• Journal of the Korea Institute of Military Science and Technology
• /
• v.12 no.3
• /
• pp.368-377
• /
• 2009

In this paper we study the gyro bias calibration method of SDINS(Strap-Down Inertial Navigation System). Generally, SDINS's calibration is performed in 2-axis(or 3-axis) rate table with chamber for varying ambient temperature. We assumed that the majority of calibration-parameter except for gyro bias is knowned. During gyrobias calibration procedure, it can be induced some disturbances(accelerometer's short-term error induced rate table rotation and anti-vibration mount's rotation). In these cases, old gyro-bias calibration methods(using velocity error or attitude error) have an error, because these disturbances are not detectable at the same time. So that, we propose a new gyro-bias calibration method(heading error minimizing using equivalent linear transformation) that can detect anti-vibration mount's rotation. And we confirm efficiency of the new gyro-bias calibration method by simulation.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.5
• /
• pp.674-679
• /
• 1998

In this paper, a new coarse alignment algorithm is proposed for roughly determining the initial attitude of the vehicle. The algorithm, referred as two-step coarse alignment algorithm, computes roll and pitch angle of the vehicle using accelerometer outputs, and then determines yaw angle with gyro outputs. With the geometric relation between sensor outputs and attitude angles, the algorithm error is analytically derived and compared with the previous coarse alignment algorithm that computes a transformation matrix using accelerometer md gyro outputs simultaneously. The simulation is also performed by varying the sensor errors. The results show that the proposed two-step coarse alignment algorithm has better performance for east tilt angle.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.4
• /
• pp.369-373
• /
• 2001

This paper is concerned with a transfer alignment of SDINS under ship motions. To reduce alignment errors induced by the ship body flexure, an error compensation method is suggested based on velocity and DCM partial matching, and by interpreting the simulation results and comparing with the conventional velocity and quaternion partial matching, it is shown that the proposed method is effective enough to improve the azimuth alignment performance.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.4
• /
• pp.362-368
• /
• 2001

We study on the velocity matching algorithm for transfer alignment of inertial navigation system(INS) using a robust H$_2$ filter. We suggest an uncertainty model and a discrete robust H$_2$filter for INS and apply the suggested robust H$_2$ filter to the uncertainty model. The discrete robust H$_2$filter is shown by simulation to have better performance time and accuracy than Kalman filter.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.53-56
• /
• 1987

Gyroscope is a key sensor for inertial navigation system (INS) which is a navigational instrument necessary to guide and control a free vehicle, and an important instrument for defense, aeronautical, and space industries that is and will be actively involved. In this study, design parameters, scale factor and linearity, of torquer which is one of the components of two degree of freedom dynamically tuned gyroscope (DTG) are presented. The magnetic circuit of torquer is so complicated that it is difficult to analyze it with analytic method. Thus these parameters are calculated by using finite element method with analysis of magnetic vector potential for axisymmetric 3-dimension magnetic field.

• Journal of Institute of Control, Robotics and Systems
• /
• v.3 no.3
• /
• pp.238-243
• /
• 1997

A new transfer alignment algorithm using the velocity and the quaternion partial matching methods is proposed to reduce the effect of a ship's Y-axis flexure on the performance of azimuth error estimation of Kalman filter. The simulation results show that it can significantly reduce the effect of Y-axis flexure on error estimation by the transfer alignment algorithm. As its results, azimuth transfer alignment error is reached up to 3 mrad under proper roll and pitch attitude motion of the ship.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1762-1763
• /
• 2007

본 논문의 목적은 이족 로봇이 스스로의 위치, 속도, 자세 등을 판단할 수 있도록 하기위한 관성항법시스템을 설계하는 것이다. 관성항법시스템은 외부장치의 도움 없이 로봇의 위치, 속도 및 자세 결정이 가능한 독립적인 항법 시스템으로 전파장애나 환경변화에 영향을 받지 않으며, 비교적 정확한 위치정보를 제공한다. 반면 시간이 지남에 따라 오차가 누적된다는 단점이 있으나 좁은 공간에서 단시간 동작하는 이족로봇에 있어 큰 문제가 되지 않는다. 이 관성항법시스템을 이용하여 독립적인 이족 로봇이 위치, 속도 및 자세를 판단 가능하여 보다 지능적인 임무를 수행할 수 있다. 본 연구에서는 관성항법시스템의 구조와 이론적 배경을 통한 설계, 그리고 이족로봇에 적용을 위한 방법을 제시한다.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.2
• /
• pp.13-22
• /
• 1997

Strapdown inertial navigation system(SDINS) is a navigational instruments necessary to guide and con- trol a free vehicle. In this study, an error analysis of mechanical parts is carried out for manufacturing a dynamically tuned gyroscope. The errors usually come from the tolerance in machining and assembly. In the error analysis, a criterion to be considered during designing and manufacturing is proposed by quanti- tatively analyzing the effect of DTG performance by tolerances. The theory of dynamic balancing is deduced and unbalance is reduced through experiment.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.17 no.4
• /
• pp.373-381
• /
• 1999

Mobile Mapping System can be defined as vehicle mapping system which collects rapidly spatial data by integrated Gps/digital imaging system. Kinematic positioning by GPS is essential technology of Mobile Mapping System. This paper aims at analysing the accuracy and efficiency of kinematic positioning by GPS platformed on moving vehicle. For the purpose, roads were surveyed by vehicle/kinematic GPS. The results show that vehicle/kinematic GPS can measure spatial position faster, and still maintain a reasonable accuracy. But inertial navigation system and GPS should be integrated to compute continuous vehicle track and overcome gaps by blocked satellite signals for the more accurate positioning.

• Journal of Korean Society for Geospatial Information Science
• /
• v.25 no.2
• /
• pp.21-29
• /
• 2017

For the efficient and stable operation of autonomous vehicles or advanced driver assistance systems being actively studied nowadays, it is important to determine the positions of the vehicle accurately and economically. A satellite based navigation system is mainly used for positioning, but it has a limitation in signal blockage areas. To overcome this limitation, sensor fusion methods including additional sensors such as an inertial navigation system have been mainly proposed but the high sensor cost has been a problem. In this work, we develop a vehicle position estimation algorithm using in-vehicle sensors and a low-cost imaging sensor without any expensive additional sensor. We determine the vehicle positions using the velocity and yaw-rate of a car from the in-vehicle sensors and the position and attitude of the camera based on the single photo resection process. For the evaluation, we built a prototype system, acquired test data using the system, and estimated the trajectory. The proposed algorithm shows the accuracy of about 40% higher than an in-vehicle sensor only method.