The safety analysis reveals several design deficiencies and physical faults for which modifications are needed. This paper also found that, when properly implemented FTA at the right point in the Software Development Life cycle, it makes requirements, design and code reviews more effective. It also identifies single point failures due to software. [ABSTRACT FROM AUTHOR]

Realization of the traditional approaches to differentiation of signals in the automatic control systems is hindered by the negative effect of gain on the accuracy of differentiation and stability to high-frequency noise. An approach was proposed based on representing the considered signal as a power function with coefficients that are calculated by repeated integration and approximate the derivative of the original signal. At that, the accuracy of differentiation and the level of noise immunity can be improved by using more integrators, rather than increasing the gains. [ABSTRACT FROM AUTHOR]

This paper discusses the assignment of generalized time constant for a non-all-pole system. The generalized time constant is found to be important because it simultaneously influences the speed of response, damping (i.e., overshoot), and robustness. For the ease of explanation, a general two-mass system is introduced as a case study, which has one pair of $j\omega$-axis zeroes. Under an ideal two-parameter control configuration, the exact lower bound of the generalized time constant is determined that results in monotonic step responses, while a moderate generalized time constant is shown to be desirable for robustness purposes. A modified-Integral–Proportional–Derivative control configuration is then adopted for the implementation of the ideal two-parameter controller. It is found that, in real applications, a specific control configuration and signal delay may also impose limits on the assignment of the generalized time constant and characteristic ratios. Due to the clear physical meaning of the polynomial method, the tradeoff relationship among the speed of response, damping, and robustness can be explicitly represented. This unique advantage leads to a straightforward controller design procedure. Finally, the theoretical analysis is validated by experimental results. [ABSTRACT FROM PUBLISHER]

The problem of sliding mode control is considered for a class of uncertain switched systems subject to actuator faults. It is assumed that there may happen degradation in each actuator channel. Besides, the authors relax the restrictive assumption that each subsystem shares the same input channel, which is different from some existing works. In this work, a weighted sum approach of the different input matrices is introduced to construct a common sliding surface. Moreover, by on-line estimating the loss of effectiveness of the actuators, an adaptive sliding mode controller is designed. This does not only compensate the effects of the actuator degradation effectively, but can also reduce the conservatism compared with some existing approaches which only utilise the bound of the gain variation. It is shown that the reachability of the specified sliding surface can be ensured, and a sufficient condition on the exponential stability of sliding mode dynamics is obtained via the average dwell time method. Finally, a numerical example is given to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The article provides an improved design for global finite-time stabilization of spacecraft and proposes 2 simple finite-time proportional-derivative (FPD) controllers that do not refer to the modeling parameters and are much simpler. Topics discussed include the advantages of the proposed controllers such as the absence of modeling parameters in the control law formulation and the ability to ensure finite-time stability at the origin globally within a finite time.

Embedded systems often involve transmitting feedback signals between multiple control tasks that are implemented on different electronic control units communicating via a shared bus. For ensuring stability and control performance, such designs require all control signals to be delivered within a specified deadline, which is ensured through appropriate timing or schedulability analysis. In this brief, we study controller design that allows control feedback signals to occasionally miss their deadlines. In particular, we provide analytical bounds on deadline misses such that the control loop retains its stability and meets its control performance requirements. We argue that such relaxation allows us to 1) use lower quality communication resources (e.g., event-triggered instead of time-triggered communication) and 2) provide more flexibility-e.g., use simulation-in communication timing analysis since analytical worst-case delay bounds for real-life communication protocols are often pessimistic. We illustrate this approach using the FlexRay communication protocol for distributed automotive control systems. [ABSTRACT FROM PUBLISHER]

In this paper, a methodology for designing an H∞ output feedback controller for discrete-time networked control systems has been considered. More precisely, network-induced delays between the sensor and the controller is modelled by a Markov chain with transition probabilities which are not assumed to be fully known. The systems parameter uncertainties are assumed to be norm-bounded and possibly time-varying. To the best of the authors knowledge, the problem of designing a partially mode delay-dependent H∞ output feedback controller for NCSs with partially known transition probability matrix has not been investigated in the literature. Based on the Lyapunov-Krasovskii functional approach, sufficient conditions for the existence of a robust partially mode delay-dependent H∞ output feedback controller are given in terms of bilinear matrix inequalities which can be solved using a cone complementarity linearization algorithm. The proposed design methodology differs from the existing design methodologies in that dynamic output feedback controllers are parameterized by both modes and transition probabilities, as opposed to the existing design approaches which parameterize controllers by modes only. The results obtained reduce to the existing results on fully known transition matrices when transition probabilities are fully known. It is shown that the proposed methodology can be applied to real world systems. The proposed design methodology is verified by using a DC servo motor system where the plant and the controller are connected via a cellular network with partially known transition probability matrix. [ABSTRACT FROM AUTHOR]

This paper looks at the problem of controlling an incinerator that burns waste gas to generate power. The system is modelled as a standard utility boiler using one known and one unknown (waste) fuel input. Standard linear controls have trouble dealing with large variations in the waste input, and in practice boiler shutdowns can occur. In this work, a nonlinear adaptive control design accounts for uncertainty in the plant parameters, and an adaptive neural-network estimates the effect of the waste input. Since a linear observer design cannot guarantee convergence away from a set point, a novel nonlinear observer design provides estimates of the states. The observer design uses fictitious states to estimate nonlinear terms in the observer dynamics. The analysis guarantees Lyapunov stability, thus the observer bounds depend on the accuracy of the observer initial conditions. Simulation results show the proposed method can obtain accurate performance and stability, improving over results obtained withproportional-integral control. [ABSTRACT FROM AUTHOR]

The operation of a tokamak device is highly sophisticated, which usually requires high performance real-time controllers. The ITER Control, Data Access and Communication (CODAC) team has made standards for Fast Controller (FC). Following the ITER CODAC standards we have designed the real-time FC (RTFC) prototype for J-TEXT.RTFC represents a general framework for controllers in both real-time control and diagnostic systems. The RTFC is designed to improve the development efficiency of real-time controller, and with minor modification it can be used in different applications. The RTFC main features are the PXI/PXIe bus with multi-core processor hardware, the Reflective-Memory, the IEEE-1588 Precision Time Protocol (PTP) support and LabVIEW real-time software. The proposed framework is capable of performing close-loop control with a time cycle below 1 ms. The RTFC supports the Experimental Physics and Industrial Control System (EPICS) for both monitoring and system configuration. It can be easily integrated into J-TEXT CODAC system which is a newly developed control system for J-TEXT. This paper introduces the main features of the RTFC. The preliminary results obtained with the prototype of RTFC show the potential effectiveness of the proposed architecture. [ABSTRACT FROM PUBLISHER]

Peculiarities of DC/DC converters based on the qZS-network were considered. Control system of the converter is described. By means of small signal model of transfer function the stability analyzes was performed. The results of the analytical analysis and experimental investigation showed that a DC/DC converter based on the qZS-network has limited but predictable stability margin. The area of coefficients of PI-regulator in which the system is stable was found. It was shown that stability margin depends on coefficients of PI-regulator and operation point of the converter. [ABSTRACT FROM AUTHOR]

This paper addresses delayed controller design in communication networks (CNs) with unstable open-loop system. Employing the Nyquist curve approach, the sufficient and necessary conditions of the gains and the delays, respectively, are obtained. The controllers are designed by using delayed positive output feedback. Some examples are presented to illustrate the effectiveness and simplicity of the designed controllers in both the time and frequency domains. [ABSTRACT FROM AUTHOR]

This study is concerned with dynamic output feedback (DOF) H∞ control for continuous-time networked control systems (NCSs). The packet dropouts and network-induced delays in the sensor-to-controller channel, and network-induced delays in the controller-to-actuator channel are taken into account. A linear estimation-based method is proposed to estimate the measurement output, and the non-uniform distribution characteristic of the measurement output arrival instant is taken into full consideration to establish a new model for the considered NCSs. Based on the newly established model and a new Lyapunov functional, the problem of DOF controller design is studied. A numerical example is given to illustrate the effectiveness of the proposed DOF controller design. [ABSTRACT FROM AUTHOR]

In this paper, an alternative approach of model-based control method called Behavior Model Control (BMC) is introduced. The BMC is designed to control processes that are often characterized by the robustness problem. The interesting feature of BMC control scheme is that it induces supplementary control inputs, which yield the process to follow the process model. This feature leads to great robustness of the closed loop system in face of certain amount of process dynamic variations. This is due to the fact that the tuning of the main controller is based on the defined process model which has known and nonvarying parameters. Most applications of BMC published so far are limited only to applications related to electrical drives. The BMC, in the present work, has been extended to control the air temperature inside a duct of the process trainer. Such process trainer is referred by the abbreviation (PT36). Note that PT36 has the basic characteristic of a large chemical process, enabling distance/velocity lag and transfer lag. Experimental results show that BMC yields better results than a conventional feedback controller. Control algorithms are implemented using Labview software as a control platform. [ABSTRACT FROM AUTHOR]

This paper deals with the impedance source (Z-source) multiphase inverter, where the maximum constant boost control method is studied and analyzed in the general case of number of phases. On the other side the impact of the modulation index and the number of phases on the duty cycle shoot-through and on the gain of the output voltage ranges is presented. To validate advantages of the Z-source multiphase inverter, the proposed topology and the maximum constant boost control are implemented in simulation and in real time experimentation with Z-source five phase inverter. The output voltage is applied to two parallel loads, a five phase resistive load and a five phase induction machine. [ABSTRACT FROM AUTHOR]

This paper presents the analysis, design, simulation and experimental results of a digital control strategy applied to an electronic ballast to supply a 70-W high-pressure-sodium lamp. The electronic ballast consists of a single-stage converter that integrates a buck converter to provide power factor correction and two flyback converters to supply the lamp, with low frequency square waveform, in order to avoid the acoustic resonance phenomenon occurrence. The proposed digital control strategy is composed of three control loops: voltage loop for lamp ignition and warm-up, an inner current loop for steady state, and a slow outer power loop to maintain the lamp power constant during its useful life. The lamp dynamic model is included to the ac model of the converter, so the effects of its right-half-plane zero are considered to design the digital control system. Fixed-point simulation is presented using Q base number format, where the exact variable values employed in the microcontroller code are used. Experimental results are included to demonstrate the performance of the proposed digital control strategy. [ABSTRACT FROM PUBLISHER]

Linear motors tend to be indispensable at present. Whether they are utilize in health service or in automation industry. It is certain that companies is always looking for something 'more' and linear motors have it. Therefore the aim of this paper is to find better solution for introduced task. How to achieve higher precision in LMPM position control? How to adjust optimal controller parameters? This paper contains answers for more than these questions and in addition compares in more detail Pole-placement method with genetic algorithm, as well. [ABSTRACT FROM AUTHOR]

In this study, a control algorithm is proposed, based on the sliding-mode technique, to regulate a single degree of freedom mechanical system subject to a unilateral constraint. The system may be in non-constrained motion at some time or in constrained motion at some other time. The system motion can be divided in three phases: free motion, constrained motion and transition (from non-constrained to constrained motion and vice versa). Only one control law is designed for the system, regardless of the motion phase. It is shown that the non-linear system is globally asymptotically stable and achieves zero steady-state position error. Numerical and experimental results show the performance of the proposed controller. [ABSTRACT FROM AUTHOR]

This paper represents an overview of three types of FACTS devices configurations, categorized by series, shunt and series-shunt consisting of TCSC, SVC and UPFC. Such devices are the most famous Flexible AC Transmission System devices in the world. In the first section features of the devices are introduced briefly, and in the next section control schemes of each are classified and reviewed for three control functions of power system such as steady state stability, transient stability and power oscillation stability. The relevant issues are also considered and discussed. [ABSTRACT FROM AUTHOR]

This paper presents a small-size low-power portable vector display system. The display system uses a micromirror which consists of a simple two-thin-film structure and is fabricated using a surface-micromachining process, i.e., Polysilicon Multi User MEMS Processes. The micromirror exhibits rotational motion around two axes as well as translational motion through four repulsive-force electrostatic actuating units. The micromirror is free of the “pull-in” effect which is associated with conventional micro electrostatic actuators. The micromirror is operated in a nonresonant mode and is capable of static positioning. Measured data show that the micromirror can achieve an optical scanning angle of \pm 2.5^\circ in each axis. The measured bandwidth (-3 dB) for each driving unit is 2000 Hz operating at a sinusoidal input voltage of 0–200 V. The settling times of the actuating unit are 2.75 and 3.32 ms with overshoots of 5% and 48% for step inputs of 200 to 0 V and 0 to 200 V, respectively. The portable vector display system is developed through integrating the micromirror, a laser source, the optics, and a microcontroller and is shown to be very effective in displaying complex geometries. Open-loop control methods using lookup table searching, spot dwelling, and scan speed control were developed to control the integrated portable device. [ABSTRACT FROM PUBLISHER]

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This paper presents design and experimental evaluation of an analogue PID, a digital PID and a fuzzy controller for a servo system. First, a servo system model is presented and the stability of the system is described. Next, a PID controller is devised and then tuned by the Ziegler-Nichols method for controlling the servo system. Then, a digital PID is formulated and subsequently tuned with the gradient descent method for controlling the system. Afterward, the self fuzzy tuning method is applied to the digital PID controller. Finally, to improve the servo system's dynamic response parameters, a fuzzy controller is proposed for controlling the system. Performance comparisons between the controllers are carried out. The results are presented and discussed. [ABSTRACT FROM AUTHOR]

This work aims to present the use of the fuzzy sliding mode controller (FSMC) applied for the three axis active control system for gravity gradient stabilized micro-satellite. Dynamic behaviour of this controller is entirely defined by the sliding surface; the surface is selected as a hyperplane in the system's state-space resulting in a PD-type (proportional derivative) sliding surface, the implemented controller keeps the dynamic part of the sliding mode controller (SMC) and in order to reduce chattering phenomenon we replace the discontinuous one by a fuzzy logic controller with two inputs-single output (TISO). The first input is the distance between the state vector of error and the sliding line, the second is the Euclidean distance between this vector and the normal vector to the sliding line; the output is the value of the command. The simulation results have been validated using Monte-Carlo method. Comparison of SMC and FSMC is presented to evaluate the performance of the control system during accurate nadir pointing control. [ABSTRACT FROM AUTHOR]