Smartphone-controlled user calling system for a mobile robot

This paper presents a calling system for a mobile robot that tracks a user´s location via a fusion of ultrasonic receivers and a global positioning system (GPS) for the measurement of short and long distances to the user, respectively. The user holds the module with an ultrasonic transmitter and a Galaxy Tab 10.1 installed with the Android operating system. The mobile robot is equipped with three ultrasonic receivers, a GPS, Bluetooth communication, and a magnetic compass sensor for being called from the user. The Galaxy Tab 10.1 calls the mobile robot and displays where the robot is while it migrates to the user. The proposed user calling system signals the mobile robot to approach the user via GPS for larger distances and reach the exact location of the user with the ultrasonic sensors that mitigate the GPS position errors. Extensive experimental results are presented to demonstrate the viability and effectiveness of the proposed user calling system.