Inside the Next-Gen EV Architecture

For today’s consumers, a car is no longer simply a means of transportation. Drivers are clamoring for more safety features, better infotainment options and hyper-personalized cabin experiences. And cars are increasingly connected to their environment—especially when it comes to electric vehicles (EVs), which must track the location and availability of charging stations.

Until recently, features like these have been delivered through discrete electronic control units (ECUs). But modern vehicles already contain 100 to 150 ECUs. Adding more would only worsen existing supply chain issues. And cramming in more ECUs creates more points of failure, adding to warranty costs. 

The wiring harnesses associated with these ECUs also present problems. As the feature list grows, so do the length, cost and heft of the wiring, which can already exceed 150 pounds. This excess weight is antithetical to EV design goals, which must reduce their load to increase driving range.

In response to these concerns, automakers are moving to a zonal architecture with fewer but more powerful ECUs. In each zone, a single ECU is responsible for the control of all nearby functions. This cuts the total number of ECUs by an order of magnitude—from over 100 to around 10—a significant boon in a time of chip shortages.

Each zonal ECU connects through a gateway to a high-performance computing cluster at the heart of the vehicle, which coordinates system-wide functionality. To build such an architecture, engineers will need not only faster chips but also a higher-bandwidth network. New technologies like the High-Speed FAKRA Mini (HFM) Interconnect System meet this need, delivering high-speed links that simplify the wiring harness and significantly cut weight.

Given these advantages, it’s no surprise that every major OEM has signaled some level of transition to a more consolidated architecture. In fact, a recent global Molex survey revealed 84% of respondents agreed that adopting zonal architecture represents the future for automotive electronics.

Unlike traditional systems, where each ECU serves a fixed function, a zonal system consolidates a variety of features into a smaller set of flexible ECUs. As a result, the particulars of vehicle functionality are determined by software.

As vehicles become more software-driven, manufacturers are increasingly using over-the-air (OTA) updates to deliver fixes and new features. Among other benefits, this can speed time to market. For example, a car can be made available even if the full suite of driver-assist features isn’t ready to go, as these features can always be added later.

Software also allows manufacturers to gain insights from analytics. Collecting data about electronic features can lead to improved designs, which can be implemented in faster cycles.

A zonal system even makes it easier to update the hardware. Manufacturers can upgrade sensors, motors and other components while leaving the data-processing architecture in place. New features and controls can be added in a modular fashion, without adding or replacing gateways. This further reduces manufacturing time and allows for easier customization.

Zonal architectures also benefit the automotive assembly process. For example, wiring harnesses are still assembled by hand, making them a costly item. And flexible wiring is not conducive to robotic handling, making it challenging to employ efficient precision automation and related quality controls. Moving to standardized, mass-manufactured wiring with a streamlined layout addresses all these pain points.

Designers are also adopting higher-voltage power, using 48 volts instead of 12 to engage sensors, motors, ECUs and other components. Higher voltages deliver the same amount of energy with less current, enabling thinner and lighter cables. Similarly, EV power trains are moving to higher-voltage architectures and adopting more efficient controller and wiring setups.

Lighter cables, wiring harnesses, smaller EV batteries and a more aerodynamic body design will help electric vehicle drivers overcome range anxiety, increasing the distance the cars can travel before needing a recharge and spurring mass adoption.

Zonal architecture could have a major impact on vehicle production, accelerating innovation and speeding the delivery of adaptive controls and safety features. But to succeed, it will require high-speed data connections that are flawless, robust and keep data flowing securely.

That’s not easy to achieve in vehicles that are exposed to wind, rain and constant shock and vibration. These conditions pose challenges for electronics, especially within lines carrying high-speed data. 

The growing number of sensors and cameras in advanced driver assistance and autonomous systems will generate unprecedented amounts of information that must be processed at high speeds. If vibration causes even a momentary break in a connection with data speeds of over 1 Gbps, large amounts of information could be lost. With safety controls becoming more automated, it is imperative to build connectors that are capable of overcoming vibration risk.

Connectors in the central computing cluster will also need to provide far greater resilience than conventional board-to-board solutions while also offering high pin counts and power connections. Engineers plan to standardize their designs to allow swappable modules, simplifying the manufacturing processes and allowing for easy upgrades. 

Molex is working closely with manufacturers and Tier 1 suppliers, leveraging its world-class signal integrity capabilities to create a new generation of hybrid and mixed connectors that can successfully carry both power and high-speed signals in harsh road conditions. In addition to improving reliability and safety, the new connectors will make installation easier since their combined functionality will result in fewer connection points. 

At the same time, Molex is building on its expertise in microminiature connections from applications like smart phones to enable tiny, high-bandwidth board-to-board attachment everywhere from the central computer to camera modules. Ultimately, it’s all about bringing efficiency to every aspect of the next-gen EV architecture.