International Journal of Research Studies in Electrical and Electronics Engineering (IJRSEEE) Volume 2, Issue 1, 2016, PP 13-20 ISSN 2454-9460 (Online) www.arcjournals.org ©ARC Page | 13 Sonar and Pi Based Aid for Blind Kavitha Viswanathan Department of Electronics and Telecommunication Vivekanand Education Society’s Institute of Technology Mumbai, Maharashtra 400074, India kavi1388@gmail.com Prof. Sharmila Sengupta Department of Computer Engineering Vivekanand Education Society’s Institute of Technology Mumbai, Maharashtra 400074, India sharmila.sengupta@ves.ac.in Abstract: This paper shows evidence of using Sound Navigation and Ranging (SONAR) based system. SONAR system has widespread applications in underwater scenarios. We have focused on its use in real-time detection of an obstacle and guidance in accordance to the position of the nearest obstacle. The device designed and described in this paper aids the blind in obstacle avoidance. The device when embedded in a walking, stick makes the system portable, hassle-free, unobtrusive and unprecedented. There are several ETAs (Electronic Travel Aids) designed to make blind navigation independent of human assistance. The development of Sonar and Pi combination does not focus on the need of path planning instead it provides obstacle avoidance. The system requires nil preplanning making it ideal for any area and location. Some of the existing systems including GPS based system (Dhristri [1], touch and go system (hand gadget with earpiece)[2] and NAVTAR[3] focus on path planning i.e. to guide the blind from source to destination. However, the sonar-pi aid aims purely at obstacle avoidance thereby making it less bulky and increased cost-effectiveness than other systems. The designed system uses Raspberry pi 2 making it suitable for further developments. Keywords: SONAR; obstacle avoidance; raspberry pi 1. INTRODUCTION As per a survey held by TOI, India has the largest blind population. Around 15 million people are either blind or have a visual disability [4]. In addition to the existing problems of a sightless person, the inattentive architectures of India accumulate and become an integral part of the visionless individual. Thus, the engineers of today have to deal with the necessity of building ETAs. Here, we present the prototype of a sonar-pi device based on the principle of echolocation. Echolocation uses sound waves and its echoes to determine the location, texture and density of obstacles around. Daniel Kish is one blind individual who is an example of human echolocation [5]. He uses his tongue clicks, which reflects back and gives him an estimate of the obstacle location. However not all blind humans are capable of such echolocation. For the vast majority incapable of human echolocation, sonar-pi device presented here will provide audio instructions to enable them seamless movement. A visually impaired individual faces two major challenges in his daily routine. One is being unaware of the path he needs to take to reach from say position A to position B. Systems designed for this purpose involve GPS systems or a database with pre-loaded digital maps [1]. Another challenge is avoiding obstacles. There are several systems designed for this as well. Some include beeping when an obstacle is nearby. An aerial obstacle detection with 3D mobile devices [6] gained popularity in the recent years. It does the same thing i.e. beams when an obstacle is nearby. The camera inbuilt in the cell phone is used for detection of obstacle. The prototype designed uses SONAR sensors to detect obstacle and using voice guidance the blind is safely navigated irrespective of his source and destination. Absence of the need to know the source and destination eliminates the dependence on GPS systems and on speech processing algorithms as well. The economical, compact and easily available sonar sensor HC-SR04 is used in the prototype in combination with Raspberry pi two Model B. This embedded system when integrated in the walking stick will prove to be an efficient aid for the blind.