The Challenges of Engineering Interconnectivity for the Connected Automobile
Today’s cars feature advanced safety, infotainment, navigation, and diagnostics capabilities. Tomorrow’s cars will require exponentially more electronics.
Thomas Scannell, Automotive Lead, Amphenol ICC
The Connected Automobile
As automobiles continue to evolve, designers are leaving yesterday’s basic vehicle technology behind, embracing today’s advanced driver assistance systems (ADAS), and preparing for tomorrow’s completely autonomous vehicle, which comes with a wide range of challenges. Automotive systems design engineers must both develop new technologies and adapt existing technologies to meet ever more critical requirements for increased bandwidth, reliability, computing power, and energy efficiency. One of the most critical factors of advanced automotive technology development is the design of new interconnection systems.
In older automotive systems, the default interconnection technology was a relatively low-speed, discrete, two-wire power and signal link that separately joined each subsystem to the vehicle’s electronic control unit (ECU). The initial automotive networking protocols, such as CAN bus, were developed as a first attempt at data integration, with the same low bandwidth and data transmission speed requirements. Today’s automotive systems are already advancing beyond CAN bus to the anticipated development of a new data communications protocol — Automotive Ethernet — which, in its first iteration, is expected to enable data transmission rates up to 1.3GHz. But even that increase in bandwidth capability (100 times faster than CAN bus), will not be sufficient to handle the data stream a truly autonomous vehicle requires.
It is understandable that next-generation hardware and software for automotive interconnection technology is being adapted from technologies used in computer systems and data centers. The expanding requirements for data transmission speeds, signal integrity, and network integration in tomorrow’s autonomous vehicles parallel the similar evolution from individual computers to networks to data centers. Today’s cars feature increasingly sophisticated internal electronics (e.g., infotainment systems, navigation, safety features, and diagnostics) and, in the near future, their connectivity will expand even further to communicate and interact with their surrounding environment, including other vehicles and drivers.
By some estimates, a typical vehicle will be expected to send and receive more than one million instructions per second while traveling at highway speeds by the year 2025. Another estimate puts the bandwidth requirement for a comprehensive ADAS-enabled vehicle at 4 terabytes per hour. Designers need to re-engineer the concept of automotive interconnection systems to enable these new bandwidth requirements.
An illustration of the exponential expansion of data communications requirements is found in the evolution of onboard vehicle camera systems. While a typical vehicle may have only a single back-up video camera connected to a dashboard display and an alarm indicator, a more comprehensive ADAS-equipped vehicle will likely feature as many as 30 cameras — some to provide a continuous 360° view around the car, and others that are fixed on specific areas to enable backup alerts, lane-change monitoring, and collision avoidance systems, among others. These cameras will have more functionality than capturing simple video images as well, featuring integrated video, radar, light detection and ranging (LiDAR), ultrasound, and other sensing technologies. They are also likely to have two-way communications capability with other vehicle systems, such as side or rearview mirrors that can serve as onboard camera system displays. Further compounding the bandwidth requirements, any of these camera functions related to critical safety or vehicle controls will need to have double- or triple-redundancy.
In addition to the expanded bandwidth this new generation of automotive interconnectivity requires, traditional automotive demands must also be met. Considerations that go beyond those of typical data centers include designing for constrained spaces and the ability to operate under extreme temperature changes, shock, or vibration. A small form-factor connector type, such as USB 3.0, may be adapted for use with several automotive systems, with the added benefit of standardization to make many of the systems backward-compatible.
For shock and vibration resistance, it is likely that connector manufacturers will adapt traditional automotive connection technologies. Compliant-pin press-fit connectors that mount securely to PCBs are one possibility, as these are not subject to the long-term failure modes that could be experienced with soldered connections. Press-fit connectors are also able to accommodate higher pin counts and the contact density that will be required for the increased signal integration of ADAS-enabled vehicles.
One of the biggest challenges currently facing connector manufacturers is to develop standards for a new data communications protocol that includes both hardware (e.g., the connector form factor), as well as increased bandwidth that enables the new levels of functionality and control required for ADAS-equipped vehicles. The development of these standards will also require the integration of higher bandwidth features that are more common to data center connectors with the ruggedized features already found in automotive connectors, as well as advanced communications protocols that can integrate the increased data transmission and prioritize the signals based on safety and control functionality. Advanced connector technology will play a critical role in the integration of advanced functionality and safety features that will soon be on our roads.