Size Effect on Navigation Using a Strapdown IMU
Abstract
Size effects in a strapdown IMU (Inertial Measurement Unit) are not always ignorable. They should be considered in the error budget for high accuracy inertial navigation. This report presents results of a study on size effects. It is found that while each individual accelerometer has only one type of size effect, an IMU has two in general, the 'mounting offset size effect' and the cluster size effect. General formulas for determining IMU size effect errors are developed in the report. Numerical examples, laboratory test results, and flight simulation results are given to demonstrate the size effects and to reveal their effect on navigation error. It is discussed that an optimum orientation for the accelerometer cluster can be chosen to minimize the navigation errors caused by size effects. It is also shown that, in principle, size effect of an IMU can be compensated using the angular rate information available from gyros. A size effect compensation concept is proposed with the associated computation algorithm given.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 27, 1979
- Accession Number
- ADA075434
Entities
People
- H. V. White
- J. C. Hung
- J. S. Hunter
- W. W. Stripling
Organizations
- United States Army Aviation and Missile Command