Low Cost System for Range Estimation Through the Combined use of Ultrasonic and Electromagnetic Signals

This invention entails a transmitter circuit that transmits an electromagnetic signal and an ultrasonic signal at the same time by accurately synchronizing their generation and transmission from point A to point B. The electromagnetic signal travels around the speed of light while the ultrasonic wave travels around 340 meters per second. The electromagnetic signal arrives much earlier than the ultrasonic signal to point B. At point B, there will be an Electromagnetic receiver for receiving the Electromagnetic signal and a microcontroller that has a counter. This counter is initialized and starts counting time when the electromagnetic wave is received. Point B has an ultrasonic receiver in addition to the electromagnetic receiver and the microcontroller. The counter controlled by the microcontroller will stop counting when the ultrasonic signal is received. This way the microcontroller has measured the time difference between the arrival of the electromagnetic signal and the arrival of the ultrasonic signal. The absolute position at certain point A can be determined if we are able to calculate the distance between A and other 4 points B,C,D, and E that already have their location known and transmitted to A.

A low cost, ground-based, range estimation system that combines Ultrasonic and Electromagnetic signals to act as a positioning system for location estimation and tracking. Used for vehicles and pedestrians alike, this system can also be used in automatic traffic management, planning for transportation and road infrastructures projects, recovery of stolen vehicles, search and rescue operation for people carrying positioning devices. Advantages An alternative to GPS High accuracy more accurate than current satellite-based positioning technology which is around 7.8 meters at a 95% confidence level Low end-user cost Coverage extensibility High capacity able to localize and track millions of users Usage scalability