The Method of Commands Identification to Voice Control of the Electric Wheelchair

Abstract

The paper shows the relevance of the task of improving the electric wheelchair control system for patients with lost or functionally limited upper limbs. A method of indirect control using voice commands is proposed. At the same time, the biometric principle is used, according to which, in the process of voice signal analysis, signs that are biometric parameters of the patient's speech are identified to prevent the operation of the control system when registering similar commands from outsiders. The main such sign is the value of the main tone frequency. To process voice signals in order to identify the four main control commands, namely forward, backward, left and right, the sliding window method is used, within which the presence of signs of the main tone is evaluated. For a specific person, this value will be individual and present only in those parts of the voice signal that correspond to vowels and consonant vocalized sounds. In this way, it is possible to segment the voice signal into such areas and identify individual voice commands based on pre-set durations of these areas. A threshold function is also used for this, which takes a certain value when the main tone frequency is present in the voice signal structure within each implementation of the sliding window and is equal to zero when there are no signs of this frequency. At the same time, it became possible to identify individual commands with higher accuracy.