Software-in-the-loop simulation for improving flight control system design: a quadrotor case study

Simulation is a standard approach used for designing complex systems like the flight controller in multi-rotor vehicles. In this paper we illustrate how the software-in-the-loop (SIL) methodology allows to detect and manage instabilities of a quadrotor control system that otherwise might not arise when considering only Matlab/Simulink simulations.The use of the SIL technique allows to understand the behavior of the flight control system by comparing and evaluating different scenarios, with a details level quite close to reality. At the same time, it is possible to discover issues that a model-in-the-loop (MIL) simulation does not necessarily detect, even if carried out through a multi-physics co-simulation approach.The paper aims to give the reader a practical and concrete evidence of such considerations through the case study of a micro quadrotor.