• Title/Summary/Keyword: Tracking algorithm

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Full Bridge Resonant Inverter Using Asymmetrical Control with Resonant-frequency Tracking for Ultrasonic Cleaning Applications

  • Jittakort, Jirapong;Sangswang, Anawach;Naetiladdanon, Sumate;Koompai, Chayant;Chudjuarjeen, Saichol
    • Journal of Power Electronics
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    • v.17 no.5
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    • pp.1150-1159
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    • 2017
  • Flexibility in the power control of ultrasonic transducers has remained a challenge for cleaning applications. This paper introduces a modification of the existing piezoelectric ceramic transducer (PCT) circuit to increase the range of operation through its impedance characteristics. The output power is controlled using the asymmetrical voltage-cancellation (AVC) method. Together with a phase-locked loop control, the switching frequency of the inverter is automatically adjusted to maintain a lagging phase angle under load-parameter variations during the cleaning process. With the proposed modification, the region of the zero-voltage switching (ZVS) operation is extended, which results in a wider range of output power control. A hardware prototype is constructed and the control algorithm is implemented using an STM32F4 microcontroller. Simulation and experimental results are provided to verify the proposed method for a 50-W PCT. The operating frequency and output power ranges under study are 37 - 41 kHz and 15.8 - 50 W, respectively.

A Study on Kohenen Network based on Path Determination for Efficient Moving Trajectory on Mobile Robot

  • Jin, Tae-Seok;Tack, HanHo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.10 no.2
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    • pp.101-106
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    • 2010
  • We propose an approach to estimate the real-time moving trajectory of an object in this paper. The object's position is obtained from the image data of a CCD camera, while a state estimator predicts the linear and angular velocities of the moving object. To overcome the uncertainties and noises residing in the input data, a Extended Kalman Filter(EKF) and neural networks are utilized cooperatively. Since the EKF needs to approximate a nonlinear system into a linear model in order to estimate the states, there still exist errors as well as uncertainties. To resolve this problem, in this approach the Kohonen networks, which have a high adaptability to the memory of the inputoutput relationship, are utilized for the nonlinear region. In addition to this, the Kohonen network, as a sort of neural network, can effectively adapt to the dynamic variations and become robust against noises. This approach is derived from the observation that the Kohonen network is a type of self-organized map and is spatially oriented, which makes it suitable for determining the trajectories of moving objects. The superiority of the proposed algorithm compared with the EKF is demonstrated through real experiments.

2D and 3D Topology Optimization with Target Frequency and Modes of Ultrasonic Horn for Flip-chip Bonding (플립칩 접합용 초음파 혼의 목표 주파수와 모드를 고려한 2차원 및 3차원 위상최적화 설계)

  • Ha, Chang Yong;Lee, Soo Il
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.1
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    • pp.84-91
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    • 2013
  • Ultrasonic flip-chip bonding needs a precise bonding tool which delivers ultrasonic energy into chip bumps effectively to use the selected resonance mode and frequency of the horn structure. The bonding tool is excited at the resonance frequency and the input and output ports should locate at the anti-nodal points of the resonance mode. In this study, we propose new design method with topology optimization for ultrasonic bonding tools. The SIMP(solid isotropic material with penalization) method is used to formulate topology optimization and OC(optimal criteria) algorithm is adopted for the update scheme. MAC(modal assurance criterion) tracking is used for the target frequency and mode. We fabricate two prototypes of ultrasonic tools which are based on 3D optimization models after reviewing 2D and 3D topology optimization results. The prototypes are satisfied with the ultrasonic frequency and vibration amplitude as the ultrasonic bonding tools.

Control of Robot System on the Elastic Base by Approximate Jacobian Operators (근사 자코비안 연산자를 이용한 탄성 지지부를 갖는 로봇 시스템의 제어)

  • Lee, Sun;Lee, Ho-Gil;Hwang, Sung-Ho;Rhee, Se-Hun
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.10
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    • pp.45-52
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    • 2001
  • This paper presents a study on the position tracking control of a robot system on the uncertain elastic base. The elastic bathe is a nonholonomic system but it can be changed into holonomic system, which is much easier to analyze, by modeling an elastic base as a virtual robot that has passive joints. Also, Jacobian operators, which represent the overall robot system including base movement, are defined and applied to the changed model. However, because base movements are not known, the exact Jacobian operators can't be estimated. The control algorithm proposed is that uses only Jacobians of a real robot as approximate Jacobian operators. Therefore the approximate Jacobian operators compensate the measured errors from external sensors. The proposed control strategy is evaluated by the simulation and experiment of a single-axis robot system on the elastic base.

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Real Time Neural Controller Design of Industrial Robot Using Digital Signal Processors (디지탈 신호 처리기를 사용한 산업용 로봇의 실시간 뉴럴 제어기 설계)

  • 김용태;한성현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.759-763
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    • 1996
  • This paper presents a new approach to the design of neural control system using digital signal processors in order to improve the precision and robustness. Robotic manipulators have become increasingly important in the field of flexible automation. High speed and high-precision trajectory tracking are indispensable capabilities for their versatile application. The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. The TMS320C31 is used in implementing real time neural control to provide an enhanced motion control for robotic manipulators. In this control scheme, the networks introduced are neural nets with dynamic neurons, whose dynamics are distributed over all the network nodes. The nets are trained by the distributed dynamic back propagation algorithm. The proposed neural network control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Performance of the neural controller is illustrated by simulation and experimental results for a SCARA robot.

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Recurrent Ant Colony Optimization for Optimal Path Convergence in Mobile Ad Hoc Networks

  • Karmel, A;Jayakumar, C
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.9
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    • pp.3496-3514
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    • 2015
  • One of the challenging tasks in Mobile Ad hoc Network is to discover precise optimal routing solution due to the infrastructure-less dynamic behavior of wireless mobile nodes. Ant Colony Optimization, a swarm Intelligence technique, inspired by the foraging behaviour of ants in colonies was used in the past research works to compute the optimal path. In this paper, we propose a Recurrent Ant Colony Optimization (RECACO) that executes the actual Ant Colony Optimization iteratively based on recurrent value in order to obtain an optimal path convergence. Each iteration involves three steps: Pheromone tracking, Pheromone renewal and Node selection based on the residual energy in the mobile nodes. The novelty of our approach is the inclusion of new pheromone updating strategy in both online step-by-step pheromone renewal mode and online delayed pheromone renewal mode with the use of newly proposed metric named ELD (Energy Load Delay) based on energy, Load balancing and end-to-end delay metrics to measure the performance. RECACO is implemented using network simulator NS2.34. The implementation results show that the proposed algorithm outperforms the existing algorithms like AODV, ACO, LBE-ARAMA in terms of Energy, Delay, Packet Delivery Ratio and Network life time.

Spatiotemporal Routing Analysis for Emergency Response in Indoor Space

  • Lee, Jiyeong;Kwan, Mei-Po
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.6
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    • pp.637-650
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    • 2014
  • Geospatial research on emergency response in multi-level micro-spatial environments (e.g., multi-story buildings) that aims at understanding and analyzing human movements at the micro level has increased considerably since 9/11. Past research has shown that reducing the time rescuers needed to reach a disaster site within a building (e.g., a particular room) can have a significant impact on evacuation and rescue outcomes in this kind of disaster situations. With the purpose developing emergency response systems that are capable of using complex real-time geospatial information to generate fast-changing scenarios, this study develops a Spatiotemporal Optimal Route Algorithm (SORA) for guiding rescuers to move quickly from various entrances of a building to the disaster site (room) within the building. It identifies the optimal route and building evacuation bottlenecks within the network in real-time emergency situations. It is integrated with a Ubiquitous Sensor Network (USN) based tracking system in order to monitor dynamic geospatial entities, including the dynamic capacities and flow rates of hallways per time period. Because of the limited scope of this study, the simulated data were used to implement the SORA and evaluate its effectiveness for performing 3D topological analysis. The study shows that capabilities to take into account detailed dynamic geospatial data about emergency situations, including changes in evacuation status over time, are essential for emergency response systems.

Development of Audio Melody Extraction and Matching Engine for MIREX 2011 tasks

  • Song, Chai-Jong;Jang, Dalwon;Lee, Seok-Pil;Park, Hochong
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2012.07a
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    • pp.164-166
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    • 2012
  • In this paper, we proposed a method for extracting predominant melody of polyphonic music based on harmonic structure. Harmonic structure is an important feature parameter of monophonic signal that has spectral peaks at the integer multiples of its fundamental frequency. We extract all fundamental frequency candidates contained in the polyphonic signal by verifying the required condition of harmonic structure. Then, we combine those harmonic peaks corresponding to each extracted fundamental frequency and assign a rank to each after calculating its harmonic average energy. We run pitch tracking based on the rank of extracted fundamental frequency and continuity of fundamental frequency, and determine the predominant melody. For the query by singing/humming (QbSH) task, we proposed Dynamic Time Warping (DTW) based matching engine. Our system reduces false alarm by combining the distances of multiple DTW processes. To improve the performance, we introduced the asymmetric sense, pitch level compensation, and distance intransitiveness to DTW algorithm.

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Development of a Vision Sensor-based Vehicle Detection System (스테레오 비전센서를 이용한 선행차량 감지 시스템의 개발)

  • Hwang, Jun-Yeon;Hong, Dae-Gun;Huh, Kun-Soo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.6
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    • pp.134-140
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    • 2008
  • Preceding vehicle detection is a crucial issue for driver assistance system as well as for autonomous vehicle guidance function and it has to be performed with high reliability to avoid any potential collision. The vision-based preceded vehicle detection systems are regarded promising for this purpose because they require little infrastructure on a highway. However, the feasibility of these systems in passenger car requires accurate and robust sensing performance. In this paper, an preceded vehicle detection system is developed using stereo vision sensors. This system utilizes feature matching, epipoplar constraint and feature aggregation in order to robustly detect the initial corresponding pairs. After the initial detection, the system executes the tracking algorithm for the preceded vehicles including a leading vehicle. Then, the position parameters of the preceded vehicles or leading vehicles can be obtained. The proposed preceded vehicle detection system is implemented on a passenger car and its performances is verified experimentally.

Robust Face Detection and Tracking Algorithm for Sudden Changes of Illumination (급격한 조명의 변화에 강인한 얼굴검출 및 추적 알고리즘)

  • Kim, Giseok;Cho, Jae-Soo;Jung, Kwanghee;Lee, Eung-Don;Cheong, Won-Sik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2011.11a
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    • pp.15-18
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    • 2011
  • 본 논문에서는 이동형 패럴랙스 배리어 방식의 모바일 3D 디스플레이에 응용하기 위해 개발된 시역계측알고리즘[1]을 실제시스템에 구현한 후 문제점을 분석하고, 그 문제점을 해결할 수 있는 새로운 방법을 제안한다. 본 연구팀에서 이동형 패럴랙스 배리어 방식의 모바일 3D 디스플레이에 응용하기 위해 개발한 이전의 시역계측기술[1]은 기존의 비올라-존스 얼굴 검출기[2]에 의한 얼굴검출 결과와 비올라-존스 얼굴 검출기의 단점을 보완하기 위해 새롭게 추가된 옵티컬-플로우 특징점 추적 알고리즘[3]에 의한 얼굴검출의 두 결과를 선형적으로 결합하여 시청자의 시역위치를 예측하였다. 하지만, 모바일 3D 디스플레이의 특성한 급격한 조명의 변화에서 옵티컬-플로우에 의한 특징점 추적알고리즘에 심각한 오류가 발생하는 문제점이 있다. 이러한 급격한 조명의 변화에 대한 문제점을 해결하기 위해 본 논문에서는 매 프레임마다 정확하게 옵티컬-플로우 얼굴 검출기의 정확도를 판단할 수 있는 방법을 제안하고, 다양한 실험을 통해 그 효과를 검증한다.

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