Vision System Non Contact Measurement of Pintail Type Fasteners
Ryan Haldimann · SAE technical papers on CD-ROM/SAE technical paper series · 2010
Accurately measuring the length of a pintail type fastener is limited by the process of forming the fastener. When the pintail is formed its overall length is not dimensionally controlled. To accurately measure the grip of the bolt a vision system is utilized that finds the notch between the tail and bolt shank. The grip, diameter and angle of the bolt prior to insertion are then measured. This method proves to be more accurate than measuring the bolt mechanically and provides a number of other advantages including; decreased measurement speed, accuracy, FOD detection and angle of the bolt in the fingers prior to insertion. INTRODUCTION Building aircraft demands accurate measurement of fasteners using in the construction process. Of all the fastener types used, pintail type fasteners are very difficult to measure because of the way they are manufactured. The pintail is formed on the fastener in a swaging operation. Because it is swaged the length of the pintail is not well controlled, thus overall bolt length is not an accurate measure of grip length. Using a vision system integrated into the head of the machine allows for measurement of critical parameters of the fastener prior to insertion into the panel. The vision system utilizes industry standard software to measure the location of the pintail/fastener interface. It is then able to calculate the bolt grip, angle and diameter, ensuring the correct bolt is installed as called for in the CNC program. This method of measurement takes less time than traditional methods allowing for decreased cycle times when closely integrated into the machine structure. MAIN PROBLEM STATEMENT Accurately measure the grip of a pintail type fastener without adding cycle time and mechanically integrate it into current machine design (Figure 1).