One of the biggest drawbacks of autonomous vehicles is the degree of dependency people will have not only on getting from one place to another, but keeping safe in the process. With the majority of self-driving cars featuring 48-volt systems in their powertrains, manufacturers can’t afford leaving any room for error. Something like a camera, radar, or Lidar unit malfunctioning could be enough to trigger a fatal accident, while a battery pack short-circuiting or electric motor in an electrical vehicle could set a vehicle ablaze.
In an effort to understand where and why failures occur in driverless vehicle systems (part of an industrywide effort to ban these problems), engineers and researchers at firms like Delphi are studying electrical gremlins in cars on the road by examining warranty data. Delphi in particular, has had talks with automakers in nations like Germany and France in an effort to adequately determine how next-generation electrical systems can be configured. One notable finding was how connectors fail due to improperly seated terminals that become loose during driving over time, contrary to the initial belief that factors like corrosion and moisture were key contributors.
Connectors malfunction and take a vehicle’s electronic accessories due to mistakes made during the car’s assembly stage. Electrical failures occur because parts of plastic housing that hold wire terminals aren’t completely mated. Regarding the industry elimination of electrical problems in driverless vehicles and other crafts like high-voltage powertrains, Delphi CTO Glen De Vos believes designing foolproof wire connectors and having flawless assembly methods to prevent the mishandling of wiring harnesses is essential moving forward.
The next generation of vehicles with autonomous capabilities will possess notable features from the commercial aviation industry, and will build redundancy into their electrical architectures. As a result, we’ll still see safety critical systems continue to function if a power interruption or other failure occurs. Delphi is investing a lot of time with OEMs developing these particular strategies. It’s especially worth noting how expensive duplicating everything is- especially if you have to in a number of different ways.
We’re essentially seeing two different development efforts. From a fundamental standpoint, this is what we have to look at in terms of providing redundancy and fail-operational capabilities. Redundancy consists of at least two sets of wire and components such as onboard computers capable of sensing when failures occur in one computer, and then provide automatic backup. Obviously, Delphi doesn’t want to leave drivers stranded, and has to assure there’s a way for these people to reach their destinations. A vehicle’s electrical architecture might go to centralized computing for safety and electrical architecture, since they ultimately back each other up.
Two of the biggest issues with incorporating redundancy are cost and weight, which is starting to be addressed by companies like Delphi. Second-generation models of cars like the Chevrolet Volt and Toyota Prius had most of their heavy copper cables eliminated when company engineers installed vehicle power electronics directly on the transmission, which houses the electric motors.
Delphi is also developing a new generation of lightweight aluminum wires that will mitigate costs. When combined with thin-wall insulation, aluminum wire can reduce weight up to 40 percent when compared to copper. This is just one of many examples demonstrating how companies like Delhi are capable of solving these problems in their efforts of improving the reliability and safety of self-driving vehicles.
