Sophisticated mobile robot sonar sensing with pseudo-random codes

Conventional time-of-flight sonar sensing is widely used within the autonomous mobile robot research community. One of its most severe problems is known as crosstalk. This paper presents experimental results of a new approach which allows one to operate a set of sonar sensors simultaneously. Nevertheless, frequent misreadings caused by crosstalk or external ultrasound sources are eliminated. This is achieved by carefully designing the emitted bursts, i.e. by using appropriate pseudo-random sequences together with a matched filter receiver well known from radar applications.