Integrated vehicle dynamics control for a mechatronic railway running gear

Abstract

Safety is especially for high-speed railway traffic one of the main aspects that has to be continuously improved to sustainably strengthen the railway sector and shift the modal split. To overcome the limitations of passive systems, an active control of mechatronic running gears provides essential advantages. In the present work, the focus is on the active control of lateral and longitudinal dynamics which are closely coupled via the tangential wheel-rail contact. Therefore, the introduced integrated control concept combines lateral and longitudinal control tasks. After the description of the lateral and longitudinal sub-level controllers the benefits of the integrated control are demonstrated. A comparison of the developed concept with a reference control using a preallocated torque for the lateral track guidance is drawn. The results of a simulation including volatile wheel-rail conditions and a jump in the desired lateral position underline the potential of integrated control to reduce braking distances and simultaneously improve lateral stability.

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

“…Second, the MPC-based lateral guidance controller is proposed. Last, an integration system that combines u d and ∆u is introduced based on [21].…”

“…The employed integration approach flexibly allocates a control torque to each of the subsystem controllers in lateral and longitudinal direction. In contrast to existing implementations [21], the use of MPC allows for an explainable and smooth shift of the control objective between lateral and longitudinal emphasis. This is done by tuning the parameters Q and R in the MPC scheme.…”

“…Loosely speaking, the cost for allocating a certain lateral control torque ∆u k (t) and for deviating from the set points x d k (t) can be adjusted by the operator in an explainable fashion. Following the approach in [21], no fixed torque values are allocated to the longitudinal and lateral controller. Rather, the output torques are determined by the integration rule…”

“…A possible solution is the introduction of a supervised integration strategy in the form of a variable allocation rule. This technique is proposed in [21] and can reduce the braking distance in the presented simulation scenario by almost 5%. However, a custom and smooth shift between emphasis on lateral or longitudinal control is not possible in [21].…”

“…This technique is proposed in [21] and can reduce the braking distance in the presented simulation scenario by almost 5%. However, a custom and smooth shift between emphasis on lateral or longitudinal control is not possible in [21]. To the best of the authors' knowledge, MPC has not been used for control of railway running gears with IRW so far.…”