• Title/Summary/Keyword: servo compensator

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Motion Control of a Single Rod Cylinder-Load System Driven by a Proportional Directional Control Valve (비례방향제어밸브에 의해 구동되는 차동 실린더 부하계의 운동제어)

  • Lee, M.W.;Cho, S.H.
    • 유공압시스템학회:학술대회논문집
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    • 2010.06a
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    • pp.81-85
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    • 2010
  • This paper deals with the issue of motion control of a single rod cylinder-load system using simple adaptive control (SAC) method. Prior to controller design, the experiment of open-loop response has been performed. Based on it, design parameters of transfer function are obtained. The effect of parallel feedforward compensator has been investigated by computer simulation, suppressing the oscillatory motion. Through experiments it is conformed that the SAC method gives good tracking performance compared to the PD control method.

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Development of Steering Control System for Autonomous Vehicle Using Geometry-Based Path Tracking Algorithm

  • Park, Myungwook;Lee, Sangwoo;Han, Wooyong
    • ETRI Journal
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    • v.37 no.3
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    • pp.617-625
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    • 2015
  • In this paper, a steering control system for the path tracking of autonomous vehicles is described. The steering control system consists of a path tracker and primitive driver. The path tracker generates the desired steering angle by using the look-ahead distance, vehicle heading, and a lateral offset. A method for applying an autonomous vehicle to path tracking is an advanced pure pursuit method that can reduce cutting corners, which is a weakness of the pure pursuit method. The steering controller controls the steering actuator to follow the desired steering angle. A servo motor is installed to control the steering handle, and it can transmit the steering force using a belt and pulley. We designed a steering controller that is applied to a proportional integral differential controller. However, because of a dead band, the path tracking performance and stability of autonomous vehicles are reduced. To overcome the dead band, a dead band compensator was developed. As a result of the compensator, the path tracking performance and stability are improved.

Motion Control of a Pneumatic Servo XY-Plotter using Neural Network (신경회로망을 이용한 공압서보 XY-플로터의 운동제어)

  • Hwang, Un-Kyoo;Cho, Seung-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.5
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    • pp.603-609
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    • 2004
  • This paper deals with the issue of Neural Network-based control for a rodless pneumatic cylinder system which is utilized for a pneumatic XY-plotter. In order to identify the system design parameters, the open loop response of a pneumatic rodless cylinder controlled by a pneumatic servovalve is investigated by applying a self-excited oscillation method. Based on the system design parameters, the PD feedback compensator is designed and then Neural Network is incorporated with it. The experiment of a trajectory tracking control using a PD-NN has been performed and proved its excellent performance by comparing with that of a PD feedback compensator.

Dynamical anti-reset windup method for saturating control systems with multiple controllers and multiloop configuration and its application to motor control systems (다중 제어기 및 다중 루우프로 구성된 포화제어시스템의 동적 리셋 와인드엎 방지 방법과 모터제어에의 응용)

  • Park, Jong-Gu;Park, Chong-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.2
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    • pp.141-150
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    • 1998
  • This paper presents a dynamical anti-reset windup (ARW) compensation method for saturating control systems with multiple controllers and/or multiloop configuration. By regarding the difference of controller states in the absence and presence of saturating actuators as an objective function, the dynamical compensator which minimizes the objective function is derived in an integrated fashion. The proposed dynamical compensator is a closed form of plant and controller parameters. The resulting dynamics of compensated controller reflects the linear closed-loop system. The proposed method guarantees total stability of the resulting system. The effectiveness of the proposed method is illustrated by applying it to a servo motor control system. The paper is an extension of the results in Park and Choi[1].

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A Design of Adaptive Controller with Nonlinear Dynamic Friction Compensator for Precise Position Control of Linear Motor System (선형모터 정밀 위치제어를 위한 비선형 동적 마찰력 보상기를 갖는 적응 제어기 설계)

  • Lee, Jin-Woo;Cho, Hyun-Cheol;Lee, Young-Jin;Lee, Kwom-Soon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.5
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    • pp.944-957
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    • 2007
  • In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it and other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstopping control method.

Position Controller of Rail Guided Unmanned Monitoring System with the Driving Slip Compensator (주행 슬립 오차 보상기를 가지는 레일 가이드 무인 설비 감시 장치의 위치 제어기)

  • Bae, Jongnam;Kwak, Yunchang;Lee, Dong-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.5
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    • pp.792-799
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    • 2017
  • The real time unmanned monitoring system of an equipment's internal parts and condition requires the monitoring device to be able to stop at a set location on the rail. However, due to the slip between the driving surface and the roller, an error occurs between the actual position and the command position. In this paper, a method to compensate the position error due to the roller slip is proposed. A proximity sensor located at both ends of the rail detects the starting point and the maximum position pulse, linearly compensating the error between the angular position of the motor and the mechanically fixed starting and maximum position pulse of the rail in forward and reverse direction. Moreover, unlike the existing servo position controller, the motor adopts the position detection method of Hall sensor in BLDC (Brushless DC) and applies an algorithm for low-speed driving so that a stable position control is possible. The proposed rail guided unmanned monitoring system with driving slip compensator was tested to verify the effectiveness.

Pre-Sliding Friction Control Using the Sliding Mode Controller with Hysteresis Friction Compensator

  • Choi, Jeong Ju;Kim, Jong Shik;Han, Seong Ik
    • Journal of Mechanical Science and Technology
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    • v.18 no.10
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    • pp.1755-1762
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    • 2004
  • Friction phenomenon can be described as two parts, which are the pre-sliding and sliding regions. In the motion of the sliding region, the friction force depends on the velocity of the system and consists of the Coulomb, stick-slip, Streibeck effect and viscous frictions. The friction force in the pre-sliding region, which occurs before the breakaway, depends on the position of the system. In the case of the motion of the friction in the sliding region, the LuGre model describes well the friction phenomenon and is used widely to identify the friction model, but the motion of the friction in the pre-sliding such as hysteresis phenomenon cannot be expressed well. In this paper, a modified friction model for the motion of the friction in the pre-sliding region is suggested which can consider the hysteresis phenomenon as the Preisach model. In order to show the effectiveness of the proposed friction model, the sliding mode controller (SMC) with hysteresis friction compensator is synthesized for a ball-screw servo system.

Comparison of CDBC controller of DC Servo Motor (DC 서보모터의 CDBC 제어기 비교)

  • 김진용;유항열;김성열;이정국;이금원
    • Proceedings of the IEEK Conference
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    • 2003.07c
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    • pp.2593-2596
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    • 2003
  • The deadbeat properties have been well known in designing digital control systems. But recently several researchers proposed a CDBC(Continuout-time DeadBeat Controller) in continuous time. They used delay or smoothing elements from the finite Laplace Transform. A delay element is made by the exponential terms. A smoothing element is used to smooth the digital control input. And eventually the process is argumentd with smoothing elements and then well-known digital deadbeat controller is designed Sometimes samplings are done in continuous time systems and some hold devices are used to relate to digital systems. So multirate sampling may enhance the efficiency of the CDBC. A DC servo motor is chosen for implementing CDBC algorithm. Especially Outputs according to the variable input and disturbance are simulated. by use of Matlab Simulink.

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A design on robust multivariable model following servo system (강인한 다변수 모델 추종형 서보시스템의 구성에 관한 연구)

  • Hwang, C.S.;Choi, Y.K.;Lee, Y.W.;Choi, I.S.
    • Proceedings of the KIEE Conference
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    • 1991.11a
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    • pp.370-373
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    • 1991
  • This paper considers the linear multivariable model following servo system synthesis method in which linear optimal regulator problem is used to design controllers that make the response of the plant should be kept close to a specified ideal response of the model. The characteristics of this system is that the constructed system is robust in the presence of the constant disturbances or the parameter perturbations of the plant. Especially, the steady state offset is excluded for the ramp response of the model by direct feedforward compensator from the reference input.

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A Study on the Speed Control of Electro - hydraulic Servo System under Load Disturbance (부하외란이 가해지는 전기.유압서보계의 속도 제어에 관한 연구)

  • 하석홍;권기수;이진걸
    • Journal of Advanced Marine Engineering and Technology
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    • v.17 no.1
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    • pp.26-32
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    • 1993
  • The loads exerted on electro-hydraulic servo system are classified into inertial, viscous, and spring load. The additional load called disturbances is also exerted on system but is generally not modeled. To deal with these kinds of loads, it is necessary to maintain the continuous signal transfer, so we can construct compensator to satisfy control specifications using feedback signal such as displacement, velocity, acceleration and pressure known as state variables. In case of controlling the speed of hydraulic motor, we must keep up robust performance for the various loads and disturbances acted on the system. However, the load flow rate in the valve is characterized by nonlinearity so that traditional theory of linear control could not be expected to give the desired performance. In this paper, it is shown that speed controller of hydraulic motor gives a good command following and disturbance rejection performance by applying sliding mode theory as a way of robust control to the nonlinearity, variation of loads and disturbances.

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