DC Servo Motor Control Research Articles

The Steady State Precision Control of DC Servo Motor Based on State Space Adaptive Pole Assignment

In this paper, the steady state precision control based on state space adaptive pole assignment is proposed in order to improve the steady state control precision of DC servo motor. The basic idea is to adaptively adjust the feedback gain matrix, and realize online, estimates of the feedback matrix and steady-state error compensation. Thus the adaptive state space pole assignment algorithm is obtained to overcome the friction effects on motor performance. Matlab simulation results show that this control algorithm can realize the online estimation and compensation for steady state precision of DC servo motor, and it is able to quickly and accurately follow the speed of the motor. The system has better dynamic and steady-state performance, and its characteristic of the closed-loop system robustness is stronger.

Design of a Fuzzy Logic Sliding mode Model Following Controller for a Brushless DC Servomotor Drivers

Problem statement: A brushless DC servomotor position control system using a fuzzy logic sliding mode model following controller or FLSMFC is presented. Approach: The FLSMFC structure consists of an integrator and variable structure system. Results: The integrator ensures the elimination of steady state error due to step and ramp command inputs, while the fuzzy control would maintain the insensitivity to parameter variation and disturbances. The FLSMFC strategy is implemented and applied to a position control of a brushless DC servomotor. Conclusion/Recommendations: Experimental results indicated that FLSMFC system performance with respect to the sensitivity to parameter variations is greatly reduced. Also, its can achieve a rather accurate servo tracking and avoids the chattering phenomenon.

Identification and control using MLP, Elman, NARXSP and radial basis function networks: a comparative analysis

This paper describes four neural networks multilayer perceptron (MLP) network, Elman network, NARXSP network and radial basis function (RBF) network. Neural networks are applied for identification and control of DC servo motor and benchmark nonlinear system. Number of epochs required and time taken to train the controller are shown in the form of bar plots for four neural networks. Levenberg-Marquardt algorithm is used for training the controller using neural network toolbox in MATLAB. Each neural network controller is run ten times. Their performances are compared for each run in terms of number of epochs required and time taken to train each controller for tracking a reference trajectory.

Genetic Algorithms: Concepts, Design for Optimization of Process Controllers

Genetic Algorithm is a search heuristic that mimics the process of evaluation. Genetic Algorithms can be applied to process controllers for their optimization using natural operators. This paper discusses the concept and design procedure of Genetic Algorithm as an optimization tool. Further, this paper explores the well established methodologies of the literature to realize the workability and applicability of genetic algorithms for process control applications. Genetic Algorithms are applied to direct torque control of induction motor drive, speed control of gas turbine, speed control of DC servo motor for the optimization of control parameters in this work. The simulations were carried out in simulink package of MATLAB. The simulation results show better optimization of hybrid genetic algorithm controllers than fuzzy standalone and conventional controllers.

PID제어기와 신경회로망 제어기를 이용한 유도전동기의 속도제어에 관한 연구

산업 자동화의 고정밀도에 따라 직류서보 전동기는 강인제어가 요구되고 있다. 하지만 PID 제어기를 갖는 전동기 제어 시스템이 부하 외란의 영향을 받게되면 제어 시스템의 강인제어는 어렵게 된다. 이에 대한 보완적인 한 방법으로 본 논문에서는 전동기 제어시스템을 위한 PID-신경망 복합형 제어기법을 제시하였다. 신경망 제어기의 출력은 부하 외란 인가시에 발생되는 오차와 오차 변화율에 의해서 결정된다. 신경망 제어기를 이용한 직류서보 전동기의 강인제어는 시뮬레이션에 의하여 확인하였다. Robust control for DC servo motor is needed according to the highest precision of industrial automation. However, when a motor control system with PID controller has an effect of load disturbance, it is very difficult to guarantee the robustness of control system. As a compensation method solving this problem, in this paper, PID-neural network hybrid control method for motor control system is presented. The output of neural network controller is determined by error and rate of error change occurring in load disturbance. The robust control of DC servo motor using neural network controller is demonstrated by computer simulation.

HMM을 기반으로 한 자율이동로봇의 음성명령 인식시스템의 개발

Generally, a mobile robot is moved by original input programs. However, it is very hard for a non-expert to change the program generating the moving path of a mobile robot, because he doesn't know almost the teaching command and operating method for driving the robot. Therefore, the teaching method with speech command for a handicapped person without hands or a non-expert without an expert knowledge to generate the path is required gradually. In this study, for easily teaching the moving path of the autonomous mobile robot, the autonomous mobile robot with the function of speech recognition is developed. The use of human voice as the teaching method provides more convenient user-interface for mobile robot. To implement the teaching function, the designed robot system is composed of three separated control modules, which are speech preprocessing module, DC servo motor control module, and main control module. In this study, we design and implement a speaker dependent isolated word recognition system for creating moving path of an autonomous mobile robot in the unknown environment. The system uses word-level Hidden Markov Models(HMM) for designated command vocabularies to control a mobile robot, and it has postprocessing by neural network according to the condition based on confidence score. As the spectral analysis method, we use a filter-bank analysis model to extract of features of the voice. The proposed word recognition system is tested using 33 Korean words for control of the mobile robot navigation, and we also evaluate the performance of navigation of a mobile robot using only voice command.

Theory and application of a combined self-tuning adaptive control and cross-coupling control in a retrofit milling machine

In this paper, the control plant is a ball screw actuated milling machine table which has been retrofit with DC servo motor control. The retrofit milling machine has nonlinear time-varying behaviors because of the effect of irregular Coulomb friction of the sliding surface and obvious backlash. Thus, it is difficult for a conventional digital controller to provide a high contouring accuracy as well as adequate disturbance rejection and parameter variation robustness. To improve contouring performance of the retrofitted milling machine, a self-tuning adaptive control strategy, combined with cross-coupled control of axial motion is proposed. The proposed control scheme has been verified as being internally stable. Experimental results show that this control method achieves satisfactory contouring accuracy, transient response, tracking and robustness under the influence of backlash on each axis and irregular Coulomb friction. This performance verifies the applicability of this economic approach to automation of traditional milling machines.

Implementation of a New Adaptive Slicing Algorithm for the Rapid Prototyping Manufacturing System

Rapid prototyping is an automated manufacturing process that quickly builds physical models from three-dimensional (3-D) prototype computer-aided design files. It dramatically speeds up design and manufacturing processes and substantially reduces the cost. This paper presents a new adaptive slicing algorithm for rapid prototyping (RP) processes. The proposed adaptive slicing approach determines the layer thickness based on comparing the contour circumference or the center of gravity of the contour with those of the adjacent layer. Most commercial rapid prototyping systems use uniform slicing procedures with a fixed layer thickness to build parts. To implement the adaptive slicing algorithm, we developed a thermal extrusion based RP mechatronics system equipped with a linear planar servo motor. The RP material is wax. The XYZ table is controlled using a PC based multi-axis DSP motion controller. The RP material flow rate for the thermal extrusion head is controlled using a dc servo motor and motion controller. The Taguchi method was used to analyze the process parameters for the proposed RP system to improve the quality of the RP part. Based on the experimental results, the proposed RP mechatronics system can produce good quality RP parts with the adaptive slicing algorithm. The proposed RP system also implements the high-precision exterior, high-speed interior slicing strategy for STL models.

Magnetic pole position detection method and control of a brushless DC servomotor with incremental encoder

AbstractOn start‐up of a brushless DC servomotor, it is necessary to detect its magnetic pole position in order to generate the torque effectively. Numerous brushless DC servomotors contain a high angle resolution encoder for the speed control and position control. It can also be used in magnetic pole position detection. There are absolute encoders and incremental encoders. If a brushless DC servomotor contains the absolute encoder, the motor can be started since its absolute position can be detected using magnetic pole position detection. However, the absolute encoder is not used except where high accuracy is required because it is expensive. The incremental encoder generally cannot detect the magnetic pole position during motor start‐up, which is why an exclusive magnetic pole position sensor is required until a standard signal output of the encoder is established.This paper describes a method of magnetic pole position detection of a brushless DC servomotor with an incremental encoder used without an exclusive magnetic pole position sensor. The feature of this method is that it allows detection of the magnetic pole position with very few revolutions in a matter of seconds during motor start‐up. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(4): 64–77, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10219

Magnetic Pole Position Detection Method and Control of Brushless DC Servomotor with Incremental Encoder

On startup of a brushless DC servomotor, it is necessary to detect of its magnetic pole position, to generate the torque effectively. Numerous brushless DC servomotors provide a high angle resolution encoder for the speed control and position control. It can use as a magnetic pole position detection, too. There are the absolute encoder and the incremental encoder. If a brushless DC servomotor provides an absolute encoder, the motor can startup, because it is necessary to detect of its absolute position for the magnetic pole position detection. However, it is not used except uses of demands for high accuracy because the encoder is expensive. The incremental encoder in general use cannot detect the magnetic pole position when the motor starts, and so it demands an exclusive magnetic pole position sensor till a standard signal output of the encoder.This paper describes a method of the magnetic pole position detection of a brushless DC servomotor with an incremental encoder only use the encoder without an exclusive magnetic pole position sensor. The feature of this method is that can detect the magnetic pole position with very little revolutions in a matter of minutes during the motor starts.

Optimum Value in the Design of DC Servomotor Control to Stepper Motor

This paper presents an optimal value for designing dc Servomotor control to stepper motor using genetic algorithm (GA) for set spreader work speed. The obtained dc Servomotor control is stable, not overdamp and have a fast position response. GA helps to solve the design optimization problem of dc Servomotor control, where the structure of dc Servomotor control in s-domain appears to be nonlinear with s-value stability stress By controlling the transfer function H(s) into an evaluation function and the stress a ≤ s ≤ b in solution space, the optimum values of the design were obtained. The simulation result of the genetic program shows that the obtained transfer function of the designed dc Servomotor control is stable, not overdamped and fast in position response.

The adaptive control for a retrofit traditional milling machine

One-step-ahead adaptive control with an input nonlinearity strategy is proposed to control the converted system of a traditional milling machine table with a lead screw transmission system. The control plant is a traditional lead screw actuated milling machine table which has been retrofitted with DC servomotor control. This old-fashioned machining table has nonlinear time-varying behavior due to the effects of irregular Coulomb friction of sliding surface and obvious backlash. Experimental results show that the control method has reasonable performance in terms of stability, transient response, tracking, and robustness under the influence of time delay of the simple motor driver and 1 mm backlash of each axis. This controller can overcome the nonlinear effect due to Coulomb friction and construct a stable closed-loop system. >

Direct current servo motor controlled four‐jaw slits for synchrotron radiation

A four‐jaw slit assembly and eight‐axis dc servo motor controller have been constructed and are in use at the Australian National Beamline Facility (ANBF) at the Photon Factory. Because of the vacuum operation of the beamline diffractometer, dc servo motors were preferred to stepper motors. Due to the large number of motors to be controlled, commercial dc servo controllers were unsuitable, and an eight‐axis controller was designed to be used in conjunction with the E500 CAMAC stepper motor controller. The system has been in use at the ANBF for about one year, and has allowed the integration of approximately 30 dc servo and stepper motors into a standard control system.

Fuzzy hybrid control for DC servomotor.

In recent years, fuzzy control has found significant applications in many engineering fields. However, the design method of fuzzy control systems has not been established yet, and it is difficult to realize a precise control because control signals are derived from fuzzy scheme of inferences. On the other hand, it is well known that a conventional PD linear control can offer a precise control.In this paper, a new hybrid control scheme is proposed, which is attempt to combine the advantages of PD control and a fuzzy control. In the points which are close to the reference point, a PD control is mainly used to obtain the precision, and in other points a fuzzy contol is mainly used to improve the transient response and to cope with the nonlinearity of systems. From the experimental results on position control of DC servomotor, it is confirmed that the proposed hybrid controller performes better than either PD or fuzzy control.

Fuzzy hybrid control of DC servomotor

Fuzzy hybrid control of DC servomotor

Computer-aided design of inverse filter algorithms for ultrasonic systems

In this paper, we propose a pre- and post-filtering approach to output feedback variable structure control of a permanent magnet DC servo motor under constant inertial load. The proposed control method is to regulate the motor speed by using the armature current measurement alone. Both the Hammerstein nonlinearity for the system input end and the Wiener nonlinearity for the output end are considered. With these static nonlinear functions carefully identified and their inverses fitted, the linearized model renders a simple dynamic mapping from the armature current to the sliding variable, which is designed as a dynamic function of the motor angular velocity. The pre-filter is the inverse of the Hammerstein function. The post-filter consists of two blocks in series: the inverse of the Wiener function and the concatenating dynamic filter, which is a linear relationship between the armature current and the sliding variable. The proposed method is robust against parameter variations in the electric subsystem such as the armature inductance and resistance.

受動的適応制御を用いたDCサーボモータの二自由度制御

受動的適応制御を用いたDCサーボモータの二自由度制御