Multi-body code and software control co-simulation for the dynamic behaviour analysis of rover exploration vehicle

Since antiquity, humans have dreamed about spaceflight. When rockets became powerful enough to overcome the force of gravity and reach orbital velocities, space was opened to human exploration. Mars has always captured humankind imagination, being a source ofinspiration for explorers and scientists. A considerable number of missions have attempted to reach the Red Planet, with varying degrees of success, focused primarily on understanding the planet geology and habitability potential. In the context of planetary surface exploration, mobile robots are the main characters, due to their capability of moving in unstructured environments. ExoMars 2020 is the mission managed by the European Space Agency (ESA) intended to deliver a rover on Mars surface in search of a sign of life. The mission will send the European ExoMars rover and a Russian surface platform to the surface of Mars with the aim of performing scienticresearch looking for organic molecules and surface characterisation. When dealing with mobile robot design, multi-body software are fundamental tools supporting engineering activities. Multi-body System Simulation (MBS) is a numerical simulation method for the study of mechanical systems motion caused by external forces acting on it. One challenging activity of the Mechanical CAE (Computer Aided Engineering) group of Thales Alenia Space Italia S.p.A., where this thesis has been developed, addresses exactly at building a dynamic model of the six-wheeled planetary rover belonging to ExoMars Mission. Moreover, the CAE group requires to drive the MBS model in order to study the rover when performing dierent manoeuvres. This can be achieved by controlling torques applied to drive and steering wheel axes. The model is built in MotionView environment, a general pre-processor for MBS simulation, and simulated through MontionSolve solver. These tools guarantee optimal performances when dealing with MBS simulation, but they are not enough to implement complex controller. In order to incorporate functions of sensing, actuation and control the Activate software tool is used.Thanks to its co-simulation interface it is possible to simulate this complex system including both the rover MBS model, simulated with MotionSolve, and the control systems, simulated with Activate. The main objective of this thesis is to develop the Activate model for co-simulation, implementing the low-level control loop of the ExoMars rover wheel actuators (DC motors) and the higher level locomotion function, which allows driving the rover given the manoeuvre commands set by the user, rather than acting on the actuator speeds and position.