IJIRST –International Journal for Innovative Research in Science & Technology| Volume 2 | Issue 11 | April 2016 ISSN (online): 2349-6010 All rights reserved by www.ijirst.org 316 Obstacle Detection using Ultrasonic Sensors Prof. D. S. Vidhya Miss Delicia Perlin Rebelo Assistant Professor (Guide) UG Student Department of Electronics and Telecommunication Engineering Department of Electronics and Telecommunication Engineering Don Bosco College of Engineering, Fatorda, India Don Bosco College of Engineering, Fatorda, India Miss Cecilia Jane D’Silva Mr. Linford William Fernandes UG Student UG Student Department of Electronics and Telecommunication Engineering Department of Electronics and Telecommunication Engineering Don Bosco College of Engineering, Fatorda, India Don Bosco College of Engineering, Fatorda, India Miss Clarissa Joella Costa UG Student Department of Electronics and Telecommunication Engineering Don Bosco College of Engineering, Fatorda, India Abstract In many applications like vehicle control, medical applications, robotic movement control, etc.; distance measurement of an object is used. This can be done using a variety of sensors- Ultrasonic, IR, radar, laser, etc. Measurement using ultrasonic sensors is the cheapest and its reliability among several others is very high. In this paper we discuss the uses of these sensors in distance measurement in vehicular applications and compare them for a small automobile prototype using Raspberry Pi, to provide an output for obstacle detection. Keywords: Sensors; Ultrasonic Sensors; Distance Measurement; Obstacle Detection _______________________________________________________________________________________________________ I. INTRODUCTION With the increasing demand for autonomous projects, the use of sensors is increasing. Sensors are sophisticated devices that convert the physical parameter (for example: temperature, pressure, humidity, speed, etc.) into a signal which can be measured electrically. They are very important to robotics. It is able to give robots remote access and make decisions as for a desired environment. It can also perceive its own environment and through programming can get the output it desires. Out of these, the motion detectors are based on the Infra-Red, Ultrasonic, and Microwave / radar technology. [1] In industrial applications, ultrasonic sensors are characterized by their reliability and outstanding versatility. Ultrasonic sensors can be used to solve even the most complex tasks involving object detection or level measurement with millimeter precision, because their measuring method works reliably under almost all conditions. Infrared sensors too, find applications in many everyday products. Their low power requirements, their simple circuitry and their portable features make them desirable.[2] II. CRITERIA TO CHOOSE A SENSOR With the large number of sensors available in the market, it is necessary to choose the right sensor. There are certain features which have to be considered when we choose a sensor: Accuracy, Environmental condition, Range, Calibration, Resolution, Cost and Repeatability. [3] In our project we have made a small prototype of an automobile for Adaptive Cruise Control where the car prototype, whose heart will be the Raspberry Pi, a microcontroller, which when set, will lock the object/car in front of it. For this we need to select a suitable sensor. Therefore, we first carried out a study of the following ultrasonic sensors. Features of Ultrasonic Sensors No other measuring method can be successfully put to use on such a wide scale and in so many different applications. 1) The device is extremely robust, making it suitable for even the toughest conditions. 2) The sensor surface cleans itself through vibration, making the sensor insensitive to dirt. 3) The physical principle—the propagation of sound—works, with a few exceptions, in practically any environment. 4) Ultrasonic sensors have proven their reliability and endurance in virtually all industrial sectors.