• Title/Summary/Keyword: Vehicle Dynamic Control System

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Dynamic Characteristics of a Urea SCR System for NOx Reduction in Diesel Engine

  • Nam, Jeong-Gil;Choi, Jae-Sung
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.3
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    • pp.235-242
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    • 2007
  • This paper discusses dynamic characteristics of a urea-SCR (Selective Catalytic Reduction) system. The urea flow rate to improve NOx conversion efficiency is generally determined by parameters such as catalyst temperature and space velocity. The urea-SCR system was tested in the various engine operating conditions governing the raw NOx emission levels, space velocity. and SCR catalyst temperature. These experiments include cold-transients to determine catalyst light-off temperature and urea flow rate transients. Likewise. ammonia storage dynamics was also investigated. The cold-transient results indicate the light-off temperature of the catalysts used in these experiments was $200-220^{\circ}C$. The ammonia storage and urea flow rate transients all indicate very slow dynamics (on the order of seconds) which presents control challenges for mobile applications. The results presented in this paper should provide an excellent starting point in developing a functional in-vehicle urea-SCR system.

Analysis of Dynamic Characteristics of Pneumatic Driving Solenoid Valve (공압구동용 솔레노이드밸브의 동특성 해석)

  • Jang, Je-Sun;Kim, Byung-Hun;Han, Sang-Yeop
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.731-736
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    • 2011
  • A pneumatic driving solenoid valve operates pneumatic control devices by opening/closing operating flow passage when the command is given by control system for the liquid-propellant feeding system of space launch vehicle. The simulation model of pneumatic driving solenoid valve is designed with AMESim to verify the designs and evaluate the dynamic characteristics and pneumatic behaviors of valve. To validate a valve simulation model, the simulation results of their operating durations of valve by AMESim analysis are compared with the results of experiments. In addition, the results of internal flow simulation with FLUENT are utilized to improve the accuracy of valve-modeling. Using the model, we analyze performance of valve; opening/closing pressure, operating time on various design factors; shape of control valve seat, drainage seat, rate of sealing diameter, volume of control cavity. This study will serve as one of reference guides to enhance the developmental efficiency of ventilation-relief valves with the various operating conditions, which shall be used in Korea Space Launch Vehicle-II.

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Design of Lane Keeping Steering Assist Controller Using Vehicle Lateral Disturbance Estimation under Cross Wind (횡풍하의 차량 외란 추정을 이용한 차선 유지 조향 보조 제어기 설계)

  • Lim, Hyeongho;Joa, Eunhyek;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
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    • v.12 no.3
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    • pp.13-19
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    • 2020
  • This paper presents steering controller for unintended lane departure avoidance under crosswind using vehicle lateral disturbance estimation. Vehicles exposed to crosswind are more likely to deviate from lane, which can lead to accidents. To prevent this, a lateral disturbance estimator and steering controller for compensating disturbance have been proposed. The disturbance affecting lateral motion of the vehicle is estimated using Kalman filter, which is on the basis of the 2-DOF bicycle model and Electric Power Steering (EPS) module. A sliding mode controller is designed to avoid unintended the lane departure using the estimated disturbance. The controller is based on the 2-DOF bicycle model and the vision-based error dynamic model. A torque controller is used to provide appropriate assist torque to driver. The performance of proposed estimator and controller is evaluated via computer simulation using Matlab/Simulink.

Speed, Depth and Steering Control of Underwater Vehicles with Four Stem Thrusters - Simulation and Experimental Results (네 대의 주 추진기를 이용한 무인잠수정의 속도, 심도 및 방위각 제어 - 시뮬레이션 및 실험)

  • JUN BONG-HUAN;LEE PAN-MOOK;LI JI-HONG;HONG SEOK-WON;LEE JIHONG
    • Journal of Ocean Engineering and Technology
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    • v.19 no.2 s.63
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    • pp.67-73
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    • 2005
  • This paper describes depth, heading and speed control of an underwater vehicle that has four stern thrusters of which forces are coupled in the diving and, steering motion, as well as the speed of the vehicle. The optimal linear quadratic controller is designed based on a linearized- state space model, developed by combining the dynamic equations of speed, steering and diving motion. The designed controller gives provides an optimal thrust distribution, minimizing the given performance index to control speed, depth and heading simultaneously. To validate the performance of the controller, a simulation and tank-test are carried out with DUSAUV (Dual Use Semi-Autonomous Underwater Vehicle), developed by KORDI as a test-bed for testing new underwater technologies. Optimal gains of the controller are tuned, using a computer simulation environment with a nonlinear 6-DOF numerical DUSAUV model, developed by PMM (Planner Motion Mechanism) test. To verify the performance of the presented controller in experiment, a tank-test with DUSAUV is carried out in the ocean engineering basin in KORDI. The experimental results are also compared with the simulation results to investigate the accordance of the numerical and the real mode.

Development of Moving Object Management System for Vehicle Monitoring/Control Management in e-Logistics Environment (e-Logistics 환경에서 차량관제를 위한 이동체 관리 시스템 개발)

  • Kim, Dong-Ho;Lee, Hye-Jin;Lee, Hyun-Ah;Kim, Jin-Suk
    • The KIPS Transactions:PartD
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    • v.11D no.6
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    • pp.1231-1238
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    • 2004
  • By virtue of the advanced Internet technology, there are lots of research works for e-Logistics which means virtual business activities or service architecture based on the Internet among the logistics companies. Because e-Logistics environment requires more dynamic and global service area, conventional vehicle monitoring and control technologies innate many problems in terms of Integrating, storing and sharing the location data. It needs the development of the moving object technology in order to resolve efficiently the limitations. In this paper, we propose the whole components of the moving object management system which supports the advanced sharing the location information as well as the integration of location data. We are sure the suggested system can be adopted to construct the next generation-logistics vehicle monitoring and control system by reducing the overall cost and time.

Experimental Study on Dynamic Track Tensioning System in Tracked Vehicles (궤도차량의 동적 궤도장력 조절시스템에 대한 실험적 연구)

  • Suh, Mun-Suk;Kim, Jae-Yong;Jeong, Soon-Kyu;Huh, Kun-Soo;Kim, Il-Min;Chung, Chung-Choo;Choi, Jae-Mo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.7
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    • pp.1193-1199
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    • 2003
  • Maintaining track tension in tracked vehicles minimizes the excessive load on the tracks and prevents the peal-off of tracks from the road-wheel, and adequately guarantees the stable and improved driving of the tracked vehicles. However, the track tension cannot be easily measured due to the limitation in the sensor technology, harsh environment, etc. In this study, the track tension is estimated in realtime from the measurable signals of tracked vehicles and controlled based on a fuzzy logic controller. The proposed control system is implemented on tracked vehicles and its performance is evaluated under various driving conditions.

Reduction of the actuator oscillations in the flying vehicle under a follower force

  • Kavianipour, O.;Khoshnood, A.M.;Sadati, S.H.
    • Structural Engineering and Mechanics
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    • v.47 no.2
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    • pp.149-166
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    • 2013
  • Flexible behaviors in new aerospace structures can lead to a degradation of their control and guidance system and undesired performance. The objectives of the current work are to analyze the vibration resulting from the propulsion force on a Single Stage to Orbit (SSTO) launch vehicle (LV). This is modeled as a follower force on a free-free Euler-Bernoulli beam consisting of two concentrated masses at the two free ends. Once the effects on the oscillation of the actuators are studied, a solution to reduce these oscillations will also be developed. To pursue this goal, the stability of the beam model is studied using Ritz method. It is determined that the transverse and rotary inertia of the concentrated masses cause a change in the critical follower force. A new dynamic model and an adaptive control system for an SSTO LV have been developed that allow the aerospace structure to run on its maximum bearable propulsion force with the optimum effects on the oscillation of its actuators. Simulation results show that such a control model provides an effective way to reduce the undesirable oscillations of the actuators.

A New Dynamic Routing Algorithm for Multiple AGV Systems : Nonstop Preferential Detour Algorithm (다중무인운반차 시스템의 새로운 동적경로계획 알고리즘 : 비정지우선 우회 알고리즘)

  • Sin, Seong-Yeong;Jo, Gwang-Hyeon
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.9
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    • pp.795-802
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    • 2002
  • We present a new dynamic routing scheme for multiple autonomous guided vehicles (AGVs) systems. There have been so many results concerned with scheduling and routing of multiple AGV systems; however, most of them are only applicable to systems with a small number of AGVs under a low degree of concurrency. With an increased number of AGVs in recent applications, these AGV systems are faced with another problem that has never been occurred in a system with a small number AGVs. This is the stop propagation problem. That is, if a leading AGV stops then all the following AGVs must stop to avoid any collision. In order to resolve this problem, we propose a nonstop preferential detour (NPD) algorithm which is a new dynamic routing scheme employing an election algorithm. For real time computation, we introduce two stage control scheme and propose a new path searching scheme, k-via shortest path scheme for an efficient dynamic routing algorithm. Finally, the proposed new dynamic routing scheme is illustrated by an example.

Performance Analysis on the IMM-PDAF Method for Longitudinal and Lateral Maneuver Detection using Automotive Radar Measurements (차량용 레이더센서를 이용한 IMM-PDAF 기반 종-횡방향 운동상태 검출 및 추정기법에 대한 성능분석)

  • Yoo, Jeongjae;Kang, Yeonsik
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.3
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    • pp.224-232
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    • 2015
  • In order to develop an active safety system which avoids or mitigates collisions with preceding vehicles such as autonomous emergency braking (AEB), accurate state estimation of the nearby vehicles is very important. In this paper, an algorithm is proposed using 3 dynamic models to better estimate the state of a vehicle which has various dynamic patterns in both longitudinal and lateral direction. In particular, the proposed algorithm is based on the Interacting Multiple Model (IMM) method which employs three different dynamic models, in cruise mode, lateral maneuver mode and longitudinal maneuver mode. In addition, a Probabilistic Data Association Filter (PDAF) is utilized as a data association algorithm which can improve the reliability of the measurement under a clutter environment. In order to verify the performance of the proposed method, it is simulated in comparison with a Kalman filter method which employs a single dynamic model. Finally, the proposed method is validated using radar data obtained from the field test in the proving ground.

Constant Altitude Flight Control for Quadrotor UAVs with Dynamic Feedforward Compensation

  • Razinkova, Anastasia;Kang, Byung-Jun;Cho, Hyun-Chan;Jeon, Hong-Tae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.14 no.1
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    • pp.26-33
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    • 2014
  • This study addresses the control problem of an unmanned aerial vehicle (UAV) during the transition period when the flying mode changes from hovering to translational motion in the horizontal plane. First, we introduce a compensation algorithm that improves height stabilization and reduces altitude drop. The main principle is to incorporate pitch and roll measurements into the feedforward term of the altitude controller to provide a larger thrust force. To further improve altitude control, we propose the fuzzy logic controller that improves system behavior. Simulation results presented in the paper highlight the effectiveness of the proposed controllers.