This M.Sc. thesis presents the design and validation of an intelligent assistance system for passengers with reduced mobility (PRM), conceived for integration on high–speed railway vehicles. The project, developed in collaboration with Alstom S.p.A., addresses one of the most critical aspects of railway accessibility: ensuring safe and autonomous boarding at the train–platform interface. After analyzing the European regulatory framework and current technological limitations, an innovative concept was defined: a roof–mounted deployable unit equipped with a stereo camera capable of monitoring the platform area and supporting the PRM lift during operation. The solution combines mechanical integration, sensor design, and automation logic into a compact and protected module compatible with high–speed train constraints.