The measurement of bodywork on cars, a crucial part of the process to ensure manufacturing quality, was traditionally carried out semi-manually. Now, the adoption of photogrammetry by the SEAT Measurement Technology and Meisterbock department enables more efficient and precise measuring, with the ability to accurately measure to tenths of a millimetre across millions of data points.
Using photogrammetry in serial measurement, adapted by and for SEAT, represents an improvement in measurement efficiency on the production line in terms of speed, precision and connectivity, it says.
Sets of parts are randomly selected from the assembly line to be thoroughly checked during each production shift. AGVs (automated robots) transport these components to the measuring facilities. There the machines, equipped with cameras, begin the work to ensure that all vehicles leaving the production line have the correct dimensions. If any deviations are detected, these can then be quickly recalibrated.
Pedro Vallejo, head of measurement technology and Meisterbock at SEAT explained: “Photogrammetry is a non-contact optical measurement technology that enables us to capture millions of points of an object through photos, marking the depth and thickness of each space. We’re the first manufacturer to roll out large-scale, continuous non-contact automated measurement, and we’ve managed to ensure that a car coming off the line has the same level throughout the life of the series, like a perfect prototype.”
The process involves taking between 200 and 300 photos per assembly, and 1,000 of the entire body, and measures the equivalent of seven million points per assembly and up to 98 million of an entire chassis.
The optical technology has saved up to 90% of the measuring time compared to conventional measurements, and allows 9,000 photos and up to 210 million points to be analysed each day.
Paco Triguero, head of internal parts measurement at SEAT, explained: “This has enabled us to profoundly transform the way we’ve been working for the last 20 or 30 years, and we’ve trained workers in more highly qualified techniques, and exponentially increased the information we obtain so that the customer receives the best possible car.”
This technique is currently being replicated on the assembly line of the SEAT Leon and the CUPRA Formentor.
This is just the tip of the iceberg in how photogrammetry might develop. The large volume of information now obtained via the technology will be used in the future to detect situations in production even before they occur, allowing unrivalled quality, according to the manufacturer.
“We’re storing all this data so that a machine learning algorithm can examine the frequency of any deviations” said Triguero. “Now we’re able to locate them and react, but later on, a programme will act proactively: it’ll analyse how often they’re repeated and make predictions to recalibrate the machine that produced the deviation”.