37 research outputs found
Walking Behavior Change Detector for a “Smart” Walker
AbstractThis study investigates the design of a novel real-time system to detect walking behavior changes using an accelerometer on a rollator. No sensor is required on the user. We propose a new non-invasive approach to detect walking behavior based on the motion transfer by the user on the walker. Our method has two main steps; the first is to extract a gait feature vector by analyzing the three-axis accelerometer data in terms of magnitude, gait cycle and frequency. The second is to classify gait with the use of a decision tree of multilayer perceptrons. To assess the performance of our technique, we evaluated different sampling window lengths of 1, 3 an 5seconds and four different Neural Network architectures. The results revealed that the algorithm can distinguish walking behavior such as normal, slow and fast with an accuracy of about 86%. This research study is part of a project aiming at providing a simple and non-invasive walking behavior detector for elderly who use rollators
Walking Behavior Change Detector for a “Smart” Walker
AbstractThis study investigates the design of a novel real-time system to detect walking behavior changes using an accelerometer on a rollator. No sensor is required on the user. We propose a new non-invasive approach to detect walking behavior based on the motion transfer by the user on the walker. Our method has two main steps; the first is to extract a gait feature vector by analyzing the three-axis accelerometer data in terms of magnitude, gait cycle and frequency. The second is to classify gait with the use of a decision tree of multilayer perceptrons. To assess the performance of our technique, we evaluated different sampling window lengths of 1, 3 an 5seconds and four different Neural Network architectures. The results revealed that the algorithm can distinguish walking behavior such as normal, slow and fast with an accuracy of about 86%. This research study is part of a project aiming at providing a simple and non-invasive walking behavior detector for elderly who use rollators
Correspondence of three-dimensional objects
First many thanks go to Prof. Hans du Buf, for his supervision based
on his experience, for providing a stimulating and cheerful research environment
in his laboratory, for letting me participate in the projects that
produced results for papers, thus made me more aware of the state of the
art in Computer Vision, especially in the area of 3D recognition. Also for
his encouraging support and his way to always nd time for discussions,
and last but not the least for the cooking recipes...
Many thanks go also to my laboratory fellows, to Jo~ao Rodrigues, who
invited me to participate in FCT and QREN projects, Jaime Carvalho
Martins and Miguel Farrajota, for discussing scienti c and technical
problems, but also almost all problems in the world.
To all persons, that worked in, or visited the Vision Laboratory, especially
those with whom I have worked with, almost on a daily basis.
A special thanks to the Instituto Superior de Engenharia at UAlg and
my colleagues at the Department of Electrical Engineering, for allowing
me to suspend lectures in order to be present at conferences.
To my family, my wife and my kids
Vehicular Instrumentation and Data Processing for the Study of Driver Intent
The primary goal of this thesis is to provide processed experimental data needed to determine whether driver intentionality and driving-related actions can be predicted from quantitative and qualitative analysis of driver behaviour. Towards this end, an instrumented experimental vehicle capable of recording several synchronized streams of data from the surroundings of the vehicle, the driver gaze with head pose and the vehicle state in a naturalistic driving environment was designed and developed. Several driving data sequences in both urban and rural environments were recorded with the instrumented vehicle. These sequences were automatically annotated for relevant artifacts such as lanes, vehicles and safely driveable areas within road lanes. A framework and associated algorithms required for cross-calibrating the gaze tracking system with the world coordinate system mounted on the outdoor stereo system was also designed and implemented, allowing the mapping of the driver gaze with the surrounding environment. This instrumentation is currently being used for the study of driver intent, geared towards the development of driver maneuver prediction models