Automated quality control: A key strategy for e-car manufacturers to speed up their throughput

Challenges: Innovations in the automotive industry bring new opportunities—and challenges in quality control

With the increasing popularity of electric vehicles (EV), a lot of engineers and quality control specialists are facing new challenges when inspecting parts. Whereas traditional cars had primarily mechanical parts, EVs now feature complex electrical-mechanical devices controlled by software. While there are few moving parts that gasoline vehicles, EVs have a myriad of complicated subsystems—all of which impact the performance and handling of these new vehicles.

In order to improve product safety and production throughput, more and more EV manufacturers are turning to automated quality control systems in the plants and right on their production floors. Anomalies can be instantaneously reported back to the engineering staff for quick corrective measures. Speeding up inspections leads to more throughput and a faster time to market.

Inefficient quality control methods and lack of skilled labour slow down throughput

In today’s tough labour market, there is a clear lack of skilled labour with the experience and expertise required to perform effective quality control inspections.

Manual inspections or inspections with conventional coordinate measuring machines (CMMs) take time. Both are prone to operator efficiency levels and human error. CMMs are often located in a dedicated lab, which means there is a lot of programming, setups, and back-and-forth with the production line. CMMs are not very fast either and require metrology experts to operate. All of these factors can greatly slow down the execution of quality control inspections.

Complex EV parts and production types beget complex inspections

Striking the right balance between speed and accuracy

As mentioned before, traditional manual or CMM inspections are dependent on a technician’s skill, which can compromise data accuracy, reliability and repeatability. CMMs in particular are also very sensitive to vibrations, dust and humidity from the surrounding production environment; in fact, CMMs often require an isolated concrete slab to guarantee inspection accuracy. This significantly adds to the cost and complexity when deploying a new CMM.

A word on accuracy. Conventional CMMs are very accurate—often too accurate for their use. For example, the tightest tolerances you will find in stamping or welding for surface profile, trim points, etc. are +/- 0.5mm. It’s not rare to even see +/-1.0 and +/-1.5mm. CMM accuracy (up to few microns) are more than 10 to 100 times more precise than the smallest of tolerances! This means that CMMs are often too precise for some applications. Therefore, CMMs should only be used in cases where their accuracy is really needed and let other, faster technologies inspect the majority of parts.