E-Mobility Engineering 019 | In conversation: Stephen Lambert l WAE EVR l Battery case materials focus l Quality control insight l Clipper Automotive Clipper Cab digest l Optimising battery chemistries insight l Powertrain testing focus

May/June 2023 | E-Mobility Engineering 49 “However, it would be defeatist to simply accept that and stop there,” he says. “Instead we should consider how important the tolerance really is to performance.” Minimising contact Non-contact measurement and inspection systems are becoming increasingly important for QC in EV manufacture, as many components and subsystems are highly sensitive to damage, Perera i Vernetta points out. “Today’s vision systems, with cameras and properly developed software, are capable of inspecting with high accuracy,” he says. Brandon White points to their adaptability, noting that non-contact measurement systems have minimal to no fixed tooling and can be reprogrammed through software to adjust for design or product changes without requiring physical tooling. Murakami and Ward say non-contact measurement is crucial because it eliminates the risk of damage from impacts inherent in contact-based systems, and because it does not encounter the physical access limitations and time constraints that prevent contact-based systems from achieving 100% coverage. “Contact-based inspection typically tests product quality in the moment,” they say. “However, visual based inspection, like 3D AOI or AXI [Automated X-ray Inspection] can determine quality and identify active defects as well as indications of failures that might occur later, in the field.” Although non-contact measurement systems are not as accurate as contact methods, broadly speaking, they are ideal for cases where speed of data capture is valuedmore than accuracy, according to Tomkinson. “For example, large body panels that don’t have tight tolerances are best assessed with camera-based or laser-based systems. On the other hand, electric motor components like stator and rotor diameters with tolerances of low numbers of microns demand tactile inspection,” he says. “To get the best of both worlds and help consolidate multiple inspection operations into a single set-up, a multi- sensor approach can now be taken using coordinate measuring machines (CMMs). Five-axis technologies give CMMs increased inspection throughput but also the ability to automatically switch between different sensors such as touch trigger, touch scanning, optical, ultrasonic thickness and surface roughness sensors.” of the production line to prevent bad components reaching the consumer,” he says. “Instead, smart processes invest in interim dimensional checks that not only pass or fail components but, more importantly, use the data gathered to make micro-adjustments to upstream processes in real time and improve the overall manufacturing process.” That raises the question of what can be and is being done to make EVs easier to inspect for quality by design. Perera i Vernetta argues for standardisation, which can simplify inspection processes by ensuring that all parts are designed to a uniform set of specifications that allow key parameters to be measured. He also notes that simplifying designs, thereby reducing the number of parts and interfaces in a subsystem, makes them easier to inspect. Designing with traceability in mind is also crucial, as it makes it much easier to identify and isolate potential quality issues. “This can be achieved by incorporating unique identifiers such as barcodes into the design of each component or subsystem,” he says. Murakami and Ward agree, adding that to make X-ray inspection easier, designers should carefully consider material types, densities and thicknesses to try to avoid the need for deeper penetration to reach key inspection points. “This can be the deciding factor between achieving basic inspection or high-quality inspection that can detect a wider range of potential defects and quality concerns,” they say. “Also, introducingmore inspection points into the production process and feeding the information back into the process and back to designers is valuable.” Another angle is to take a realistic look at how tight tolerances need to be, an idea embodied in the saying: ‘If you can’t measure it, you can’t make it’. Tomkinson vouches for the truth of this, commenting that it is pointless setting a tolerance that is so tight that nomeasuring equipment can practically inspect it. Insight | Quality control Manufacturing execution systems such as Rockwell’s AutoSuite gather large amounts of information from production processes and inline inspection systems, feeding into QC (Courtesy of Rockwell)