Mohamed Fezari

An Ultrasonic Navigation System for Blind People

The aim of this paper is to investigate the development of a navigation aid for blind and visually impaired people. It is based on a microcontroller with synthetic speech output. This aid is portable and gives information to the user about urban walking routes to point out what decisions to make. On the other hand, and in order to reduce navigation difficulties of the blind, an obstacle detection system using ultrasounds and vibrators is added to this device. The proposed system detects the nearest obstacle via stereoscopic sonar system and sends back vibro-tactile feedback to inform the blind about its localization.

A Navigation Tool for Blind People

This paper describes the development of a navigation aid in order to assist blind and visually impaired people to navigate easily, safely and to detect any obstacles. The system is based on a microcontroller with synthetic speech output. In addition, it consists of two vibrators, two ultrasonic sensors mounted on the user’s shoulders and another one integrated into the cane. This aid is able to give information to the blind about urban walking routes and to provide real-time information on the distance of over-hanging obstacles within six meters along the travel path ahead of the user. The suggested system consists then in sensing the surrounding environment via sonar sensors and sending vibro-tactile feedback to the user of the position of the closest obstacles in range. For the ultrasonic cane, it is used to detect any obstacle on the ground.

Speech and sensor in guiding an electric wheelchair

Many people with disabilities do not have the dexterity necessary to control a joystick on an electric wheelchair. Moreover, they have difficulty to avoid obstacles. The aim of this work is to implement a multi-modal system to control the movement of an Electric wheelchair using small vocabulary word recognition system and a set of sensors to detect and avoid obstacles. The methodology adopted is based on grouping a microcontroller with a speech recognition development kit for isolated word from a dependent speaker and a set of sensors. In order to gain in time design, tests have shown that it would be better to choose a speech recognition kit and to adapt it to the application.

The Development of a pedestrian navigation aid for the blind

An Electronic Travel Aid is a form of assistive technology having the purpose of enhancing mobility for blind individuals. This paper examines a pedestrian navigation system for the Blind, which is based on a microcontroller with synthetic speech output. This aid is a portable, self contained system that will allow blind people to travel without the assistance of guides. It is designed for a battery-powered portable model. In addition, it is focused on low power consumption, small size, lightweight, and easy manipulation. The proposed system provides information to the user about urban walking routes using spoken words to indicate what decisions to make.

A NAVIGATION SYSTEM FOR BLIND PEDESTRIANS

Abstract An electronic travel aid is a form of assistive technology having the purpose of enhancing mobility for the blind. This paper describes the development of a microcontroller based navigation system for blind pedestrians. It is a portable, self contained portable electronic system that will allow visually impaired individuals to travel through familiar and unfamiliar environments without the assistance of guides. In addition, this system can supply the blind person with assistance about walking routes by using coded sounds to point out what decisions to make.

New speech processor and ultrasonic sensors based embedded system to improve the control of a motorised wheelchair

This paper describes a design of an embedded system used to facilitate the control of a wheelchair. Wheelchair users are able to operate a joystick to control the chair, however many more severely handicapped users need some other means of controlling this type of robot. The designed system is based on grouping a microcontroller with a new voice recognition processor for isolated word and speaker dependent and a set of ultrasonic modules. The resulting design is used to control a wheelchair for a handicapped individuals based on a vocal command. The input of the system are a set of eight Arabic words used to control the movement of an electric wheelchair, a vector of information on the context given by a set of sensors and a joystick for security actions; The output is a corresponding command and a set of indicator LED (Light Emitting Diodes). The system is developed in order to be installed on the wheelchair. Therefore it should be easy to carry, no bulky, with low power consumption, and easy in operation.

A voice command system for autonomous robots guidance

In this paper, a voice guidance system for autonomous robots is proposed as a project based on microcontroller. The proposed system consists of a microcontroller and a voice recognition processor that can recognize a limited number of voice patterns. The commands of autonomous robots are classified and are organized such that one voice recognition processor can distinguish robot commands under each directory. Thus, the proposed system can distinguish more voice commands than one voice recognition processor can. A voice command system for three autonomous robots is implemented with a microcontroller from Microchip PIC16F876, a voice recognition processor RSC364 from Sensory and a set of radio frequency emitters- receivers. The possibility to increase the number of robots to be controlled is also described

Towards developing a voice pathologies detection system

Most voice features used in predicting the voice when a person has voted with instability in the vocal fold vibration cause problems in estimating such period; as a result of this challenge, scientists have focused on the development of powerful features independent of pitch estimation. The major goal of this paper is to study and investigate the Acoustic Voice Analysis methods (AVA) based on adaptive features. This investigation will lead to the development of a system of detection. The essential parts of this topic is related to database (described later), sampling the sounds (and satisfying) from the German database with many diseases, degenerative neurological disease (such as chronic inflammation of the larynx and vocal fold nodules). Under the supervision of the used algorithm to accomplish the above task, the Mel-Frequency Cepstral Coefficients (MFCCs with different Jitter and Shimmer), as by likely flux model mixture (GMM) are used in the AVA. MATLAB was used to simulate such a study for the extraction of features as well as making the training and testing process. The achieved results showed that with some kind of analysis, it is possible to find different sound patterns of diseases, e.g. excessive twang, where additional spectral components exist due to the increase in air flow in nasal cavities. Another focal point is some mathematical transformations both in the temporal domain or frequency. These changes can improve the capacity of some voice features voice; however, there is a need to multivariate analysis of parameters which measure the various problems in the process of phonation; after that, it is necessary to analyse the importance of finding and sorting those features that provide more information. Finally, automatic classification of pathological voices was made using any of the known techniques for this purpose. Our achieved results prove that a good classification rate needs efficient features to characterize each class, in this work, on one hand the accuracy of system increases with the number of parameters (best accuracy with 39 coefficients including Jitter & Shimmer) which means that the difference between normal and abnormal become noticeable with second derivate of MFCC and energy more than the others.

Speech as a high level control for teleoperated manipulator arm

In this work a tele-operated system for a robot arm is designed and controlled by the operator, in witch voice control mode occur to carry out remote tasks. A voice command system for the manipulator arm is implemented as a high level control design and compared to a low level control design based on joystick. The high level control paradigm adopted is based on a spotted words recognition system using stochastic model, robust HMM (Hidden Markov Model) with Cepstral coefficients as parameters witch is used in automatic speech recognition system. To implement the approach on a real-time application, a Personal Computer USB interface was designed to transmit commands via Bluetooth components to control the movement of a Robot Arm (the TR-45). The user can control the movements of four degree of freedom (DOF) for TR-45 using a vocal phrase containing spotted words or using a joystick.

Safe motion using viability kernels

A prerequisite to safe robot motion is to avoid Inevitable Collision States (ICS). However, the characterization of the ICS set is a challenge. Several approximation methods have been proposed, most of which either are overly conservative or fail to provide proper motion safety guarantees. In order to to improve safety guarantees, we build upon Viability Theory and adapt an algorithm designed to approximate the Viability Kernel, a concept similar to ICS. Our algorithm is applied first to a challenging static environment scenario. It is then extended to handle dynamic environments. Although it is not possible in general to ensure safety forever, we manage nonetheless to achieve infinite motion safety in two special cases.