• Title/Summary/Keyword: Cross-coupling control

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Cross-Coupling Controller for High-Speed Nonlinear Contour Machining (고속의 비선형 윤곽가공을 위한 교차축 연동제어기)

  • Jee, Sung-Chul;Lee, Yong-Seok
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.446-451
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    • 2000
  • In this paper, a new adaptive cross-coupling control (CCC) algorithm with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy more effectively than the existing method.

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Adaptive Cross-Coupling Control for High-Speed Nonlinear Contour Machining (고속의 비선형 윤곽가공을 위한 적응 교차축 연동제어)

  • Lee, Yong-Seok;Jee, Sung-Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.11
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    • pp.108-114
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    • 2000
  • In this paper, a new adaptive cross-coupling control(CCC) method with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy more effectively than the existing method.

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Roll-Pitch-Yaw Integrated H Controller Synthesis for High Angle-of-Attack Missiles

  • Choi, Byung-Hun;Kang, Seon-Hyeok;Kim, H. Jin;Won, Dae-Yeon;Kim, Youn-Hwan;Jun, Byung-Eul;Lee, Jin-Ik
    • International Journal of Aeronautical and Space Sciences
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    • v.9 no.1
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    • pp.66-75
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    • 2008
  • In this work, we explore the feasibility of roll-pitch-yaw integrated autopilots for high angle-of-attack missiles. An investigation of the aerodynamic characteristics of a surface-to-air missile is presented, which reveals the strong effects of cross coupling between the longitudinal and lateral dynamics. Robust control techniques based on $H_{\infty}$ synthesis are employed to design roll-pitch-yaw integrated autopilots. The performance of the proposed roll-pitch-yaw integrated controller is tested in high-fidelity nonlinear five-degree-of-freedom simulations accounting for kinematic cross-coupling effects between the lateral and longitudinal channels. Against nonlinearity and cross-coupling effects of the missile dynamics, the integrated controller demonstrates superior performance when compared with the controller designed in a decoupled manner.

Position Control of Linear Motor by Using Enhanced Cross-Coupling Algorithm (개선된 교차축 연동제어기를 이용한 리니어 모터의 위치제어)

  • Han, Sang-Oh;Huh, Kun-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.3
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    • pp.369-374
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    • 2010
  • Linear motors are easily affected by load disturbances, force ripples, friction, and parameter variations because there are no mechanical transmissions that can reduce the effects of model uncertainties and external disturbance. In this study, a nonlinear adaptive controller to achieve high-speed/high-accuracy position control of a two-axis linear motor is designed. The operation of this controller is based on a cross-coupling algorithm. Nonlinear effects such as friction and force ripples are estimated and compensated for. An enhanced cross-coupling algorithm is proposed for effectively improving the biaxial contour accuracy while achieving closed-loop stability. The proposed controller is evaluated by performing computer simulations.

Fully Adaptive Feedforward Feedback Synchronized Tracking Control for Stewart Platform Systems

  • Zhao, Dongya;Li, Shaoyuan;Gao, Feng
    • International Journal of Control, Automation, and Systems
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    • v.6 no.5
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    • pp.689-701
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    • 2008
  • In this paper, a fully adaptive feedforward feedback synchronized tracking control approach is developed for precision tracking control of 6 degree of freedom (6DOF) Stewart Platform. The proposed controller is designed in decentralized form for implementation simplicity. Interconnections among different subsystems and gravity effect are eliminated by the feedforward control action. Feedback control action guarantees the stability of the system. The gains of the proposed controller can be updated on line without requiring any prior knowledge of Stewart Platform manipulator. Thus the control approach is claimed to be fully adaptive. By employing cross-coupling error technology, the proposed approach can guarantee both of position error and synchronization error converge to zero asymptotically. Because the actuators work in synchronous manner, the tracking performances are improved. The corresponding stability analysis is also presented in this paper. Finally, simulation is demonstrated to verify the effectiveness of the proposed approach.

A Study on Synchronization Control Technique of Dual-Servo Press System (듀얼 서보모터 구동형 프레스 시스템의 동기화 제어기법 연구)

  • Na, Sang-Gun;Kwon, O-Shin;Kang, Jae-Hoon;Heo, Hoon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.2
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    • pp.206-215
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    • 2013
  • In this paper, a synchronization control technique of dual-servo motor driven press system is proposed. An independent cascade PID control technique has been applied to the conventional press system for advancement of control stability. However, it is not easy to reduce synchronous error using the independent cascade PID control technique when some different load disturbances are involved in each motor. The eccentric error of the slide caused by the problem degrade the control performance of the BDC(Bottom Dead Center). In order to achieve reduction of the synchronous error between two servo motors and accurate position control simultaneously, a new control scheme comprised with cascade PID control loop and cross-coupling loop is proposed. In simulation using Matlab SIMULINK, the AC servo system is designed. The control performance of proposed technique is compared with conventional control technique to the model of AC servo system. Also, the sub-scale model of dual-servo motor driven press system which can replicate the slide motion is constructed for experimental verification for the performance of the proposed control technique. The cross-coupling control technique reveals more precise and stable performances in the position and synchronization controls.

Improving the Performance of Hot Rolling Process through Cross Control (Cross Control 기법을 통한 열연 공정의 성능 개선)

  • Jung, Jae-Kyung;Park, Ju-Hyun;Shim, Woo-Chul;Kwon, Oh-Min;Won, Sang-Chul
    • Proceedings of the KIEE Conference
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    • 1999.11c
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    • pp.561-563
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    • 1999
  • The looper of a hot strip finishing mill is installed between each pair of stands and plays a key role to enhance the product quality of strip by controlling the tension and height of strip in each inter-stand. Though the conventional looper control has achieved the mass products of strip so far, it has difficulties not only tuning gains by means of errors which are caused by coupling effects between strip tension and looper angle both utilizing tension feedback. Therefore, the non-interactive control employing cross controller and tension feedback has been introduced in looper control system in order to overcome the coupling effects existing between tension and looper angle and track the reference tension efficiently. In this paper, we present the cross controllers which play a role to decouple reciprocal effects between tension and looper angle and show better performance.

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Multiple Decoupling Current Control Strategies for LCL Type Grid-Connected Converters Based on Complex Vectors under Low Switching Frequencies

  • Liu, Haiyuan;Shi, Yang;Guo, Yinan;Wang, Yingjie;Wang, Wenchao
    • Journal of Power Electronics
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    • v.19 no.4
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    • pp.1034-1044
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    • 2019
  • In medium-voltage and high-voltage high-power converters, the switching devices need to operate at a low switching frequency to reduce power loss and increase the power capacity. This increases the delay of the signal sampling and PWM. It also makes the cross-couplings of the d-q current components more severe. In addition, the LCL filter has three cross-coupling loops and is prone to resonance. In order to solve these problems, this paper establishes a complex vector model of an LCL type grid-connected converter. Based on this model, two multiple decoupling current control strategies with passive damping / notch damping are proposed for the LCL type grid-connected converter. The proposed strategies can effectively eliminate the cross-couplings of the converter, achieve independent control of the d-q current components, expand the stable region and suppress the resonance of the LCL filter. Simulation and experimental results verify the correctness of the theoretical analysis and the feasibility of the proposed strategies.