Detection and location of surfaces in a 3D environment through a single transducer and ultrasonic spherical caps

Abstract

In this paper, an ultrasonic arc map method for flat mapping is extended to three-dimensional space replacing the circumference arcs by spherical caps. An enclosed environment is scanned by employing a single ultrasonic device. The range, position, and orientation of the transducer are used to digitize the uncertainty caps and place them in a three-dimensional map. Through the spatial voting method, the generated voxels are elected in order to distinguish those which mark the true position of an obstacle and discard those that are produced by cross talk, noise, fake ranges, and angular resolution. The results show that it is possible to obtain sufficient information to build a three-dimensional map for navigation by employing inexpensive sensors and a low power data processing.

Keywords

• Ultrasonic arc map
• sonar resolution
• SLAM
• Bresenham algorithm
• voxelized spherical cap
• beam pattern
• spatial voting