Inertial reference unit

About: Inertial reference unit is a research topic. Over the lifetime, 1306 publications have been published within this topic receiving 22068 citations. The topic is also known as: IRU.

Autonomous Inertial Relative Navigation with Sight-Line-Stabilized Sensors for Spacecraft Rendezvous

Abstract: consists of the inertial position and velocity of the client satellite governed by a high-fidelity nonlinear orbital dynamics model. The error covariance matrix is formulated in terms of the estimation error in the relative position and velocity of the client satellite, consistent with the sensor measurements. Inertial attitude pointing and rate commands for tracking the client satellite are determined using the estimates of the client’s inertial relative position and velocity. To estimate the inertial attitude of the chaser satellite outside the space-integrated Global Positioning System/inertialnavigationsystem,anewthree-axissteady-stateanalyticalattitudeestimatorisdevelopedthatblends thegyro-andthestar-tracker-measuredattitudes.Thesimulationresultsofamidrangespacecraftrendezvoususing glideslope guidance validate this new six-state autonomous inertial relative navigation technique. The simulation resultsshowthattheimagingsensor’ssightlinecanbestabilizedattheclientsatelliteinmidrangeaccuratelyenough to enable the laser range finder to measure the range occasionally, but these measurements are not necessary for the midrangerendezvousphase,becausetheextendedKalman filtercanestimatetherangewiththeanglemeasurements of the imaging sensor.

Fiber-optic strapdown inertial system with sensing cluster continuous rotation

Abstract: This research describes a technique and a performance analysis of a fiber-optic strapdown inertial system with sensing cluster continuous rotation around the vertical body axis of the vehicle. The bias errors of these inertial sensors, gyros and accelerometers with cluster rotation, will have periodically varying corresponding components along the body axes. The modulated sensor errors produce reduced system errors. Simulation results indicate that, compared with the conventional method, the proposed approach attenuates the navigation errors and alignment errors due to the gyros' error and the accelerometers' error.

Design and implementation of IMU-based human arm motion capture system

Abstract: This paper presents the design of a generic inertial measurement unit (IMU) module for motion capture system. The module consists of 32-bit microcontroller with gyroscope, accelerometer, and magnetometer to provide orientation estimation of human limbs. An orientation estimation algorithm that compensates magnetic distortion is implemented. Our main contribution is on the sensor network which is low cost but high speed. We developed a serial-chain network for sensors interconnection in which UART communication is used. We also consider frame alignment issue in developing human arm motion capture to improve tracking accuracy. A simple frame calibration method is implemented and tested.

Attitude correction apparatus and method for inertial navigation system using camera-type solar sensor

Abstract: Disclosed herein is an attitude correction apparatus for an Inertial Navigation System (INS) using a camera-type solar sensor. The present invention relates to a system for correcting errors occurring in an inertial navigation system, in which inertial sensors, such as gyroscopes and accelerometers are combined with each other to calculate the attitude, velocity and position of an airplane, and to an apparatus for utilizing a sun-line of sight vector, generated by a camera-type solar sensor, that uses images of the moving sun, and the output value of the inertial navigation system, thus correcting the attitude of an airplane and the errors of sensors. The attitude correction apparatus of the present invention includes a camera-type solar sensor for detecting the sun, a signal processing unit for receiving and synchronizing information, and a data collection processing unit for performing post-processing on information, thus correcting an error.

Method and system for estimation of inertial sensor errors in remote inertial measurement unit

Abstract: A method and system for estimation of inertial sensor errors is provided. The method includes receiving first inertial output data from a master inertial measurement unit (IMU) mounted on a host platform, with the first inertial output data comprising a change in velocity (delta V) and a change in angle (delta theta), and receiving second inertial output data from a remote IMU mounted on the host platform at a predetermined fixed distance from the master IMU, with the second inertial output data comprising a delta V and a delta theta. The first inertial output data is compared with the second inertial output data to determine a difference between the delta V of the first inertial output data and the delta V of the second inertial output data, and to determine a difference between the delta theta of the first inertial output data and the delta theta of the second inertial output data. The determined differences are applied to estimate inertial sensor errors in the remote IMU.