The objective of this Master Project is the modelisation, simulation and optimisation of a mechatronic system with Matlab/Simulink. The mechatronic system comprises the following parts: three-phase Brushless DC motor, driving electronics and mechanics. The motor is connected to a large mass of 600 kg via a gear box and a drive belt. The simulations are run with a given displacement profile of the mass. The motor speed follows the profile in the case of the simulated and measured results.