@article{5671, abstract = {{Multi-attribute value theory (MAVT)-based recommender systems have been proposed for dealing with issues of existing recommender systems, such as the cold-start problem and changing preferences. However, as we argue in this paper, existing MAVT-based methods for measuring attribute importance weights do not fit the shopping tasks for which recommender systems are typically used. These methods assume well-trained decision makers who are willing to invest time and cognitive effort, and who are familiar with the attributes describing the available alternatives and the ranges of these attribute levels. Yet, recommender systems are most often used by consumers who are usually not familiar with the available attributes and ranges and who wish to save time and effort. Against this background, we develop a new method, based on a product configuration process, which is tailored to the characteristics of these particular decision makers. We empirically compare our method to SWING, ranking-based conjoint analysis and TRADEOFF in a between-subjects laboratory experiment with 153 participants. Results indicate that our proposed method performs better than TRADEOFF and CONJOINT and at least as well as SWING in terms of recommendation accuracy, better than SWING and TRADEOFF and at least as well as CONJOINT in terms of cognitive load, and that participants were faster with our method than with any other method. We conclude that our method is a promising option to help support consumers' decision processes in e-commerce shopping tasks.}}, author = {{Scholz, Michael and Dorner, Verena and Schryen, Guido and Benlian, Alexander}}, journal = {{European Journal of Operational Research}}, keywords = {{E-Commerce, Recommender System, Attribute Weights, Configuration System, Decision Support}}, number = {{1}}, pages = {{205 -- 215}}, publisher = {{Elsevier}}, title = {{{A configuration-based recommender system for supporting e-commerce decisions}}}, volume = {{259}}, year = {{2017}}, } @inproceedings{9966, abstract = {{Usage of copper wire bonds allows to push power boundaries imposed by aluminum wire bonds. Copper allows higher electrical, thermal and mechanical loads than aluminum, which currently is the most commonly used material in heavy wire bonding. This is the main driving factor for increased usage of copper in high power applications such as wind turbines, locomotives or electric vehicles. At the same time, usage of copper also increases tool wear and reduces the range of parameter values for a stable process, making the process more challenging. To overcome these drawbacks, parameter adaptation at runtime using self-optimization is desired. A self-optimizing system is based on system objectives that evaluate and quantify system performance. System parameters can be changed at runtime such that pre-selected objective values are reached. For adaptation of bond process parameters, model-based self-optimization is employed. Since it is based on a model of the system, the bond process was modeled. In addition to static model parameters such as wire and substrate material properties and vibration characteristics of transducer and tool, variable model inputs are process parameters. Main simulation result is bonded area in the wiresubstrate contact. This model is then used to find valid and optimal working points before operation. The working point is composed of normal force and ultrasonic voltage trajectories, which are usually determined experimentally. Instead, multiobjective optimalization is used to compute trajectories that simultaneously optimize bond quality, process duration, tool wear and probability of tool-substrate contacts. The values of these objectives are computed using the process model. At runtime, selection among pre-determined optimal working points is sufficient to prioritize individual objectives. This way, the computationally expensive process of numerically solving a multiobjective optimal control problem and the demanding high speed bonding process are separated. To evaluate to what extent the pre-defined goals of self-optimization are met, an offthe- shelf heavy wire bonding machine was modified to allow for parameter adaptation and for transmitting of measurement data at runtime. This data is received by an external computer system and evaluated to select a new working point. Then, new process parameters are sent to the modified bonding machine for use for subsequent bonds. With these components, a full self-optimizing system has been implemented.}}, author = {{Meyer , Tobias and Unger, Andreas and Althoff, Simon and Sextro, Walter and Brökelmann, Michael and Hunstig, Matthias and Guth, Karsten}}, booktitle = {{IEEE 66th Electronic Components and Technology Conference}}, keywords = {{Self-optimization, adaptive system, bond process, copper wire}}, pages = {{622--628}}, title = {{{Reliable Manufacturing of Heavy Copper Wire Bonds Using Online Parameter Adaptation}}}, doi = {{10.1109/ECTC.2016.215}}, year = {{2016}}, } @inproceedings{29973, abstract = {{Haushaltsgeräte aus der Klasse der "Weißen Ware" tragen mit etwa einem Drittel ($34,2%$ \citeBDEW2013) zum privaten Energieverbrauch bei. Diese Veröffentlichung präsentiert eine Struktur und die dafür notwendige optimale Betriebsstrategie für Weiße Ware in einer Umgebung mit Strompreisen, die wegen der Volatilität der Regenerativen Energien stark fluktuieren. Das vorgeschlagene Konzept nutzt dafür ein dezentrales Energiemanagementsystem, das über drei Hierarchieebenen verteilt ist: die Geräteebene, die Haushaltsebene und die Ortsnetzebene. Auf der Geräteebene nutzt dieses Konzept zusätzlich Betriebsflexibilitäten der Haushaltsgeräte aus.}}, author = {{Stille, Karl Stephan Christian and Böcker, Joachim and Bettentrup, Ralf and Kaiser, Ingo}}, booktitle = {{ETG-Fachtagung "Von Smart Grids zu Smart Markets"}}, keywords = {{Energy management, hybrid energy storage system, self-optimization, multi-objective optimization, adaptive systems, pareto set, SFB614-D1, SFB614-D2, LEA-Publikation, Eigene}}, publisher = {{VDE}}, title = {{{Hierarchisches Optimierungskonzept für die Laststeuerung von Haushaltsgeräten}}}, year = {{2015}}, } @article{9885, abstract = {{Intelligent mechatronic systems, such as self-optimizing systems, allow an adaptation of the system behavior at runtime based on the current situation. To do so, they generally select among several pre-defined working points. A common method to determine working points for a mechatronic system is to use model-based multiobjective optimization. It allows finding compromises among conflicting objectives, called objective functions, by adapting parameters. To evaluate the system behavior for different parameter sets, a model of the system behavior is included in the objective functions and is evaluated during each function call. Intelligent mechatronic systems also have the ability to adapt their behavior based on their current reliability, thus increasing their availability, or on changed safety requirements; all of which are summed up by the common term dependability. To allow this adaptation, dependability can be considered in multiobjective optimization by including dependability-related objective functions. However, whereas performance-related objective functions are easily found, formulation of dependability-related objective functions is highly system-specific and not intuitive, making it complex and error-prone. Since each mechatronic system is different, individual failure modes have to be taken into account, which need to be found using common methods such as Failure-Modes and Effects Analysis or Fault Tree Analysis. Using component degradation models, which again are specific to the system at hand, the main loading factors can be determined. By including these in the model of the system behavior, the relation between working point and dependability can be formulated as an objective function. In our work, this approach is presented in more detail. It is exemplified using an actively actuated single plate dry clutch system. Results show that this approach is suitable for formulating dependability-related objective functions and that these can be used to extend system lifetime by adapting system behavior.}}, author = {{Meyer , Tobias and Sondermann-Wölke, Christoph and Sextro, Walter}}, journal = {{Conference Proceedings of the 2nd International Conference on System-Integrated Intelligence}}, keywords = {{Self-optimization, multiobjective optimization, objective function, dependability, intelligent system, behavior adaptation}}, pages = {{46--53}}, title = {{{Method to Identify Dependability Objectives in Multiobjective Optimization Problem}}}, doi = {{10.1016/j.protcy.2014.09.033}}, volume = {{15}}, year = {{2014}}, } @inproceedings{10677, author = {{Ho, Nam and Kaufmann, Paul and Platzner, Marco}}, booktitle = {{2014 {IEEE} Intl. Conf. on Evolvable Systems (ICES)}}, keywords = {{Linux, cache storage, embedded systems, granular computing, multiprocessing systems, reconfigurable architectures, Leon3 SPARe processor, custom logic events, evolvable-self-adaptable processor cache, fine granular profiling, integer unit events, measurement infrastructure, microarchitectural events, multicore embedded system, perf_event standard Linux performance measurement interface, processor properties, run-time reconfigurable memory-to-cache address mapping engine, run-time reconfigurable multicore infrastructure, split-level caching, Field programmable gate arrays, Frequency locked loops, Irrigation, Phasor measurement units, Registers, Weaving}}, pages = {{31--37}}, title = {{{Towards self-adaptive caches: A run-time reconfigurable multi-core infrastructure}}}, doi = {{10.1109/ICES.2014.7008719}}, year = {{2014}}, } @inproceedings{36917, abstract = {{The ever-increasing complexity of heterogeneous electronic systems demand for intensified abstraction and automation efforts to improve design, verification and validation productivity, especially in earlier phases of system engineering. Within the verification activity various metrics can be applied to determine functional correctness or the overall progress. Here, a supporting verification methodology defining high-level verification planning down to the actual metric code development is essential. Moreover, an advanced assistance for the designer, such as a tooling infrastructure to automatize and accelerate the metric code implementation, is needed to minimize the influence of errorprone manual coding. In this article we present a single-source verification metric code-generation methodology for improved coverage automation. We determine (i) a suitable metric model for model-based capture of verification metrics as well as (ii) an assisted model-based processing and generation flow of the verification environment and metric skeletons. We apply our method to a SystemC case-study, in doing so, targeting metric code implementation productivity and consistency enhancement.}}, author = {{Kuznik, Christoph and Müller, Wolfgang and Defo, Gilles Bertrand}}, keywords = {{System Design, Verification}}, title = {{{An Assisted Single Source Verification Metric Model Code Generation Methodology}}}, year = {{2014}}, } @inproceedings{34585, abstract = {{In this paper, we present an efficient approach to virtual platform modeling for TriCore-based SoCs by combining fast and open software emulation with IEEE-1666 Standard SystemC simulation. For evaluation we consider Infineon's recently introduced AURIX processor family as a target platform, which utilizes multiple CPU cores operating in lockstep mode, memories, hierarchical buses, and a rich set of peripherals. For SoC prototyping, we integrate the fast and open instruction accurate QEMU software emulator with the TLMu library for SystemC co-verification. This article reports our most recent efforts of the implementation of the TriCore instruction set for QEMU. The experimental results demonstrate the functional correctness and performance of our TriCore implementation.}}, author = {{Koppelmann, Bastian and Messidat, Bernd and Becker, Markus and Müller, Wolfgang and Scheytt, J. Christoph}}, booktitle = {{Proceedings of the Design and Verification Conference Europe (DVCON Europe)}}, keywords = {{System Design, Verification}}, title = {{{Fast and Open Virtual Platforms for TriCore-based SoCs Using QEMU}}}, year = {{2014}}, } @article{35906, abstract = {{Against the background of a European-wide strategy of governance aimed at improving support for parents and families, the following report details the conceptualization and evaluation of a federal state program4 in Baden- Württemberg (Germany) which was launched in 2008 to encourage fam- ily and parent education. Two program components, a voucher system for parents with a new-born child and an element that emphasizes educa- tional offers for families with special needs in particular living situations, were started to increase requests for educational courses. The aim was to establish and deepen cooperation between different public and private professional services that are in contact with parents and their children. The results show that main goals of the program were reached.}}, author = {{Landhäußer, Sandra and Faas, Stefan and Treptow, Rainer}}, journal = {{Center for Educational Policy Studies Journal (CEPS)}}, keywords = {{family and parent education, cooperation, voucher system, support for families with special needs in particular living situations, program evaluation}}, number = {{No 4}}, title = {{{Encouraging Family and Parent Education: Program Development and Evaluation in the Federal State of Baden-Württemberg, Germany}}}, doi = {{https://files.eric.ed.gov/fulltext/EJ1129548.pdf}}, volume = {{Vol 4}}, year = {{2014}}, } @inproceedings{34583, abstract = {{In this paper, we present an efficient approach to virtual platform modeling for TriCore-based SoCs by combining fast and open software emulation with IEEE-1666 Standard SystemC simulation. For evaluation we consider Infineon's recently introduced AURIX processor family as a target platform, which utilizes multiple CPU cores operating in lockstep mode, memories, hierarchical buses, and a rich set of peripherals. For SoC prototyping, we integrate the fast and open instruction accurate QEMU software emulator with the TLMu library for SystemC co-verification. This article reports our most recent efforts of the implementation of the TriCore instruction set for QEMU. The experimental results demonstrate the functional correctness and performance of our TriCore implementation.}}, author = {{Koppelmann, Bastian and Messidat, Bernd and Kuznik, Christoph and Müller, Wolfgang and Becker, Markus and Scheytt, J. Christoph}}, booktitle = {{Proceedings of the Design and Verification Conference Europe (DVCON Europe)}}, keywords = {{System Design, Verification}}, title = {{{Fast and Open Virtual Platforms for TriCore-based SoCs Using QEMU}}}, year = {{2014}}, } @inproceedings{11816, abstract = {{In this paper, we consider the Maximum Likelihood (ML) estimation of the parameters of a GAUSSIAN in the presence of censored, i.e., clipped data. We show that the resulting Expectation Maximization (EM) algorithm delivers virtually biasfree and efficient estimates, and we discuss its convergence properties. We also discuss optimal classification in the presence of censored data. Censored data are frequently encountered in wireless LAN positioning systems based on the fingerprinting method employing signal strength measurements, due to the limited sensitivity of the portable devices. Experiments both on simulated and real-world data demonstrate the effectiveness of the proposed algorithms.}}, author = {{Hoang, Manh Kha and Haeb-Umbach, Reinhold}}, booktitle = {{38th International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013)}}, issn = {{1520-6149}}, keywords = {{Gaussian processes, Global Positioning System, convergence, expectation-maximisation algorithm, fingerprint identification, indoor radio, signal classification, wireless LAN, EM algorithm, ML estimation, WiFi indoor positioning, censored Gaussian data classification, clipped data, convergence properties, expectation maximization algorithm, fingerprinting method, maximum likelihood estimation, optimal classification, parameters estimation, portable devices sensitivity, signal strength measurements, wireless LAN positioning systems, Convergence, IEEE 802.11 Standards, Maximum likelihood estimation, Parameter estimation, Position measurement, Training, Indoor positioning, censored data, expectation maximization, signal strength, wireless LAN}}, pages = {{3721--3725}}, title = {{{Parameter estimation and classification of censored Gaussian data with application to WiFi indoor positioning}}}, doi = {{10.1109/ICASSP.2013.6638353}}, year = {{2013}}, } @inproceedings{5685, abstract = {{In double-sided markets for computing resources an optimal allocation schedule among job offers and requests subject to relevant capacity constraints can be determined. With increasing storage demands and emerging storage services the question how to schedule storage jobs becomes more and more interesting. Since such scheduling problems are often in the class NP-complete an exact computation is not feasible in practice. On the other hand an approximation to the optimal solution can easily be found by means of using heuristics. The problem with this attempt is that the suggested solution may not be exactly optimal and is thus less satisfying. Considering the two above mentioned solution approaches one can clearly find a trade-off between the optimality of the solution and the efficiency to get to a solution at all. This work proposes to apply and combine heuristics in optimization to gain from both of their benefits while reducing the problematic aspects. Following this method it is assumed to get closer to the optimal solution in a shorter time compared to a full optimization.}}, author = {{Finkbeiner, Josef and Bodenstein, Christian and Schryen, Guido and Neumann, Dirk}}, booktitle = {{18th European Conference on Information Systems (ECIS 2010)}}, keywords = {{Decision Support System, Algorithms, Optimization, Market Engineering}}, title = {{{Applying heuristic methods for job scheduling in storage markets}}}, year = {{2010}}, } @inproceedings{9763, abstract = {{Recent advances in information processing enable new kinds of technical systems, called self-optimizing systems. These systems are able to adapt their objectives and their behavior according to the current situation and influences autonomously. This behavior adaptation is non-deterministic and hence self-optimization is a risk to the system, e.g. if the result of the self-optimization process does not match the suddenly changed situation. In contrary, self-optimization could be used to increase the dependability by pursuing objectives like reliability and availability. In our preceding publications we introduced the so called multi-level dependability concept to cope with this new kind of systems (cf. [6]). This concept comprises the monitoring of the system behavior, the classification of the current situation, and the selection of the appropriate measure, if reliability limits are exceeded. In this paper we present for the first time experimental results. The dependability concept is implemented in the self-optimizing active guidance system of a railway vehicle. The test drives illustrate clearly that the proposed concept is able to cope with, e.g., sensor failures, and is able to increase the reliability and availability of the active guidance module.}}, author = {{Sondermann-Wölke, Christoph and Geisler, Jens and Sextro, Walter}}, booktitle = {{Reliability and Maintainability Symposium (RAMS), 2010 Proceedings - Annual}}, issn = {{0149-144X}}, keywords = {{availability, dependability concept, multilevel dependability concept, railway vehicle, reliability, self optimizing active guidance system, self optimizing railway guidance system, situation classification, system behavior monitoring, optimal control, railways, reliability theory, self-adjusting systems}}, pages = {{1 --6}}, title = {{{Increasing the reliability of a self-optimizing railway guidance system}}}, doi = {{10.1109/RAMS.2010.5448080}}, year = {{2010}}, } @inproceedings{11726, abstract = {{In this paper we present a robust location estimation algorithm especially focused on the accuracy in vertical position. A loosely-coupled error state space Kalman filter, which fuses sensor data of an Inertial Measurement Unit and the output of a Global Positioning System device, is augmented by height information from an altitude measurement unit. This unit consists of a barometric altimeter whose output is fused with topographic map information by a Kalman filter to provide robust information about the current vertical user position. These data replace the less reliable vertical position information provided the GPS device. It is shown that typical barometric errors like thermal divergences and fluctuations in the pressure due to changing weather conditions can be compensated by the topographic map information and the barometric error Kalman filter. The resulting height information is shown not only to be more reliable than height information provided by GPS. It also turns out that it leads to better attitude and thus better overall localization estimation accuracy due to the coupling of spatial orientations via the Direct Cosine Matrix. Results are presented both for artificially generated and field test data, where the user is moving by car.}}, author = {{Bevermeier, Maik and Walter, Oliver and Peschke, Sven and Haeb-Umbach, Reinhold}}, booktitle = {{7th Workshop on Positioning Navigation and Communication (WPNC 2010)}}, keywords = {{altitude measurement unit, barometers, barometric altimeter, barometric error Kalman filter, barometric height estimation, direct cosine matrix, global positioning system, Global Positioning System, GPS device, height information, height measurement, inertial measurement unit, Kalman filters, loosely-coupled error state space Kalman filter, loosely-coupled Kalman-filter, map matching, robust information, robust location estimation, sensor fusion, topographic map information, vertical user position}}, pages = {{128--134}}, title = {{{Barometric height estimation combined with map-matching in a loosely-coupled Kalman-filter}}}, doi = {{10.1109/WPNC.2010.5650745}}, year = {{2010}}, } @article{6067, abstract = {{Implicit change detection demonstrates how the visual system can benefit from stored information that is not immediately available to conscious awareness. We investigated the role of motor action in this context. In the first two experiments, using a one-shot implicit change detection paradigm, participants responded to unperceived changes either with an action (jabbing the screen at the guessed location of a change) or with words (verbal report), and sat either 60 cm or 300 cm (with a laser pointer) away from the display. Our observers guessed the locations of changes at a reachable distance better with an action than with a verbal judgment. At 300 cm, beyond reach, the motor advantage disappeared. In experiment 3, this advantage was also unavailable when participants sat at a reachable distance but responded with hand-held laser pointers near their bodies. We conclude that a motor system specialized for real-time visually guided behavior has access to additional visual information. }}, author = {{Tseng, Philip and Tuennermann, Jan and Roker-Knight, Nancy and Winter, Dorina and Scharlau, Ingrid and Bridgeman, Bruce}}, issn = {{0301-0066}}, journal = {{Perception}}, keywords = {{implicit change detection, action perception, visual system, perceptual judgment, verbal fluency, Analysis of Variance, Awareness, Female, Humans, Male, Psychomotor Performance, Random Allocation, Reaction Time, Visual Perception, Visual Memory, Visual Stimulation, Implicit Memory, Judgment, Perceptual Discrimination}}, number = {{10}}, pages = {{1311 -- 1321}}, title = {{{Enhancing implicit change detection through action.}}}, volume = {{39}}, year = {{2010}}, } @inproceedings{37011, abstract = {{Safety-critical automotive systems must fulfill hard real-time constraints for reliability and safety. This paper presents a case study for the application of an AUTOSAR-based language for timing modeling and analysis. We present and apply the Timing Augmented Description Language (TADL) and demonstrate a methodology for the development of a speed-adaptive steer-by-wire system. We examine the impact of TADL and the methodology on the development process and the suitability and interoperability of the applied tools with respect to the AUTOSAR-based tool chain in the context of our case study.}}, author = {{Klobedanz, Kay and Kuznik, Christoph and Thuy, Andre and Müller, Wolfgang}}, booktitle = {{Proceedings of DATE’10, Dresden}}, keywords = {{Timing, Programming, Automotive engineering, Application software, Hardware, Computer architecture, Communication system software, Software architecture, Delay, Software standards}}, location = {{Dresden}}, publisher = {{IEEE}}, title = {{{Timing Modeling and Analysis for AUTOSAR-Based Software Development - A Case Study}}}, doi = {{10.1109/DATE.2010.5457125}}, year = {{2010}}, } @inproceedings{37037, abstract = {{Today we can identify a big gap between requirement specification and the generation of test environments. This article extends the Classification Tree Method for Embedded Systems (CTM/ES) to fill this gap by new concepts for the precise specification of stimuli for operational ranges of continuous control systems. It introduces novel means for continuous acceptance criteria definition and for functional coverage definition.}}, author = {{Krupp, Alexander and Müller, Wolfgang}}, booktitle = {{Proceedings of DATE’10}}, keywords = {{System testing, Automatic testing, Object oriented modeling, Classification tree analysis, Automotive engineering, Mathematical model, Embedded system, Control systems, Electronic equipment testing, Software testing}}, location = {{Dresden}}, publisher = {{IEEE}}, title = {{{A Systematic Approach to Combined HW/SW System Test}}}, doi = {{10.1109/DATE.2010.5457186}}, year = {{2010}}, } @inproceedings{37046, abstract = {{In this article, we present a flexible simulation environment for embedded real-time software refinement by a mixed level cosimulation. For this, we combine the native speed of an abstract real-time operating system (RTOS) model in SystemC with dynamic binary translation for fast Instruction Set Simulation (ISS) by QEMU. In order to support stepwise RTOS software refinement from system level to the target software, each task can be separately migrated between the native execution and the ISS. By adapting the dynamic binary translation approach to an efficient but yet very accurate synchronization scheme the overhead of QEMU user mode execution is only factor two compared to native SystemC. Furthermore, the simulation speed increases almost linearly according to the utilization of the task set abstracted by the native execution. Hereby, the simulation time can be considerably reduced by cosimulating just a subset of tasks on QEMU.}}, author = {{Becker, Markus and Zabel, Henning and Müller, Wolfgang}}, editor = {{Kleinjohann, L. and Kleinjohann, B.}}, isbn = {{978-3-642-15233-7}}, keywords = {{Application Programming Interface User Mode Kernel Space System Level Design Mixed Level}}, publisher = {{Springer Verlag}}, title = {{{A Mixed Level Simulation Environment for Stepwise RTOS Software Refinement}}}, doi = {{10.1007/978-3-642-15234-4_15}}, year = {{2010}}, } @inproceedings{11723, abstract = {{In this paper we present a novel vehicle tracking algorithm, which is based on multi-level sensor fusion of GPS (global positioning system) with Inertial Measurement Unit sensor data. It is shown that the robustness of the system to temporary dropouts of the GPS signal, which may occur due to limited visibility of satellites in narrow street canyons or tunnels, is greatly improved by sensor fusion. We further demonstrate how the observation and state noise covariances of the employed Kalman filters can be estimated alongside the filtering by an application of the Expectation-Maximization algorithm. The proposed time-variant multi-level Kalman filter is shown to outperform an Interacting Multiple Model approach while at the same time being computationally less demanding.}}, author = {{Bevermeier, Maik and Peschke, Sven and Haeb-Umbach, Reinhold}}, booktitle = {{6th Workshop on Positioning Navigation and Communication (WPNC 2009)}}, keywords = {{covariance matrices, expectation-maximisation algorithm, expectation-maximization algorithm, global positioning system, Global Positioning System, GPS, inertial measurement unit, interacting multiple model approach, Kalman filters, multilevel sensor fusion, narrow street canyons, narrow tunnels, online parameter estimation, parameter estimation, road vehicles, robust vehicle localization, sensor fusion, state noise covariances, time-variant multilevel Kalman filter, vehicle tracking algorithm}}, pages = {{235--242}}, title = {{{Robust vehicle localization based on multi-level sensor fusion and online parameter estimation}}}, doi = {{10.1109/WPNC.2009.4907833}}, year = {{2009}}, } @inproceedings{11724, abstract = {{In this paper we present a novel vehicle tracking method which is based on multi-stage Kalman filtering of GPS and IMU sensor data. After individual Kalman filtering of GPS and IMU measurements the estimates of the orientation of the vehicle are combined in an optimal manner to improve the robustness towards drift errors. The tracking algorithm incorporates the estimation of time-variant covariance parameters by using an iterative block Expectation-Maximization algorithm to account for time-variant driving conditions and measurement quality. The proposed system is compared to an interacting multiple model approach (IMM) and achieves improved localization accuracy at lower computational complexity. Furthermore we show how the joint parameter estimation and localizaiton can be conducted with streaming input data to be able to track vehicles in a real driving environment.}}, author = {{Bevermeier, Maik and Peschke, Sven and Haeb-Umbach, Reinhold}}, booktitle = {{IEEE 69th Vehicular Technology Conference (VTC 2009 Spring)}}, keywords = {{computational complexity, expectation-maximisation algorithm, Global Positioning System, inertial measurement unit, inertial navigation, interacting multiple model, iterative block expectation-maximization algorithm, Kalman filters, multi-stage Kalman filter, parameter estimation, road vehicles, vehicle positioning, vehicle tracking}}, pages = {{1--5}}, title = {{{Joint Parameter Estimation and Tracking in a Multi-Stage Kalman Filter for Vehicle Positioning}}}, doi = {{10.1109/VETECS.2009.5073634}}, year = {{2009}}, } @inproceedings{11881, abstract = {{A combination of GPS (global positioning system) and INS (inertial navigation system) is known to provide high precision and highly robust vehicle localization. Notably during times when the GPS signal has a poor quality, e.g. due to the lack of a sufficiently large number of visible satellites, the INS, which may consist of a gyroscope and an odometer, will lead to improved positioning accuracy. In this paper we show how velocity information obtained from GSM (global system for mobile communications) signalling, rather than from a tachometer, can be used together with a gyroscope sensor to support localization in the presence of temporarily unavailable GPS data. We propose a sensor fusion system architecture and present simulation results that show the effectiveness of this approach.}}, author = {{Peschke, Sven and Bevermeier, Maik and Haeb-Umbach, Reinhold}}, booktitle = {{6th Workshop on Positioning Navigation and Communication (WPNC 2009)}}, keywords = {{cellular radio, distance measurement, global positioning system, Global Positioning System, global system for mobile communications, GPS positioning approach, GSM velocity, gyroscopes, gyroscope sensor, inertial navigation, inertial navigation system, odometer, sensor fusion system architecture, sensors}}, pages = {{195--202}}, title = {{{A GPS positioning approach exploiting GSM velocity estimates}}}, doi = {{10.1109/WPNC.2009.4907827}}, year = {{2009}}, }