Showing papers in "IEEE Transactions on Industrial Electronics in 1985"
TL;DR: In this paper, the rotor position was detected by monitoring the winding currents of the rotor rotor in a helicopter or series-resistance drive over the complete speed range of a stepping motor.
Abstract: The paper describes new methods of detecting rotor position in stepping and switched motors, with chopper or series-resistance drives, by monitoring winding currents. In contrast to previous methods of waveform detection, the new techniques are reliable over the complete speed range. It is shown that the most useful indicators of rotor position are: i) current rise times arising from chopping an unexcited phase at low current and ii) the initial rate of current rise as a phase is switched on in a series-resistance drive. Implementation is via simple low-cost electronic circuits and the paper includes discussion of how the techniques can be applied to closed-loop stepping motor control, ministep drives, and optimization of step response.
273 citations
TL;DR: In this article, a sliding curve is used instead of a straight line to define the sliding curve in such a way that in general the system responds following a max acceleration curve, then a max speed curve, and finally a max deceleration curve.
Abstract: Sliding mode control is an effective means to keep a system insensitive to parametric variations and disturbances. In the conventional sliding mode control applied to position servo systems, the sliding mode regime is restricted near the origin, and, therefore, insensitivity cannot be ensured throughout an entire response. This paper presents a new method in which a sliding curve is used instead of a straight line. The sliding curve is defined in such a way that in general the system responds following a max acceleration curve, then a max speed curve, and finally a max deceleration curve. Experimental results confirm that the new method can keep the system robust completely throughout a transient response, which demonstrates the advantage of the proposed sliding curve over the conventional sliding mode strategy.
155 citations
TL;DR: In this article, the authors describe a new, systematic, and unified approach to model the low-frequency behavior of power switches in Switch-Mode Power Supplies (SMPS) by making use of an impulse-response method and averaging technique.
Abstract: This paper describes a new, systematic, and unified approach to model the low-frequency behavior of power switches in Switch-Mode Power Supplies (SMPS). This approach starts with a simplification of the switching converter circuit to a Minimum Separable Switching Configuration (MISSCO) containing all power switches but a minimum number of other components, before analysis on the MISSCO is carried out. Then by making use of an impulse-response method and averaging technique, a set of equations describing the low-frequency behavior of the MISSCO are derived. The resultant equations can be used to generate a low-frequency equivalent circuit of the MISSCO, which can then be combined with the rest of the SMPS circuit to form a complete equivalent circuit.
94 citations
TL;DR: In this paper, a novel Switch-Mode-Rectifier (SMR) structure is proposed and analyzed, which employs a high-frequency sine PWM cycloconverter to provide highfrequency ohmic isolation between the source and the load.
Abstract: A novel Switch-Mode-Rectifier (SMR) structure is proposed and analyzed in this paper The proposed converter structure employs a high-frequency sine PWM cycloconverter to provide high-frequency ohmic isolation between the source and the load Furthermore, it draws high-quality current from the ac source thus requiring only small input reactive components Consequently, the proposed converter structure exhibits high power density and has low implementation cost
84 citations
TL;DR: In this paper, an analysis of a resonant converter which contains a capacitive-input output filter, rather than the more conventional inductor-input input filter, is presented along with design curves along with experimental data.
Abstract: Resonant dc-dc converters offer several advantages over the more conventional PWM converters. Some of these advantages include: 1) low switching losses and low transistor stresses; 2) medium speed diodes are sufficient (transistor parasitic, inverse-parallel diodes can be used, even for frequencies in the hundreds of kilohertz); and 3) ability to step the input voltage up or down. This paper presents an analysis of a resonant converter which contains a capacitive-input output filter, rather than the more conventional inductor-input output filter. The switching waveforms are derived and design curves presented along with experimental data. The results are compared to the inductor-input filter case obtained from an earlier paper.
76 citations
TL;DR: In this article, a computer-controlled vehicle which is part of a nursing robot system currently under development at the Technion-Israel Institute of Technology is described. And the vehicle applies a motion control strategy which avoids slippage and minimizes position errors.
Abstract: This paper describes a computer-controlled vehicle which is part of a nursing robot system currently under development at the Technion-Israel Institute for Technology. The platform of this vehicle can also be used for household robots. Design considerations, control algorithms, and the necessary sensory devices are discussed. The vehicle applies a motion control strategy which avoids slippage and minimizes position errors. Experimental results, performed on a prototype vehicle, are described as well.
71 citations
TL;DR: In this article, a methodology is presented to locate faulty cylinder(s) by using a mathematical model of the engine dynamics, which takes into account the cylinder gas pressure, engine inertia, and load.
Abstract: The general fault analysis problem can be divided into two parts: fault detection and diagnosis (location). Fourier series, autocorrelation, and other techniques have been used for fault detection. However, these approaches cannot be utilized for locating the faults. In this paper a methodology is presented to locate faulty cylinder(s). The procedure involves the development of a mathematical model of the engine dynamics. This model takes into consideration the cylinder gas pressure, engine inertia, and load. The resultant torque is computed by using parameter estimation techniques. The parameter estimation technique employed can determine time-varying parameters without prior knowledge of the structure of the parameter. In the problem at hand, this is an important requirement. The resultant torque is the net of the cylinder gas torque and the frictional torque. The model and the estimation procedure have been verified by performing tests on a single-cylinder engine. A discriminant function has been defined to classify the performance of each cylinder. Our results indicate that the amplitude of the resultant torque can be used to identify the faulty cylinder(s). We have verified this approach by tests and studies on a six-cylinder engine. In our experiments we have studied cases involving one or two faulty cylinders.
53 citations
TL;DR: The focus is on techniques that will enable the location of the fault and involves the analysis of the instantaneous angular velocity of the flywheel, which is computationally more complex than the other approaches.
Abstract: Several studies have been performed to detect faults in engines. Fourier series and autocorrelation-based methods have been shown to be useful for this purpose. However, these and other methods discussed in the literature cannot locate the fault. In this paper, the focus is on techniques that will enable the location of the fault. In general, our approach involves the analysis of the instantaneous angular velocity of the flywheel. Three methods of analysis are presented. The first method depends on the computation of a set of statistical correlations. The second method is based on evaluation of similarity measures. These methods are able to locate faults in several tests that have been performed. The third approach uses pattern recognition methods and involves three stages?data extraction, functional approximation to determine a feature vector, and classification based on a Bayesian approach. This method is computationally more complex than the other approaches. However, on the basis of the experimental results it appears that the third method leads to a lower error rate. Cases involving faults in one and two cylinders are presented.
51 citations
TL;DR: In this paper, an optimal model-following suspension design was verified experimentally by means of a microcomputerized suspension model, and the experimental results indicated promising potential application of the proposed scheme to real-world systems.
Abstract: The problem of vibration isolation is investigated from the standpoint of modern control and optimization theory. The proposed optimal model-following suspension design was verified experimentally by means of a microcomputerized suspension model. The experimental results are very encouraging and indicate promising potential application of the proposed scheme to real-world systems. This paper describes the modeling and formulation of an optimal control suspension reference model, and the implementation algorithm of the proposed microcomputerized optimal model-following suspension scheme.
49 citations
TL;DR: Research in the area of machine vision for traffic monitoring and control is being actively pursued in several countries and current efforts are surveyed.
Abstract: The large increase in traffic density during the last 25 years in the US, Europe, and Japan has required the automation of some functions of traffic control and monitoring. Buried magnetic loops are widely used for this purpose, but there are functions such as incident detection, vehicle tracking, etc., which are not implementable with them. In addition, magnetic loops are not flexible. Image processing represents a potentially much more powerful tool for this application. Its main disadvantage is the high initial cost. Research in the area of machine vision for traffic monitoring and control is being actively pursued in several countries. This paper surveys current efforts.
47 citations
TL;DR: In this paper, a microprocessor-based control method is developed to obtain uniform weld quality regardless of the changing welding environments, which utilizes a proportional (P) control algorithm, incorporating with the electrode movement as a feedback variable.
Abstract: Quality assurance has been of a great concern in the process of resistance spot welding, since considerable variation in the weld quality often arises even when the machine variables are held constant. In this paper a new microprocessor-based control method is developed to obtain uniform weld quality regardless of the changing welding environments. The control system utilizes a proportional (P) control algorithm, incorporating with the electrode movement as a feedback variable. The controller generates the welding control current so as to track a desired trace of the electrode movement (reference electrode movement curve) throughout weld cycle. A series of experiments was performed to evaluate the performance of this control method. The results show that, as a result of the electrode movement tracking, weld strengths of all the weldments approach to a desired strength level.
TL;DR: In this paper, a dc to 3-phase series-resonant converter (s.r.converter) is presented for sub-megawatt industrial applications with variable-frequency sine-wave currents.
Abstract: A type of dc to 3-phase series-resonant converter (s.r.converter) or potentially submegawatt industrial applications is presented. The converter provides variable-frequency sine-wave currents, with low harmonic distortion at the output terminals, and with the frequency ranging from -200 through dc to +200 Hz. The converter can transfer power in both forward and reverse power-flow directions to almost any type of load circuit. The methods of control are formulated such that they can be implemented easily with high-speed logical circuits. Test results for a 1-kW demonstration converter are supplied.
TL;DR: In this article, the authors present a design technique for integration operators which allows the simulation time step to be chosen independent of the system eigenvalues while guaranteeing stability of the simulation, which is particularly useful for the real-time simulation of stiff systems where critical constraints are often imposed on the simulation increment.
Abstract: This paper presents a design technique for integration operators which allows the simulation time step to be chosen independent of the system eigenvalues while guaranteeing stability of the simulation. The technique is particularly useful for the real-time simulation of stiff systems where critical constraints are often imposed on the simulation increment. A significant savings in computation time can be realized with this technique when compared with conventional methods for simulating stiff systems. Examples are presented which illustrate the stability and accuracy properties of this design method.
TL;DR: In this paper, the phase-locked loop with Voltage Pump Phase Frequency Detector (VPPFD) was investigated and resolved the differences in explanation about its somehow peculiar behavior appearing in the literature.
Abstract: This paper is concerned with the phase-locked loop with Voltage Pump Phase Frequency Detector (VPPFD) and resolves the differences in explanation about its somehow peculiar behavior appearing in the literature.
TL;DR: In this paper, a digital position servo for brushless dc steering motors on the CMU Rover has been implemented with a microprocessor and programmable timer to calculate concurrently the actuating signals, time sampling periods and pulsewidths, as well as to provide commutation.
Abstract: Pulsewidth modulation (PWM) control of brushless dc motors is implemented with digital servo mechanisms for robotic applications. Under the assumption that the pulse period is much smaller than the motor time-constants, the motor is modeled by a discrete-time transfer function with the pulsewidth playing the role of the control signal. This model enables the application of classical linear control engineering to the design of a digital position servo for the brushless dc steering motors on the CMU Rover. The controller is implemented with a microprocessor and programmable timer to calculate concurrently the actuating signals, time sampling periods, and pulsewidths, as well as to provide commutation. Computer simulation and real-time hardware implementation of the servo demonstrate the efficacy of the approach.
TL;DR: In this article, a new synthesis method for the efficiency-optimized speed control system for the separately excited dc motor system is proposed on the basis of an improved optimal regulator theory.
Abstract: A new synthesis method for the efficiency-optimized speed control system for the separately excited dc motor system is proposed on the basis of an improved optimal regulator theory. The optimal ratio of the armature current and the field current that gives the maximum efficiency is analytically derived, and the error term of the current ratio is included in a performance index. Then, the control system which realizes both the satisfactory response and the optimal current ratio giving the optimal efficiency is constructed in the systematic design procedure. In simulational and experimental results, close agreement between them is obtained. Also, considerable improvement on the efficiency of the motor system at the steady state is obtained.
TL;DR: In this paper, a simple generalized approach, based on numerical evaluation of the Fourier coefficients, is presented to evaluate the comprehensive performance of three-phase phase-controlled thyristor ac voltage controllers.
Abstract: A simple generalized approach, based on numerical evaluation of the Fourier coefficients, is presented to evaluate the comprehensive performance of three-phase phase-controlled thyristor ac voltage controllers. Three-phase balanced resistive and inductive loads of different power factors are considered. The method of solution adopted is simple, accurate, fast, and does not require the derivation of Fourier coefficient equations. Various electrical properties are compared graphically for the different circuit configurations. The branch-controlled deltaconnected load is considered to have the best performance, giving the highest power factor per unit of power delivered.
TL;DR: In this paper, a series-resonant converter (SRC) able to generate an output voltage either lower or higher than the source voltage is described, and a novel control scheme is presented which renders two degrees of freedom for control and which guarantees symmetrical steady-state waveforms in all operation modes.
Abstract: A series-resonant converter (SRC) able to generate an output voltage either lower or higher than the source voltage is described. Moreover, a novel control scheme is presented which renders two degrees of freedom for control and which guarantees symmetrical steady-state waveforms in all operation modes. Both the average resonant current as well as the peak voltage of the resonant capacitor can be controlled independently. Special attention is given to an operation mode which facilitates converter operation when the output voltages approximately equal the source voltage (q approx equal to 1). Test results are presented of both controller and converter.
TL;DR: In this paper, the authors describe several pulsewidth modulation (PWM) waveforms where a predetermined number of unwanted harmonics can be canceled, and the advantages and disadvantages of different methods of delaying the signals in small microprocessor controlled PWM inverter drive systems are considered.
Abstract: Microprocessor control of power electronic systems offers the possibility of improvements in reliability, maintenance and servicing, and increased control flexibility. This paper describes several pulsewidth modulation (PWM) waveforms where a predetermined number of unwanted harmonics can be canceled. The advantages and disadvantages of the different methods of delaying the signals in small microprocessor controlled PWM inverter drive systems are considered. Several examples of single-phase and three-phase PWM inverters, with the laws which govern the commutation angles, output waveforms, and their respective frequency spectra are presented.
TL;DR: In this paper, an implementation based on piecewise linear interpolation from motor characteristic curves is presented, which takes into account motor nonlinearities and is compared with those of other controllers.
Abstract: This paper describes methods of calculating current references for ministepping step motor controllers. An implementation based on piecewise-linear interpolation from motor characteristic curves is presented. This method takes into account motor nonlinearities. Ministepping accuracy so obtained is compared with those of other controllers.
TL;DR: The paper is concerned with the application of a signal processor in the control of inverters modulated with a subharmonic technique and the distinct advantages offered by such an application over analog circuitry or a conventional microcomputer are illustrated.
Abstract: The paper is concerned with the application of a signal processor in the control of inverters modulated with a subharmonic technique. The distinct advantages offered by such an application over analog circuitry or a conventional microcomputer are illustrated. Description of how the PWM inverter control can be implemented on a signal processor is given. A single-phase PWM inverter controller is developed as an example and its hardware and software structures are presented. A complete set of experimental results is also included.
TL;DR: The J3 SCR model as mentioned in this paper is a continuous topology computer model for the SCR and its circuit analog and parameter estimation procedure are uniformly applicable to popular computer-aided design and analysis programs such as SPICE2 and SCEPTRE.
Abstract: The J3 SCR model is a continuous topology computer model for the SCR. Its circuit analog and parameter estimation procedure are uniformly applicable to popular computer-aided design and analysis programs such as SPICE2 and SCEPTRE. The circuit analog is based on the intrinsic three pn junction structure of the SCR. The parameter estimation procedure requires only manufacturer's specification sheet quantities as a data base.
TL;DR: In this article, the authors present a computer-optimized adaptive suspension technology (COAST), which is capable of providing near-optimum performance for any land surface vehicle in any environment and can be implemented in a relatively simple and cost effective manner.
Abstract: This paper presents a fundamental vehicle suspension system using real-time computer control. This Computer-Optimized Adaptive Suspension Technology (COAST) consists of a microprocessor-controlled, fully integrated, adaptive suspension system. COAST is capable of providing near-optimum performance for any land surface vehicle in any environment and can be implemented in a relatively simple and cost-effective manner.
TL;DR: The results of the work show that the dynamic equations of motion are valuable in robotic systems to develop an appropriate control scheme, to determine suitable ranges of feedback gains, and to be used on-line to generate a feed-forward control input.
Abstract: A dynamic control scheme for a three degree-of-freedom robot leg, which has been interfaced to a PDP-11/70 minicomputer, is developed and implemented. A CSMP (Continuous System Modeling Program) simulation is also used to study the dynamic characteristics of the leg off-line. The results of the work show that the dynamic equations of motion are valuable in robotic systems to develop an appropriate control scheme, to determine suitable ranges of feedback gains, and to be used on-line to generate a feed-forward control input.
TL;DR: In this article, a new method for detecting fluctuations in the fundamental frequency component of a power system, by relating it to a leakage coefficient in the FFT, is presented, which is used advantageously to increase spectral resolution.
Abstract: A new method for detecting fluctuations in the fundamental frequency component of a power system, by relating it to a leakage coefficient in the FFT, is presented. The phenomenon of leakage in the FFT is used advantageously to increase spectral resolution. The leakage coefficient is a quantitative measure of the deviation from the fundamental frequency component with respect to the sampling frequency. Theoretical aspects are considered along with a method for on-line implementation.
TL;DR: Existing GM vehicle communication systems are reviewed, their characteristics are described, and the future development trends of such systems are discussed, to provide a tutorial on the current uses of digital communications in General Motors vehicle products.
Abstract: The purpose of this paper is to provide a tutorial on the current uses of digital communications in General Motors (GM) vehicle products. Existing GM vehicle communication systems are reviewed, their characteristics are described, and the future development trends of such systems are discussed. Long-term development of automotive digital communications will require a more complete understanding of the technologies applied. Local area network technology is proving to be very effective in lowering the cost of communication in land-based systems, due to the rapid growth and development of low-cost computing and data storage. Vehicle designers are now applying many of these same technologies to reduce the life cycle costs of increasingly complex electrical/electronic systems.
TL;DR: In this paper, the performance of a large generator under abnormal operating conditions through physical modeling and simulation is investigated. But the authors focus on the performance analysis of a single generator and do not consider the effects of different operating conditions on the generator.
Abstract: Micromachines are small machines specially designed so that their parameters, on a per unit basis, are similar to those of large generators in power systems, and they are widely used to study the performance of these large machines under abnormal operating conditions through physical modeling and simulation.
Journal Article•
TL;DR: In this paper, a dc 1500 V GTO (gate turnoff thyristor) circuit breaker controlled by a single-chip microcomputer is presented, with the GTO junction temperature observation.
Abstract: Power semiconductor circuit-breaker application suggests the need for microcomputers that provide firing control, excellent dc short-circuit fault interrupting performance, precise overload protection of themselves, as well as high reliability with minimum components. This paper deals with the prototype dc 1500 V GTO (gate turnoff thyristor) circuit breaker controlled by a single-chip microcomputer. Emphasis is on the GTO junction temperature observation.
TL;DR: This method provides an insight into limitations of the leastsquare fit method normally obscured in other algorithms, and can be used to decrease the extensive computational overhead needed to evaluate the simultaneous equations used in other least square fit algorithms making it suitable for use with small systems.
Abstract: In many experimental and industrial situations, data is sampled at predefined but irregular intervals by a small dedicated microcomputer. This paper details a general method of fitting such data to an Nth-order polynomial according to the least square criterion. The approach can be used to decrease the extensive computational overhead needed to evaluate the simultaneous equations used in other least square fit algorithms making it suitable for use with small systems. Methods of differentiation, interpolation, and data smoothing are detailed. Estimates of the errors in the fitting parameters are given. This method provides an insight into limitations of the least square fit method normally obscured in other algorithms. The computational time saving increases as the polynomial order N increases. Two applications are briefly discussed.