9,601 research outputs found
LineMarkNet: Line Landmark Detection for Valet Parking
We aim for accurate and efficient line landmark detection for valet parking,
which is a long-standing yet unsolved problem in autonomous driving. To this
end, we present a deep line landmark detection system where we carefully design
the modules to be lightweight. Specifically, we first empirically design four
general line landmarks including three physical lines and one novel mental
line. The four line landmarks are effective for valet parking. We then develop
a deep network (LineMarkNet) to detect line landmarks from surround-view
cameras where we, via the pre-calibrated homography, fuse context from four
separate cameras into the unified bird-eye-view (BEV) space, specifically we
fuse the surroundview features and BEV features, then employ the multi-task
decoder to detect multiple line landmarks where we apply the center-based
strategy for object detection task, and design our graph transformer to enhance
the vision transformer with hierarchical level graph reasoning for semantic
segmentation task. At last, we further parameterize the detected line landmarks
(e.g., intercept-slope form) whereby a novel filtering backend incorporates
temporal and multi-view consistency to achieve smooth and stable detection.
Moreover, we annotate a large-scale dataset to validate our method.
Experimental results show that our framework achieves the enhanced performance
compared with several line detection methods and validate the multi-task
network's efficiency about the real-time line landmark detection on the
Qualcomm 820A platform while meantime keeps superior accuracy, with our deep
line landmark detection system.Comment: 29 pages, 12 figure
Defending against Sybil Devices in Crowdsourced Mapping Services
Real-time crowdsourced maps such as Waze provide timely updates on traffic,
congestion, accidents and points of interest. In this paper, we demonstrate how
lack of strong location authentication allows creation of software-based {\em
Sybil devices} that expose crowdsourced map systems to a variety of security
and privacy attacks. Our experiments show that a single Sybil device with
limited resources can cause havoc on Waze, reporting false congestion and
accidents and automatically rerouting user traffic. More importantly, we
describe techniques to generate Sybil devices at scale, creating armies of
virtual vehicles capable of remotely tracking precise movements for large user
populations while avoiding detection. We propose a new approach to defend
against Sybil devices based on {\em co-location edges}, authenticated records
that attest to the one-time physical co-location of a pair of devices. Over
time, co-location edges combine to form large {\em proximity graphs} that
attest to physical interactions between devices, allowing scalable detection of
virtual vehicles. We demonstrate the efficacy of this approach using
large-scale simulations, and discuss how they can be used to dramatically
reduce the impact of attacks against crowdsourced mapping services.Comment: Measure and integratio
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