Flight Simulation Software

2 Software Methods in Simulation

There are two methods in software design. One is to make the program so simple, there are obviously no errors. The other is to make it so complicated, there are no obvious errors.

Tony Hoare

Software used in flight simulators differs in many ways from software developed for commercial or scientific applications:

• Much of the underlying software is implemented as linear sequences of equations, with relatively few data structures.
• The data for models may be supplied by manufacturers in graphical or tabular form and tools are needed to transform this data to code to be used without loss of accuracy.
• The emphasis is on real-time performance, typically provided by distributed architectures, where the simulator data is shared between multiple processors with data passed in packets transmitted over a local network.
• Aircraft systems are often defined as transfer functions, and techniques to simulate transfer functions are commonplace in simulator development.
• Many of the equations are given in the form of differential equations, which are solved by numerical methods in real-time simulation (Benyon, 1968).

2.1 The Laplace Transform

By understanding the physical relationships of electrical and mechanical components and their interconnections as a network, it is possible to derive a mathematical model of a system. For many systems, it is also possible to describe a model as a set of differential equations. The problem of describing a system in a notation ...