Power liftgates and zonal architectures

More than a reference design, our fully assembled power liftgate demonstrator kit is an ode to common sense.

The biggest challenge for an automotive engineer is adopting the most sensible technologies and avoiding those that won't be remembered. Differentiating between the two can be difficult due to market forces pushing innovations over practicality. Therefore, it's important to take a step back and view the car in terms of zones rather than domains.

This is the essence of our AutoDevKit power liftgate demonstrator kit (AEKD-TRUNKL1), which offers a complete platform to manage not just the trunk but the entire rear of the car. While it shows how to create a cost-effective and reliable power trunk liftgate, it also targets the control of rear windows, audio alert systems, contactless car keys, and more. Our power liftgate demonstrator helps engineers focus on practical, efficient solutions for the overall vehicle. Put simply, it can help determine if an engineering choice will stand the test of time.

Here are three principles for common sense designs that engineers should adopt.

The shift away from physical buttons seems to be complete, and as the dust settles, car manufacturers are reining in haptic feedback, gesture control, and all touchscreen surfaces where the simplest command implies cascading through multiple menus. The problem wasn’t that automotive engineers adopted these new user experiences, but that some implementations didn't consider their impact on drivers and passengers, thus lacking common sense. Take, for example, the first powered tailgate that could be opened and closed using a foot movement. Initial models used expensive sonar systems that failed to recognize simple kicks, causing some brands to have to "teach" their customers how to "kick."

Our power liftgate demonstrator kit solves this challenge by using time-of-flight sensors instead of sonars. These ranging sensors are significantly more cost-effective and, because they track a greater range of movement, can more easily detect natural leg movements. In a nutshell, the ST platform shows that a common sense approach doesn’t shy away from new features but implements them in a way that works with existing user behavior. Common sense is about focusing on human-centered experiences rather than innovation for its own sake and ensuring that users are better off with a feature than without.

Designing a car platform is challenging because its foundation must last for years, sometimes decades, while the tech world marches on at a breakneck pace. Consequently, designers often struggle to build an architecture that can stand the test of time. Some of the industry’s best examples of these issues come from the luxury market, where using a lackluster platform can lead to poor quality and the inability to add popular features, leading to sluggish sales and a loss of confidence in the brand itself. It became even more apparent with the arrival of some early electric vehicles, in which bad technical decisions had rippled for years and cost millions in battery replacements.

It’s why the industry is moving toward zonal architectures. By looking at a platform by zones instead of domains or distributed nodes, it’s possible to vastly increase data throughput and computational power while striving for electrical efficiency and optimizations. For instance, certain manufacturers have been able to shrink harness weight by 20% when moving to a zonal architecture. It’s exactly the type of innovation that can help pave the way for more sensors and AI drive modes. It’s common sense that systems continuously need faster and bigger data transfers and processing. A zonal architecture enables that, and the AEKD-TRUNKL1 allows engineers to build a platform that can thus stand the test of time.

Due to a car’s mechanical and inherently analog nature, it’s easy to overlook its digital aspect. Yet, if anything, engineers must plan to move to digital in places that they probably didn’t think of before. For instance, fuses are moving from traditional switches and relays to electronically controlled devices. The reason is simple. eFuses are much more flexible since they can reset themselves. They are also vastly smaller, lighter, more accurate, and faster. Consequently, the earlier engineers plan a move to digital, the more their design will last. Adopting a digital system also implies a focus on ecosystems to simplify the integration of multiple technologies.
 

The AutoDevKit power liftgate demonstrator kit (AEKD-TRUNKL1) promotes the move to digital devices, from a digital LED driver board for lighting to an NFC card reader for contactless keys and more.

Additionally, its integration into the AutoDevKit ecosystem of libraries and IDE streamlines developments thanks to the AutoDevKit Studio (STSW-AUTODEVKIT) with its user-friendly graphical interface. Put simply, adding features and moving to digital solutions become a lot more straightforward when all the components are designed to work together. As cars adopt digital systems, a common sense approach looks at how varied solutions fit together instead of trying to patch disparate modules. One ecosystem should easily spawn multiple applications.