1. Field of the Invention
The present invention relates to a method for controlling an active running gear of a rail vehicle, and also relates to a device for controlling an active running gear of a rail vehicle as well as to a rail vehicle equipped with a device according to the invention.
2. Description of Related Art
Running gear of rail vehicles are normally subject to a conflict of aims between track stability at high running speeds on straight sections and good curve compliance characteristics on curved sections. Track stability at high running speeds on straight sections requires rigid longitudinal guidance of the wheel units (wheel sets or wheel pairs) while good curve compliance characteristics require curve-radial adjustment of the wheel units and thus soft longitudinal guidance. With respect to known solutions in standard gauge railways, rail vehicles with good curve compliance characteristics therefore usually have a stability-governed maximum speed, which is substantially less than in the case of high-speed trains, which are designed for distances with few curves or such with very wide curve radii. The running gear of high-speed trains in turn are not very curve friendly. Passive solutions obviously can always only reach a compromise between these two conflicting requirements.
Furthermore, in the case of very tight track curves as they occur, for example, in tram networks the ability of the wheel units to self-adjust to curve-radii fails for physical reasons. In order to overcome this disadvantage, German Patent DE 198 61 086 A1 for example proposes an active system for adjusting the wheel sets by the radius of curvature, which however cannot make any contribution to stabilizing running at high speeds—not arising at all in tramway operations anyway.
In contrast to this a solution is known from DE 101 37 443 A1 eliminating the conflicting aims described above. An active controlling method and a corresponding device, which achieves optimized operating characteristics for both objects, are described for a running gear with wheel sets guideably attached to the bogie frame. Thus, by control in a first, preferably lower frequency range, adjustment of the wheel sets in accordance with the curvature of the track present in the curve is achieved, while in a second preferably higher frequency range the reaction to track outlay disturbances is compensated and the onset of instability is prevented.
Both with respect to the input quantities used for the control and also the control of the actuator adjusting the wheel sets as well as its working principle and arrangement in the running gear of the rail vehicle, DE 101 37 443 A1 indicates a series of alternative embodiments, which all achieve the object aimed at.
A disadvantage of this control however lies in the fact that because of adherence to the ideal line when running on the track a very sharply defined wear pattern can develop comparatively quickly on the wheels, as a result of which the service life of the wheels can be substantially reduced.