Floor surface condition detection device, distance measuring device equipped with same, floor surface condition detection method, and floor surface condition detection program

A floor surface condition detection method for detecting the condition of a floor surface on which an object has been placed with a device comprising a lighting device and an image sensor, the method comprising:

• emitting from the lighting device, electromagnetic waves toward the target;
• acquiring information about the distance to the target according to the amount of reflection of the electromagnetic waves emitted from the lighting device toward the target and received by the image sensor;
• detecting the condition of the floor surface on which the target has been placed on the basis of the acquired information about the distance;
• acquiring angle information corresponding to each pixel included in the distance image;
• converting the information about the acquired distance into three dimensional coordinates on the basis of the acquired angle information;
• detecting a floor surface on which the target has been placed;
• calculating an installation height (h) of a distance measuring device on the basis of the converted three dimensional coordinates from information about a distance to the detected floor surface;
• calculating a rotary coordinates (Xr, Yr, Zr) obtained by rotating around an axis the three dimensional coordinates converted from the information about the distance and the acquired angle information;
• comparing the coordinate (Zr) in a height direction of the calculated rotary coordinates (Xr, Yr, Zr) with the calculated installation height (h), and if an object having a positive or negative dimension in the height direction is detected, detects this object as an irregularity of the floor surface;
• and
• setting a first threshold value, a second threshold value, and a third threshold value used in the detection of irregularities, wherein
• calculating the installation height comprises calculating, as the installation height (h), an average value of coordinate values in an optical axis direction from among the plurality of coordinate values re-acquired by rotating an orthogonal coordinate system of the distance measuring device around an axis by the angle formed by a vertical line of the detected floor surface and the optical axis of the distance measuring device, and
• comparing the coordinate (Zr) in a height direction comprises determining that there is the object on the floor when the difference (h−Zr) between the installation height (h) and the coordinate (Zr) is at or above the first threshold value, and that there is a hole on the floor when the difference (h−Zr) is below the second threshold value, and that there is a slope on the floor when an amount of change (ΔZr/ΔXr+ΔZr/ΔYr) of the distance in the height direction from the floor between adjacent pixels is above the third threshold value.

A non-transitory computer readable medium storing a floor surface condition detection program for detecting the condition of a floor surface on which a target has been placed with a device comprising a lighting device and an image sensor, wherein the program when read and executed causes a computer to execute a floor surface condition detection method comprising:

• emitting from the lighting device, electromagnetic waves toward the target;
• acquiring information about the distance to the target according to the amount of reflection of the electromagnetic waves emitted from the lighting device toward the target and received by the image sensor;
• and
• detecting the condition of the floor surface on which the target has been placed on the basis of the information about the acquired distance information about the distance;
• acquiring angle information corresponding to each pixel included in the distance image;
• converting the information about the acquired distance into three dimensional coordinates on the basis of the acquired angle information;
• detecting a floor surface on which the target has been placed;
• calculating an installation height (h) of a distance measuring device on the basis of the converted three dimensional coordinates from information about a distance to the detected floor surface;
• calculating a rotary coordinates (Xr, Yr, Zr) obtained by rotating around an axis the three dimensional coordinates converted from the information about the distance and the acquired angle information;
• comparing the coordinate (Zr) in a height direction of the calculated rotary coordinates (Xr, Yr, Zr) with the calculated installation height (h), and if an object having a positive or negative dimension in the height direction is detected, detects this object as an irregularity of the floor surface;
• and
• setting a first threshold value, a second threshold value, and a third threshold value used in the detection of irregularities, wherein calculating the installation height comprises calculating, as the installation height (h), an average value of coordinate values in an optical axis direction from among the plurality of coordinate values re-acquired by rotating an orthogonal coordinate system of the distance measuring device around an axis by the angle formed by a vertical line of the detected floor surface and the optical axis of the distance measuring device, and
• comparing the coordinate (Zr) in a height direction comprises determining that there is the object on the floor when the difference (h−Zr) between the installation height (h) and the coordinate (Zr) is at or above the first threshold value, and that there is a hole on the floor when the difference (h−Zr) is below the second threshold value, and that there is a slope on the floor when an amount of change (ΔZr/ΔXr+ΔZr/ΔYr) of the distance in the height direction from the floor between adjacent pixels is above the third threshold value.