Thorsten Stützle

Wheelslide and Wheelskid Protection for a Single-Wheel Drive and Brake Module (SDBM) for Rail Vehicles

In this paper, the dynamic behaviour of a rail vehicle with single-wheel drive and brake modules is analysed. It is shown that in the wheelslide or wheelskid case, the linearised plant obtains an unstable pole whose location is determined by the shape of the current creep force curve. By considering possible variations in the shape of the creep force curve, the corresponding variation of the pole location in the right-half plane is calculated and a controller structure for creepage control and creep velocity control is suggested. If the controller design takes the worst-case pole location into account, the resulting controller stabilises the closed loop even at small velocities. Finally, this fact is illustrated through simulation results.

CONTROL OF A HYBRID MOTOR PROSTHESIS FOR THE KNEE JOINT

Abstract Functional Electrical Stimulation (FES) is used for gait restitution in paraplegic patients. One of the major problems is the heavily increased muscle fatigue due to unphysiological stimulation. As a possible solution, this paper introduces a hybrid neuroprosthesis for the knee joint, where muscle stimulation is complemented by a motor-driven exoskeleton. A control concept based on model predictive control is designed that employs both actuators cooperatively and varies their participation corresponding to their capabilities.

Analysis of the braking performance of a rail vehicle emphasizing mechatronic components

For the development of mechatronic components for railway vehicles, suitable methods, processes and tools have to be applied. As an example, the use of these methods and tools for the design of a wheelslide protection system will be addressed in this article. Modern simulation techniques for mechatronic systems enable more unique versions of the implemented algorithm on the controller hardware and in the design and simulation test environment. To simulate the braking behaviour of a railway vehicle, creep force characteristics at different friction conditions have been shaped out from measurements and implemented in the multi-body simulation program SIMPACK. As statements from pure off-line simulations of the braking performance of a rail vehicle are limited, a roller rig has been designed that enables tests and improvements of a wheelslide protection controller. Finally, only practical field tests can prove the function of a new developed system. Following the V-model for the design process of mechatronic systems, results from integrated off-line simulations, tests on a single-wheel roller rig and field tests will be explained. †This article includes words that are asserted to be a proprietary term or trade mark. Its inclusion does not imply it has acquired for legal purposes a non-proprietary or general significance, nor is any other judgement implied concerning its legal status.

Creepage control for use in wheelslide protection systems

Abstract In order to achieve acceptable braking distances, the wheelslide protection controller of a railway vehicle should hold an operating point in the macro-slip range on the decreasing branch of the creep force curve. Based on mathematical models of the railway vehicle, the creep force characteristics and the brake system, a stability analysis is performed for the open-loop system during braking in the macro-slip range. In addition, a creepage controller that stabilises the closed loop over the entire vehicle velocity range is presented and its performance is discussed with the help of simulation results.

Adaptiver Gleitschutz für Schienenfahrzeuge (Adaptive Wheelslide Protection System for Railway Vehicles)

Abstract Dieser Beitrag beschäftigt sich mit der Auslegung und dem Test einer Gleitschutzregelung für Schienenfahrzeuge. Als Grundlage für die Reglerentwicklung werden zunächst einfache Modelle des Schienenfahrzeugs, der Kraftschlussbeanspruchung und des Bremssystems vorgestellt. An Hand einer Analyse des Gesamtmodells kann der Wertebereich eines bestimmten Modellparameters berechnet werden, der bei der Auslegung des linearen, robusten Schlupfreglers berücksichtigt werden muss. Daneben wird die Adaption der Reglerverstärkung an einen leicht zu identifizierenden Fahrzeugparameter (Bremszustandsfaktor) beschrieben. Schließlich werden Versuchsergebnisse von Testfahrten mit einer Regelung im Mikroschlupfbereich vorgestellt und diskutiert.