• Title/Summary/Keyword: Reference tracking

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A Trajectory Tracking Control of Wheeled Mobile Robot Using a Model Reference Adaptive Fuzzy Controller (모델참조 적응 퍼지제어기를 이용한 휠베이스 이동 로봇의 궤적 추적 제어)

  • Kim, Seung-Woo;Seo, Ki-Sung;Cho, Young-Wan
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.7
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    • pp.711-719
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    • 2009
  • This paper presents a design scheme of torque control for wheeled mobile robot(WMR) to asymptotically track the target reference trajectory. By considering the kinematic model of WMR, trajectory tracking control generates the desired tracking trajectory, which is transformed into the command velocity vector for the real WMR to track the target reference trajectory. The dynamic equation of the state error between the target reference trajectory and the desired tracking trajectory is represented by Takagi-Sugeno fuzzy model, and this model is used as the reference model for the real mobile robot error dynamics to follow. The control parameters are updated by adaptive laws that are designed for the error states of the real WMR to asymptotically follow the states of reference error model for the desired tracking trajectory. The proposed control is applied to a typical wheeled mobile robot and simulation studies are carried out to verify the validity and effectiveness of the control scheme.

Fast Reference Region Adjustment Using Sizing Factor Generation in Correlation-Based Image Tracking

  • Sung, Si-Hun;Chien, Sung-Il
    • Journal of Electrical Engineering and information Science
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    • v.3 no.2
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    • pp.230-238
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    • 1998
  • When size and shape of moving object have been changed, a correlator often accumulates walk-off error. A success of correlation-based tracking largely depends on choosing suitable window size and position and thus transferring the proper reference image to the next frame. For this, we propose the Adaptive Window Algorithm with Four-Direction Sizing Factors (AWA-FSF) for fast adjusting a reference region to enhance reliability of correlation-based image tracking in complex cluttered environments. Since the AWA-FSF is capable of adjusting a reference image size more rapidly and properly, we can minimize the influence of complex background and clutter. In addition, we can finely tune the center point of the reference image repeatedly after main tracking process. Thus we have increased stability and reliability of correlation-based image tracking. We tested performance of the AWA-FSF using 45 real image sequences made of over 3400 images and had the satisfied results for most of them.

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An Charge-Recycling Technique with Dual Outputs for Field Color Sequential applied in the RGB LED Backlight

  • Yang, Chih-Yu;Hsieh, Chun-Yu;Chen, Ke-Horng
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1088-1091
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    • 2009
  • A boost converter with charge-recycling technique fabricated by $0.25{\mu}m$ CMOS BCD process can provide different supply voltages to drive series RGB LEDs in sequence for reducing the power consumption on the constant current generator. The proposed technique stores and restores extra energy to improve the efficiency, as well as enhances the reference tracking response. Experimental results show that the period of reference-tracking response can be improved. When the load current is 100mA, the periods of reference down-tracking and uptracking are smaller than $10{\mu}s$ and $20{\mu}s$, respectively. Experimental results demonstrate fast and efficient reference tracking performance is achieved.

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An Implementation of Markerless Augmented Reality Using Efficient Reference Data Sets (효율적인 레퍼런스 데이터 그룹의 활용에 의한 마커리스 증강현실의 구현)

  • Koo, Ja-Myoung;Cho, Tai-Hoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.11
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    • pp.2335-2340
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    • 2009
  • This paper presents how to implement Markerless Augmented Reality and how to create and apply reference data sets. There are three parts related with implementation: setting camera, creation of reference data set, and tracking. To create effective reference data sets, we need a 3D model such as CAD model. It is also required to create reference data sets from various viewpoints. We extract the feature points from the mode1 image and then extract 3D positions corresponding to the feature points using ray tracking. These 2D/3D correspondence point sets constitute a reference data set of the model. Reference data sets are constructed for various viewpoints of the model. Fast tracking can be done using a reference data set the most frequently matched with feature points of the present frame and model data near the reference data set.

Virtual Reference Input Generation Using Direct Learning Control (직접학습제어를 이용한 가상 기준입력 생성)

  • Ahn, Hyun-Sik;Jeong, Gu-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.3
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    • pp.611-614
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    • 2007
  • In this paper, a Direct Learning Control (DLC) method is presented to generate a virtual reference input for linear feedback systems to improve the output tracking performance. The original reference input is effectively modified by the DLC without any iterative learning process. The presented DLC is designed based on the information on the relative degree of a system and previously generated virtual reference inputs. It is illustrated by simulations that the virtual reference input generated by the proposed DLC can achieve high tracking performance, although the reference input cannot be appropriately shaped by using existing DLC methods.

Reference State Tracking in Distributed Leader-Following Wireless Sensor Networks with Limited Errors

  • Mou, Jinping;Wang, Jie
    • Journal of Communications and Networks
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    • v.17 no.6
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    • pp.602-608
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    • 2015
  • In this paper, the limited error tracking problem is investigated for distributed leader-following wireless sensor networks (LFWSNs), where all sensors share data by the local communications, follower sensors are influenced by leader sensors directly or indirectly, but not vice versa, all sensor nodes track a reference state that is determined by the states of all leader sensors, and tracking errors are limited. In a LFWSN, the communicating graph is mainly expressed by some complete subgraphs; if we fix subgraphs that are composed of all leaders while all nodes in complete subgraphs of followers run on the sleeping-awaking method, then the fixed leaders and varying followers topology is obtained, and the switching topology is expressed by a Markov chain. It is supposed that the measurements of all sensors are corrupted by additive noises. Accordingly, the limited error tracking protocol is proposed. Based on the theory of asymptotic boundedness in mean square, it is shown that LFWSN keeps the limited error tracking under the designed protocol.

Tracking Control for Mobile Robot Based on Fuzzy Systems (퍼지 시스템을 이용한 이동로봇의 궤적제어)

  • 박재훼;이만형
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.6
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    • pp.466-472
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    • 2003
  • This paper describes a tracking control for the mobile robot based on fuzzy systems. Since the mobile robot has the nonholonomic constraints, these constraints should be considered to design a tracking controller for the mobile robot. One of the well-known tracking controllers for the mobile robot is the back-stepping controller. The conventional back-stepping controller includes the dynamics and kinematics of the mobile robot. The conventional back-stepping controller is affected by the derived velocity reference by a kinematic controller. To improve the performance of the conventional back-stepping controller, this paper uses the fuzzy systems known as the nonlinear controller. The new velocity reference for the back-stepping controller is derived through the fuzzy inference. Fuzzy rules are selected for gains of the kinematic controller. The produced velocity reference has properly considered the varying reference trajectories. Simulation results show that the proposed controller is more robust than the conventional back-stepping controller.

A Direct Adaptive Fuzzy Control of Nonlinear Systems with Application to Robot Manipulator Tracking Control

  • Cho, Young-Wan;Seo, Ki-Sung;Lee, Hee-Jin
    • International Journal of Control, Automation, and Systems
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    • v.5 no.6
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    • pp.630-642
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    • 2007
  • In this paper, we propose a direct model reference adaptive fuzzy control (MRAFC) for MIMO nonlinear systems whose structure is represented by the Takagi-Sugeno fuzzy model. The adaptive law of the MRAFC estimates the approximation error of the fuzzy logic system so that it provides asymptotic tracking of the reference signal for the systems with uncertain or slowly time-varying parameters. The developed control law and adaptive law guarantee the boundedness of all signals in the closed-loop system. In addition, the plant state tracks the state of the reference model asymptotically with time for any bounded reference input signal. To verify the validity and effectiveness of the MRAFC scheme, the suggested analysis and design techniques are applied to the tracking control of robot manipulator and simulation studies are carried out. In the control design, the MRAFC is combined with feedforward PD control to make the actual joint trajectories of the robot manipulator with system uncertainties track the desired reference joint position trajectories asymptotically stably.

An Implementation of Markerless Augmented Reality and Creation and Application of Efficient Reference Data Sets (마커리스 증강현실의 구현과 효율적인 레퍼런스 데이터 그룹의 생성 및 활용)

  • Koo, Ja-Myoung;Cho, Tai-Hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.204-207
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    • 2009
  • This paper presents how to implement Markerless Augmented Reality and how to create and apply reference data sets. There are three parts related with implementation: setting camera, creation of reference data set, and tracking. To create effective reference data sets, we need a 3D model such as CAD model. It is also required to create reference data sets from various viewpoints. We extract the feature points from the model image and then extract 3D positions corresponding to the feature points using ray tracking. These 2D/3D correspondence point sets constitute a reference data set of the model. Reference data sets are constructed for various viewpoints of the model. Fast tracking can be done using a reference data set the most frequently matched with feature points of the present frame and model data near the reference data set.

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GLOBAL ASYMPTOTIC OUTPUT TRACKING FOR A CLASS OF NONLINEAR SYSTEMS

  • Alimhan, Keylan;Inaba, Hiroshi
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.557-560
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    • 2005
  • This paper considers a global asymptotic output tracking problem with a prescribed constant reference signal for a class of single-input and single output-output nonlinear systems. It is shown that under some mild conditions on such a system there is a smooth output feedback achieving global asymptotic output tracking and such a smooth output controller is explicitly constructed by a new design method proposed. The usefulness of our result is illustrated by a numerical example.

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