• Title/Summary/Keyword: stabilized gimbal

Search Result 14, Processing Time 0.029 seconds

A Simultaneous Experimental Disturbances Identification of Gyro Stabilized 2-Axes Gimbal System for Disturbance Feedforward Compensation Control (2-축 자이로 안정화 김발 시스템의 외란보상 앞먹임 제어를 위한 실험적 2-축 외란 동시 식별)

  • Yeo, Sung Min;Kang, Min Sig
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.21 no.4
    • /
    • pp.508-519
    • /
    • 2018
  • This paper concerns on stabilization control of a gyro-stabilized 2-axes gimbal system which is mounted on a moving vehicles such as automobiles, armored vehicles, ships, flying vehicles, etc. A target image acquisition system is attached on the inner gimbal, and the gimbal systems are required to retain high stabilization accuracy in the absolute coordinate in order to provide fine target image while vehicle is moving. The stabilization control performance is hardly depended upon disturbance rejection ability of control, and disturbance feedforward compensation is effective because feedforward compensation reduce the amount of disturbance before the disturbance disturbs the systems. This paper suggests an experimental method which can estimate system parameters and disturbance torques by using 3-axes accelerometer mounted on the inner gimbal. Furthermore, a simple disturbance identification method which can be applied to any slanted base conditions has been suggested to identify mass unbalance vector and friction torques of each gimbal simultaneously. By using the estimated parameters, a feedforward compensation has been applied to the gyro-stabilized 2-axes gimbal system. The experimental results showed that the feedforward compensation based on the identification method suggested is effective to improve stabilization performances.

Control System Design for a UAV-Mounted Camera Gimbal Subject to Coulomb Friction (쿨롱마찰을 고려한 무인항공기용 영상 김발의 제어시스템 설계)

  • Hwang, Sung-Pil;Park, Jea-Ho;Hong, Sung-Kyung
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.18 no.7
    • /
    • pp.680-687
    • /
    • 2012
  • One of the frequent problems in the stabilized gimbal system is the rejection of disturbances associated with moving components. Very often such disturbances have non-linear characteristics. In a typical gimbal system, each gimbal and platform are connected by a mutual bearing which induces inevitable friction. Particularly, the non-linear Coulomb friction causes position errors as well as slow responses that lead to unfavorable performance. In this paper, a modified PID controller that is augmented by Coulomb friction estimator is presented. Through constantly estimating the Coulomb friction torque, it is applied to the output of the existing PID controller. The effectiveness of the proposed controller is evaluated through a series of experiments.

The Control for the 2-Axis Stabilized Gimbal using the PI-LEAD Algorithm (PI-LEAD 알고리즘을 이용한 2축 안정화 짐벌 시스템 제어)

  • Lee, Jin-Bok;Choi, Han-Go
    • Journal of the Institute of Convergence Signal Processing
    • /
    • v.14 no.2
    • /
    • pp.117-123
    • /
    • 2013
  • Since the nonlinear factors such as friction in a mechanical servo system can't be easily measured nor estimated accurately. Therefore, it is difficult to compensate friction correctly. Friction makes a significant error in a 2-axis stabilized gimbal system and finally fails to reach the ultimate control performance goals. To solve these problems, lots of studies on the control methods applying observer have been performed. However, these methods can be used in specific conditions and are limited to apply them to the accurate 2-axis stabilized gimbal system in military sector. This paper deals with the PI-LEAD algorithm which is modified with a general and robust PID algorithm, proves the effect of the algorithm through modeling and simulation, and verifies the performance by applying the algorithm to the real 2-axis stabilized system. It is verified through the performance test that the PI-LEAD algorithm minimizes the error caused by friction and meets requirements of the accurate servo system.

The Design of a Direct Driving Gimbal System Using the DSP(TMS320F240) Controller and the Gyroscope (DSP제어기, 자이로센서를 이용한 GIMBAL시스템 설계)

  • 류정오;최중경;최승진;안기호;박성수
    • Proceedings of the IEEK Conference
    • /
    • 2001.06e
    • /
    • pp.139-142
    • /
    • 2001
  • This paper presents a design of two gimbal system. One is two axes stabilized platform that is targeted to preserve direction while vehicle that is adhered antiaircraft fire, radar or EOTS is moving. The system maintains stabilization by recovering error using the rate gyro. The other is three axes gimbal system that is intended to simulate various angle movement in space and to test three axes gyroscope. This system determines gyro condition comparing gyro output value with converted motor encoder value.

  • PDF

Delay Dependent Fuzzy H Control of Radar Gimbal Stabilization System with Parameter Uncertainty and Time Delay (파라미터 불확실성 및 시간지연을 갖는 레이더 김벌 안정화 시스템의 지연종속 퍼지 H 제에)

  • Kim, Tae-Sik;Lee, Hae-Chang;Lee, Kap-Rai
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.11 no.11
    • /
    • pp.920-929
    • /
    • 2005
  • This paper presents controller design method for nonlinear radar gimbal system with parameter uncertainty and time delay. In order to consider nonlinearity of gimbal bearing frictional torque, we firstly represent fuzzy model for the nonlinear gimbal system, which is achieved by fuzzy combination of linear models through nonlinear fuzzy membership functions. And secondly we propose a delay dependent fuzzy $H_\infty$ controller design method for the delayed fuzzy model with parameter uncertainty and design radar gimbal controller. The designed controller stabilize gimbal system and guarantee $H_\infty$ performance. A computer simulation is given to illustrate stabilized control performances of the designed controller.

A Study of Motion for Four-Axis Stabilized Platform Including Effects of Gimbal Bearing Friction (김벌 베어링 마찰의 영향을 고려한 4축 안정화 플랫폼의 운동에 관한 연구)

  • Shin, Y.J.;Cho, K.R.;Lee, J.K.;Cho, S.;Choi, S.
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.12 no.6
    • /
    • pp.52-63
    • /
    • 1995
  • This paper presents a detailed derivation of the equations of motion for the stable member of a four-axis platform. Gimbal bearing friction is considered for motion analysis. First, dynamic characteristics of platform, gimbal and gyro with Coulomb friction are studied due to vehicle's angular motion. Second, Vehicle's motion is assumed the sinusoidal function and dynamic characteristics of platform, gimbal and gyro are studied. Conclusively, considering effects of Coulomb friction, they could not follow the vehicle's angular motion and have constant errors. In case of sinusoidal motion, relative angles for each gimbal are amplified, but they are sinusoidal function with almost the same phases.

  • PDF

Maneuverability Improvement of EOTS by Driving the Outer Gimbal First (외부짐발 선구동에 의한 EOTS의 기동성 개선)

  • Yim, Jong-Bin;Kim, Sung-Su;Lyou, Joon
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.19 no.10
    • /
    • pp.873-878
    • /
    • 2013
  • An EOTS (Electro-Optical Tracking System) provides stabilized images while tracking a moving target. This paper presents a novel concept of driving the outer gimbal first for improving the maneuverability of an EOTS, contrary to the conventional inner gimbal mode. It has the advantages of faster positioning performance and stable operation in Nadir-point. Analysis of frequency responses reveal that the present scheme results in a wider control bandwidth and larger gain margin, compared to those of the previous one. The actual experimental results confirm that the maneuvering is stable although the input command has a large angular acceleration.

A Control System Design for the Line-of-Sight Stabilization based on Low-Cost Inertial Sensors (저가 관성센서 기반의 시선안정화 제어시스템 설계)

  • 위정현;홍성경
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.9 no.3
    • /
    • pp.204-209
    • /
    • 2003
  • The line-of-sight stabilization system is an equipment which is loaded on a vehicle and stabilizes the direction of the line-of-sight of the vision sensor to obtain a not-swayed image in the existence of external disturbances. To obtain accurate Euler angles and angular velocities simultaneously we usually need a control system which uses high-price inertial sensors including Vertical Gyro(VG) or Rate Integrating Gyro(RIG). In this paper, we design and implement a control system of a gimbal, which is a line-of-sight stabilization system using a low-cost mixed algorithm of a rate gyro and an accelerometer instead of a VG and a RIG. In the experiment where we laid the implemented line-of-sight stabilization system on the rate table. we can see the stabilized performance to external disturbances.

Robust Controller Design for a Stabilized Head Mirror

  • Keh, Joong-Eup;Lee, Man-Hyung
    • International Journal of Precision Engineering and Manufacturing
    • /
    • v.3 no.4
    • /
    • pp.78-86
    • /
    • 2002
  • In this paper, LMI (Linear Matrix Inequality) based on H$\_$$\infty$/ controller for a lire of sight (LOS) stabilization system. It shows that the proposed controller has more excellent stabilization performance than that of the conventional PI-Lead controller. An H$\_$$\infty$/ control has been also applied to the system for reducing modeling errors and the settling time of the system. The LMI-based H$\_$$\infty$/ controller design is more practical in view of reducing a run-time than Riccati-based H$\_$$\infty$/ controller. This H$\_$$\infty$/ controller is available not only to decrease the gain in PI-Lead control, but also to compensate the identifications for the various uncertain parameters. Therefore, this paper, shows that the proposed LMI-based H$\_$$\infty$/ controller had good disturbance attenuation and reference input tracking performance compared with the control performance of the conventional controller under any real disturbances.

Compensation for the Body-Coupling in the 2-Gimballed Seeker Homing Loop on BTT Missile

  • Sangkeun Jeong;Kim, Eulgon;Chanho Song;Hangju Cho
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.156.1-156
    • /
    • 2001
  • It is observed that if the 2-gimballed seeker is stabilized using rate gyros mounted along its primary axis, line of sight change measured in the seeker is induced by the rolling due to the bank-to-turn(BTT) steering as well as the actual change. This body-coupling within BTT homing includes the spurious target maneuver effect and the coupling loop due to the rate gyro misalignment. In this paper we formulates the linear BTT homing loop model with a 2-gimballed seeker including those body-coupling effects. With the model, we analyze the effects of the couplings, and show that the roll rate coupling to the rate gyro for the stabilztion of gimbal could seriously deteriorate the homing loop stability. And we propose a direct linear compensator for the coupling to recover the stability.

  • PDF