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EPE-PEMC 2006 - Topic 05: MOTION CONTROL, ROBOTICS, ADJUSTABLE SPEED DRIVES
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	3D Vision in Industrial Robot Working Process   By Isak Karabegovic, Samir Vojic, Vlatko Dolecek	[View]   [Download]
Abstract: With digital computers development possibility for change of certain human intellect based action raised. Because of a need for human vision replacement, needs that require simplicity, speed and low price in robotized mounting systems, usage in objects recognition and their settlement on exact place robot vision systems took place. This paper explains 3D vision systems implementation industrial robotics. Here are given elements of robot vision systems, ways of assembly and implementation examples.
	A Novel Fault Tolerant Reconfigurable Concept for Vector Control of Induction Motors   By Farzad Tahami, Ali Shojaee	[View]   [Download]
Abstract: AC drive users with sophisticated applications are demanding greater reliability to avoid process interruptions. AC motor drive systems are susceptible to sensors failure. A novel fault tolerant Field Oriented Control system for induction motors is introduced. The system maintains speed control in the event of sensors malfunction and adverse signal conditions, providing enhanced reliability. Different motor models are combined by a Fuzzy aggregation system in order to give a reliable estimate of flux vector. The proposed control system is an effective and easy to implement method giving a potential for motor drive reliability enhancement.
	A Performance Improvement of V/f Control using a Disturbance Observer   By Junichi Itoh, Tetsuma Hoshino, Takayuki Kaneko	[View]   [Download]
Abstract: This paper proposes a dead-time compensation method with a disturbance observer and a current controller for V/f control. Dead-time compensation is very important to improve motor drive performances in the low speed region. The proposed compensation method is composed in the d-q rotational frame. The ripple of the d-axis current caused by the dead-time is suppressed by an auto current regulator, the ripple of the q-axis current according to the dead-time is suppressed by the disturbance observer. The control of the d-axis current is added the auto current regulator to the V/f control. As a result, the magnitude of the motor current can keep more than the rated exciting current in spite of the low speed region with the V/f control. The control of the q-axis current only uses the disturbance observer to suppress the voltage error of the dead-time. In this paper, the performance of the proposed controller in the low speed region is discussed based on the experimental results. The proposed method can improve the current distortion to less than quarter against the conventional method. Although the disturbance observer requires motor parameters, it is not so sensitive.
	A Self-Tuning Loss-Model based Efficiency Controller for an Induction Motor Drive   By Gerardo Mino-Aguilar, Juan Manuel Moreno-Eguilaz, Bogdan Pryymak, Juan Peracaula	[View]   [Download]
Abstract: In this paper, a vector-controlled induction motor drive with efficiency optimization using a loss model based approach is presented. To improve the robustness of the control system, a self-tuning controller has been designed. On-line estimators for rotor resistance and magnetizing inductance are included in the controller to improve performance. Analysis, modeling and simulation results are presented to demonstrate the validity of the proposed method.
	A Simple Approach on Rotor Flux Estimation Without Integration for a DSP based Speed Sensorless Vector Control of Induction Motor   By Debashis Chatterjee, Ashoke Kumar Ganguli, Rupendranath Chakrabarti	[View]   [Download]
Abstract: In this paper a simple field orientation control scheme for induction motor is described. The principle is based on the idea of a simplified equivalent circuit of the machine and the orientation of the fluxes, currents and voltage vectors. Here the determination of stator flux avoids integration, which is increasingly difficult when the speed reference becomes lower down to zero. In order to estimate the stator flux, a simple algorithm based on the principle of orthogonality of stator flux and stator induced e.m.f. vectors is used. The proposed control technique is validated by some simulation results and also experiments were conducted which showed conformity to the theoretical basis and simulation results.
	A Study on High Accuracy Dscrete-Time Sliding Mode Control   By Asif Sabanovic, Khalid Abidi, Meltem Elitas	[View]   [Download]
Abstract: In this paper a Discrete-Time Sliding-Mode based controller design for high accuracy motion control systems is presented. The controller is designed for a general SISO system with nonlinearity and external disturbance. Closed-Loop behavior of the general system with the proposed control and Lyapunov stability is shown and the error of the closed loop system is proven to be within an o(T2). The proposed controller is applied to a stage driven by a piezo drive that is known to suffer from hysteresis nonlinearity in the control gain. Proposed SMC controller is proven to offer chattering-free motion and rejection of the disturbances represented by hysteresis and the time variation of the piezo drive parameters. As a separate idea to enhance the accuracy of the closed loop system a combination of disturbance rejection method and the SMC controller is explored and its effectiveness is experimentally demonstrated. Closed-loop experiments are presented using PID controller with and without disturbance compensation and Sliding-Mode Controller with and without disturbance compensation for the purpose of comparison.
	Analysis of Induction Motor Drive Losses in the Field-Weakening Region   By Tine Marcic, Gorazd Stumberger, Miralem Hadziselimovic, Ivan Zagradisnik	[View]   [Download]
Abstract: Operation of adjustable-frequency drives is accompanied by generation of losses in the converter and motor. These losses depend on the modulation frequency and on the drive output power. The change of modulation frequency modifies converter losses and also motor losses, because of the modified motor current waveform. Thus, it modifies total drive losses. Variation of the drive output power also modifies total drive losses and can be problematic when the drive operates in the field-weakening region. The paper presents a complete analysis of motor losses, converter losses and losses of the entire drive in the field-weakening region of an open loop controlled induction motor drive supplied by a voltage source inverter. Losses are presented in dependence of the voltage source inverter output frequency and the drive’s output power. Presented results show that the modified voltage to frequency ratio causes an increase of the total drive losses in the region of high frequencies and high output powers. The paper also presents an analysis of the impact of modulation frequency on drive losses.
	Automatic Approach to Parameter Scaling in Induction Motor Control Algorithms   By Miran Rodic, Uros Rupar, Joze Korelic, Karel Jezernik	[View]   [Download]
Abstract: An approach for time-to-product reduction is presented in the paper. The work presents a solution to the problem of automatic calculation of scaling factors in the induction motor control algorithms with optimization of range and accuracy. The resulting algorithms can be applied to 16b fixed point processors. A successful application is presented with experimental results for DFOC algorithm.
	Behavioral Cloning and Obstacle Avoiding for Two Different Autonomous Vehicle   By Ranka Kulic, Zoran Vukic	[View]   [Download]
Abstract: The problem of dynamic path generation for an autonomous vehicle in environments with unmoving and moving obstacles is presented. The first vehicle kinematical and then an complete mathematical model is given by nonlinear equations describing a 12 state dynamical system simulated in Matlab or Simulink environment. The goal is to find the regulator design method for the named autonomous vehicle in 3D- space in situation with infinite number of obstacles. To design the vehicle regulator in this paper the behavioral cloning approach is applied. In behavioral cloning, the system learns from control traces of a human operator. The advantage of the named approach lies in the fact that a complete path can be defined without using sophisticated symbolical models of obstacles. The proposed methodology it substantially differs from the others. The other advantage of the proposed methodology is the fact meaning that some of the learning algorithms enable a complete path off-line defining.
	Correlation of Dynamical with Steady State Properties of Converter Fed Drives   By Roman Muszynski	[View]   [Download]
Abstract: In the paper the analysis of the correlation of dynamical with steady state properties of the converter fed drives is presented. The analysis, based on the equations of the system, is made for the self commutated synchronous motor (SCSM), called also as the load commutated inverter fed synchronous motor (LCI-SM). First, the requirements of suitable acceleration of the drive and ratio of current increase during the dynamical state are transposed to the adequate commutation and control reserves of the converters. Then the influence of the reserves, kept in the steady state, on torque versus current characteristic, maximum available torque (overload capacity), selection of current limitation, power factor, loss and efficiency of the drive is analyzed. The obtained dependencies are illustrated in figures and with use of a number data. In the paper the deterioration of the steady state properties with increase of dynamics of the drive is concluded.
	Direct Torque Control of Induction Motors using a Fuzzy Inference System for Reduced Ripple Torque and Current Limitation   By Julio C. Viola, Jose A. Restrepo, Victor M. Guzman, Maria I. Gimenez	[View]   [Download]
Abstract: In this work a Fuzzy Inference System is employed for the control of a PWM based Direct Torque Control (DTC), driving an induction machine, to reduce ripple torque while limiting the current during start-up or when the stator flux magnitude changes. The proposed control scheme uses a Fuzzy Inference System to modulate the stator voltage vector applied to the induction motor, in magnitude and phase. This scheme allows for amplitude regulation according to the requirements of ripple reduction or stator current limitation. The proposed scheme performance was analyzed using simulation programs written in the C computer language and executed on a prototype system called PLATAFORMA III, developed by the SIEP Group at Universidad Sim´on Bol´ývar.
	Discrete Free and Fixed End-Point Optimal Control Problems for Linear Electrical Drive Systems   By Corneliu Botan, Florin Ostafi	[View]   [Download]
Abstract: The paper presents fixed and free end-point linear quadratic problems for drive systems with brushless or d.c. motors. Symmetrical algorithms for the both problems are proposed. These algorithms can be easier implemented by comparison with classical procedures. Simulation results and a comparison between the two type of problems are presented in the last section.
	Discrete Space Vector Modulation Applied on a PMSM Motor   By David Ocen, Luis Romeral, Juan Antonio Ortega, Jordi Cusido, Antoni Garcia	[View]   [Download]
Abstract: The Permanent Magnet Synchronous Motors (PMSM) are extensively used in high-performance industrial applications. The electromagnetic torque in a PMSM is proportional to the angle between the stator and rotor flux linkages. Therefore, high dynamic response can be achieved by means of Direct Torque Control (DTC). However, because the rotor flux linkage is fixed on the rotor of PMSM, high torque ripple is produced when making use of full voltage vectors in classical DTC. The paper presents an improved PMSM DTC scheme by using a simplified space vector modulation technique, which addresses the problem by introducing a higher number of predefined voltage space vectors. The voltage vectors are tabulated in more precise switch tables which also take the emf induced in the stator windings into account. While still using switch tables to maintain the simplicity of the classical DTC scheme, the torque ripple results significantly decreased. Theoretical development and simulation results from the classical and improved DTC are presented and compared to support the research. Results show that the torque, flux linkage and stator current ripple are significantly decreased with the improved DTC.
	Discrete-Time Modelling-Flux and Torque Deadbeat Control for Induction Machine   By Jean-Claude Alacoque	[View]   [Download]
Abstract: This paper deals with induction motor deadbeat control. The main objective of such a control is the flux and torque dynamics, against feeding voltage drop and load torque disturbances, to comply under voltage and current limitations, the specific railway requirements, including line and motor harmonic management. A novel discretization method of the induction motor state-space equations is carried out, which leads to their exact inversion, and therefore to the calculation of the voltage space-vector components, to obtain in one-step, the flux and torque reference inputs. The magnetization current set-point is analytically calculated as a function of flux reference in transient analysis. This method is generalized to other types of motors or actuators such as surface mounted permanent magnet synchronous motors.
	Experimental Comparison of Discrete Time Sliding Mode and Conventional, PI Current Controller for IM Drives   By Mehmet Dal, Karel Jezernik	[View]   [Download]
Abstract: An approach to discrete-time sliding-mode (SM) current control and conventional SM with smoothing filter is presented for field-oriented induction motor (IM) drives. Design of both proposed SM controllers is based on space vector PWM scheme by introducing some parts of the stator model as control input, which may correspond to voltage vector command. The control input was obtained employing the error between measured and reference currents of the stator. In order to compare the performance of proposed two SM current controllers with each other and with a conventional PI controller, they were simulated and also experimentally implemented for the indirect field oriented drives of an IM. The results verified to validity of proposed both SM current controllers and superiority of discrete time SM controller to conventional PI controller and SM with low pass filter (LPF).
	Fan Drive Starting into Naturally Rotating Load by Sinusoidal Sensorless Permanent Magnet Motor Control   By Ana Borisavljevic, Eddy Ho, Toshio Takahashi	[View]   [Download]
Abstract: A permanent magnet (PM) motor is a primary motor of choice for small fan motor drive applications. A traditional fan drive based on a permanent magnet motor uses position feedback sensors such as Hall effect sensors. Recently PM motor drive with sinusoidal current and no position sensor has been demanded for many applications including air conditioner outdoor unit fan control. The elimination of sensors is required due to the increased reliability demand and low cost requirement for a drive. Some fan and pump applications require that the drive has to start into naturally forward rotating load without stopping the load first. A fan used in the air conditioner outdoor unit, for example, is one of these applications. A fan needs to be started at any naturally rotating forward speed or from standstill and brought to the desired speed. When it naturally rotates in reverse direction, the drive must transition from reverse to forward rotation in a drive system without regeneration capability. With the traditional fan drive, which includes a Hall sensor to detect the rotor position of PM motor, this is a relatively simple task since excitation angle and speed of the controller at startup can be synchronized to the angle and speed at which the fan naturally rotates. In case of the drive without the position sensor, this task is more elaborate due to the fact that speed reversal is required without position sensing. This paper describes a new algorithm for starting a PM motor drive into the forward and reverse naturally rotating load, where drive system does not have a regeneration capability and has only one current feedback sensor installed in the dc bus link. The algorithm is implemented on a chip belonging to a new motion controller family, which has been recently introduced by International Rectifier. The chip features a hardware computation engine, called Motion Control Engine (MCE), for sinusoidal sensorless PM motor control. Experimental results are included.
	Forced Dynamic Control of Electric Drives with Vibration Modes in the Mechanical Load   By Stephen James Dodds, Krzysztof Szabat	[View]   [Download]
Abstract: The general theory of forced dynamic control is first given. Its application to electric drives with significant vibration modes in the mechanical load is then considered. Simulation and experimental results are compared for a two-mass system comprising a DC motor driving a balanced mass via a thin shaft.
	FPGA based BLDC Motor Current Control with Spectral Analysis   By Dejan Kos, Milan Curkovic, Karel Jezernik	[View]   [Download]
Abstract: This article presents two different approaches of brushless dc motor torque control, PI and discontinuous sliding mode regulator. Algorithms were implemented on NI 7831R board consisted of Xilinx FPGA device and peripheral (A/D and D/A converters). Frequency analysis of motor current has been made to demonstrate the influence of using specific control algorithm on the motor power signal frequency content.
	Fuzzy Logic Speed Controller Robust Against Drive Parameters Variation   By Tomasz Pajchrowski, Krzysztof Zawirski	[View]   [Download]
Abstract: This paper deals with the problem of robust speed control of electrical servodrives. A robust controller is developed using a nonlinear PI controller. The controller nonlinear characteristics is obtained due to fuzzy logic technique application. An original method of controller settings adjustment is presented. The use of this adjustment procedure ensures robust speed control against the variations of the moment of inertia. Simulations and laboratory results validate the robustness of the servodrive with Permanent Magnet Synchronous Motor
	Haptic Information Sharing by Multilateral Control   By Toshiyuki Suzuyama, Seiichiro Katsura, Kiyoshi Ohishi	[View]   [Download]
Abstract: In recent years, bilateral system has been widely researched for its functionality and availability. The system is effective in the fields of medical treatment, but application is limited to one-on-one system. The purpose of this study is development of basic technology for haptic information sharing technology. In this paper, a noble bilateral control method is introduced to realize multiple inputs or plural outputs bilateral system. At first, bilateral system based on acceleration control is discussed. Acceleration control is accomplished by disturbance observer. Both of master and slave are controlled by position regulator and force servoing, and these two controllers are decomposed into two modes in the virtual space. Decomposed controller helps to control position and force information individually. Second, the bilateral control is extended and generalized as a multilateral control which based on the decomposed controller. In the proposed multilateral control, interactivity and synchronism are achieved easier than conventional control. Third, numerical simulation and experimental results are shown. Proposed method is easy to expand to infinite dimension. As a minimum dimension of the multilateral control, the series of experiments are conducted by six robots. The numerical simulation and experimental results show the viability of the proposed method.
	High-Speed Robot Motion Control under Visual Guidance   By Theodor Borangiu, Mitica Manu, Florin Daniel Anton, Silvia Tunaru, Anamaria Dogar	[View]   [Download]
Abstract: The paper describes a vision based method and implementing procedure allowing for collision-free, on-thefly grasping of objects travelling on conveyor belts. The ensemble conveyor belt + actuator + sensor is configured as a 3 ¡Ü m -axis Cartesian robot, leading to a problem of cooperation between multiple robot manipulators subject to the multitasking control of a computer. The collision-free grasping of recognised and located objects is checked at run time by projecting the fingerprints of the gripper onto the image plane, and estimating whether they "cover" only background pixels. A structured programming environment is used for exemplifying the multi tasking control of horizontally articulated (SCARA) robots tracking moving objects for collision-free grasping, under guidance vision; experimental results are also reported.
	Hybrid Control for Multiple Robots in Grasping and Manipulation   By Ryogo Kubo, Kouhei Ohnishi	[View]   [Download]
Abstract: This paper presents a grasping/manipulating control method using mode transformation. Discrete Fourier transform (DFT) matrices are utilized as transformation matrices. In grasping/manipulating control systems, decomposition into grasping motion and manipulating motion remains a key problem. By means of the proposed method, the grasping controller and the manipulating controller can be designed independently as a grasping mode and a manipulating mode, respectively. The grasping mode indicates internal force control and the manipulating mode indicates position control of COG (center of gravity). Hence, hybrid position/force control is achieved in grasping and manipulating an object using multiple robots. The validity of the proposed method is shown by the numerical and experimental results.
	Intelligent Electric Vehicle Motion and Crossroad Control   By Mikhail Gorobetz, Anatoly Levchenkov, Leonids Ribickis	[View]   [Download]
Abstract: The purpose of this work is to organize coordination between intelligent trams and intelligent traffic lights. The main idea is to realize electric transport movement without stops excepting stops for taking passengers. The supposition is the effective decrease of electric energy charges causing with acceleration and breaking cycles. Following methods of control are proposed: intelligent agent system, and negotiations between these agents with the superagent as coordinator to solve possible conflicts. Intelligent agents are created using Web-technologies: a database and the appropriate programming languages that allow to realize negotiation easy and effectively.
	On-line Trained Neural Speed Controller with Variable Weight Update Period for Direct-Torque-Controlled AC Drive   By Lech M. Grzesiak, Vincent Meganck, Jakub Sobolewski, Bartlomiej Ufnalski	[View]   [Download]
Abstract: The paper investigates further improvements of an adaptive ANN (Artificial Neural Network)-based speed controller employed in a DTC-SVM (Direct Torque Controlled - Space Vector Modulated) drive. An on-line trained ANN serves as a speed controller and does not need a process model to predict future performance. In comparison to the previously published solution, autoadjusting ability has been added to the controller. The recurrent feedback inside the neural controller has been also introduced. Adaptive behaviour manifests in robustness to moment of inertia variation greater than 10 times. This feature is achieved by the learning algorithm running during system operation. Mentioned variable update period refers to one of the parameters connected with learning algorithm, namely frequency of calling backpropagation procedure (weights update procedure). Proposed control algorithm has been tested in simulation and verified experimentally. The behaviour of the drive has been compared to the one with previously proposed ANN-based speed controller with fixed settings of training algorithm.
	Optimal Control of Transistor SRM Converters with Reduced Number of Switching Element   By Laszlo Szamel	[View]   [Download]
Abstract: The paper investigates further improvements of an adaptive ANN (Artificial Neural Network)-based speed controller employed in a DTC-SVM (Direct Torque Controlled - Space Vector Modulated) drive. An on-line trained ANN serves as a speed controller and does not need a process model to predict future performance. In comparison to the previously published solution, autoadjusting ability has been added to the controller. The recurrent feedback inside the neural controller has been also introduced. Adaptive behaviour manifests in robustness to moment of inertia variation greater than 10 times. This feature is achieved by the learning algorithm running during system operation. Mentioned variable update period refers to one of the parameters connected with learning algorithm, namely frequency of calling backpropagation procedure (weights update procedure). Proposed control algorithm has been tested in simulation and verified experimentally. The behaviour of the drive has been compared to the one with previously proposed ANN-based speed controller with fixed settings of training algorithm.
	Optimization of PM Brushless DC Motor Drive Speed Controller using Modification of Ziegler-Nichols Methods based on Bode Plot   By Petar Crnosija, Krishnan Ramu, Toni Bjazic	[View]   [Download]
Abstract: The most commonly used methods for design of the industrial speed controllers are: experimental, root locus, frequency and optimization methods. The most commonly used experimental methods are Ziegler-Nichols methods: stability margin and step response function. Ziegler-Nichols methods are applied for design of speed controller of PM brushless DC motor drive. Both methods give the controller parameters, which result in relatively high overshoot in response to reference signal. Therefore, optimal speed controller parameters are determined by modification of Ziegler-Nichols methods based on Bodé’s frequency diagrams. Thereby, controller integral time constant is increased and controller gain is reduced (increased) to achieve faster and better load torque compensation than traditional controller synthesis based on compensation of maximum time constant of drive. Desired overshoot in response to reference change is achieved by adding a first order filter at the drive input. Synthesis results and responses are given in this paper.
	Permanent Magnet Motor Control in Full Speed Range without Mechanical Sensors   By Guillermo Bisheimer, Maximiliano Osvaldo Sonnaillon, Cristian Hernan De Angelo, Jorge Alberto Solsona, Guillermo Oscar Garcia	[View]   [Download]
Abstract: This paper presents a control method for permanent magnet (PM) motors based on a combination of a non linear full–order observer and a signal injection scheme. Mechanical–sensorless operating range down to zero speed is obtained using only voltage and current sensors. The signal injection scheme uses the asymmetry of the motor’s d and q axis inductances to estimate rotor position and speed. Such asymmetry is also taken into account in the motor model used to construct the observer. The performance of the proposed scheme is validated through experimental results.
	Position Sensorless Direct Torque Control of SR Motors   By Manabu Mitani, Hiroki Goto, Hai-Jiao Guo, Osamu Ichinokura	[View]   [Download]
Abstract: Switched Reluctance motors (SR motors) have several desirable features, including simple construction, high reliability and low cost. But large torque ripple and expensive position sensors used in SR motor drive systems are considered as drawbacks for wide application. Several studies have succeeded in torque ripple reduction for SR motors using Direct Torque Control (DTC) technique. In this paper, a new position sensorless Direct Torque Control method is proposed. The validity and the performance of the proposed method are demonstrated through the computer simulation.
	Predictive Trajectory Tracking Control for Mobile Robots   By Gregor Klancar, Igor Skrjanc	[View]   [Download]
Abstract: A model predictive trajectory tracking control applied to a mobile robot is presented in this paper. Prediction model derived from linearized tracking error dynamics is used to predict future system behavior. A control law is derived from quadratic cost function consisting of system tracking error and control effort. Experimental results on a real mobile are presented and a comparison of the obtained control to a time-varying state feedback controller is given. The proposed controller includes velocity and acceleration constraints to prevent mobile robot from slipping and a Smith predictor is used to compensate for vision system dead-time. Some future work ideas are discussed as well.
	Proportional-Integral LQ Control of a Two-Mass System   By Maciej Tondos, Grzegorz Sieklucki, Adam Pracownik	[View]   [Download]
Abstract: The paper concerns the proportional-integral LQ control of a two-mass system. The LQ problem with the solution of both the continuous and discrete task of proportional-integral control of electrical drive is presented in the paper. The principle of design of the state and disturbance observer, used to reconstruct the state variables of the investigated plant, is also discussed. A control system, employing fixed-point calculation blocks (digital control) is presented in the final section of this paper, simulation results are included.
	Reliable Control using Equivalent Transfer Function for Position Servo System   By Kaoru Ishikawa, Tsutomu Ohmae	[View]   [Download]
Abstract: In this paper, a reliable control method is proposed for a position servo system using multiple loops. The position servo system has two minor-loops which are a speed loop and a current loop. If one minor feedback loop fails, such as a case of the speed sensor break down, the position servo system becomes unstable. To cope with this problem, the proposed method uses an equivalent transfer function (ETF) as an active redundancy compensation after the loop failure. The ETF is designed so that it does not change the transfer function of the whole system before and after the loop failure. Therefore, the stability of the position control system using this proposed method is guaranteed even if the speed feedback loop fails or the current feedback loop fails. The effectiveness of this proposed method is confirmed by the experimental results.
	Robust Current Regulator with 2 DOF Structure and Stability Analysis for IPMSM Drives under High Speed Region   By Masaru Hasegawa, Yasuhiro Nitta, Keiju Matsui	[View]   [Download]
Abstract: This paper proposes a new current regulator for IPMSM sensorless drives under high speed region. It has been pointed out that the conventional current control system for IPMSM becomes unstable under high speed region, which caused by position estimation error. First, this paper shows that this phenomenon is caused by position estimation error, and this instability is especially emphasized under high speed region. To overcome this instability, two degrees of freedom (2 DOF) controller is proposed in this paper. Stability using the proposed current regulator is then analyzed theoretically, and the proposed controller can enlarge stable region of position sensorless control for IPMSM drives, which can conclude that the proposed controller is superior to that using conventional one.
	Robust H-inf-Optimal PI Control for Servo Drive Applications Solved by a Genetic Algorithm   By Karsten Peter, Marat Vinogradski, Andre Tenhagen, Matthias Joost, Bernd Orlik	[View]   [Download]
Abstract: Controlling a multi-mass system is a common problem in industrial automation. Varying or even unknown parameters cause the difficulty of the control. A powerful tool in order to control systems with uncertain parameters is a robust H‡-control. Unfortunately the complex structure and the mathematical theory prevent known H‡ controllers from the usage in many industrial applications. In this work the design of a robust control for a two-mass system will be described. In many cases a twomass system is a sufficient model for the controller synthesis because it includes the lowest resonance case. The structure of the controller is a common structure of a popular PI/P cascade control. However, the desired parameters of the robust cascade control are calculated by a genetic algorithm with respect to the H‡-Norm. Measurements will complete the paper.
	Rotor Flux Observer in Pseudo - Sliding Mode for Vector Controlled Induction Motor Drives   By Martin Hrasko, Jan Vittek, Rastislav Havrila, Ivan Lokseninec	[View]   [Download]
Abstract: A kind of speed sensorless sliding – mode observers for induction motors has been developed. In this paper a new topology of such observer is investigated in order to determine its feasibility, robustness to parameter changes and practical applicability on digital signal processor. The positive feature of the proposed scheme is that it doesn’t require the rotor speed feedback or adaptation, only measured variables such as stator current and DC voltage are required. Experimental results on DSP TI LF2407A, presented in the end of the paper show good correspondence with proposed theory.
	Run-Time Reconfiguration of Tandem Inverter for Induction Motor Drives   By Jozsef Vasarhelyi, Maria Imecs, Csaba Szabo, Ioan Iov Incze	[View]   [Download]
Abstract: The paper presents a short introduction to reconfigurable systems and why are they used or should be used in control of AC drives. The reconfigurable vector control system is introduced and there are treated the reconfiguration problems. There is analyzed the reconfigurable control system and it is motivated the need for reconfiguration in motor control. The control of the induction motor fed by the tandem inverter needs reconfiguration if the supply is made only from one inverter instead of the both component ones. Finally a simulation and fast prototyping method is shown using Field Programmable Gate Arrays.
	Sensorless Control of IM in Mining Applications   By Gregor Edelbaher, Branko Fosner, Joze Korelic, Evgen Urlep, Milan Curkovic, Miran Rodic	[View]   [Download]
Abstract: A power inverter applying a speed sensorless induction motor control is presented in the paper. It was designed with the goal to be used in applications positioned in the Ex-environment of the underground mines. Direct field oriented control, using rotor flux and speed observer is used. The speed sensorless observer scheme is based on the back-emf observer. Applied hardware and software are presented. Operation is described with the use of experimental results, which were obtained from the actual application operating in the coal mine. The project is a good example of cooperation between the academia and industry.
	Shaft Sensorless Speed Control of Induction Motor Drive   By Pavol Makys, Greg M. Asher, Mark Sumner, Qiang Gao, Jan Vittek	[View]   [Download]
Abstract: In this paper, the test voltage injection coupled with tracking of magnetic saliencies created by saturation and rotor slotting was used for shaft sensorless speed control of induction motor drives at zero and low speed. Method does not require additional wire connections and is usable for star or delta machine connection. The paper is proposing low memory method of elimination saturation effect from position signals, which are obtained from sensors of line current derivations. Experimental results are presented shoving tracking of rotor speed and position, signal processing with proposed method and shaft sensorless speed control as well.
	Sliding Mode based Position Control of a Flexible-Link Arm   By Aydemir Arisoy, Metin Gokasan, O. Seta Bogosyan	[View]   [Download]
Abstract: In this study, sliding mode (SM) based partial feedback linearization (PFL) control method is applied to a single flexible link arm (FLA) with payload. A sliding mode based partial feedback linearization controller is designed to achieve set point precision positioning control for a FLA. Flexible robot arms have structural flexibilities and resulting high number of passive degrees-of-freedom. They cannot be decoupled due to the highly nonlinear structure. Since exact feedback linearization control methods cannot be applied to these systems, partial feedback linearization control methods are suitable for the flexible systems. For set-point control, sliding mode control based approach is applied to achieve the precise tip position of a single FLA. To do this, active and passive dynamics of the system are included in a new output equation and appropriate sliding manifold is defined using this new output equation. Proposed control algorithm is compared with PD based collocated PFL control method. Then, the performance of both controllers for the tip-position precision of a single FLA is demonstrated by simulations. Numerical simulations of a single FLA demonstrate that the SM based approach gives rise to a better performance than the PD based one.
	Speed Estimation of PM Stepper Motors. Robustness Aspects   By Andres Leon, Jorge Alberto Solsona	[View]   [Download]
Abstract: This work deals with speed estimation in electric drives that include a Permanent Magnet Stepper Motor. On the one hand a nonlinear observer is designed, whereas on the other hand the rotor speed is estimated by using the dirty derivative from the measured position. By assuming model uncertainty and noisy measurements a comparison from the robustness point of view is presented. Advantages and disadvantages of both techniques are commented.
	Study and Simulation of Direct Torque Control of Double-Star Induction Motor Drive   By Khoudir Marouani, Farid Khoucha, Abdelaziz Kheloui, Lotfi Baghli, Djafar Hadiouche	[View]   [Download]
Abstract: The major drawback of usual dual three-phase AC machines when supplied by a voltage source inverter (VSI), is the occurrence of extra harmonic currents. These extra currents circulate only in the stator windings and cause additional losses. One solution to reduce their amplitude is to act on the supply side using dedicated PWM control strategies. In this paper, we present a Direct Torque Control technique of a double-star induction motor drive (DSIM). The induction machine has two sets of three-phase stator windings spatially phase shifted by 30 electrical degrees. Each set of three-phase stator windings is excited by a three-phase inverter. Simulation results have been presented to show the effectiveness of the dual-three phase DTC scheme for double star induction motor.
	System Design and Software Architecture of Traction Vehicle Control Computer   By Jiri Zdenek	[View]   [Download]
Abstract: The overview of system design and software architecture of the distributed control computer (DCC) of an electric locomotive is presented. The DCC is organized as a local computer network with the master-slave mode access method with a dual serial bus. User task activities in nodes are organized by the preemptive Real Time Operating System with dynamic planning or by simple static executive. Network communication services are uniformly used in all nodes to support reliable and user friendly transfer of process data inside DCC. The system design is based on criteria as functionality, reliability, fault tolerance and maintainability.
	Technical Issues on Velocity Measurement for Motion Control   By Toshiaki Tsuji, Mariko Mizuochi, Kouhei Ohnishi	[View]   [Download]
Abstract: Robust motion control requires accurate velocity information. The authors have proposed “synchronousmeasurement method (S method)” that measures the velocity synchronous with alteration of pulse numbers. Accurate velocity measurement is achieved in all speed ranges with this method. The method, however, has several technical issues for application in practice: accuracy often deteriorates with nonideality of interpulse angles in optical encoders; and disturbance observer needs modification to deal with nonregular velocity measurement. This paper proposes some solutions for the issues in S method. Experimental results verify the validity of the solutions.
	The Use of Small Voltage Vectors of Matrix Converters in Direct Torque Control of Induction Machines   By Carlos Ortega, Antoni Arias, Josep Balcells, Cedric Caruana, Cyril Spiteri, Joseph Cilia	[View]   [Download]
Abstract: The effects on torque performance when using small voltage vectors of Matrix Converters is investigated in this paper. These vectors are used in order to reduce the electromagnetic torque ripple which appears when Direct Torque Control technique is used in Induction Motors. Direct Torque Control for Induction Motors using Matrix Converters is reviewed and it is pointed out the problem of the electromagnetic torque ripple which is one of the most important drawbacks of the Direct Torque Control. A new look-up table for Direct Torque Control using small vectors of Matrix Converters is developed. With the new look-up table, the system will differentiate between small and large torque errors and consequently reduce the electromagnetic torque ripple. A comparison between the classical Direct Torque Control using Matrix Converters and the proposed method is carried out. Results which demonstrate the improvement of the novel Direct Torque Control are shown.
	Trajectory Planning of Biped Robot with Two Kinds of Inverted Pendulums   By Tomoyuki Suzuki, Kouhei Ohnishi	[View]   [Download]
Abstract: In recent years, studies about walking motion of biped robots have been developed rapidly. In many researches, biped robots are often treated as inverted pendulums since the structure of biped robots are very complicated. This simplification makes trajectory planning for a biped robot easy. An inverted pendulum model, however, gives some constraints to the robot.Walking motion using one kind of inverted pendulum has low robustness of walking. Hence, we propose a trajectory planning method with combination of two kinds of inverted pendulums in this paper. Trajectory planning of the swing leg for this new method is also proposed. With these, more stable and humanlike walking motion is achieved than that with one kind of inverted pendulum. The proposed method is more effective when a biped robot walks with lager range of strides.
	Using Artifical Potential Field Methods and Fuzzy Logic for Mobile Robot Control   By Viorel Stoian, Mircea Ivanescu, Elena Stoian, Cristina Pana	[View]   [Download]
Abstract: This paper presents a new control method for mobile robots moving in its work field which is based on fuzzy logic and artificial potential field. First, the artificial potential field method is presented. The paper treats unconstrained movement based on attractive artificial potential field and after that discuss the constrained movement based on attractive and repulsive artificial potential field. A fuzzy controller is designed. Finally, some applications are presented.
	Wideband Motion Control by Acceleration Disturbance Obsever   By Kouhei Irie, Seiichiro Katsura, Kiyoshi Ohishi	[View]   [Download]
Abstract: Motion control has been widely used in industry applications. One of the key technologies of motion control is a disturbance observer, which quarries a disturbance torque of a motion system and realizes a robust acceleration control. The disturbance observer can observe and suppress the disturbance torque within its bandwidth. Recent motion systems begin to spread in the society and they are required to have ability to contact with unknown environment. Such a haptic motion requires much wider bandwidth. However, since the conventional disturbance observer attains the acceleration response by the second order derivative of position response, the bandwidth is limited due to the derivative noise. This paper proposes a novel multi-sensor based acceleration disturbance observer (MADO). The proposed MADO uses an acceleration sensor for enlargement of bandwidth. Generally, the bandwidth of an acceleration sensor is from 1 Hz to more than 1kHz. To cover DC range, the second order derivative of position is integrated. The integrated acceleration value realizes lower observation noise and higher bandwidth than a conventional estimated acceleration. Thus, the proposed MADO can get at wide frequency response than conventional one. And, it made dramatically more responsive a position control and a force control. Results are verified by simulation.