A novel mechatronic running gear: concept, simulation and scaled roller rig testing

Abstract

The basic idea of the concept of the novel mechatronic running gear consists of independently rotating wheels with a mechatronic guidance system to overcome the disadvantages which conventional wheelsets show under certain operating conditions. Especially in narrow curves or at very high speed, oscillation problems linked with noise and increased wear can be observed at conventional wheelsets (curve squeal, hunting instability). Otherwise, vehicles with independently rotating wheels often need a higher maintenance effort to ensure low wear at the wheels. The aim of the concept is the development of a running gear which offers a better running performance than a conventional running gear under all operation conditions in combination with a low maintenance effort. This means a lower emission level of vibrations to the ground and the air as well as less friction at curves and therefore a lower need for traction energy. Additionally, the running gear concept enables more comfortable train concepts such as low floor trams or double deck trains with two continuous decks, because of the abdication of the wheelset axle. The principle is applicable to bogies as well as running gears with a single pair of wheels. These ambitious aims require high demands of the sensor and control system. For instance, the sensor must be able to identify the position of the wheels relative to the track and the control system must be fast enough to avoid flange contact even at highly disturbed tracks at high speed. In the first step a scaled 1:5 roller rig is build (picture) and a model of the scaled roller rig is set up as Multi-Body-System (MBS). In the roller rig force-torque-sensors are used as position sensors. The model can be validated by measurements at the test rig. Then the validated model is used for the design process of the control-algorithms which are tested in the roller rig. Only a model-based control system is able to meet the high demands under the different operation conditions of a train. In a second step the developed control algorithms are transferred into a MBS-model of a 1:1 vehicle to demonstrate the functional capability and the advantages of the simulated operation conditions. Currently this work has the function of a demonstrator and to identify the further research emphasis for an implementation in a real vehicle concept. At the end this novel mechatronic running gear will increase the competitiveness and acceptance of the railway by a cost-effective and low emission running gear. This work is integrated in the DLR-Project Next Generation Train.