A position reference system for flight test, based on GPS/IRS integration

Nowadays, several flight test organizations recognize the potential of the Navstar Global Positioning System (GPS) for flight test trajectorydetermination. In 1990 the National Aerospace Laboratory of the Netherlands (NLR) started the development of a Position Reference System (PRS) based on an Inertial Reference System (IRS), updated by GPS...

Some aerospace applications of estimation theory

In this report, the application of estimation theory to three problems from aerospace research is described. The applications considered deal with spacecraft attitude estimation, software reliability modelling and estimation, and with a satellite-based navigation algorithm. Maximum likelihood estimation is used in the software reliability case...

In-flight attitude estimations and control experiments with Iras based on modern control theory

One of the research activities of the Space Division of the National Aerospace Laboratory NLR is the application of modern estimation and control theory to spacecraft attitude control problems. Algorithms for spacecraft state estimation and attitude control, as well as for inertial-optical attitude determination have been developed previously...

Application of model following control and estimation techniques to attitude control of manoeuvring spacecraft Part I: Theory and simulation results

This document presents an approach to sampled data, on-board estimation and control of the attitude motion of manoeuvring spacecraft. Algorithms which are developed include: a - model following control of attitude manoeuvres b - estimation of spacecraft state (attitude, angular velocity, disturbance torque) c - optical-inertial attitude...

Experimental and system study of Reaction Wheels. Part I: Measurement and statistical analysis of force and torque irregularities

Torque and force irregularities of running reaction wheels were studied. In this first part of the study report results from noise measurements at constant wheel speeds on various types of current technology European reaction wheels, both with ball- and magnet bearings and with DC or AC drive motor, are presented. The measured noise in radial...

Experimental and system study of Reaction Wheels. Part II: System study on wheel state feedback

The increasing power of on-board processors allows more freedom in the design and operation of reaction wheel control systems. This report discusses several performance and implementation aspects of the operation of wheel systems which have their own internal feedback control system. A model following control concept is found to be superior. The...

Digital filtering methods, with applications to spacecraft attitude determination in the presence of modelling errors. Part II: Extension of theory, and applications

The present issue is the second and final part of a report describing the results of a study about digital filtering. The first part is available as the report NLR TR 760U8 U. The report considers a number of digital filtering methods and gives examples of their application. The methods include batch processing methods and recursive methods....

Accurate spacecraft attitude estimation with the ESA starmapper

The ESA starmapper is an optical-electronic instrument with an array of photo-sensitive slits, to "be strapped down to spinning spacecraft. Recorded times of passage of known stars over these slits, together with mathematical models for spacecraft dynamics and starmapper instrument, provide the basis for recursive estimation of the spacecraft...

Evaluation of a method to extract performance data from dynamic maneuvers for a jet transport aircraft

A very accurate measurement system and a data reduction method have been developed to extract performance data from a single dynamic maneuver, in order to reduce the large amoimt of flight hours required for the determination of these data by means of measurements in steady flight. In order to evaluate the applicability of this method to a modem...