Extracting Data from a Technical Drawing: Not a Cake-Walk!

Have you tasked your team with extracting data from technical drawings? We have a strong opinion for you: use our API and focus your resources on leveraging the results for your use case. 

This article illustrates the challenges that everyone developing such a technology has to deal with. 

Entering the world of Automation, a manufacturing company would surely come across the idea of automating the most cumbersome and crucial process: Reading Engineering Drawings. One might argue that it is as simple as deploying an OCR (Optical Character Recognition) to read characters, numbers, and symbols on a piece of paper. Did you have the same idea too?  

If so, we challenge you to extract the bounding box of this simple drawing automatically. We’ll show you the steps we take, and you’ll see it’s not a Cake-Walk!

What are the challenges in reading Engineering Drawings automatically?

Reading complex Engineering Drawings is a challenge itself. That’s why you hire trained engineers rather than fresh high-school graduates to handle the drawings in your company. Just like humans, Artificial Intelligence needs specialized training to understand these drawings. Werk24’s AI has spent the past four years going to Engineering School. A technical drawing of an Endbolt given below. Let’s try to understand:

Separation

Let’s dive into a few of these challenges and understand how they can turn out to be trickier than imagined. The very first thing to realize in an engineering drawing is the various views that give a basic idea about the layout of the drawing. To calculate the bounding box, we need first to separate the views and then understand how the views relate to one another.

The separation is simple in this case but remember that there are frequent edge-cases to consider: views might overlap, views might be damaged, labels might be equidistant to two views, views might be nested, etc...

Relationships of Views

Let’s assume that you solved all these situations. Then we need to understand how the views relate to each other. The views are oriented based on two Projection Methods: The First Angle (primarily used in Europe) and Third Angle (primarily used in the USA and Canada) Projection Methods. Let’s assume we limit ourselves to European drawings. Then we still need to determine the views and how they relate to one another. Some special cases you might want to handle, include Detail Views or Magnifiers that connect to the main view.

Main Process

Let’s assume your drawings are straightforward. Then we must determine whether we are dealing with a flat part, a turned part, a block, etc. The outcome affects how we will interpret the views. Single-view drawings are a simple example. Both flat parts and turned parts get described with a simple view.  

But of course, for a turned part, the view describes the x- and y- projection and allows us to calculate the bounding box. For flat parts, that is not the case. Here the part’s thickness is likely given as a note, detail view, leader, or as part of the material description or not provided at all.  

3D reassembly

Let’s specialize only in turned parts. Then the next step is identifying the measure labels and understanding which distance they describe on the three-dimensional work piece.  

The result is a noisy, partially annotated approximation of the work piece in 3D. Again, here are many cases to consider: chained measures, missing annotations, implicitly defined heights through the reference to a standard, etc. Solving this is left as an exercise to the inclined reader. 

Our Recommendation: Don’t Do Your Own!

Extracting data from a technical drawing is not a Cake-Walk! Werk24 has spent four years and processed millions of CAD Drawings to get to the robustness that we have today. We handle all these special cases and many more. Is it a wise decision to develop this technology internally?  Our API will save you millions of Euros in development costs and allow you to implement your use-cases today. Werk24 creates very granular result documents – and we are delighted to extend our service to include additional features that you might need for your use case. 

So, working with Werk24 allows you to skip the data extraction steps and focus your development resources on processing the results – essentially leveraging your domain knowledge where it counts – in the interpretation of the data.  

Give us a call and we show you what our solutions can do for you. On top of that, we can even show you using the extracted information to benchmark your purchasing prices in a couple of seconds. Our partner Saphirion has been offering its customers with the most comprehensive mathematical pricing analysis solution, and the Werk24-Saphirion partnership offers a straightforward answer for everyone; high-quality data and a proven costing method. You may find more information in the Press Release.

Start today and get your savings. There is no need to wait any longer.