• Title/Summary/Keyword: Heading estimation

Search Result 126, Processing Time 0.022 seconds

Sampled-data Fuzzy Observer Design for an Attitude and Heading Reference System and Its Experimental Validation

  • Kim, Han Sol;Park, Jin Bae;Joo, Young Hoon
    • Journal of Electrical Engineering and Technology
    • /
    • v.12 no.6
    • /
    • pp.2399-2410
    • /
    • 2017
  • In this paper, a linear matrix inequality-based sampled-data fuzzy observer design method is proposed based on the exact discretization approach. In the proposed design technique, a numerically relaxed observer design condition is obtained by using the discrete-time fuzzy Lyapunov function. Unlike the existing studies, the designed observer is robust to the uncertain premise variable because the fuzzy observer is designed under the imperfect premise matching condition, in which the membership functions of the system and observer are mismatched. In addition, we apply the proposed method to the state estimation problem of the attitude and heading reference system (AHRS). To do this, we derive a Takagi-Sugeno fuzzy model for the AHRS system, and validate the proposed method through the hardware experiment.

Mechanism Development and Heading Control of Catamaran-type Sail Drone

  • Man, Dong-Woo;Kim, Hyun-Sik
    • Journal of Ocean Engineering and Technology
    • /
    • v.35 no.5
    • /
    • pp.360-368
    • /
    • 2021
  • The need for energy harvesting in marine environments is gradually increasing owing to the energy limitation of marine robots. To address this problem, a catamaran-type sail drone (CSD), which can harvest marine energies such as wind and solar, was proposed in a previous study. However, it was designed and manufactured without considering the stability, optimal hull-form, and maintenance. To resolve these problems, a CSD with two keels, a performance estimator, V-shape hulls, and modularized components is proposed and its mechanism is developed in this study. To verify the performance of the CSD, the performance estimation using smoothed-particle hydrodynamics (SPH) and the heading control using fuzzy logic controller (FLC) are performed. Simulation results show the attitude stability of the CSD and the experimental results show the straight path of the CSD according to wind conditions. Therefore, the CSD has potential applications as an energy harvesting system.

Iterative Polynomial Fitting Technique Using Polynomial Coefficients for the Nonlinear Line Array Shape Estimation (비선형 선배열 형상 추정을 위한 계수 반복 다항 근사화 기법)

  • Cho, Chom Gun
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.9 no.2 s.25
    • /
    • pp.20-25
    • /
    • 2006
  • Low frequency towed line array with high array gain and beam resolution is a long range surveillance sensor for anti-submarine warfare. The beam characteristics is however deteriorated due to the distorted line array sensor caused by low towing speed, wind, current, and towing ship maneuvering. An adaptive beamforming method is utilized in this paper to enhance the distorted line array beam performance by estimating and compensating the nonlinear array shape. A polynomial curve fitting in the least square sense is used to estimate the array shape iteratively with the distributed heading sensors data along the array. Real time array shape estimation and nonlinear array beam calculation is applied to a very long towed line array sensor system and the beam performance is evaluated and compared to the linear beamformer for the simulation and sea trial data.

The Posture Estimation of Mobile Robots Using Sensor Data Fusion Algorithm (센서 데이터 융합을 이용한 이동 로보트의 자세 추정)

  • 이상룡;배준영
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.16 no.11
    • /
    • pp.2021-2032
    • /
    • 1992
  • A redundant sensor system, which consists of two incremental encoders and a gyro sensor, has been proposed for the estimation of the posture of mobile robots. A hardware system was built for estimating the heading angle change of the mobile robot from outputs of the gyro sensor. The proposed hardware system of the gyro sensor produced an accurate estimate for the heading angle change of the robot. A sensor data fusion algorithm has been developed to find the optimal estimates of the heading angle change based on the stochastic measurement equations of our readundant sensor system. The maximum likelihood estimation method is applied to combine the noisy measurement data from both encoders and gyro sensor. The proposed fusion algorithm demonstrated a satisfactory performance, showing significantly reduced estimation error compared to the conventional method, in various navigation experiments.

Iterative Polynomial Fitting Technique for the Nonlinear Array Shape Estimation (비선형 선배열 형상 추정을 위한 반복 다항 근사화 기법)

  • 조요한;조치영;서희선
    • The Journal of the Acoustical Society of Korea
    • /
    • v.20 no.8
    • /
    • pp.74-80
    • /
    • 2001
  • Because of ocean waves, swell, steering corrections, etc, the hydrophones of a towed array will not live along a straight line. However the degradation of bearing estimation performance occurs when beamforming is carried out on the hydrophone outputs of an acoustic towed array which is not straight. So it is required to estimate the shape of the array for the improved beamformer output. In this paper, an iterative array shape estimation technique is presented, which is based on the use of the least squares polynomial fitting to the data from heading sensors. The estimation error and the influence of deformations on the performance of the conventional beamformer output are investigated. Finally, the suggested method is applied to the real system in order to investigate the applicability.

  • PDF

Bezier Curve-Based Path Planning for Robust Waypoint Navigation of Unmanned Ground Vehicle (무인차량의 강인한 경유점 주행을 위한 베지어 곡선 기반 경로 계획)

  • Lee, Sang-Hoon;Chun, Chang-Mook;Kwon, Tae-Bum;Kang, Sung-Chul
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.17 no.5
    • /
    • pp.429-435
    • /
    • 2011
  • This paper presents a sensor fusion-based estimation of heading and a Bezier curve-based motion planning for unmanned ground vehicle. For the vehicle to drive itself autonomously and safely, it should estimate its pose with sufficient accuracy in reasonable processing time. The vehicle should also have a path planning algorithm that enables to adapt to various situations on the road, especially at intersections. First, we address a sensor fusion-based estimation of the heading of the vehicle. Based on extended Kalman filter, the algorithm estimates the heading using the GPS, IMU, and wheel encoders considering the reliability of each sensor measurement. Then, we propose a Bezier curve-based path planner that creates several number of path candidates which are described as Bezier curves with adaptive control points, and selects the best path among them that has the maximum probability of passing through waypoints or arriving at target points. Experiments under various outdoor conditions including at intersections, verify the reliability of our algorithm.

Vehicle Reference Dynamics Estimation by Speed and Heading Information Sensed from a Distant Point

  • Yun, Jeonghyeon;Kim, Gyeongmin;Cho, Minhyoung;Park, Byungwoon;Seo, Howon;Kim, Jinsung
    • Journal of Positioning, Navigation, and Timing
    • /
    • v.11 no.3
    • /
    • pp.209-215
    • /
    • 2022
  • As intelligent autonomous driving vehicle development has become a big topic around the world, accurate reference dynamics estimation has been more important than before. Current systems generally use speed and heading information sensed from a distant point as a vehicle reference dynamic, however, the dynamics between different points are not same especially during rotating motions. In order to estimate properly estimate the reference dynamics from the information such as velocity and heading sensed at a point distant from the reference point such as center of gravity, this study proposes estimating reference dynamics from any location in the vehicle by combining the Bicycle and Ackermann models. A test system was constructed by implementing multiple GNSS/INS equipment on an Robot Operating System (ROS) and an actual car. Angle and speed errors of 10° and 0.2 m/s have been reduced to 0.2° and 0.06 m/s after applying the suggested method.

The Position and Heading Estimation System of Mobile Robot Using the Extended Kalman Filter (확장칼만필터를 이용한 이동로봇의 위치와 자세 추정 시스템)

  • Jin, Kwang-Sik;Yun, Tae-Sung
    • Proceedings of the KIEE Conference
    • /
    • 1999.11c
    • /
    • pp.683-686
    • /
    • 1999
  • 이동로봇은 주행성을 가지며 설정된 이동 경로에 따라 목적지까지 자율적으로 이동하기 위해서는 이동로봇의 실제 위치에 대한 정확한 정보가 확보되어야 한다. 정보확보를 위해서 보통 엔코더, 자이로센서, 비젼센서, 레이저 거리등의 센서를 주로 사용한다. 본 연구에서 주행중인 이동로봇의 위치는 상대센서인 엔코더를 통해 측정된 운동변화량과 출발점에서 이동로봇의 위치로부터 자기유도 주행방법에 의해 계산된다. 이들 상대센서는 이동로봇의 실제 이동에 따라 주행거리 및 주행 방향 변화를 항상 측정할 수 있으므로, 전체 주행구간에 걸쳐 이동로봇의 위치를 연속적으로 측정할 수 있다는 장점이 있으나, 상대센서 측정값에 발생된 오차가 위치 평가값이 연속적으로 누적되므로 실제 위치에 대한 오차가 발생하는 단점이 있다. 즉, 바닥의 미끄럼, 요철, 로봇의 요동(Vibration)등 큰 오차의 요인이 된다. 본 연구에서는 위치를 직접 추정하지 않고 엔코드에서 나온 위치오차, Heading 오차, 자체 엔코드오차 그리고, 자이로 오차와 지자기 센서 오차를 Extended Kalman Filter를 통해 추정하여 이 오차를 다시 위치 계산과 Heading에 되돌려 줌으로서 오차를 보정하는 방법을 제시한다.

  • PDF

Vibration-Robust Attitude and Heading Reference System Using Windowed Measurement Error Covariance

  • Kim, Jong-Myeong;Mok, Sung-Hoon;Leeghim, Henzeh;Lee, Chang-Yull
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.18 no.3
    • /
    • pp.555-564
    • /
    • 2017
  • In this paper, a new technique for attitude and heading reference system (AHRS) using low-cost MEMS sensors of the gyroscope, accelerometer, and magnetometer is addressed particularly in vibration environments. The motion of MEMS sensors interact with the scale factor and cross-coupling errors to produce random errors by the harsh environment. A new adaptive attitude estimation algorithm based on the Kalman filter is developed to overcome these undesirable side effects by analyzing windowed measurement error covariance. The key idea is that performance degradation of accelerometers, for example, due to linear vibrations can be reduced by the proposed measurement error covariance analysis. The computed error covariance is utilized to the measurement covariance of Kalman filters adaptively. Finally, the proposed approach is verified by using numerical simulations and experiments in an acceleration phase and/or vibrating environments.

Performance Improvement of an INS by using a Magnetometer with Pedestrian Dynamic Constraints

  • Woyano, Feyissa;Park, Aangjoon;Lee, Soyeon
    • IEIE Transactions on Smart Processing and Computing
    • /
    • v.6 no.1
    • /
    • pp.1-9
    • /
    • 2017
  • This paper proposes to improve the performance of a strap down inertial navigation system using a foot-mounted low-cost inertial measurement unit/magnetometer by configuring an attitude and heading reference system. To track position accurately and for attitude estimations, considering different dynamic constraints, magnetic measurement and a zero velocity update technique is used. A conventional strap down method based on integrating angular rate to determine attitude will inevitably induce long-term drift, while magnetometers are subject to short-term orientation errors. To eliminate this accumulative error, and thus, use the navigation system for a long-duration mission, a hybrid configuration by integrating a miniature micro electromechanical system (MEMS)-based attitude and heading detector with the conventional navigation system is proposed in this paper. The attitude and heading detector is composed of three-axis MEMS accelerometers and three-axis MEMS magnetometers. With an absolute algorithm based on gravity and Earth's magnetic field, rather than an integral algorithm, the attitude detector can obtain an absolute attitude and heading estimation without drift errors, so it can be used to adjust the attitude and orientation of the strap down system. Finally, we verify (by both formula analysis and from test results) that the accumulative errors are effectively eliminated via this hybrid scheme.