• Title/Summary/Keyword: path-smoothing

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Path Planning of the Low Altitude Flight Unmanned Aerial Vehicle for the Neutralization of the Enemy Firepower (대화력전 임무수행을 위한 저고도 비행 무인공격기의 경로계획)

  • Yang, Kwang-Jin;Kim, Si-Tai;Jung, Dae-Han
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.4
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    • pp.424-434
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    • 2012
  • This paper presents a path planning algorithm of the unmanned aerial vehicle for the neutralization of the enemy firepower. The long range firepower of the ememy is usually located at the rear side of the mountain which is difficult to bomb. The path planner not only consider the differential constraints of the Unmanned Aerial Vehicle (UAV) but also consider the final approaching angle constraint. This problem is easily solved by incorporating the analytical upper bounded continuous curvature path smoothing algorithm into the Rapidly Exploring Random Tree (RRT) planner. The proposed algorithm can build a feasible path satisfying the kinematic constraints of the UAV on the fly. In addition, the curvatures of the path are continuous over the whole path. Simulation results show that the proposed algorithm can generate a feasible path of the UAV for the bombing mission regardless of the posture of the tunnel.

A Study on Flight Trajectory Generations and Guidance/Control Laws : Validation through HILS (무인항공기의 비행경로 생성 및 유도제어 알고리즘 연구 : HILS를 통한 검증)

  • Baek, Soo-Ho;Hong, Sung-Kyung
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.12
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    • pp.1238-1243
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    • 2008
  • This paper presents an HILS(Hardware in the Loop Simulations) based experimental study for the UAV's flight trajectory planning/generation algorithms and guidance/control laws. For the various mission that is loaded on each waypoint, proper trajectory planning and generation algorithms are applied to achieve best performances. Specially, the 'smoothing path' generation and the 'tangent orbit path' guidance laws are presented for the smooth path transitions and in-circle loitering mission, respectively. For the control laws that can minimize the effects of side wind, side slip angle($\beta$) feedback to the rudder scheme is implemented. Finally, being implemented on real hardwares, all the proposed algorithms are validated with integrations of hardware and software altogether via HILS.

Mission Path Planning to Maximize Survivability for Multiple Unmanned Aerial Vehicles based on 3-dimensional Grid Map (3차원 격자지도 기반 생존성 극대화를 위한 다수 무인 항공기 임무경로 계획)

  • Kim, Ki-Tae;Jeon, Geon-Wook
    • IE interfaces
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    • v.25 no.3
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    • pp.365-375
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    • 2012
  • An Unmanned Aerial Vehicle (UAV) is a powered pilotless aircraft, which is controlled remotely or autonomously. UAVs are an attractive alternative for many scientific and military organizations. UAVs can perform operations that are considered to be risky or uninhabitable for humans. UAVs are currently employed in many military missions and a number of civilian applications. For accomplishing the UAV's missions, guarantee of survivability should be preceded. The main objective of this study is to suggest a mathematical programming model and a $A^*PS$_PGA (A-star with Post Smoothing_Parallel Genetic Algorithm) for Multiple UAVs's path planning to maximize survivability. A mathematical programming model is composed by using MRPP (Most Reliable Path Problem) and MTSP (Multiple Traveling Salesman Problem). After transforming MRPP into Shortest Path Problem (SPP),$A^*PS$_PGA applies a path planning for multiple UAVs.

Any-angle Path Planning Algorithm considering Angular Constraint for Marine Robot (해양 로봇의 회전 반경을 고려한 경로 계획 알고리즘)

  • Kim, Han-Guen;Myung, Hyun;Choi, Hyun-Taek
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.4
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    • pp.365-370
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    • 2012
  • Most path planning algorithms for a marine robot in the ocean environment have been developed without considering the robot's heading angle. As a result, the robot has a difficulty in following the path correctly. In this paper, we propose a limit-cycle circle set that applies to the $Theta^*$ algorithm. The minimum turning radius of a marine robot is calculated using a limit-cycle circle set, and circles of this radius is used to generate a configuration space of an occupancy grid map. After applying $Theta^*$ to this configuration space, the limit-cycle circle set is also applied to the start and end nodes to find the appropriate path with specified heading angles. The benefit of this algorithm is its fast computation time compared to other 3-D ($x,y,{\theta}$) path planning algorithms, along with the fact that it can be applied to the 3-D kinematic state of the robot. We simulate the proposed algorithm and compare it with 3-D $A^*$ and 3-D $A^*$ with post smoothing algorithms.

Launch Point Estimation for a Ballistic Missile using the Phase Division Least Square Method (단계 분리형 최소 자승법을 이용한 탄도 미사일의 발사지점 예측 연구)

  • Kim, Jun-Ki;Lee, Dong-Kwan;Cho, Kil-Seok;Song, Taek-Lyul
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.4
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    • pp.414-421
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    • 2014
  • This paper presents a method of ballistic missile launch point estimation using phase division least squares. The proposed algorithm employs smoothing to enhance estimation accuracy and generates functions of time for total velocity, flight path angle and heading angle, allowing extrapolation to estimate the launch point. Performance of the proposed algorithm is tested in conjunction with the extended Kalman filter and the Kalman filter.

Comparative Analysis of TOA and TDOA method for position estimation of mobile station (이동국 위치 추정을 위한 TOA와 TDOA방법의 비교 분석)

  • 윤현성;이창호;변건식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.3
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    • pp.595-602
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    • 2000
  • This paper is aimed at developing an location tracking system of mobile station based on currently available mobile communication network or mobile Phone and PCS(Personal Communication System). When the location tracking of mobile stations is in services, Emergency-119, all of crime investigation, effective urban traffic management and the safety protection of Alzheimer's patients can be available. In order to track the location of the mobile and base station, assumption in this paper is to use the statistic characteristics of LOS when modeling the standard noise in case that radio path is LNOS environment. The standard variation of the standard noise is $\pm150$. First, location is estimated by the positioning algorithms of TOA and TDOA and compared each other. Second, after canceling the standard noise by Kalman filter, location is estimated by the above two positioning algorithms. Finally, the location by the Kalman filter and two positioning algorithms is estimated by smoothing method. As a result, 2 dimensional average location error is imvoved by 51.2m in TOA and 34.8m in TDOA when Kalman filer and two positioning algorithms are used, compared with the two positioning algorithm used. And there is 3 more meter improvement after smoothing than Kalman filer and two positioning algorithms used.

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Development of an Improved Geometric Path Tracking Algorithm with Real Time Image Processing Methods (실시간 이미지 처리 방법을 이용한 개선된 차선 인식 경로 추종 알고리즘 개발)

  • Seo, Eunbin;Lee, Seunggi;Yeo, Hoyeong;Shin, Gwanjun;Choi, Gyeungho;Lim, Yongseob
    • Journal of Auto-vehicle Safety Association
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    • v.13 no.2
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    • pp.35-41
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    • 2021
  • In this study, improved path tracking control algorithm based on pure pursuit algorithm is newly proposed by using improved lane detection algorithm through real time post-processing with interpolation methodology. Since the original pure pursuit works well only at speeds below 20 km/h, the look-ahead distance is implemented as a sigmoid function to work well at an average speed of 45 km/h to improve tracking performance. In addition, a smoothing filter was added to reduce the steering angle vibration of the original algorithm, and the stability of the steering angle was improved. The post-processing algorithm presented has implemented more robust lane recognition system using real-time pre/post processing method with deep learning and estimated interpolation. Real time processing is more cost-effective than the method using lots of computing resources and building abundant datasets for improving the performance of deep learning networks. Therefore, this paper also presents improved lane detection performance by using the final results with naive computer vision codes and pre/post processing. Firstly, the pre-processing was newly designed for real-time processing and robust recognition performance of augmentation. Secondly, the post-processing was designed to detect lanes by receiving the segmentation results based on the estimated interpolation in consideration of the properties of the continuous lanes. Consequently, experimental results by utilizing driving guidance line information from processing parts show that the improved lane detection algorithm is effective to minimize the lateral offset error in the diverse maneuvering roads.

Effects of Acceleration and Deceleration Parameters on the Machining Error for Large Area Laser Processing (대면적 레이저 가공을 위한 가감속 파라미터가 가공오차에 미치는 영향)

  • Lee, Jae Hoon;Yoon, Kwang Ho;Kim, Kyung Han
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.8
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    • pp.721-728
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    • 2014
  • In this paper, it is proposed a method of optimizing path parameters for large-area laser processing. On-the-fly system is necessary for large-area laser processing of uniform quality. It is developed a MOTF(Marking On-The-Fly) board for synchronizing the stage and scanner. And it is introduced the change of the error due to the change of parameters and algorithm for large-area laser processing. This algorithm automatically generates stage path and a velocity profile using acceleration and deceleration parameters. Since this method doesn't use a G-code, even if without expert knowledge, it has an advantage that can be accessed easily. Angle of one of the square of $350{\times}350mm$ was changed from $50^{\circ}$ to $80^{\circ}$ and analyzed the error corresponding to the value of Ta. It is calculated the value of Ta of the best with a precision of 20um through measurement of accuracy according to the Ta of each angle near the edge.

Design of a CDBC Using Multirate Sampling (Multirate 샘플링을 이용한 CDBC의 설계)

  • 김진용;김성열;이금원
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.4
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    • pp.47-51
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    • 2003
  • Due to the asymptotic property, deadbeat control which is well used in digital control system can not be applied to the continuous time system. But recently by use of the finite Laplace Transform to transfer function and establishment of some settling conditions, CDBC(Continuous time Deadbeat Control) is studied. For CDBC design, transfer function is constituted with delay elements and then order and interpolation conditions are derived. In other way, digital deadbeat controller is implemented and it's output is changed to continuous type by smoothing elements. In this paper multirate sampling is used and so inner controller is sampled faster than output feedback loop. And End order smoothing elements is placed to the output of digital deadbeat controller. By the multirate sampling overall output response is improved. The controller is impleneted as a serial integral compensator in the forward path and a local feedback compensator introduced into the outpute feedback loop. Matlab Simulink is used for simulation.

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A Study on the Pixel-Paralled Image Processing System for Image Smoothing (영상 평활화를 위한 화소-병렬 영상처리 시스템에 관한 연구)

  • Kim, Hyun-Gi;Yi, Cheon-Hee
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.11
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    • pp.24-32
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    • 2002
  • In this paper we implemented various image processing filtering using the format converter. This design method is based on realized the large processor-per-pixel array by integrated circuit technology. These two types of integrated structure are can be classify associative parallel processor and parallel process DRAM(or SRAM) cell. Layout pitch of one-bit-wide logic is identical memory cell pitch to array high density PEs in integrate structure. This format converter design has control path implementation efficiently, and can be utilize the high technology without complicated controller hardware. Sequence of array instruction are generated by host computer before process start, and instructions are saved on unit controller. Host computer is executed the pixel-parallel operation starting at saved instructions after processing start. As a result, we obtained three result that 1)simple smoothing suppresses higher spatial frequencies, reducing noise but also blurring edges, 2) a smoothing and segmentation process reduces noise while preserving sharp edges, and 3) median filtering, like smoothing and segmentation, may be applied to reduce image noise. Median filtering eliminates spikes while maintaining sharp edges and preserving monotonic variations in pixel values.