Showing papers in "IEEE Transactions on Industrial Electronics in 1987"

Microprocessor-Controlled DC Motor for Load-Insensitive Position Servo System

Abstract: The conventional proportional P controller has been often used as the position controller of the dc servo motor. When the unknown and inaccessible load torque, such as the coulomb friction, the gravity, and so on, is imposed on the dc servo motor, this control system has the steady-and/or transient-state error.

A Microprocessor-Based Robot Manipulator Control with Sliding Mode

Abstract: The application of a sliding-mode control based on a Variable Structure System (VSS) for a multijoint manipulator is presented. The high-gain effect of a sliding-mode control suppresses the complicated interactions between each joint of a robot arm. The resulting system is completely robust whereas the obtained control law is simple and easy to apply to on-line computer control. In this-paper, the practical sliding-mode controller, which has a simple nonlinear compensator and proper continuous function, is implemented for a two-linkage manipulator. The validity of this technique is confirmed in experiments where the system shows robust performance in spite of the existing nonlinear interactions and unknown parametric changes. In addition, this sliding-mode control is improved to track the desired path.

Formulation of Joint Trajectories for Industrial Robots Using B-Splines

Abstract: In this paper, we describe a new procedure for constructing robot trajectories. The procedure uses the theory of B-splines. The motion of the robot, as specified by a time sequence of position and orientation knots of the end effector, is first transformed into sets of joint displacements. B-splines are then used to fit these sequences for each joint. The procedure consists of a simple recursive algorithm and allows constraints to be imposed on the magnitudes of the joint velocities and accelerations as well as on their initial and final values. A trajectory constructed by this method has the property that a local modification can be made quickly and easily without recomputing the entire trajectory. The method has been used for generating trajectories for a PUMA 560 robot.

Microprocessor-Controlled SIT Inverter for Solar Energy System

Abstract: A microprocessor-controlled static induction transistor (SIT) inverter is proposed to link a solar battery with a utility ac power line. The main control objectives are to optimize the power flow from the solar battery to the utility power line and to compensate the reactive power, including harmonic distortion. The performance is well realized by the experimental setup.

An Automatic Guidance System of a Self-Controlled Vehicle

Abstract: An automatically guided vehicle, traveling without fixed guide ways, has been developed. In this paper, the construction of the vehicle, the control algorithm, and its general performance are described.

Gyrators Application in Power Processing Circuits

Abstract: The gyrator is a lossless two-port network which transforms one-port networks into its dual with respect to its gyration conductance. For example, capacitance at the gyrator output is viewed as inductance at the input and a voltage source is transformed to a current source.

Analog and Digital Speed Control of DC Drives Using Proportional-Integral and Integral-Proportional Control Techniques

Abstract: A comparative study of proportional-integral (P-I) and integral-proportional (I-P) control schemes, for the speed control of a dc drive, using both analog-and microprocessor-based digital circuits, is presented. The often-neglected current response is discussed and results are presented. The speed response to step changes in speed reference and load torque, using both the control schemes, is compared to evaluate the merits of I-P control. A brief discussion of sensitivity to controller gains is also given. It is shown that the I-P control scheme offers some distinctive advantages over P-I control. Experimental and simulation results are also presented.

Influence Matrix Approach to Fault Diagnosis of Parameters in Dynamic Systems

Abstract: A new diagnostic method has been developed, which consists of on-line identification of system models, fault detection, and fault estimation using an influence matrix. A fault in system parameters is detected by the changes in the identified models, and the faulty parameter and its variation are estimated using the influence matrix. This method can detect a step-as well as a gradual-change fault and is applicable where the physical values of parameters are not known accurately. Simulation studies have been carried out on a motor driving system with very good results.

Simplified Electronics for Torque Control of Sensorless Switched-Reluctance Motor

Abstract: Sensorless control of the switched-reluctance (SR) stepping motor using pulsewidth modulation was introduced in an earlier paper by the authors. This scheme senses the dc link current and permits the motor to operate efficiently with a narrow pulsewidth under normal conditions. Changes in load are sensed by the dc link current, and the pulsewidth is adjusted appropriately. This paper describes the electric implementation of the controller.

Transient Tests on a Voltage-Regulated Controlled-Current PWM Converter

Abstract: The controlled-current PWM converter has the capability of delivering near sinusoidal current waveforms with unity and even leading power factors. This paper describes its transient characteristics when operated with a simple proportional feedback control to ensure regulated dc voltage output. Experimental tests show that it has fast step response and that it survives abnormal operational conditions such as brown-outs and loss of a single phase.

Cost-Constrained Power Factor Optimization with Source Harmonics Using LC Compensators

Abstract: A method is presented for finding the optimum LC combination for power factor compensation at linear loads in the presence of voltage source harmonics while the total voltamperes of the compensator capacitor and reactor is constrained. The end product is displayed in graph form where for any given compensator voltampere rating or cost, the maximum possible power factor and corresponding LC combination can be found. Examples are included showing that the cost of such an LC compensator may be less than that of a purely capacitive optimum compensator achieving the same power factor.

An Adaptive Digital Pump Controller for Phase-Locked Servo Systems

Abstract: A novel adaptive digital pump (phase/voltage) controller (ADPC) is presented for use in phase-locked servo systems without utilizing RC loop filters and high line-density encoders. The proposed ADPC is a multirate processor, of which the linear discrete-time model for the digital pump phase-locked servo system (DPPLS) is constructed. Simulation results that verify the theoretical work are also conducted.

A Novel Approach to Automotive Navigation and Map Display

Abstract: A novel approach to automatic navigation and map display is described. In order for a navigation and display system to be both cost effective and useful in automobiles, solutions are needed to problems in navigation, map database, data storage, and display.

A Brushless DC Motor Controlled by a Microprocessor with Examples for a Three-Phase Motor

Abstract: The principle and the characteristics of a brushless dc motor and a driver circuit using bipolar transistors are described briefly. Motor control by microprocessor, including hardware and software commutation, speed measurement, and control via software algorithms, is described in more detail. Different current choppers were investigated: the hysteresis current chopper, the fixed-frequency current chopper, and the software current chopper (Patent EP 0 093 182 A1, US 4 514 667). Application examples and implementation details for the print-band drive of an impact printer are discussed. Finally, microprocessors are ideal devices to detect, to isolate, and to pass on errors for display.

A Linear-State Feedback Plus Adaptive Feed-Forward Control for DC Servomotors

Abstract: This paper proposes a linear-state feedback plus adaptive feed-forward control to control position for DC servomotors. The aim is to control DC servomotors submitted to inertia and Coulomb friction variations. Conditions for stability depending on the frequency richness of the reference input are presented. Experimental results show the improvement with respect to classical tachometric feedback.

Microprocessor-Based High-Efficiency Drive of a DC Motor

Abstract: This paper presents a method to improve the efficiency of dc motors, dc shunt motors, and dc series motors. The method is based upon the field control. It is derived that the ratio of the armature current to the field current should be maintained constant to maximize the efficiency at a specific speed. The power circuits and the control loops are suggested to realize the principle, and the real-time control is implemented with a microprocessor. Also, in order to assess the stability of the overall systems, the proposed systems are analyzed with the small signal linearization. Experimental results show that the remarkable improvement in efficiency has been accomplished by the proposed method and the suggested systems are stable.

Induction Motor Identification by a Microcomputer-Based Structure

Abstract: The paper deals with the parameter estimation of an induction motor performed through a microcomputer-based data acquisition system and recursive identification algorithms (RLS and RGLS) implemented by means of a general purpose computer The microcomputer-based data acquisition system is essentially made by connecting the Z80 CPU with its peripherals and auxiliary memories through a bus standard The motor is represented by a classical fifth-order model linearized around a usual working point; an approximate third-order model, obtained via balanced realization, is in good correlation with the original one according to the identification aims and to the measurement set efficiency An original CAD procedure is utilized to determine the electrical parameters

A Methodology of Specification and Implementation of Distributed Discrete Control Systems

Abstract: The SECOIA (Specification, Emulation and Conception of an Integrated Automation) Project is an attempt to provide an integrated methodology to specify and implement distributed discrete control systems, particularly those intended to the control of Flexible Manufacturing Systems (FMS).

Unpositioned Workpieces Handling Robot with Visual and Force Sensors

Abstract: A robot which can handle unpositioned workpieces using a three-dimensional (3-D) vision sensor and a force sensor has been developed. It can pick up an unpositioned small connector and mount it correctly on a printed circuit board. This paper presents the robot system configuration and its operation

Robust Identification from Impulse and Step Responses

Abstract: A robust identification method that is insensitive to anomalous data is presented to estimate system models from the samples of their impulse and step responses. The power and usefulness of the proposed approach is illustrated with the help of simulated and real-life examples.

Low-Cost Electronic-Controlled Variable-Speed Reluctance Motors

Abstract: This paper describes the design features, drive circuits, and performance of single-phase switched reluctance motors (SRM's) for low-power variable-speed drives. The main advantages of these motors lie in their simple robust construction, simple control circuitry, and low manufacturing cost. Two prototypes have been built and tested, showing satisfactory performance.

Efficiency-Optimized Speed Control System with Feed-Forward Compensation

Abstract: A partial-state and an output feedback control system synthesis method with feed-forward compensation, which doesn't make use of the state observer procedure, are proposed. These are applied to an efficiency-optimized speed control system of a dc motor system. This leads to a decrease in the number of current detectors of the motor system and the channel of the A/D converter. Although they are useful in practice, these control systems are, to some extent, susceptible to noise due to the inclusion of high-order difference actions in the controller. It is inevitable that the transient response becomes slow if the weighting factors in the performance index are chosen so that the influence of noise is decreased. The feed-forward compensation is useful for improvement on the transient response of the control system. But, the feed-forward compensation method for the partial-state or the output feedback control system has not been proposed until now. In this paper, the feed-forward compensation method, which can be applied to all the control systems, is proposed and the effectiveness is examined experimentally. Also, the influence of noise for each control system and the improvement of the efficiency are investigated experimentally.

Constant Power Acceleration Profiles for Electric Vehicles

Abstract: Constant power acceleration has been shown to extend the range of electric vehicles However, this type of acceleration generally requires accelerations above a vehicles maximum attainable acceleration when the vehicle is at low velocities A practical approach is to accelerate at the maximum until a velocity is reached such that constant power acceleration from that point onward does not require accelerations larger than the maximum available To implement this approach it is necessary to know the time at which to begin constant power acceleration and the constant power to use This paper formulates and solves this problem

Practical Model Reduction Methods

Abstract: Model reduction is important in control and instrumentation. Numerous papers on model reduction have been published. In this paper model reduction methods are classified into three categories according to their underlying principles. The three categories are continued fraction expansion, dominant mode, and optimum fitting. Given numerical examples, the effectiveness and the merit of simplified models are evaluated on the basis of the simulation of the step response and the least sum of squares of the sample errors.

Closed-Loop Control of a Manipulator Arm Using a Wrist Force Sensor

Abstract: Robot force sensing and force control have been researched for several years, producing a variety of sensing methods and control strategies Most of the published work has been theoretical in nature, with little emphasis on the practical problems encountered in the implementation of a system This paper describes the interfacing of a 6-axis wrist force sensor to a manipulator and the design and implementation of a control system incorporating the sensor as a feedback device (in addition to existing position control)

A High-Frequency Resonant Inverter Using Current-Vector Control Scheme and Its Performance Evaluations

Abstract: The authors introduce a new configuration of resonant-type high-frequency inverter having inherent fast control response of the output power and variable-voltage variable-frequency (VVVF) capability. The circuit is composed of a parallel combination of two series-resonant inverters with common input and output terminals. Both inverter units are operated at synchronous frequency and with an adjustable phase difference from 0° to 180°, allowing control of the output power from full to null power, respectively. Operation of this inverter is explained and computer-simulated operating waveforms and characteristic curves are shown in terms of normalized control variables and circuit parameters. A prototype inverter using Power MOSFET modules has been originally tested with a high-frequency induction heating and melting load to demonstrate experimentally the proposed control principle and the steady-state inverter performances under parallel tuned load conditions.

On the Application of Modern Control Theory to Automotive Engine Control

Abstract: This study deals with how modern control theory can be applied to automotive engine control. Appropriate models are indispensable in the application of modern control theory, the present study achieves engine modeling using physical and statistical approaches. Also, for a concrete application of modern control theory, the present focus is on a torque servo engine, because torque is the output most necessary for an engine. Modern control techniques are used to control a torque servo engine to obtain the most fuel-saving operation possible. It is found that a high potential could be achieved compared with conventional control methods.