325 research outputs found

    The role of driver models in testing highly-automated driving: a survey [Die Rolle von Fahrermodellen fĂĽr das Testen hoch-automatisierter Fahrfunktionen: Eine Ăśbersicht]

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    Eine besondere Herausforderung bei der Entwicklung hoch-automatisierter Fahrfunktionen ist die Validierung dieser Systeme. Ein möglicher Ansatz, den Validierungsaufwand zu meistern, ist der Einsatz von Simulationen. Hierbei können Simulatoren für verschiedene Aspekte des Validierungs-Prozesses verwendet werden. Um verwendbare Ergebnisse zu erhalten, müssen die einzelnen Aspekte der Realität dabei durch entsprechende Modelle abgebildet werden. Basierend auf einer Analyse verschiedener Anwendungsfälle für Simulationen, werden in diesem Beitrag verschiedene Klassen von Modellen für das menschliche Fahrverhalten hinsichtlich ihrer An-wendbarkeit im Rahmen der simulativen Absicherung evaluiert

    Guaranteed state estimation using a bundle of interval observers with adaptive gains applied to the induction machine

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    he scope of this paper is the design of an interval observer bundle for the guaranteed state estimation of an uncertain induction machine with linear, time-varying dynamics. These guarantees are of particular interest in the case of safety-critical systems. In many cases, interval observers provide large intervals for which the usability becomes impractical. Hence, based on a reduced-order hybrid interval observer structure, the guaranteed enclosure within intervals of the magnetizing current’s estimates is improved using a bundle of interval observers. One advantage of such an interval observer bundle is the possibility to reinitialize the interval observers at specified timesteps during runtime with smaller initial intervals, based on previously observed system states, resulting in decreasing interval widths. Thus, unstable observer dynamics are considered so as to take advantage of their transient behavior, whereby the overall stability of the interval estimation is maintained. An algorithm is presented to determine the parametrization of reduced-order interval observers. To this, an adaptive observer gain is introduced with which the system states are observed optimally by considering a minimal interval width at variable operating points. Furthermore, real-time capability and validation of the proposed methods are shown. The results are discussed with simulations as well as experimental data obtained with a test bench

    A robust fault detection method using a zonotopic Kaucher set-membership approach

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    This paper presents a robust fault detection method using a zonotopic Kaucher set-membership method. The fault detection approach is based on checking the consistency between the model and the data. Consistency is given if there is an intersection between the feasible parameter set and the nominal parameter set. To allow efficient computation the feasible set is approximated by a zonotope. Due to the usage of Kaucher interval arithmetic the results are mathematically guaranteed. The proposed approach is assessed using an illustrative application based on a well-known four-tank case study. The study shows that it is possible to detect even small errors in a noisy settingPeer ReviewedPostprint (published version

    A Systematic Review

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    Music therapy (MT) and music-based interventions (MBIs) are increasingly used for the treatment of substance use disorders (SUD). Previous reviews on the efficacy of MT emphasized the dearth of research evidence for this topic, although various positive effects were identified. Therefore, we conducted a systematic search on published articles examining effects of music, MT and MBIs and found 34 quantitative and six qualitative studies. There was a clear increase in the number of randomized controlled trials (RCTs) during the past few years. We had planned for a meta-analysis, but due to the diversity of the quantitative studies, effect sizes were not computed. Beneficial effects of MT/ MBI on emotional and motivational outcomes, participation, locus of control, and perceived helpfulness were reported, but results were inconsistent across studies. Furthermore, many RCTs focused on effects of single sessions. No published longitudinal trials could be found. The analysis of the qualitative studies revealed four themes: emotional expression, group interaction, development of skills, and improvement of quality of life. Considering these issues for quantitative research, there is a need to examine social and health variables in future studies. In conclusion, due to the heterogeneity of the studies, the efficacy of MT/ MBI in SUD treatment still remains unclear

    Model predictive control and trajectory optimization of large vehicle-manipulators

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    In this paper, a model predictive control (MPC) is developed for on- and off-road mid-sized heavy duty vehicle-manipulator systems with a hydraulic working arm. The proposed concept for the control model is also new in the sense of working only within a local reference coordinate-system relative to the reference trajectory (so-called Fren´et-System). The control model only needs the errors to the reference trajectory. In contrast to other state-of-the-art approaches, there is no global localization method necessary. The control model is kept as simple as possible, to allow real-time motion prediction of the real system. For this reason, a kinematic model is used in the MPC which consists of a bicycle model and a planar robotic arm with two control variables. The dynamics of the overall system are considered as optimization constraints, assuming that the optimized system inputs and states are kinetically and dynamically feasible. Through this control method, the dual-trajectories are also optimized and they provide smooth motions for the overall system. The underlying control of the robotic arm is realized with a proportional–integral–derivative (PID) controller with feedback linearization and gravity compensation. The control algorithm is tested and validated in a MATLAB/Simulink simulation environment

    Efficient Construction of Homozygous Diploid Strains Identifies Genes Required for the Hyper-Filamentous Phenotype in Saccharomyces cerevisiae

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    Yeast cells undergo diploid-specific developments such as spore formation via meiosis and pseudohyphal development under certain nutrient-limited conditions. Studies on these aspects require homozygous diploid mutants, which are generally constructed by crossing strains of opposite mating-type with the same genetic mutation. So far, there has been no direct way to generate and select diploids from haploid cells. Here, we developed a method for efficient construction of homozygous diploids using a PGAL1-HO gene (galactose-inducible mating-type switch) and a PSTE18-URA3 gene (counter selection marker for diploids). Diploids are generated by transient induction of the HO endonuclease, which is followed by mating of part of the haploid population. Since the STE18 promoter is repressed in diploids, diploids carrying PSTE18-URA3 can be selected on 5-fluoroorotic acid (5-FOA) plates where the uracil prototrophic haploids cannot grow. To demonstrate that this method is useful for genetic studies, we screened suppressor mutations of the complex colony morphology, strong agar invasion and/or hyper-filamentous growth caused by lack of the Hog1 MAPK in the diploid ÎŁ1278b strain background. Following this approach, we identified 49 suppressor mutations. Those include well-known positive regulator genes for filamentous growth signaling pathways, genes involved in mitochondrial function, DNA damage checkpoint, chromatin remodeling, and cell cycle, and also previously uncharacterized genes. Our results indicate that combinatorial use of the PGAL1-HO and PSTE18-URA3 genes is suitable to efficiently construct and select diploids and that this approach is useful for genetic studies especially when combined with large-scale screening
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