17,189 research outputs found
FastDepth: Fast Monocular Depth Estimation on Embedded Systems
Depth sensing is a critical function for robotic tasks such as localization,
mapping and obstacle detection. There has been a significant and growing
interest in depth estimation from a single RGB image, due to the relatively low
cost and size of monocular cameras. However, state-of-the-art single-view depth
estimation algorithms are based on fairly complex deep neural networks that are
too slow for real-time inference on an embedded platform, for instance, mounted
on a micro aerial vehicle. In this paper, we address the problem of fast depth
estimation on embedded systems. We propose an efficient and lightweight
encoder-decoder network architecture and apply network pruning to further
reduce computational complexity and latency. In particular, we focus on the
design of a low-latency decoder. Our methodology demonstrates that it is
possible to achieve similar accuracy as prior work on depth estimation, but at
inference speeds that are an order of magnitude faster. Our proposed network,
FastDepth, runs at 178 fps on an NVIDIA Jetson TX2 GPU and at 27 fps when using
only the TX2 CPU, with active power consumption under 10 W. FastDepth achieves
close to state-of-the-art accuracy on the NYU Depth v2 dataset. To the best of
the authors' knowledge, this paper demonstrates real-time monocular depth
estimation using a deep neural network with the lowest latency and highest
throughput on an embedded platform that can be carried by a micro aerial
vehicle.Comment: Accepted for presentation at ICRA 2019. 8 pages, 6 figures, 7 table
Towards Fast-Convergence, Low-Delay and Low-Complexity Network Optimization
Distributed network optimization has been studied for well over a decade.
However, we still do not have a good idea of how to design schemes that can
simultaneously provide good performance across the dimensions of utility
optimality, convergence speed, and delay. To address these challenges, in this
paper, we propose a new algorithmic framework with all these metrics
approaching optimality. The salient features of our new algorithm are
three-fold: (i) fast convergence: it converges with only
iterations that is the fastest speed among all the existing algorithms; (ii)
low delay: it guarantees optimal utility with finite queue length; (iii) simple
implementation: the control variables of this algorithm are based on virtual
queues that do not require maintaining per-flow information. The new technique
builds on a kind of inexact Uzawa method in the Alternating Directional Method
of Multiplier, and provides a new theoretical path to prove global and linear
convergence rate of such a method without requiring the full rank assumption of
the constraint matrix
ShuffleNet: An Extremely Efficient Convolutional Neural Network for Mobile Devices
We introduce an extremely computation-efficient CNN architecture named
ShuffleNet, which is designed specially for mobile devices with very limited
computing power (e.g., 10-150 MFLOPs). The new architecture utilizes two new
operations, pointwise group convolution and channel shuffle, to greatly reduce
computation cost while maintaining accuracy. Experiments on ImageNet
classification and MS COCO object detection demonstrate the superior
performance of ShuffleNet over other structures, e.g. lower top-1 error
(absolute 7.8%) than recent MobileNet on ImageNet classification task, under
the computation budget of 40 MFLOPs. On an ARM-based mobile device, ShuffleNet
achieves ~13x actual speedup over AlexNet while maintaining comparable
accuracy
Development of an automated aircraft subsystem architecture generation and analysis tool
Purpose β The purpose of this paper is to present a new computational framework to address future
preliminary design needs for aircraft subsystems. The ability to investigate multiple candidate
technologies forming subsystem architectures is enabled with the provision of automated architecture
generation, analysis and optimization. Main focus lies with a demonstration of the frameworks
workings, as well as the optimizers performance with a typical form of application problem.
Design/methodology/approach β The core aspects involve a functional decomposition, coupled
with a synergistic mission performance analysis on the aircraft, architecture and component levels.
This may be followed by a complete enumeration of architectures, combined with a user defined
technology filtering and concept ranking procedure. In addition, a hybrid heuristic optimizer, based on
ant systems optimization and a genetic algorithm, is employed to produce optimal architectures in both
component composition and design parameters. The optimizer is tested on a generic architecture
design problem combined with modified Griewank and parabolic functions for the continuous space.
Findings β Insights from the generalized application problem show consistent rediscovery of the
optimal architectures with the optimizer, as compared to a full problem enumeration. In addition
multi-objective optimization reveals a Pareto front with differences in component composition as well
as continuous parameters.
Research limitations/implications β This paper demonstrates the frameworks application on a
generalized test problem only. Further publication will consider real engineering design problems.
Originality/value β The paper addresses the need for future conceptual design methods of complex
systems to consider a mixed concept space of both discrete and continuous nature via automated methods
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