iDistanceM: A Real-time Smartphone-based Distance Measurement for the Americans with Disabilities Act Compliance Assessment Tool (ADACAT)

The measurement kit of the ADA-CAT (Americans With Disabilities Act-Compliance Assessment Toolkit) consists of measurement instruments, such as a measuring tape, a sound level meter, a light level meter, and a magic slope block. Perhaps the most important tool is the measuring tape for length and height measurement as distances are used so prolifically in the ADA assessment process. Currently, ultrasonic sensors are widely used for distance measurement all around the world. In this paper measuring the height and length of an obstacle by using an ultrasonic sensor and a smartphone through Wi-Fi communication is presented. To the best of our knowledge we are the first to use a smartphone with an ultrasonic sensor for measuring length and height through a Wi-Fi network. We have validated our system by conducting two different experiments and found a high degree of accuracy in length measurement. Compared to other existing smartphonebased measurement tools, our application demonstrated the lowest absolute error.