Efficiency Optimisation of Tracked Vehicles Using Secondary Control in a Single-Circuit Load Sensing System

The paper describes a concept of a secondary controlled traction drive integrated in a common Load Sensing system. When used in a single circuit system, a secondary controlled drive for tracked vehicles shows a big efficiency optimisation potential compared to other drives. The high losses at turns can be avoided if two secondary controlled units are connected to a single Load Sensing valve. The traction drive is still supplied in a traditional way using Load Sensing. For steering, the secondary controlled units are integrated in a control loop where the steering ratio is used as command value

A Control Flow based Static Analysis of GRAFCET using Abstract Interpretation

The graphical modeling language GRAFCET is used as a formal specification language in industrial control design. This paper proposes a static analysis approach based on the control flow of GRAFCET using abstract interpretation to allow verification on specification level. GRAFCET has different elements leading to concurrent behavior, which in general results in a large state space. To get precise results and reduce the state space, we propose an analysis suitable for GRAFCET instances without concurrent behavior. We point out how to check for the absence of concurrency and present a flow-sensitive analysis for these GRAFCET instances. The proposed approach is evaluated on an industrial-sized example.Comment: \c{opyright} 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other work

Unambiguous Interpretation of IEC 60848 GRAFCET based on a Literature Review

IEC 60848 GRAFCET is a standardized, graphical specification language for control functions. Because of the semiformal nature of IEC 60848, the details of specifications created with GRAFCET can be interpreted in different ways, possibly leading to faulty implementations. These ambiguities have been partially addressed in existing literature, but solved in different manners. Based on a literature review, this work aims at providing an overview of existing interpretations and, based on that, proposes a comprehensive interpretation algorithm for IEC 60848, which takes all relevant ambiguities from the literature review into account.Comment: Submitted to ETFA 2

Unternehmensübergreifende Simulation mobiler Arbeitsmaschinen - Ein Vorschlag für eine standardisierte Vorgehensweise. [Kurzfassung]

Mobile Arbeitsmaschinen sind komplexe Systeme und stellen eine Verknüpfung vieler verschiedener Ingenieursfachdisziplinen wie Mechanik, Hydraulik, Pneumatik oder Regelungstechnik dar, deren Zusammenwirken die Leistungen und Funktionen einer solchen Maschine erst ermöglichen. Dieses Zusammenwirken erschwert die Simulation solcher Maschinen. Im vorliegenden Beitrag wird daher ein Vorschlag für eine standardisierte Vorgehensweise vorgestellt, mit deren Hilfe eine mobile Arbeitsmaschine über Unternehmensgrenzen hinweg simuliert werden kann. Grundlage hierfür ist der Gedanke einer Plattform, auf der die Simulation durchgeführt werden soll

Unternehmensübergreifende Simulation mobiler Arbeitsmaschinen - Ein Vorschlag für eine standardisierte Vorgehensweise

Mobile Arbeitsmaschinen sind komplexe Systeme und stellen eine Verknüpfung vieler verschiedener Ingenieursfachdisziplinen wie Mechanik, Hydraulik, Pneumatik oder Regelungstechnik dar, deren Zusammenwirken die Leistungen und Funktionen einer solchen Maschine erst ermöglichen. Dieses Zusammenwirken erschwert die Simulation solcher Maschinen. Im vorliegenden Beitrag wird daher ein Vorschlag für eine standardisierte Vorgehensweise vorgestellt, mit deren Hilfe eine mobile Arbeitsmaschine über Unternehmensgrenzen hinweg simuliert werden kann. Grundlage hierfür ist der Gedanke einer Plattform, auf der die Simulation durchgeführt werden soll

Standardisierte Vorgehensweise bei der Co-Simulation zur Simulation einer mobilen Arbeitsmaschine

Mobile Arbeitsmaschinen sind komplexe Systeme und stellen eine Verknüpfung vieler verschiedener Ingenieursfachdisziplinen wie Mechanik, Hydraulik, Pneumatik oder Regelungstechnik dar, deren Zusammenwirken die Leistungen und Funktionen einer solchen Maschine erst ermöglichen. Dieses Zusammenwirken erschwert die Simulation solcher Maschinen. Im vorliegenden Beitrag wird daher ein Vorschlag für eine standardisierte Vorgehensweise vorgestellt, mit deren Hilfe eine mobile Arbeitsmaschine über Unternehmensgrenzen hinweg simuliert werden kann. Grundlage hierfür ist der Gedanke einer Plattform, auf der die Simulation durchgeführt werden soll

On the interplay between microstructure, residual stress and fracture toughness of (Hf-Nb-Ta-Zr)C multi-metal carbide hard coatings

The development of sputtered coatings with improved hardness-toughness property combination is widely sought after. Multi-element ceramic carbide (Hf-Nb-Ta-Zr)C coatings with excess carbon, synthesized by DC co-sputtering is presented in this study as a promising candidate to achieve this objective. The specific roles of microstructure and residual stress are decoupled in order to understand their influence on the mechanical properties. Extensive mechanical characterization through in situ testing of focused ion beam fabricated microcantilevers and nanoindentation based approaches are adopted to quantitatively separate the effect of residual stresses on the fracture toughness of the (Hf-Nb-Ta-Zr)C coatings. Residual stress free, microcantilever testing in notched and unnotched conditions, in combination with microstructural characterization unambiguously reveals the intrinsic mechanical behavior of coatings, which solely depend on the microstructure. On the other hand, nanoindentation based testing techniques probe the influence of residual stress and microstructure on the measured mechanical properties. The segregation and thickening of carbon-rich clusters, especially to the grain boundaries with increasing deposition temperatures is speculated to lead to substantial degradation in all mechanical properties measured. An easier fracture path through grain boundaries leads to a reduction in fracture resistance, which is possibly related to carbon enrichment

Electron transfer rates for asymmetric reactions

We use a numerically exact real-time path integral Monte Carlo scheme to compute electron transfer dynamics between two redox sites within a spin-boson approach. The case of asymmetric reactions is studied in detail in the least understood crossover region between nonadiabatic and adiabatic electron transfer. At intermediate-to-high temperature, we find good agreement with standard Marcus theory, provided dynamical recrossing effects are captured. The agreement with our data is practically perfect when temperature renormalization is allowed. At low temperature we find peculiar electron transfer kinetics in strongly asymmetric systems, characterized by rapid transient dynamics and backflow to the donor.Comment: 13 pages, 4 figures, submitted to Chemical Physics Special Issue on the Spin-Boson Problem, ed. by H. Grabert and A. Nitza

Correlates of Adverse Outcomes in Abdominally Obese Individuals: Findings from the Five-Year Followup of the Population-Based Study of Health in Pomerania

Background. Abdominal obesity is a major risk factor of cardiovascular disease (CVD), type 2 diabetes (T2DM), and premature death. However, it has not been resolved which factors predispose for the development of these adverse obesity-related outcomes in otherwise healthy individuals with abdominal obesity. Methods. We studied 1,506 abdominal obese individuals (waist-to-height ratio (WHtR) ≥ 0.5) free of CVD or T2DM from the population-based Study of Health in Pomerania and assessed the incidence of CVD or T2DM after a five-year followup. Logistic regression models were adjusted for major cardiovascular risk factors and liver, kidney diseases, and sociodemographic status. Results. During follow-up time, we observed 114 and 136 new T2DM and CVD cases, respectively. Regression models identified age, waist circumference, serum glucose, and liver disease as predictors of T2DM. Regarding CVD, only age, unemployment, and a divorced or widowed marital status were significantly associated with incident CVD. In this subgroup of obese individuals blood pressure, serum glucose, or lipids did not influence incidence of T2DM or CVD. Conclusion. We identified various factors associated with an increased risk of incident T2DM and CVD among abdominally obese individuals. These findings may improve the detection of high-risk individuals and help to advance prevention strategies in abdominal obesity