4,915 research outputs found
A dual, fault-tolerant aerospace actuator
The requirements for mechanisms used in the Space Transportation System (STS) are to provide dual fault tolerance, and if the payload equipment violates the Shuttle bay door envelope, these deployment/restow mechanisms must have independent primary and backup features. The research and development of an electromechanical actuator that meets these requirements and will be used on the Transfer Orbit Stage (TOS) program is described
Integrating a Non-Uniformly Sampled Software Retina with a Deep CNN Model
We present a biologically inspired method for pre-processing images applied to CNNs
that reduces their memory requirements while increasing their invariance to scale and rotation
changes. Our method is based on the mammalian retino-cortical transform: a
mapping between a pseudo-randomly tessellated retina model (used to sample an input
image) and a CNN. The aim of this first pilot study is to demonstrate a functional retinaintegrated
CNN implementation and this produced the following results: a network using
the full retino-cortical transform yielded an F1 score of 0.80 on a test set during a 4-way
classification task, while an identical network not using the proposed method yielded an
F1 score of 0.86 on the same task. The method reduced the visual data by e×7, the input
data to the CNN by 40% and the number of CNN training epochs by 64%. These results
demonstrate the viability of our method and hint at the potential of exploiting functional
traits of natural vision systems in CNNs
Object Edge Contour Localisation Based on HexBinary Feature Matching
This paper addresses the issue of localising object
edge contours in cluttered backgrounds to support robotics
tasks such as grasping and manipulation and also to improve
the potential perceptual capabilities of robot vision systems. Our
approach is based on coarse-to-fine matching of a new recursively
constructed hierarchical, dense, edge-localised descriptor,
the HexBinary, based on the HexHog descriptor structure first
proposed in [1]. Since Binary String image descriptors [2]–
[5] require much lower computational resources, but provide
similar or even better matching performance than Histogram
of Orientated Gradient (HoG) descriptors, we have replaced
the HoG base descriptor fields used in HexHog with Binary
Strings generated from first and second order polar derivative
approximations. The ALOI [6] dataset is used to evaluate
the HexBinary descriptors which we demonstrate to achieve
a superior performance to that of HexHoG [1] for pose
refinement. The validation of our object contour localisation
system shows promising results with correctly labelling ~86% of edgel positions and mis-labelling ~3%
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