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.

Method and system for processing pulse signals within an inertial navigation system

Abstract: A method and system (100) for processing pulse signals within an inertial device is provided. The inertial device may have inertial sensors, such as accelerometers (110, 112, 114) and gyroscopes (104, 106, 108). The inertial sensors may output signals represen tative of a moving body's motion. The signals may require correction due to imperfections and other errors of the inertial sensors. The inertial device may receive signals from the inertial sensors and process the signals on a signal-by-signal basis so that when processing the signals, the inertial device at least recognizes which sensor output a signal and when the signal was output. The inertial device may then correlate signals that were output from the inertial sensors at selected times in order to transform the signals into desired navigational frame of reference.

Extrinsic parameter calibration of a vision-aided inertial navigation system

Abstract: This disclosure describes various techniques for use within a vision-aided inertial navigation system (VINS). A VINS comprises an image source to produce image data comprising a plurality of images, and an inertial measurement unit (IMU) to produce IMU data indicative of a motion of the vision-aided inertial navigation system while producing the image data, wherein the image data captures features of an external calibration target that is not aligned with gravity. The VINS further includes a processing unit comprising an estimator that processes the IMU data and the image data to compute calibration parameters for the VINS concurrently with computation of a roll and pitch of the calibration target, wherein the calibration parameters define relative positions and orientations of the IMU and the image source of the vision-aided inertial navigation system.

Personal inertial surveying system

Abstract: A personal inertial surveying system includes an inertial sensor and processing equipment adapted to be mounted to or carried by a person walking through a region being surveyed. As the person walks inaccuracies in position measurement due to drifts in the inertial sensor can be conveniently corrected. Corrections can be performed often during brief pauses as the person paces though the region, resulting in improved accuracy in the survey.

Method and apparatus for improving the accuracy of position estimates in a satellite based navigation system using velocity data from an inertial reference unit

Abstract: A method and apparatus for computing a precise position estimate for a receiver at or near the surface of the Earth uses a inertial reference unit associated with the receiver and a satellite-based navigation system. The satellite-based navigation system is used to determine a position estimate for the receiver at consecutive positions along its path of motion. The inertial reference unit is used to determine velocity vectors for the receiver. Each velocity vector corresponds to travel of the receiver between the consecutive positions. The velocity vectors from the inertial reference unit are used to refine the position estimates of the satellite-based navigation system to obtain precise position estimates.

The Compensation Effects of Gyros' Stochastic Errors in a Rotational Inertial Navigation System

Abstract: The errors of an inertial navigation system (INS) in response to gyros' errors can be effectively reduced by the rotation technique, which is a commonly used method to improve an INS's accuracy. A gyro's error consists of a deterministic contribution and a stochastic contribution. The compensation effects of gyros' deterministic errors are clear now, but the compensation effects of gyros' stochastic errors are as yet unknown. However, the compensation effects are always needed in a rotational inertial navigation system's (RINS) error analysis and optimization study. In this paper, the compensation effects of gyros' stochastic errors, which are modelled as a Gaussian white (GW) noise plus a first-order Markov process, are analysed and the specific formulae are derived. During the research, the responses of an INS's and a RINS's position error equations to gyros' stochastic errors are first analysed. Then the compensation effects of gyros' stochastic errors brought by the rotation technique are discussed by comparing the error propagation characteristics in an INS and a RINS. In order to verify the theory, a large number of simulations are carried out. The simulation results show a good consistency with the derived formulae, which can indicate the correctness of the theory.