Uwe Becker

Lateral stabilization of vehicle-trailer combinations against crosswind disturbances by means of sliding control

This paper reports the basic properties and robust control of a vehicle-trailer combination crosswind disturbance conditions. In practice it is known that unstable roll movements may occur, especially with unfavorable combinations of vehicle and trailer conditions, operating slightly above the permissible maximum speed. This may lead to accidents mostly due to improper driver behavior. First we present two dynamic model vehicle-trailer combinations (single- and double track), using a wind model based on the Dryden spectrum. After analysis of these the single-track model is used for designing a sliding mode controller. The controllers parameters are found through linear optimization, minimizing steering activity and lateral deviation. Finally the controller is validated using the double-track model of the system. Simulations show that the controlled system is able to follow a predefined trajectory, which is generated using an inverted single-track model of the system. The system could also reliably stabilize roll movements induced by crosswinds. The controller proved to be very robust towards parameter variations (e.g. loading conditions or vehicle velocity) as well as towards the influence of crosswind with wind speeds up to 50 m/s.

Evaluation and simulation of building automation systems based on their AutomationML description

The planning and layout of a building automation and control system (BACS) is a complex process characterised by the application and interconnection of several different functions. Such a complex process is prone to planning errors that are often only recognised during the initial operation of the building. In order to guarantee earlier fault detection and function analysis, a basic approach for efficient production of functional models of BACS was developed. This approach combines an AutomationML-based manufacturer-independent description of the BACS with a manufacturer-specific room-automation function database to generate a Petri net model enabling simulation of the BACS. This functional model enables an early analysis of the system behaviour and performance.

Comparison of traffic incident data in individual and public transport

2011 to 2020 has been declared the “Decade of Action” by the World Health Organisation (WHO) to tackle the problem of (road) traffic casualties [1]. To better understand the concept of safety in general and to provide simulation capabilities, transitions of a model for traffic safety have to be defined. Data from very different sources were integrated to provide a comparison of train, tram, bus, ship, car and airplane incidents. Additionally sources for normalization were integrated to allow analyses of scales from local to regional to global. With the presented tool an explorative identification of distribution functions for incident severity and mean time between failure (MTBF) rates for further model application is available. The R programming language was used to build a web-based tool for interactive data exploration and analysis.

Requirements engineering and modelling for building automation systems

The planning and layout of a building automation system is a complex process characterized by the selection, application and interconnection of multiple different functions. Planning mistakes are often not recognized before the initial operation of the building. In order to allow an earlier fault and function analysis and to ease planning, an approach for an efficient development of a functional model for the building automation system has been developed. This functional model offers not only a simulation of the building automation system but also the automatic configuration of the hardware components of the building automation system.

Particle Filter technique for position estimation in GNSS-based localisation systems

The usage of filter techniques for position estimation for safety-relevant purposes is an extensive field of research. Depending on the needed application for the Global Navigation Satellite System (GNSS) the state estimation can be achieved by several techniques. State estimation by means of Kalman Filter (KF), as well as Extended Kalman Filter (EKF) and Particle Filter (PF) have been developed and tested. Map-matching algorithms integrate the localisation data provided by GNSS with spatial road network data (also called “digital map”) to identify the correct line (or track) on which a vehicle is traveling and to determine the location of a vehicle within the line (or track). The goal of map-matching techniques is to exploit prior information contained in road or railway networks. However, incorporating digital map information within the conventional KF framework is not easy, because this constraint leads to highly non-Gaussian posterior densities that are difficult to represent accurately using conventional techniques. Since the PF approach presents no restrictions regarding non-linearity of models and noise distribution the velocity and heading measurement errors can be accurately modelled. The most significant advantages of the PF approach for map-matching application are: 1) PF approach provides a natural way for road map information to be incorporated into vehicle position estimation. 2) PF approach is capable of capturing multi-modal distributions. The selected PF-based location estimators presented here is oriented to work within an intelligent GNSS-based localisation system. The PF-based map matching techniques are presented in a mathematical ground and tests are performed, as part of a developed satellite localisation system based on artificial intelligence (AI) tools. In the railway domain the same integration can be performed by means of a “digital trap map” to identify the location within the tracks. A map-matching algorithm can be the key component of the data fusion to improve the performance of localisation systems that support the navigation function of intelligent transport systems (ITS).

Methods and platforms for certification of satellite based localisation systems in transportation

The (satellite based) localisation will become more important for safety related applications, in future. Therefore, its certification will be mandatory. In this paper, an approach is described to be able to implement a certification (partly) independent of the specific domain of transportation (e.g. rail or road transportation). This affects both, the normative or methodical and the experimental dimension of such a process

Modellbasierte Inbetriebnahme und online-Konfiguration von Gebäudeautomationssystemen

Zusammenfassung Ein Gebäudeautomationssystem (GA-System) ist durch eine Vielzahl von automatisierten Funktionen geprägt. Die Planung und Auslegung eines GA-Systems ist daher ein aufwändiger und fehlerträchtiger Vorgang. Um eine frühzeitige Funktionsanalyse und Fehlererkennung zu gewährleisten, wurde ein Ansatz für eine effiziente Erstellung eines funktionalen Modells für die GA entwickelt, mit dem ein GA-System simuliert, ausgelegt und konfiguriert werden kann. Dieser Ansatz wurde nun weiterentwickelt, um die Parameter aus dem Modell für die Inbetriebnahme, die online-Diagnose und die online-Anpassung des GA-Systems zu nutzen.

Accuracy analysis of BeiDou receivers for lane detection applications

The future of Intelligent Transportation Systems (ITS) relies on a properly constructed Control Transportation System (CTS) based on a dynamically accurate localisation system. In urban scenarios applications for lane detection, as part of intelligent highways, Global Navigation Satellite Systems (GNSS) receivers provide tangential and perpendicular locations for localisation systems, by means of trueness and precision in the dynamic frame of the lane. Results show that the circular error probable (CEP) approach is not a realistic representation of the dynamic behaviour of the receivers, so the new Mahalanobis Ellipses Filter (MEF) approach was tested and proven to be a better dynamic accuracy representation for ground vehicles. Also, the MEF results from collected data in urban scenarios in Beijings 3rd Ring Road present a significant representation of the potential applications for the several GNSS configuration tested, proving that a Multi-GNSS configuration can already properly work for lane detection applications. Conclusively, the results presented here show the MEF approach to be significantly better to test and validate lane detection applications. The separation into tangential and perpendicular deviations components allows a better technique to achieve the accuracy requirements description, for GNSS-based urban ground vehicle localisation system within a safety-relevant ITS.

Repeatability test method of GNSS for safe train localisation in real and simulated environments

Safe train localization is the key element to provide reliable Position, Velocity and Timing (PVT) information for Automatic Train Operation (ATO), and will enable future applications such as moving block, real-time safety margin estimation for adjacent trains, and many more. The safety-assured train localization under many repeated tests along the test railway line providing acceptable performance level will allow Global Navigation Satellite Systems (GNSS) as part of the localization unit to be adopted into the elements of ATO system to perform localization function. But under real railway operation environmental conditions, the accuracy performance shows strong variations; but using the simulated GNSS signals in the laboratory will have more consistent and repeatable test sequence for GNSS receiver testing. The GNSS receiver for the application of ATO is based on the performance requirements for the localization function in predefined environmental conditions, both simulation and real world test procedures including standard test definitions will enable the possibility to examine the repeatability of GNSS performance in acknowledged railway operation environment. Based on this, the test results will give the repeatability facts of the tested GNSS receiver, then the repeatability performance criteria can be set for later railway application in different environments. But for the performance evaluation of the repeatability property as part of the GNSS performance testing concept, accuracy can be seen as the foundation of all the other performance properties. Accuracy in both along-track and cross-track direction of the train should be evaluated under dynamic movement using bidirectional error models. The dynamic train localization accuracy is among one of the key tests for the GNSS receiver for safe applications in railway applications. This paper firstly describes the repeatability performance as part of the GNSS receiver quality for safe train localization in definition and also the relation among the major performance properties of a GNSS receiver under dynamic measurements. Secondly, the test scenario and the data collection strategy on an existent railway line is settled for both real world and simulated data analysis. Then the collected data is evaluated using the proposed dynamic accuracy evaluation method with the consideration of measurement uncertainty caused by the movement of the measurement object. Thirdly, the accuracy evaluation is based on the GNSS receiver as the system under test (SUT) and the mobile reference measurement system (MRMS) developed based on mature solutions and further developed platform in our research lab. The same datasets for real world accuracy evaluation are loaded into the Spirent GSS8000 for the repeatability performance evaluation. The test procedure is restricted to follow the standard test requirements in both railway and navigation societies. Finally, with the test results following the defined procedure and evaluation method in this paper, the repeatability performance criteria can be clearly shown for the level of safety application in railway train operation.

Durchgängiges modellbasiertes Engineering von Gebäudeautomationssystemen

Zusammenfassung Ein Gebäudeautomationssystem (GA-System) ist durch eine Vielzahl von automatisierten Funktionen geprägt. Die Planung und Auslegung eines GA-Systems ist daher ein aufwändiger und fehlerträchtiger Vorgang. Dabei werden Planungsfehler oft erst bei der Inbetriebnahme des Gebäudes erkannt. Um eine frühzeitige Funktionsanalyse und Fehlererkennung zu gewährleisten, wurde ein Ansatz für eine effiziente Erstellung eines funktionalen Modells für die GA entwickelt, mit welchem ein GA-System simuliert, ausgelegt und konfiguriert werden kann.