Adhesion-Based Maximum-Seeking Brake Control for Railway Vehicles

Abstract

The emerging integration of mechatronic systems in modern railway vehicles enables significant improvements with respect to safety, comfort, and wear reduction. To fully exploit the potential of mechatronic systems, the German Aerospace Center (DLR) complements its validated estimation and control concepts in the field of lateral vehicle dynamics with approaches for longitudinal dynamics. The present work introduces an adhesion-based maximum-seeking brake control that offers a benefit in contrast to slip-based approaches especially in safety critical scenarios.

Integrated Model Predictive Control of High-Speed Railway Running Gears With Driven Independently Rotating Wheels

“…In this context, estimator design is out of scope, and the MBS outputs are used as direct measurements for feedback control. However, powerful nonlinear Kalman Filters (KF) do exist for comparable applications [10,30], and an estimator-controller combination has to be employed in future implementations. This is of importance since the estimator can be used to obtain state information even if certain variables are difficult or costly to measure, as is the case with states y TrAx and ψ TrAx in the current setting [10,30].…”

“…However, powerful nonlinear Kalman Filters (KF) do exist for comparable applications [10,30], and an estimator-controller combination has to be employed in future implementations. This is of importance since the estimator can be used to obtain state information even if certain variables are difficult or costly to measure, as is the case with states y TrAx and ψ TrAx in the current setting [10,30]. In addition, the fusion of model and sensor information can reduce noise and improve physical consistency.…”

“…A possibility to overcome this problem is the application of maximum-seeking controllers. An example, which is based on a sliding mode approach, is shown in [10,11]. Crucial for this concept is the availability of reliable real-time slip and adhesion estimates.…”

Integrated vehicle dynamics control for a mechatronic railway running gear

“…when 𝜏 𝑖𝑗 causes the wheels to slip into the unstable macro slip area, the commanded torque is reduced. This task is realized via a bang-bang longitudinal controller based on [2]. It detects the stable and the unstable adhesion area by the evaluation of the following criterion…”

“…In [1] a deceleration-based control concept addressing repeatability is validated in field tests. A control algorithm for emergency brake maneuvers especially under bad and volatile environmental conditions is presented in [2]. However, both control concepts address only longitudinal dynamics and neglect the lateral component.…”