Real Time Data Smoothing to Improve the Performance of a Strapdown Nongyroscopic Attitude Propagation Inertial Unit

摘要

The possibility of using a strapdown nongyroscopic inertial unit for attitude propagation is analyzed. A design made up exclusively of linear accelerometers is considered. The use of accelerometers leads to a cheaper and simple design but poses problems related to the level of the attainable accuracy. This can be attenuated by eliminating most of the systematic errors with the help of calibration. However, the purely random errors can only be eliminated if smoothing of the accelerometers output data is done. In the paper a scheme to do this in real time is proposed, where data smoothing by curve fitting is adopted using Kalman filtering and a state noise estimation technique. Tests with digitally simulated data indicate feasibility of using the proposed strapdown design for satellite missions requiring low accuracy in attitude control.