Cables, Connectors, and Screws (Oh My!): Improve Detection of Common Assembly Defects to Reduce Latent Failures

Photometry-based assembly verification performs better than typical machine vision or human inspectors when it comes to catching subtle defects in complex electro-mechanical assemblies, helping decrease your rate of escapes and latent product failures

Machine vision systems are common in many assembly line inspection applications. These systems provide the quantifiable data necessary to automate processes, and offer speed to meet production demands. However, many vision systems today are limited in their ability to detect defects in complex assemblies—especially low-contrast components or those with very fine spatial tolerances. While human inspectors excel at identifying anomalies and subtle details, their inspection performance is slower and less consistent, limiting production efficiency and permitting costly escapes.

Electro-mechanical production and assembly may encompass any manner of components and sub-components, from connectors and batteries, to heat sinks, screws, fasteners, cables, and labels. If defective units are not detected, they escape down the line and lead to waste and cost when the finished device is rejected. In the worst case, if a defective device passes functional testing and ends up in customer hands, latent failures can lead to warranty and return/replacement costs, not to mention damage to consumer satisfaction and brand reputation.

Inspect for multiple, subtle defects simultaneously, in­cluding cable routing, connector alignment, presence or absence of screws and components, and label placement.

Standard machine vision systems lack the high resolution to detect all defects in very complex assemblies, especially unexpected or random defects, or those in low-contrast areas. Human inspectors have greater visual acuity to detect subtle defects, but they are subject to fatigue and inconsistency. They are also unable to capture meaningful quality data at production speeds.

INSPECT.assembly™ will help you detect and prevent the following common assembly issues:

Cable Routing. Cables need to be properly routed in their designated channels, through the guides and clips that hold them in place. A cable that is routed over guides or too close to other components can be pinched or damaged, leading to shorts and breaks that may cause an electrical failure of the device. Detecting misrouted cables can be difficult for humans and automated systems alike given the slight difference between a properly- and improperly-installed cable. INSPECT.assembly readily identifies misrouted cables and flags them as a failure.

Improper cable routing can lead to electrical failures due to shorts or breaks.

Connectors. Misaligned or improperly-seated connectors can be missed by machine vision and human inspection, yet connector faults quickly lead to system failures because of poor or lost connections once the system is in regular use. For example, connectors may come loose due to vibrations. INSPECT.assembly’s integrated camera technology produces high-resolution images to detect gaps or angle differences between components of less than 1 mm, ensuring connectors are fastened securely.

Connector faults can cause system failures because of poor or lost connections once the system is in regular use (e.g., due to vibrations).

Where’s the Screw? A missing screw presents more than one possible problem. It could mean a component is not firmly attached and could come loose in the future, or simply that components are not fixed together with the necessary pressure to maintain contact between leads, power sources, or buttons. A missing screw also begs the question: where did the screw go? Is it on the assembly room floor, or did it fall out along the line? Or, worse, is it still loose inside the device where it may end up sealed inside the housing to damage other delicate interior components during transport? Machine vision typically has trouble capturing low-contrast components such as a black screw on a black surface, so will not reliably detect the issue. The broad dynamic range of the INSPECT.assembly makes it capable of detecting very low-contrast features such as missing screws on any surface color or texture.

These are just a few examples of the precision inspection that photometry-based measurement systems offer. INSPECT.assembly is a turnkey, automated inspection station that can roll right up to the production line to perform sophisticated pass/fail analysis for fast, accurate defect detection, providing the acuity of human vision at production speeds.

Employing the INSPECT-assembly photometry-based inspection station can help you realize improved product quality and production efficiency, reducing escapes and latent failures, lowering costs, and safeguarding brand perception.

Recognized for Innovation
Radiant Vision Systems was honored with a Silver-level award at the Vision Systems Design 2017 Innovators Awards for our INSPECT.assembly system (formerly the VIS-I system).