Title: A wavelet- and neural network-based voice interface system for wheelchair control

Authors: Q.P. Ha, T.H. Tran, G. Dissanayake

Addresses: Faculty of Engineering, ARC Centre of Excellence for Autonomous Systems (CAS), University of Technology, Sydney, PO Box 123, Broadway, NSW 2007, Australia. ' Faculty of Engineering, ARC Centre of Excellence for Autonomous Systems (CAS), University of Technology, Sydney, PO Box 123, Broadway, NSW 2007, Australia. ' Faculty of Engineering, ARC Centre of Excellence for Autonomous Systems (CAS), University of Technology, Sydney, PO Box 123, Broadway, NSW 2007, Australia

Abstract: Voice control has long been considered as a natural mechanism to assist powered wheelchair users. However, one implementation difficulty is that a voice input system may fail to recognise a user|s voice. Indeed, speech activated interface between human and autonomous/semi-autonomous systems requires accurate detection and recognition. In this area pitch and end-point detection are of vital importance. This paper presents a new method for pitch detection based on the continuous wavelet transform phase. The proposed technique can serve as an accurate pitch detector, and also can offer an efficient solution to the end-point detection problem. The extracted features from a user|s speech are then used to train a neural network for speech recognition. Experimental results are provided for the detection of pitch periods and end points and the recognition of a number of commands of male and female users. Laboratory tests are reported for the proposed voice control wheelchair system.

Keywords: pitch detection; end-point detection; continuous wavelet transform; neural networks; powered wheelchairs; voice control; biorobotics; biomechatronics; speech recognition; wheelchair control; voice recognition; human-robot interface; human-robot interaction.

DOI: 10.1504/IJISTA.2005.007307

International Journal of Intelligent Systems Technologies and Applications, 2005 Vol.1 No.1/2, pp.49 - 65

Published online: 05 Jul 2005 *

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