Three-dimensional additive manufacturing device, control method, and program

1 . A three-dimensional additive manufacturing device for manufacturing a layered structure by supplying powder for manufacturing the layered structure while changing a positional relationship between a discharge port from which the powder is discharged and the layered structure, the device comprising:

a powder supply unit that supplies powder from the discharge port toward the layered structure;

a light irradiation unit that irradiates the powder with a light beam to melt and harden the powder to manufacture the layered structure;

an imaging unit that captures an image of a manufacturing site where the layered structure is being manufactured;

a distance detector that detects a distance from the manufacturing site to the powder supply unit on a basis of the image; and

a feedback controller that adjusts a moving speed of the powder supply unit relative to the layered structure on a basis of a detection result of the distance;

wherein the distance detector executes binarization processing based on luminance on the image to divide the image into a first region having higher luminance, in which a molten pool formed of melted powder is captured in the image, and a second region having luminance lower than the luminance of the first region and detects the distance on a basis of an area of the first region.

2 . The three-dimensional additive manufacturing device according to claim 1 , wherein the feedback controller adjusts the moving speed in a direction orthogonal to a layering direction of the layered structure on the basis of the detection result of the distance.

3 . The three-dimensional additive manufacturing device according to claim 2 , wherein the feedback controller decreases the moving speed when the distance is longer than a predetermined threshold range, and increases the moving speed when the distance is shorter than the predetermined threshold range.

4 . The three-dimensional additive manufacturing device according to claim 1 , wherein

the distance detector determines that the distance is longer than a predetermined threshold range when the area of the first region is smaller than a predetermined area threshold range, and determines that the distance is shorter than the predetermined threshold range when the area of the first region is larger than the area threshold range, and

the feedback controller decreases the moving speed when the distance is longer than the predetermined threshold range, and increases the moving speed when the distance is shorter than the predetermined threshold range.

5 . The three-dimensional additive manufacturing device according to claim 1 , wherein

the light irradiation unit includes a tube in which a light beam emission port from which the light beam is emitted is formed,

the imaging unit captures the image including the manufacturing site and an inner peripheral surface around the light beam emission port of the tube, and

the distance detector detects the distance on a basis of a region in which the manufacturing site is captured and a region in which the inner peripheral surface is captured in the image.

6 . The three-dimensional additive manufacturing device according to claim 1 , wherein the feedback controller adjusts output of the light beam on a basis of the image.

7 . A control method for controlling a three-dimensional additive manufacturing device, the device including a powder supply unit that supplies powder and a light irradiation unit that irradiates the powder with a light beam to melt and harden the powder to form a layered structure; the method comprising the steps of:

capturing an image of a manufacturing site where the layered structure is being manufactured;

executing binarization processing based on luminance on the image to divide the image into a first region having higher luminance, in which a molten pool formed of melted powder is captured in the image, and a second region having luminance lower than the luminance of the first region;

detecting a distance from the manufacturing site to the powder supply unit on a basis of an area of the first region; and

adjusting a moving speed of the powder supply unit relative to the layered structure on a basis of the distance.

8 . A non-transitory computer readable medium for causing a computer to execute a control method for controlling a three-dimensional additive manufacturing device, the device including a powder supply unit that supplies powder and a light irradiation unit that irradiates the powder with a light beam to melt and harden the powder to form a layered structure; the medium causing the computer to execute the steps of:

capturing an image of a manufacturing site where the layered structure is being manufactured;

executing binarization processing based on luminance on the image to divide the image into a first region having higher luminance, in which a molten pool formed of melted powder is captured in the image, and a second region having luminance lower than the luminance of the first region;

detecting a distance from the manufacturing site to the powder supply unit on a basis of an area of the first region; and

adjusting a moving speed of the powder supply unit relative to the layered structure on a basis of the distance.

9 . The three-dimensional additive manufacturing device according to claim 5 , wherein the distance detector detects the distance on a basis of a ratio between luminance of the region in which the manufacturing site is captured and luminance of the region in which the inner peripheral surface is captured in the image.