System and method for object distance detection and positioning

A system to detect the distance of an object and position a motorized autofocus device in relation thereto, for improved first-time quality and accuracy in laser brazing applications, the system comprising:

• a computing device configured to establish a desired distance among a plurality of designated sites on the object, the computing device further comprising an image recognition module configured to calculate the actual distance among the plurality of designated sites, wherein the image recognition module will conduct at least the following steps to calculate the actual distance among the plurality of designated sites:
• (i) positioning regions of interest around each of the plurality of designated sites;
• (ii) determining a pixel intensity within each region of interest;
• (iii) for each pixel intensity:
• determining an X-axis coordinate value relative to the center of the pixel intensity, wherein the X-axis coordinate value is defined by the following equation:
• x
• cm
• =
• ∑
• i
• N
• ⁢
• ⁢
• x
• i
• ⁢
• I
• i
• ∑
• i
• N
• ⁢
• I
• i
• and wherein xcm is an X-axis location of intensity center of mass, x is an X-axis pixel value, and I is an X-axis pixel intensity;
• determining a Y-axis coordinate value relative to the center of the pixel intensity, wherein the Y-axis coordinate value is defined by the following equation:
• x
• cm
• =
• ∑
• i
• N
• ⁢
• ⁢
• x
• i
• ⁢
• I
• i
• ∑
• i
• N
• ⁢
• I
• i
• and wherein ycm is a Y-axis location of intensity center of mass, y is a Y-axis pixel value, and/is a Y-axis pixel intensity;
• and
• wherein the X-axis and Y-axis coordinate values represent a center coordinate value;
• and
• (iv) determining the distance between the center coordinate values of each pixel intensity,
• the image recognition module further configured to determine if error exists between the actual distance and desired distance of the plurality of designated sites;
• the autofocus device configured to adjustably focus onto the plurality of designated sites;
• wherein, the autofocus device will adjust the focus when error is determined to exist between the actual distance and desired distance of the plurality of designated sites.

A method for detecting the distance among a plurality of designated sites on an object and positioning an autofocus device in relation to those designated sites, for improved first-time quality and accuracy in laser brazing applications, the method comprising:

• (a) identifying, via a computing device, a desired distance among the plurality of designated sites on an object;
• (b) adjusting a focus, via a motorized autofocus device of a brazing-welding device, to a focal distance that can monitor the plurality of designated sites, by moving the autofocus device closer to the object so as to decrease the focal distance or moving the autofocus device farther from the object so as to increase the focal distance;
• (c) calculating, via an image recognition module, the actual distance among the plurality of designated sites, wherein the image recognition module will conduct at least the following steps to calculate the actual distance among the plurality of designated sites:
• (i) positioning regions of interest around each of the plurality of designated sites;
• (ii) determining a pixel intensity within each region of interest;
• (iii) for each pixel intensity:
• determining an X-axis coordinate value relative to the center of the pixel intensity, wherein the X-axis coordinate value is defined by the following equation:
• x
• cm
• =
• ∑
• i
• N
• ⁢
• ⁢
• x
• i
• ⁢
• I
• i
• ∑
• i
• N
• ⁢
• I
• i
• and wherein xcm is an X-axis location of intensity center of mass, x is an X-axis pixel value, and I is an X-axis pixel intensity;
• determining a Y-axis coordinate value relative to the center of the pixel intensity, wherein the Y-axis coordinate value is defined by the following equation:
• x
• cm
• =
• ∑
• i
• N
• ⁢
• ⁢
• x
• i
• ⁢
• I
• i
• ∑
• i
• N
• ⁢
• I
• i
• and wherein ycm is a Y-axis location of intensity center of mass, y is a Y-axis pixel value, and/is a Y-axis pixel intensity;
• and
• wherein the X-axis and Y-axis coordinate values represent a center coordinate value;
• and
• (iv) determining the distance between the center coordinate values of each pixel intensity;
• (d) calculating, via the image recognition module, an error value which corresponds to a discrepancy between the actual distance and the desired distance;
• (e) calculating, via a feedback control loop, a focus correction value based on the error value, the focus correction value configured to reduce the error value to zero;
• and
• (f) readjusting the focus, via the autofocus device, to a distance which corresponds to the focus correction value.