Method of detecting weld lines
AssigneeKabushiki Kaisha Komatsu Seisakusho
InventorsNaohiko Yokoshima, Toshisuke Isoya, Masayuki Mishiro
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Abstract
In a method of detecting a weld line, the positions of the weld line and the welding wire are detected from the video signal of the weld, which is provided by an industrial television camera. The video signal of the weld is compared with a predetermined threshold so as to be binary-coded into a signal representing a dark part and a signal representing a bright part. Clock signals having a predetermined frequency are counted with the binary-coded signals as gating signals, thereby to count the lengths of the dark part and the bright parts. The count values are subjected to difference processing, so that the positions of the weld line and the welding wire are detected from the maximum values of the results of the difference processing.
Claims12
Apparatus for detecting a weld line, comprising:
- video signal generating means for providing a video signal of a weld;
- binary-coding means for binary-coding said video signal into a signal representative of a dark part and a signal representative of a bright part in a weld portion;
- counting means for counting the length of at least one of said bright part or dark part in the direction of scan of said video signal according to said binary-coded signals;
- and
- detecting means for subjecting the outputs of said counting means to difference processing, to detect the position of said weld line according to the difference processing.
Apparatus for determining the position of a weld line, comprising:
- a video signal generator for performing a line by line video scan of a weld area;
- binary coding means for providing a signal of a first level when the output of the video signal generator is scanning a weld and for providing a signal of a second level when the video signal generator is scanning the area surrounding the weld;
- measurement means for measuring the time during each line scan that the output of the binary coding means is at one of the first or second levels;
- and
- detecting means for differentially processing the measurement times from sequential line scan measurements to determine the position of the weld line.
A method of controlling the position of a weld wire with respect to a weld line, comprising the steps of:
- performing a line by line video scan of an area including a welding arc to thereby generate a video signal having bright portions corresponding to the scanning of the welding arc and dark portions corresponding to the scanning of the weld wire and area surrounding the welding arc;
- determining the length of a predetermined bright portion or dark portion of each line scan and storing said determined length in a memory;
- differentially processing said stored lengths to determine the location of the welding arc and the location of the welding wire;
- and
- generating a weld wire position control signal in response to said differential processing to thereby move the weld wire to a desired position with respect to the welding arc.
Dependencies are inferred from the claim text.