New NXP System Drives Sensor Fusion for Autonomous Vehicles

July 1, 2016

Terry Costlow

NXP’s BlueBox system collects data from multiple sensors, combining inputs so safety decisions can be determined.

Silicon suppliers are stepping up to help facilitate progress in the road to autonomous driving. NXP Semiconductors has unveiled its BlueBox, which handles sensor fusion, analysis and complex networking.

NXP, which became the largest automotive semiconductor supplier last year by acquiring Freescale, provides all the silicon in the system. The module underscores chipmakers’ growing focus on systems. Last year, Renesas teamed up with a number of partners whose sensors and other components augment its autonomous driving platform.

As safety systems that make decisions on braking and steering pave the way for more autonomous driving, central controllers collect input from multiple sensors and stitch it together so it can be analyzed. These controllers will typically classify vehicles, pedestrians and other objects, then determine whether and how these objects impact the vehicle’s movement.

NXP’s BlueBox utilizes two main processors to fuse inputs and make decisions. A networking device handles communications while a safety controller combines inputs from cameras, radar, lidar and vehicle-to-vehicle communications. The centralized controller, which includes significant RAM, has fairly low power requirements.

“The box runs at 90,000 DMIPS (million instructions per second) and draws less than 40W, which fits the power budget of vehicles,” said Mark O’Donnell, the company's Automotive Marketing Manager. “Everything on the vehicle these days is power hungry, so that’s a big concern.”

The safety controller has four microprocessor cores and hardware accelerators. The networking chip is larger, with eight cores. That level of computing power and a shift to Ethernet highlight the huge volumes of data that will flow into a centralized computer that combines several sensor inputs.

“We’ve got to change the networking architecture, going from CAN and LIN to Ethernet,” said Lars Reger, NXP's Automotive CTO. “On high-end cars, the cabling weighs more than I do, Ethernet can help reduce that weight. We need domain architectures so if the infotainment branch is attacked, it doesn’t go any further. Ethernet enables this architecture and includes the ability to add security and gateways.”

The BlueBox is an open platform with Linux software. It’s designed for easy customization by OEMs and Tier 1s. Reger noted that OEMs will want to write their own software rather than relying on neural networks and 'deep learning,' which let the car develop some of its own rules over time.

“It does not help if the car has the same level of recognition that a person has; it’s not important to know whether a car is old or new or whether a pedestrian is male or female,” Reger said. “Vehicles just need a highly reliable and deterministic system that does object detection and object classification.”

He also addressed the legal climate that will play a critical role in the eventual rollout of autonomous and active safety systems.

“If a carmaker in court needs to defend why a car turned left instead of right, they don’t want to explain that a neural network made the decision,” Reger said.