paper (gzipped PostScript, 44K)Carreira-Perpinan, M. A. (1994): "The modelling of the thermal subsystem in spacecraft real-time simulators", Proc. of the 3rd Workshop on Simulators for European Space Programmes, ESA/ESTEC, Noordwijk, The Netherlands, pp. 69-78.
Two different approaches to thermal simulation of spacecraft exist in widespread use: one operates by carrying out some kind of interpolation over a finite set of selected, typical scenarios for which the thermal behaviour is known; networks of heaters and thermistors are often used in this approach. The other technique is essentially an integrator: first, the thermal system is nodalised, giving as a result a discrete network of nodes and conductors; second, the heat transfer equations are applied to this network, thus yielding a system of partial differential equations that can be solved using a numerical integrator (finite difference methods are very common).
To present, the thermal subsystem of the real-time satellite simulators developed at the Simulation Systems Section at ESOC, Germany, has always been an implementation of an interpolation method; the main reasons for this policy are the speed of computation and the somewhat loose requirements for accuracy. Examples of it are the Italsat, ISO, ERS-1, Eureca and Pastel satellite simulators. However, the computing power available has increased in such a way that integration methods are no longer prohibitive in real-time simulation.
In this paper, both simulation schemes are presented and criticised in terms of efficiency, accuracy, flexibility and ease of model construction. The possibility of using integrators for real-time simulation of simplified spacecraft models is discussed, putting particular emphasis on ESATAN, the standard thermal analysis code employed at the European Space Agency.
Thermal modelling, real-time simulation, spacecraft simulation.
paper (gzipped PostScript, 44K)
slides (gzipped PostScript, 56K)
University of Toronto | Dept. of Computer Science | Machine learning group | MACP's Home Page |