Environment map generation program and three-dimensional sensor control device

A three-dimensional sensor control device comprising:

• at least one memory that stores a computer program;
• and
• at least one processor that executes a computer program to implement:
• acquiring orthogonal coordinates of data points found in a plurality of photograph frames photographed by at least one three-dimensional sensor with a photographing range;
• converting the orthogonal coordinates of the data points into polar coordinates using a first formula for conversion from orthogonal coordinates to polar coordinates;
• searching sub-regions of the photographing range to locate in each sub-region a set of polar coordinates representing a farthest data point that is located farthest in distance from the three-dimensional sensor,
• wherein the sub-regions are defined in the photographing range to have a generally quadrangular pyramid shape, and
• further wherein
• the polar coordinates are expressed by a spherical coordinate system including coordinates of a vector radius, a polar angle, and an azimuth angle, wherein the sub-region is defined by a polar angle interval and an azimuth angle interval, and
• searching each sub-region to locate the farthest data point comprises searching each sub-region to locate a set of polar coordinates having a largest vector radius;
• converting the polar coordinates of a collection of the farthest data points into orthogonal coordinates using a second formula for conversion from the polar coordinates to the orthogonal coordinates;
• and
• outputting environment map data of the photographing range developed based on the orthogonal coordinates of the collection of the farthest data points.