[...] resist the pressure to use a given cam- era system to detect objects beyond its original scope. Common smart cameras today may acquire images at 60 per second, and GigE cameras may acquire images nearly three times that fast, but the processor may require 30 to 300 milliseconds to calculate a result dependent on the complexity of the inspection. [...] true throughput is the speed of the camera plus the program.
Success through the lens Automotive company tells vision success story, gives advice to vision systems newcomers By Evan Wollak I and Brian King ndustrial vision systems are versatile; so ver- machine and wire it into an existing electrical satile, in fact, Borg Warner Automotive Sys- system within a day or so. Complete the cam- tems in Bellwood, Ill., uses vision systems to era programming in an hour for simple applica- detect visual defects, deﬁne parts for a robotic tions. This quick deployment makes the system pickup, conﬁrm unique identiﬁcation mark- ideal for responses to customer complaints or ings, and, most importantly, stop assembly lines product launches with tight timelines. when defects are present. Vision systems are also useful to reduce If there is not an easy way to mechanically or changeover times. Machines that have mechan- electrically detect the defect or process varia- ical inspections and run multiple part types of- tion, consider a vision system. There are many ten need part-speciﬁc tools. A camera system products targeted toward speciﬁc applications can change the inspection parameters auto- (low-cost simple cameras, high-resolution cam- matically and drastically reduce setup times. eras, or cameras with serious processing pow- er). Using the right camera for the job will help Job evaluation bring the solution to the plant ﬂoor quickly and Any poka-yoke device requires regular rabbit- under budget. testing or calibration to remove any variation in Most of the best candidates for vision in- the process when performing coordinate trans- spection are those presented with a random formations. Whenever performing a vision mea- orientation. The cost of engineering a me- surement and comparing it to limits deﬁned in chanical system to orient parts and present millimeters or inches, check the camera’s deﬁ- them to a mechanical poka-yoke (mistake- nition of a millimeter or inch. This procedure proof ) device is high; however, the time need- is different for each system and will ensure the ed to develop and implement such a sys- system performs as intended. Just like a mi- tem is usually the largest constraint. crometer or coordinate measuring machines, You can mount a camera sys- a camera that uses a standard measurement of tem with an off-the-shelf length needs calibration. lens or light to a Within a normal production setup, use “rabbit parts” to test the system. Rabbit parts are known defects presented to the vision system. If the system performs as intended, the rab- bit parts are marked as defects
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