From simulations to operations: Development in Test and Verification Equipment for Spacecraft TNG-GEN-TP-002

Supported by Research and Development programs of the European Space Agency (ESA), simulation and test tools are being developed to improve the life cycle cost efficiency of spacecraft development. Standardisation and rationalisation, use of (C)OTS products, reuse of both software and hardware are some of the lines along which schedule...

Discussion of basic measurement and filtering approaches for stationary grond-based GNSS Integrety and health monitoring

This report discusses approaches for integrity monitoring of GNSS radio navigation signals. GNSS integrity monitoring is defined as, Ref.9,: "A GNSS subsystem which enables the timely detection and indication of malfunctions in GNSS operations to ensure that the user is aware whether or not the system is operating within its specified...

Attitude estimation for low-cost spacecraft equipped with GPS

The objective of the present paper is to give an overview of spacecraft attitude determination with GPS. GPS receivers with single or multiple antennas nowadays are low-cost sensors that constitute a valuable complement to existing sensor suites. GPS has been widely used for positioning and vehicle navigation. However, using GPS as an attitude...

Spacecraft attitude and orbit control systems testing

Contemporary AOCS are equipped with local Attitude Control Computers which provide sophisticated Attitude and Orbit Control functions, automatic Failure Detection and Isolation functions and extensive Telemetry and Telecommand handling functions. Generic models of the design, development and test life cycle approaches for such Intelligent AOCS...

Preliminiary evaluation of control methods for TPHTS EM

In the two-phase heat transport system (TPHTS) Engineering Model considered in this study, the temperature and the vapour quality of the two-phase mixture are to be controlled, such that super heated vapour does not occur and a constant vapour temperature is obtained. Feasible control methods for this system should be reviewed.

Development and analysis of dynamic models for the vapour pressure control loop for TPHTS EM

In the two-phase heat transport system (TPHTS) Engineering Model considered in this study, the temperature and the vapour quality of the two-phase mixture are to be controlled, such that super heated vapour does not occur and a constant vapour temperature is obtained. Feasible control methods for this system should be reviewed.

Development and analysis of dynamic models, inherent stability and interaction of centrifugally pumped, parallel vapour quality control loops for TPHTS EM

In the two-phase heat transport system (TPHTS) Engineering Model considered in this study, the temperature and the vapour quality of the two-phase mixture are to be controlled, such that super heated vapour does not occur and a constant vapour temperature is obtained. Feasible control methods for this system should be reviewed.

Inertial-optical systems, in-flight alignment calibration of attitude sensors

Some baseline algorithms for in-flight alignment calibration of attitude sensors are presented. The angular separations between attitude reference sources (stars, sun, earth), at a common time-point, are accurately known from ephemeris data processing, and can also be calculated from the measurements of the attitude sensors to be aligned. Thus...

Experiments in modern control on-board iras

The paper describes algorithms for on-board commanding, estimation and control of the attitude of manoeuvring spacecraft using an on-board computer. Their performance is demonstrated in in-flight experiments with the Infra Red Astronomical Satellite. The following items are discussed: - on-board conmanding of the spacecraft attitude motion, - a...

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...

Inertial-optical attitude determination and model following control of manoeuvring spacecraft

The paper presents an approach to on-board commanding, estimation, and control of the attitude motion of manoeuvring spacecraft, based on modern control principles. Firstly the control algorithms are discussed. The control law is based on explicit model following. It comprises single-axis models of the spacecraft motion, which generate a target...

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...

Application of model following control and estimation techniques to attitude control of manoeuvring spacecraft Part II: Simulation software description

This document describes two computer programs developed during a study of the application of modern control techniques in the area of spacecraft attitude control. Theory and simulation results are described in part I of this report. In part II a general overview of the tasks of the simulation program is presented, and program design aspects are...

Application of model following control and estimation techniques to attitude control of manoeuvring spacecraft

The paper presents an approach to sampled data, on-board estimation and control of the attitude motion of manoeuvring spacecraft. Algorithms for (1) estimation of gyroscope parameters (drift rate bias, scale factor error) and spacecraft state (attitude, angular velocity, disturbance torque), and (2) model following control of attitude manoeuvres...