Object identification apparatus, object identification method, and nontransitory computer readable medium storing control program

An object identification method comprising:

• acquiring a plurality of reflection point data units as a first data unit group, the plurality of reflection point data units being obtained by irradiating an irradiation light from an irradiation point toward irradiation directions that are successively changed in an irradiation direction range and receiving a reflected light that is light irradiated toward each irradiation direction and reflected at a reflection point of an object, the plurality of reflection point data units respectively corresponding to the reflection points that respectively correspond to the irradiation directions, the plurality of reflection point data units including reflection point position coordinates that include the irradiation directions and distances between each reflection point and the irradiation point;
• converting a second data unit group including a plurality of reflection point data units in which the reflection point corresponding to each reflection point data unit belongs to a three-dimensional object among the first data unit group into a third data unit group including a plurality of projection point data units by projecting the second data unit group onto a horizontal plane in a world coordinate system;
• clustering the plurality of projection point data units into a plurality of clusters based on positions of these units on the horizontal plane;
• and
• setting a space of interest in the world coordinate system for each cluster by using the plurality of reflection point data units corresponding to the plurality of projection point data units included in each of the clustered clusters, wherein
• in the clustering, a division is repeated to thereby form the plurality of clusters until a condition that the number of projection point data units included in each cluster is a predetermined number or less and that a Bayes information criterion after the division is smaller than a modified criterion obtained by multiplying the Bayes information criterion before the division by a predetermined coefficient greater than zero and less than one is satisfied, and
• in the setting of the space of interest, a plurality of spaces of interest are set for the plurality of formed clusters, and a space of interest obtained by integrating two spaces of interest that overlap each other in the horizontal plane among the plurality of spaces of interest respectively set in the plurality of formed clusters is further set.

A non-transitory computer readable medium storing a control program for causing an object identification apparatus to execute the following processing of:

• acquiring a plurality of reflection point data units as a first data unit group, the plurality of reflection point data units being obtained by irradiating an irradiation light from an irradiation point toward irradiation directions that are successively changed in an irradiation direction range and receiving a reflected light that is light irradiated toward each irradiation direction and reflected at a reflection point of an object, the plurality of reflection point data units respectively corresponding to the reflection points that respectively correspond to the irradiation directions, the plurality of reflection point data units including reflection point position coordinates that include the irradiation directions and distances between each reflection point and the irradiation point;
• converting a second data unit group including a plurality of reflection point data units in which the reflection point corresponding to each reflection point data unit belongs to a three-dimensional object among the first data unit group into a third data unit group including a plurality of projection point data units by projecting the second data unit group onto a horizontal plane in a world coordinate system;
• clustering the plurality of projection point data units into a plurality of clusters based on positions of these units on the horizontal plane;
• and
• setting a space of interest in the world coordinate system for each cluster by using the plurality of reflection point data units corresponding to the plurality of projection point data units included in each of the clustered clusters, wherein
• in the clustering, a division is repeated to thereby form the plurality of clusters until a condition that the number of projection point data units included in each cluster is a predetermined number or less and that a Bayes information criterion after the division is smaller than a modified criterion obtained by multiplying the Bayes information criterion before the division by a predetermined coefficient greater than zero and less than one is satisfied, and
• in the setting of the space of interest, a plurality of spaces of interest are set for the plurality of formed clusters, and a space of interest obtained by integrating two spaces of interest that overlap each other in the horizontal plane among the plurality of spaces of interest respectively set in the plurality of formed clusters is further set.