Multi-Object Tracking with Interacting Vehicles and Road Map Information

In many applications, tracking of multiple objects is crucial for a perception of the current environment. Most of the present multi-object tracking algorithms assume that objects move independently regarding other dynamic objects as well as the static environment. Since in many traffic situations objects interact with each other and in addition there are restrictions due to drivable areas, the assumption of an independent object motion is not fulfilled. This paper proposes an approach adapting a multi-object tracking system to model interaction between vehicles, and the current road geometry. Therefore, the prediction step of a Labeled Multi-Bernoulli filter is extended to facilitate modeling interaction between objects using the Intelligent Driver Model. Furthermore, to consider road map information, an approximation of a highly precise road map is used. The results show that in scenarios where the assumption of a standard motion model is violated, the tracking system adapted with the proposed method achieves higher accuracy and robustness in its track estimations

Environment Perception Framework Fusing Multi-Object Tracking, Dynamic Occupancy Grid Maps and Digital Maps

Autonomously driving vehicles require a complete and robust perception of the local environment. A main challenge is to perceive any other road users, where multi-object tracking or occupancy grid maps are commonly used. The presented approach combines both methods to compensate false positives and receive a complementary environment perception. Therefore, an environment perception framework is introduced that defines a common representation, extracts objects from a dynamic occupancy grid map and fuses them with tracks of a Labeled Multi-Bernoulli filter. Finally, a confidence value is developed, that validates object estimates using different constraints regarding physical possibilities, method specific characteristics and contextual information from a digital map. Experimental results with real world data highlight the robustness and significance of the presented fusing approach, utilizing the confidence value in rural and urban scenarios

Situation-Aware Environment Perception Using a Multi-Layer Attention Map

Within the field of automated driving, a clear trend in environment perception tends towards more sensors, higher redundancy, and overall increase in computational power. This is mainly driven by the paradigm to perceive the entire environment as best as possible at all times. However, due to the ongoing rise in functional complexity, compromises have to be considered to ensure real-time capabilities of the perception system. In this work, we introduce a concept for situation-aware environment perception to control the resource allocation towards processing relevant areas within the data as well as towards employing only a subset of functional modules for environment perception, if sufficient for the current driving task. Specifically, we propose to evaluate the context of an automated vehicle to derive a multi-layer attention map (MLAM) that defines relevant areas. Using this MLAM, the optimum of active functional modules is dynamically configured and intra-module processing of only relevant data is enforced. We outline the feasibility of application of our concept using real-world data in a straight-forward implementation for our system at hand. While retaining overall functionality, we achieve a reduction of accumulated processing time of 59%.Comment: Update 1: Removed minor typos, corrected FKZ. Update 2: Extension of Section III-E. Rewording in some sections to improve clarity. Added IEEE Copyright Notic

Energetics of a black hole: constraints on the jet velocity and the nature of the X-ray emitting region in Cyg X-1

We investigate the energetics of the jet and X-ray corona of Cyg X-1. We show that the current estimates of the jet power obtained from Halpha and [O III] measurements of the optical nebula surrounding the X-ray source allow one to constrain the bulk velocity of the jet. It is definitely relativistic (v >0.1c) and most probably in the range (0.3-0.8)c. The exact value of the velocity depends on the accretion efficiency. These constraints are obtained independently of, and are consistent with, previous estimates of the jet bulk velocity based on radio measurements. We then show that the X-ray emission does not originate in the jet. Indeed, the energy budget does not allow the corona to be ejected to infinity at relativistic speed. Rather, either a small fraction of the corona escapes to infinity, or the ejection velocity of the corona is vanishingly low. Although the corona could constitute the jet launching region, it cannot be identified with the jet itself. We discuss the consequences for various X-ray emission models.Comment: 9 pages, 4 figures, to appear in MNRA

On the Role of the Accretion Disk in Black Hole Disk-Jet Connections

Models of jet production in black hole systems suggest that the properties of the accretion disk - such as its mass accretion rate, inner radius, and emergent magnetic field - should drive and modulate the production of relativistic jets. Stellar-mass black holes in the "low/hard" state are an excellent laboratory in which to study disk-jet connections, but few coordinated observations are made using spectrometers that can incisively probe the inner disk. We report on a series of 20 Suzaku observations of Cygnus X-1 made in the jet-producing low/hard state. Contemporaneous radio monitoring was done using the Arcminute MicroKelvin Array radio telescope. Two important and simple results are obtained: (1) the jet (as traced by radio flux) does not appear to be modulated by changes in the inner radius of the accretion disk; and (2) the jet is sensitive to disk properties, including its flux, temperature, and ionization. Some more complex results may reveal aspects of a coupled disk-corona-jet system. A positive correlation between the reflected X-ray flux and radio flux may represent specific support for a plasma ejection model of the corona, wherein the base of a jet produces hard X-ray emission. Within the framework of the plasma ejection model, the spectra suggest a jet base with v/c ~ 0.3, or the escape velocity for a vertical height of z ~ 20 GM/c^2 above the black hole. The detailed results of X-ray disk continuum and reflection modeling also suggest a height of z ~ 20 GM/c^2 for hard X-ray production above a black hole, with a spin in the range 0.6 < a < 0.99. This height agrees with X-ray time lags recently found in Cygnus X-1. The overall picture that emerges from this study is broadly consistent with some jet-focused models for black hole spectral energy distributions in which a relativistic plasma is accelerated at z = 10-100 GM/c^2.Comment: Accepted for publication in Ap

UNICARagil – New architectures for disruptive vehicle concepts

This paper provides an overview of the research topics of the UNICARagil project with the focus on different architectures, such as the mechatronic, the software, and the mechanic architecture. The main research questions as well as possible solutions, which will be investigated in this project, are described. The project is funded by the Federal Ministry of Education and Research of Germany In terms of the mechatronic and the software architecture, this paper focuses on the ECU concept: the main tasks of the automated driving process are executed on three ECUs, which are called the cerebrum, the brainstem and the spinal cord. This architecture supports the modular approach regarding functional safety, the ability of future updates and upgrades, and the service orientated architecture (SOA) of the software. The well-known SOA approach is transferred to automotive applications and becomes the automotive service orientated architecture (ASOA). Furthermore, the mechanic structure of the four vehicles AUTOtaxi, AUTOelfe, AUTOliefer and AUTOshuttle is described

Discovery of a parsec-scale bipolar nebula around MWC 349A

We report the discovery of a bipolar nebula around the peculiar emission-line star MWC 349A using archival Spitzer Space Telescope 24 um data. The nebula extends over several arcminutes (up to 5 pc) and has the same orientation and geometry as the well-known subarcsecond-scale (~400 times smaller) bipolar radio nebula associated with this star. We discuss the physical relationship between MWC 349A and the nearby B0 III star MWC 349B and propose that both stars were members of a hierarchical triple system, which was ejected from the core of the Cyg OB2 association several Myr ago and recently was dissolved into a binary system (now MWC 349A) and a single unbound star (MWC 349B). Our proposal implies that MWC 349A is an evolved massive star (likely a luminous blue variable) in a binary system with a low-mass star. A possible origin of the bipolar nebula around MWC 349A is discussed.Comment: 9 pages, 6 figures, accepted for publication in A&