A person-following robotic cart controlled via a smartphone application: design and evaluation

Person following ground robots can have applications in military, civil, and domestic settings. Various sensors may be used to detect a person including cameras, infrared, laser, and ultrasonic sensors. This paper describes the implementation and testing of a robotic cart that is controlled via a smart phone application and can be tele-operated, as well as set into a follower mode where it uses ultrasonic sensors to locate the person walking in front of it, and keeps a constant distance. The cart's usable loading area is 80x60 cm. The maximum carry capacity is 80 kilograms, but at an impractical velocity of 0.15 meters per second. Its maximum velocity is 1.4 meters per second at no load, and 1 meter per second at a load of 40 kilograms. The maximum operation time is 2 hours at full speed, but at a moderate weight and velocity, it reaches 4 hours.