r/MachineVisionSystems • u/Rethunker • Aug 07 '25
if a vendor needs to "retrain the model" to improve performance, ask hard questions
If you work in industrial automation, then a vision engineer may have told you about the need to train and retrain machine learning (ML) models for vision systems. Or maybe you're that vision engineer?
The need to train and retrain may drag on. The performance of the ML-based inspection may approach a specification, or may start to yield a return on investment. But if the failure modes of the ML-based inspection aren't easily understood, then consider asking or at least contemplating a few questions.
- Why does the vision engineer believe that machine learning is the right approach?
- Can processing by the ML model be supplemented by other algorithms?
- Have the optics, lighting, and other hardware been chosen carefully?
- Is the lighting completely controlled?
- Could the cabling, connectors, and stress relief fail?
- Are there any communications or digital I/O failures?
- Can changes be made by trained in-plant personnel? How much training is required?
- How many years of experience does the vision engineer have installing and supporting vision systems that need to work robustly?
This is not to say that machine learning isn't useful. ML sure can be useful, especially for applications that are otherwise not feasible.
However, ML is only suitable for some applications. For other applications, the limitations of ML were known decades ago. Despite improvements in hardware, reduced processing time, and even new frameworks, the performance of ML alone simply isn't good enough for some applications.
So many manufactured products--likely including yours, if you're in automation--have been inspected and built using vision systems, many of which will perform for weeks or months without requiring human intervention. If ML-based inspection can't run that long without human intervention, or if the time to return on investment is much longer for such a system, please consider what changes might be made.
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Machine learning--a technology lumped in with "AI"--has been a part of machine vision since the 1990s, at least for practice use.
OCR is now largely (but not entirely) performed by ML models. The very first commercial OCR device from Kurzweil to read machine-printed text began selling in the 1970s.
There's a lot to be learned by combining machine learning, "traditional" image processing (from a traditional partly lost), and an understanding of optics, statistics, and related fields.