Long-running Experiments using the Minirobot Khepera with Automatic Charging Station

Abstract

Ultrasonic sensors enable mobile autonomous systems to obtain information about obstacles in large environments. In the presented work, taking the limited energy resources of a mobile robot into account, only one transmitter is used. The employment of two receivers permits the calculation of the distance and direction of objects. Using pseudo-random sequences, simultaneously transmitting and receiving with the continuous perception of the environment is possible. The sequences are modulated in order to op- timise the signal-to-noise ratio and energy consumption with respect to the transducers’ bandwidth. With the gained signals the echo-intensity £eld is calculated for object detec- tion. Furthermore, several robots could operate in the same region applying orthogonal sequences.