Mechatronic system simulation of a full scale roller rig for a single wheelset

A complete numerical model of a full scale roller rig mechatronic system is proposed in this paper. It is composed of a multi-body system model of the roller rig, interfaced with a model of the motor driving the roller and of the control unit substructures. Based on the mechatronic system model a method to derive the control signals for the control unit to perform the test is proposed. The simulation results show that this approach enables the actual behaviour of the wheelset in the line to be closely reproduced. However, non-negligible differences are observed in the running behaviour of the wheelset tested on the roller, compared with the same wheelset in the line. The reasons are discussed in the paper and are ascribed mainly to differences in the longitudinal creepage, in the related creep forces and in the gravitational terms involved with the lateral motion of the wheelset. Based on the results presented, a preliminary discussion of the best strategies for roller rig testing is provided.