Finding the optimum balance of electronic content in automotive design.
Advanced driver assistance systems (ADAS) have made tremendous strides in the past decade. The technology is part of the larger thrust to improve safety of cars, which cause over a million deaths per year around the world. Fortunately, fatal crashes have been on a steady decline for decades even as automobile usage has gone up. This is due in large part to safety-related technologies, including ADAS, in more brands and models, including economy cars.
For all its obvious benefits, there is a growing number of engineering challenges with regards to ADAS, mostly related to the proliferation of sensors. That in turn, leads to the issue of efficiently processing the data gathered by these sensors and extracting useful information. The task, then, is to find the optimum balance of electronic content, ADAS-related and otherwise, to maximize the ability to reach new, tech-hungry customers while minimizing the cost of adding these features.
Complex wire harness design
ADAS is one of several factors that are directly responsible for accelerating the increase of systems and components in automotive design today. All this growth in electronics is having a significant impact on automotive wire harness design, which physically links all the electronics together.
A crucial and complex part of the electrical system, it is rather surprising that most automotive wire harnesses are still created and assembled today within a highly manual process. But the growth of electrical/electronic content is pushing even the best manual processes to their breaking point. A modern vehicle can have many dozens to hundreds of ECUs and 5 miles or more of wire, posing difficulties in wiring layout, vehicle weight, integration and development time.
Even as additional electrical design challenges come to the fore — multi-voltage systems, dual redundancy in critical circuits and resultant new challenges in EMI —physical space for wiring remains constant. When combined with the growing expectation of customers wanting a greater selection in options, wiring systems are becoming almost unique to each vehicle. Meeting that level of variety is an enormous design challenge for the industry.
Faced with these issues, leading automotive companies and suppliers are now adopting advanced engineering capabilities that support all aspects of creating a complex electrical harness: from product definition through electrical system design, harness manufacture and vehicle maintenance. These tools, such as Mentor Automotive Capital Products, deliver cycle-time reductions and support improved engineering processes by incorporating powerful design asset reuse and correct-by-construction technology that automatically generates optimized platform-level wiring. Using these powerful solutions, wire harness designers can efficiently deliver the new electronic features demanded by the automotive buyer, while minimizing the cost and weight of the wire harness.
Importance of software
Those working on the software side of ADAS technologies face balancing acts of their own. The data generated by the many ADAS sensors requires real-time digital signal and image processing either at the sensor node or in some central processing unit. The information then needs to be transmitted, collated and analyzed over a data network that provides deterministic, high-data-rate links. Much of the challenge stems from issues of centralization, particularly when it comes to processing sensor data. There are obvious advantages to moving to a smaller number of more powerful onboard computers. A minor fender bender can quickly get expensive if it damages a radar module that includes a complex SoC. Better to have sensors and cameras with minimal circuitry that send data back to a central processing hub.
One way to consolidate functions is to combine multiple complex domains. A technique gaining traction is using a virtualization technology, such as a hypervisor, that allows various software applications to share a single ECU. In essence, the ECU is divided into several virtual environments, each running its own distinct, secure real-time operating system and software. The individual applications think they have their own physical piece of hardware, and so can work side by side on the ECU, without knowing anything about each other. A recent article by Ann Steffora Mutschler delves into the details of hypervisors.
The benefits of consolidation of multiple functions into a single device means fewer ECUs are required, significantly lowering the cost and complexity of the overall system. And because virtualization uses the software already in operation, minimal time is needed to re-engineer or rewrite the software – saving design teams and companies the costs typically associated with software and subsystem creation. Ultimately, this means lowering development risk while improving time to market.
ADAS’ growing role
Most industry analysts expect to see ADAS-related revenues increase by more than 10% annually through 2020, according to a McKinsey report. The design teams — and technology vendors, like Mentor — that will rise to the fore in ADAS will be the ones that can handle cascading systems engineering challenges, from software platforms to hardware design to data and electrical automotive networking.