Analysis on the effect of beam overlap of a low directivity ultrasonic sensor ring

This paper presents the analysis on the effect of beam overlap of a low directivity ultrasonic sensor ring. It is assumed that a set of ultrasonic sensors of the same type are arranged along a circle of non-zero radius at regular spacings with their beams overlapped. Due to beam overlap of an ultrasonic sensor ring, the detection zone of each ultrasonic sensor can be divided into three smaller sub-zones, and also for a given obstacle distance, its uncertainty arc can be divided into three smaller sub-arcs. First, taking into account the range of sensing distance as well as the dead angle region, the entire range of obstacle detection of an overlapped ultrasonic sensor ring is specified. Second, the effective beam width of an overlapped ultrasonic sensor ring is assessed in terms of the lengths of uncertainty sub-arcs. Third, alternative assessment of effective beam width of an overlapped ultrasonic sensor ring is proposed in terms of the areas of detection sub-zones. Lastly, using a commercial low directivity ultrasonic sensors, the changes of the effective beam widths depending on the parameter of an overlapped ultrasonic sensor ring are examined.