A comprehensive description of a model-based, continous development process for AUTOSAR systems with integrated quality assurance

Der AUTOSAR-Standard definiert neben einer durchgängig werkzeuggestützten und modellbasierten Methodik zur Entwicklung von Steuergeräte-Software eine technische Infrastruktur als standardisierte Steuergeräte-Basissoftware zur Implementierung dieser Systeme im Automobil. Die wesentlichen Herausforderungen in der Entwicklung automotiver Systeme ergeben sich dabei nicht nur aus der stetig steigenden Menge korrekt umzusetzender Funktionalität, sondern auch aus der wachsenden Anzahl zusätzlich zu erfüllender Qualitätsanforderungen, wie z.B. Sicherheit, Performanz oder Kosten. Die Integration von Ansätzen zur frühzeitigen, Entwicklungsphasen begleitenden Überprüfung von Korrektheits- und Qualitätskriterien kann dabei maßgeblich zur Beherrschbarkeit der Komplexität dieser Systeme beitragen. Es wird ein entsprechend durchgängig werkzeuggestützter und modellbasierter Entwicklungsprozess, basierend auf dem V-Modell sowie dessen Integration in die AUTOSAR-Methodik definiert. Neben der Überprüfung der funktionalen Korrektheit durch systematische Testverfahren sieht das erweiterte Prozessmodell die Bewertung beliebiger Qualitätskriterien für das zu entwickelnde System vor. Es wird beschrieben, wie insbesondere im AUTOSAR-Kontext der Entwurf der Systemarchitektur die hierfür entscheidende Design-Phase darstellt und als Grundlage für Qualitätsabschätzungen durch Architektur-Evaluation dienen kann. Die Vorgehensweise in den einzelnen Entwicklungsschritten wird detailliert anhand einer umfangreichen, vollständig AUTOSAR-konformen Fallstudie, bestehend aus einem vereinfachten PKW-Komfortsystem, demonstriert. Die durchgängige Toolkette umfasst alle Phasen von der Anforderungsspezifikation bis zur Implementierung auf einem prototypischen Hardware-Demonstrator bestehend aus vier über CAN vernetzten Steuergeräten und HIL-Schnittstellen für die Testdurchführung. Es wird auf ausgewählte Implementierungsdetails, notwendige Workarounds und Besonderheiten der prototypischen Umsetzung eingegangen.The AUTOSAR standard defines a seamless tool supported and model based methodology for ECU software design and engineering. Furthermore, the standard specifies a technical infrastructure by means of standardized basic software modules for ECU networks, serving as a uniform implementation platform for AUTOSAR systems. The major challenges in automotive systems development not only arise as a result of the contiuously growing amount of functionality to be realized correctly, but also from the increasing number of quality requirements to be taken into account, e.g. safety, performance, and costs. The integration of approaches for early checking of correctness and quality criteria accompanying the different development phases makes a significant contribution towards coping with the complexity of such systems. We describe such a model based development process and a corresponding tool chain based on the V-modell and its embedding into the AUTOSAR methodology. For the validation of functional correctness systematic testing approaches are applied, and for quality criteria according evaluation methods are used. We discuss that especially in the context of AUTOSAR, the phase of architectural system design is crucial for the quality properties of the system under development, and to what extent architecture evaluation can be used for quality estimation. The practices in the different development steps are illustrated in detail by means of a comprehensive, AUTOSAR compliant case study, i.e. a body comfort system. The tool chain proposed comprises all development stages, starting from the requirements specification, and concluding with the system implementation on a hardware demonstrator prototype. The demonstrator consists of ECUs coupled via CAN, as well as HIL interfaces for test case applications. We give detailled insights in selected impl. issues, workarounds required, and the configuration steps needed for the AUTOSAR operating system. A discussion of the pro's and con's regarding the potential of AUTOSAR concludes

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.Peer reviewe

Measurement of b jet shapes in proton-proton collisions at root s=5.02 TeV

We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb(-1). To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.Peer reviewe

Measurement of the Jet Mass Distribution and Top Quark Mass in Hadronic Decays of Boosted Top Quarks in pp Collisions at root s=13 TeV

A measurement is reported of the jet mass distribution in hadronic decays of boosted top quarks produced in pp collisions at root s = 13 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9 fb(-1). The measurement is performed in the lepton + jets channel of t (t) over bar events, where the lepton is an electron or muon. The products of the hadronic top quark decay t -> bW -> bq (q) over bar' are reconstructed as a single jet with transverse momentum larger than 400 GeV. The t (t) over bar cross section as a function of the jet mass is unfolded at the particle level and used to extract a value of the top quark mass of 172.6 +/- 2.5 GeV. A novel jet reconstruction technique is used for the first time at the LHC, which improves the precision by a factor of 3 relative to an earlier measurement. This highlights the potential of measurements using boosted top quarks, where the new technique will enable future precision measurements.Peer reviewe