GPS/INS

About: GPS/INS is a research topic. Over the lifetime, 3554 publications have been published within this topic receiving 62784 citations.

Hybrid processing method and apparatus, navigation system, program storage device and computer data signal embodied in carrier wave

Abstract: A hybrid processing apparatus outputs current position data, indicating a current position of a movable body, on the basis of self-contained positioning data from a self-contained positioning apparatus ( 10 ) and GPS measurement data from a GPS receiver ( 18 ). In the hybrid apparatus, a judging device ( 20 ) judges whether or not an estimated error of the self-contained positioning data is greater than a predetermined threshold value. A first calculation device ( 20 ) calculates the current position by combining the GPS measurement data with the self-contained positioning data or a second calculation device ( 20 ) calculates the current position without combining the GPS measurement data, depending upon a judgment result of the judging device.

Development of a low-cost GPS/INS integrated system for tractor automatic navigation

Abstract: The use of low-cost single GPS receivers and inertial sensors for auto-guidance applications has been limited by their reduced accuracy and signal drift over time compared to real-time kinematic (RTK) differential GPS units and fiber-optic gyroscope (FOG) sensors. In this study, a prototype low-cost GPS/INS integrated system consisting of a triangle-shaped array of three Garmin 19x GPS receivers and an Xsens inertial measurement unit (IMU) to improve the accuracy of position and heading angle measured with a single GPS receiver was developed. A triangular algorithm that uses data collected from the three single GPSs mounted on the angular points of a triangular frame was designed. A sensor fusion algorithm based on the Kalman filter combining the GPS and IMU data was developed by integrating position data and heading angles of a triangular array of GPS receivers. The optimized values of two noise covariance matrixes (Q and R) for the Kalman filtering were determined using the Central Composite Design (CCD) method. As compared to the use of a single Garmin GPS receiver, use of the developed GPS/INS system showed improved accuracy performance in terms of both position and heading angle, with reductions in root mean square errors (RMSEs) from 2.7 m to 0.64 m for position and from 8.9o to 2.1o for heading angle. The accuracy improvements show new potential for agricultural auto-guidance applications. Keywords: global positioning system, tractor, automatic navigation, sensor fusion, Kalman filter, inertial sensor, heading angle DOI: 10.3965/j.ijabe.20171002.3070 Citation: Han X Z, Kim H J, Jeon C W, Moon H C, Kim J H. Development of a low-cost GPS/INS integrated system for tractor automatic navigation. Int J Agric & Biol Eng, 2017; 10(2): 123–131.

A Compensator to Advance Gyro-Free INS Precision

Abstract: The proposed inertial measurement unit (IMU) is composed of accelerometers only. It can determine a vehicle's position and attitude, which is the Gyro-free INS. The Gyro-free INS error is deeply affected by the sensor bias, scale factor and misalignment. However, these parameters can be obtained in the laboratory. After these misalignments are' corrected, the Gyro-free strap-down INS could be more accurate. This paper presents a compensator design for the strap-down six-accelerometer TNS to correct misalignment. A calibration experiment is taken to get the error parameters. A simulation results show that it will decrease the INS error to enhance the performance after compensation.

An Enhanced Error Model for EKF-Based Tightly-Coupled Integration of GPS and Land Vehicle’s Motion Sensors

Abstract: Reduced inertial sensor systems (RISS) have been introduced by many researchers as a low-cost, low-complexity sensor assembly that can be integrated with GPS to provide a robust integrated navigation system for land vehicles. In earlier works, the developed error models were simplified based on the assumption that the vehicle is mostly moving on a flat horizontal plane. Another limitation is the simplified estimation of the horizontal tilt angles, which is based on simple averaging of the accelerometers’ measurements without modelling their errors or tilt angle errors. In this paper, a new error model is developed for RISS that accounts for the effect of tilt angle errors and the accelerometer’s errors. Additionally, it also includes important terms in the system dynamic error model, which were ignored during the linearization process in earlier works. An augmented extended Kalman filter (EKF) is designed to incorporate tilt angle errors and transversal accelerometer errors. The new error model and the augmented EKF design are developed in a tightly-coupled RISS/GPS integrated navigation system. The proposed system was tested on real trajectories’ data under degraded GPS environments, and the results were compared to earlier works on RISS/GPS systems. The findings demonstrated that the proposed enhanced system introduced significant improvements in navigational performance.

On Real-Time High Precision Velocity Determination for Standalone GPS Users

Abstract: The NAVSTAR Global Positioning System (GPS) is a satellite-based radionavigation system designed for positioning, velocity determination and timing. The relative movement between a GPS receiver and a GPS satellite causes the received signal frequency to differ from the transmitted frequency due to the Doppler effect. This frequency difference, an observable in GPS measurements, is referred to as the Doppler shift. However, the Doppler shift is biased by the inherent errors in the signal propagation. Since velocities of GPS satellites are known, the velocity of a user can be determined through observing four or more satellites, similar to GPS positioning.When the GPS selective availability (SA) was activated, errors imposed on the ephemeris and satellite clocks significantly affected the accuracy of both GPS positioning and velocity determination. The removal of SA has enabled a significant improvement on the accuracy of both GPS satellite orbits and clocks. As a result, velocity accuracy at sub-c...