Inertial navigation system

About: Inertial navigation system is a research topic. Over the lifetime, 14582 publications have been published within this topic receiving 190618 citations. The topic is also known as: intertial guidance system & inertial reference platform.

A Robust Solution to High-Accuracy Geolocation: Quadruple Integration of GPS, IMU, Pseudolite, and Terrestrial Laser Scanning

Abstract: Reliable and accurate geolocation is essential for airborne and land-based remote sensing applications. The detection, discrimination, and remediation of unexploded ordnance (UXO) and other munitions and explosives of concern (MEC) using the currently available detection and geolocation technologies often yield unsatisfactory results, failing to detect all MEC present at a site or to discriminate between MEC and nonhazardous items. Thus, the goal of this paper is to design and demonstrate a high-accuracy geolocation methodology that will address centimeter-level relative accuracy requirements of a man-portable electromagnetic (EM) sensor system in open and impeded environments. The proposed system design is based on the tight quadruple integration of the Global Positioning System (GPS), the inertial measurement unit (IMU) system, the terrestrial radio-frequency (RF) system pseudolite (PL), and terrestrial laser scanning (TLS) to support high-accuracy geolocation for a noncontact EM mapping system in GPS-challenged environments. The key novel component of the proposed multisensor system is the integration of TLS that can provide centimeter-level positioning accuracy in a local frame and thus enables a GPS/IMU/PL-based navigation system to achieve both high absolute and relative positioning accuracy in GPS-impeded environments. This paper presents the concept design of the quadruple integration system, the algorithmic approach to data integration with a special emphasis on TLS integration with GPS/IMU/PL, and the performance assessment based on real data, where centimeter-level relative geolocation accuracy is demonstrated during the GPS signal blockage.

Estimation of Information Sharing Error by Dynamic Deformation Between Inertial Navigation Systems

Abstract: Dynamic deformation of a vehicle and relative position of inertial navigation systems will cause large errors during information sharing. Such errors should be estimated and compensated effectively, or it will cause large errors to navigation information output. Therefore, the model between deformation angle and dynamic lever arm is established to verify that the influence is not coaxial but decussate. Then, estimation and compensation methods for deformation angle and dynamic lever arm are proposed with real-time closed-loop correction of the lever-arm length. Simulation results demonstrate that, for the estimation of misalignment angle, the proposed method has a faster convergence than the traditional method. Moreover, the deformation angle and dynamic lever-arm estimation also takes less time with a higher accuracy than the traditional method.

Time and phase synchronisation via direct-path signal for bistatic synthetic aperture radar systems

Abstract: Bistatic synthetic aperture radar (BiSAR) operates with distinct transmitter and receiver that are mounted on separate platforms. Such a spatial separation results in problems and special requirements that are either not encountered or encountered in less serious form for monostatic SAR. Directly associated with these requirements one has to solve the problems of highly accurate time and phase synchronisations. The impact of oscillator frequency instability on BiSAR is analysed, and a time and phase synchronisation technique via direct-path signal is proposed. With the proposed technique, the direct-path signal of transmitter is received with one appropriative antenna and divided into two channels, one is passed through an envelope detector and used to synchronise the sampling clock, and the other is down-converted and used to compensate the phase synchronisation errors. Finally, the residual time synchronisation error is compensated with range alignment, and the residual phase synchronisation error is compensated with global positioning system/inertial navigation system/inertial measurement units (GPS/INS/IMU) information; then the focusing of BiSAR image can be achieved. Based on this technique, a prototype linearly frequency modulated BiSAR synchronisation system is constructed.The effectiveness of this proposed technique is verified with simulation data.

Method for in-field updating of the gyro thermal calibration of an intertial navigation system

Abstract: An in-field method for correcting the thermal bias error calibration of the gyros of a strapdown inertial navigation system. The method is begun after initial alignment while the aircraft remains parked with the inertial navigation system switched to navigation mode. Measurements are made of navigation system outputs and of gyro temperatures during this data collection period. A Kalman filter processes the navigation system outputs during this time to generate estimates of gyro bias error that are associated with the corresponding gyro temperature measurements. Heading error correcting is performed after the extended alignment data collection period as the aircraft taxis prior to takeoff. The gyro bias error-versus-temperature data acquired, along with the heading error corrections, are employed to recalibrate the existing thermal model of gyro bias error by means of an interpolation process that employs variance estimates as weighting factors.

Golf Swing Motion Tracking Using Inertial Sensors and a Stereo Camera

Abstract: A golf swing motion tracking algorithm is proposed in which the golf club trajectory (position and velocity) and club face orientation information are given. Two sensors are used in the algorithm: an inertial sensor unit on the golf club, and a stereo camera that captures infrared light emitting diodes (LEDs), also on the golf club. During the address and impact golf swing phases, the camera captures the infrared LEDs on the golf club. Using the infrared LEDs as landmarks, the position and orientation of the golf club are computed. When the golf club is moving, an inertial navigation algorithm is used to compute the golf club trajectory. An indirect Kalman filter with nine states is used to combine the inertial sensor and vision data. The average position accuracy is about 3.6 cm and the maximum error is about 13.2 cm. The proposed system can be used to analyze golf swings quantitatively.