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.

Heading alignment with summarized inertial pose constraints

Abstract: A discontinuity seems to exist in present aided inertial navigation systems - the operational availability of high cost inertial navigation currently depends on the availability of a valid GPS lock. In general GPS solutions can be two or more orders cheaper than their inertial sensors counterparts. This paper addresses the north alignment by gyrocompassing in the context of more modern smoothing techniques. Incremental smoothing is becoming a serious contender for in-situ state estimation. The work here presents a probabilistic model for north alignment with an analysis towards the achievable accuracy of such a system. A pose graph formulation is used to estimate inertial sensor calibration terms over a long spanning trajectory, from which a true north alignment can be extracted. The preintegral method is used to condense high rate inertial data, but allow for post integration bias correction. Results show that the proposed alignment scheme is feasible, and would for gyrocompassing alignment relaxed sensor performance constraints.

A review on measuring cervical range of motion using an inertial measurement unit

Abstract: Objectives: The purpose of this study was to review the article using an IMU(Inertial Measurement Unit) for measuring the cervical range of motion and to evaluate the feasibility of using an IMU for measuring the cervical range of motion. Method: Scopus was used to search for the articles relating to the inclusion criteria. Which is measuring the cervical range of motion using an IMU. A total of 15 articles were selected through discussion. Degree and the reliability of the cervical range of motion and the validity of the data within the articles were extracted. Results: The measurement of the cervical range of motion using an IMU were 92.25o to 138.2 o , 122.4o to 154.9o, 73.75o to 93.1o on the sagittal plane, transverse plane, and coronal plane respectively. 38 of the 43 values showed good reliability. They were larger than 0.75. 5 of the 43 values showed reliability less than 0.75. They were measured by smart phone. 16 of the 21 values showed good validity. The remaining 5 were measured by smart phone. The lower reliability and validity of smart phone were related to the protocol. The IMU can measure the coupling motion and may be used in various situations. Conclusion: The IMU may become a gold standard for measuring the cervical range of motion. The IMU measured not only the cervical range of motion but also the coupling motion. Furthermore, IMU may be used in various situations. Therefore, IMU must be considered a valuable measurement device.

Ring laser gyros

Abstract: Along with advanced digital computing a revolutionary new inertial sensor has changed the design of inertial navigation systems. This new sensor, the ring laser gyroscope, is discussed

Method for installing an inertial reference unit in an aircraft, and aircraft equipped in this way

Abstract: The invention relates to a method for installing an inertial reference unit in an aircraft, in which: a reference unit support ( 1 ) is fixed to a structural element of the aircraft; support installation angles—in heading, roll and pitch—representative of angular errors of positioning of the reference unit support relative to an aircraft coordinate system are determined, this determination being based on the measurement of coordinates of points of a previously defined reference coordinate system and of characteristic points of the reference unit support; the said support installation angles are recorded in memory means, for the purposes of subsequent correction of data measured by the inertial reference unit. Preferably the reference coordinate system used is defined by means of targets formed on the structure of a segment of the aircraft for the purposes of joining this segment with an adjacent segment.