• Title, Summary, Keyword: pure-pursuit algorithm

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Hybrid Control Strategy for Autonomous Driving System using HD Map Information (정밀 도로지도 정보를 활용한 자율주행 하이브리드 제어 전략)

  • Yu, Dongyeon;Kim, Donggyu;Choi, Hoseung;Hwang, Sung-Ho
    • Journal of Drive and Control
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    • v.17 no.4
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    • pp.80-86
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    • 2020
  • Autonomous driving is one of the most important new technologies of our time; it has benefits in terms of safety, the environment, and economic issues. Path following algorithms, such as automated lane keeping systems (ALKSs), are key level 3 or higher functions of autonomous driving. Pure-Pursuit and Stanley controllers are widely used because of their good path tracking performance and simplicity. However, with the Pure-Pursuit controller, corner cutting behavior occurs on curved roads, and the Stanley controller has a risk of divergence depending on the response of the steering system. In this study, we use the advantages of each controller to propose a hybrid control strategy that can be stably applied to complex driving environments. The weight of each controller is determined from the global and local curvature indexes calculated from HD map information and the current driving speed. Our experimental results demonstrate the ability of the hybrid controller, which had a cross-track error of under 0.1 m in a virtual environment that simulates K-City, with complex driving environments such as urban areas, community roads, and high-speed driving roads.

Development of Steering Control System for Autonomous Vehicle Using Geometry-Based Path Tracking Algorithm

  • Park, Myungwook;Lee, Sangwoo;Han, Wooyong
    • ETRI Journal
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    • v.37 no.3
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    • pp.617-625
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    • 2015
  • In this paper, a steering control system for the path tracking of autonomous vehicles is described. The steering control system consists of a path tracker and primitive driver. The path tracker generates the desired steering angle by using the look-ahead distance, vehicle heading, and a lateral offset. A method for applying an autonomous vehicle to path tracking is an advanced pure pursuit method that can reduce cutting corners, which is a weakness of the pure pursuit method. The steering controller controls the steering actuator to follow the desired steering angle. A servo motor is installed to control the steering handle, and it can transmit the steering force using a belt and pulley. We designed a steering controller that is applied to a proportional integral differential controller. However, because of a dead band, the path tracking performance and stability of autonomous vehicles are reduced. To overcome the dead band, a dead band compensator was developed. As a result of the compensator, the path tracking performance and stability are improved.

Basic Control Algorithm for Parallel Formation of Multi-mining Robots (다중 집광로봇의 수평대형유지를 위한 기초 알고리즘 연구)

  • Yoon, Suk-Min;Yeu, Tae-Kyeong;Hong, Sup;Kim, Sang-Bong
    • Ocean and Polar Research
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    • v.36 no.4
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    • pp.465-473
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    • 2014
  • This paper proposes a formation control method by which multi-mining robots maintain a specified formation and follow a path. To secure the path tracking performance, a pure-pursuit algorithm is considered for each individual robot, and to minimize the deviation from the reference path, speed reduction in the steering motion is added. For the formation, in which two robots are parallel in a lateral direction, the robots track the specified path at a constant distance. In this way, the Leader-Follower method is adopted and the following robot knows the position and heading angle of the leader robot. Through the experimental test using two ground vehicle models, the performance is verified.

Development of Walking Assistive System using Body Weight Supporting and Path Planning Strategy (인체 자중 보상 및 로봇 경로계획법을 이용한 이동형 보행 재활 시스템 개발)

  • Yu, Seung-Nam;Shon, Woong-Hee;Suh, Seung-Whan;Lee, Sang-Ho;Han, Chang-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.10
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    • pp.939-947
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    • 2010
  • With the rising numbers of elderly and disabled people, the demand for welfare services using a robotic system and not involving human effort is likewise increasing. This study deals with a mobile-robot system combined with a BWS (Body Weight Support) system for gait rehabilitation. The BWS system is designed via the kinematic analysis of the robot's body-lifting characteristics and of the walking guide system that controls the total rehabilitation system integrated in the mobile robot. This mobile platform is operated by utilizing the AGV (Autonomous Guided Vehicle) driving algorithm. Especially, the method that integrates geometric path tracking and obstacle avoidance for a nonholonomic mobile robot is applied so that the system can be operated in an area where the elderly users are expected to be situated, such as in a public hospital or a rehabilitation center. The mobile robot follows the path by moving through the turning radius supplied by the pure-pursuit method which is one of the existing geometric path-tracking methods. The effectiveness of the proposed method is verified through the real experiments those are conducted for path tracking with static- and dynamic-obstacle avoidance. Finally, through the EMG (Electromyography) signal measurement of the subject, the performance of the proposed system in a real operation condition is evaluated.

Trajectory Generation, Guidance, and Navigation for Terrain Following of Unmanned Combat Aerial Vehicles (무인전투기 근접 지형추종을 위한 궤적생성 및 유도 항법)

  • Oh, Gyeong-Taek;Seo, Joong-Bo;Kim, Hyoung-Seok;Kim, Youdan;Kim, Byungsoo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.11
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    • pp.979-987
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    • 2012
  • This paper implements and integrates algorithms for terrain following of UCAVs (Unmanned Combat Aerial Vehicles): trajectory generation, guidance, and navigation. Terrain following is very important for UCAVs because they perform very dangerous missions such as Suppression of Enemy Air Defences while the terrain following can improve the survivability of UCAVs against from the air defence systems of the enemy. To deal with the GPS jamming, terrain referenced navigation based on nonlinear filter is chosen. For the trajectory generation, Voronoi diagram is adopted to generate horizontal plane path to avoid the air defense system. Cubic spline method is used to generate vertical plane path to prevent collisions with ground while flying sufficiently close to surface. Follow-the-Carrot and pure pursuit tracking methods, which are look-ahead point based guidance algorithms, are applied for the guidance. Numerical simulation is performed to verify the performance of the integrated terrain following algorithm.