|TuSimple's AI technology combines with a retrofitted camera array to give trucks level 4 autonomy without the aid of LiDAR. (Image source: TuSimple)|
Ask Xioadi Hou, Co-Founder and CTO of TuSimple, about his startup company's methodology for creating artificial intelligence for autonomous trucks, and one answer quickly jumps out: “We're not using LiDAR,” Hou told Design News. “The biggest difference between us and other companies is we do a lot of camera-based analysis.”
Since its founding in 2015, Hou's company—TuSimple, a Beijing- and San Diego-based startup—has been developing AI for autonomous trucking. This domain of the autonomous vehicle space is populated by only a handful of other companies, such at Otto (now a subsidiary of Uber). The company's name comes from the Chinese character tu, which means “image"—playing up the company's goal to make computer vision and image recognition simplified. But it's also a play on “too simple.” “It's very sarcastic because we're overly optimistic,” Hou joked.
“I wouldn't really consider LiDAR as an evil thing. I'm from the utilitarian point of view, where anything that works should be incorporated into the vehicle,” Hou said. “But, frankly speaking, LiDAR today is not an option for a production level vehicle, which is why we have to work really hard on a camera solution to solve the problem.” And, sarcasm aside, while the autonomous car has yet to be perfected, Hou said that trucking brings its own set of challenges. Speaking with Design News from the 2018 GPU Technology Conference (GTC), Hou and his team readily admit that their shunning of LiDAR tends to raise eyebrows. But they have a good reason behind forgoing the laser sensor technology in favor of camera-based systems.
Hou said TuSimple is open to implementing LiDAR into its solution when the technology is more ready. But he offered that the same issues that make a commercial truck so difficult to drive compared to a car also mean that autonomous systems have to be approached in a different way. “For trucking, you're talking about an 18-wheeler driving 60-65 miles per hour on a highway. At that speed, you just can't stop the vehicle within 100 meters of braking distance,” Hou said. “There are claims that LiDAR can see over 200 meters, but it's not always guaranteed. Sometimes the LiDAR can only see about 100 meters or lower. It's not guaranteed that LiDAR can see everything at 200 meters.”
There are also issues, such as material reflectance, that affect LiDAR's perception quality. Things like a black car or a pedestrian wearing fleece could compromise a LiDAR system. In fact, LiDAR was blamed as the culprit behind a fatal autonomous car accident that happened back in March in which a self-driving car fatally struck a pedestrian on a bike at night.
All Cameras, All the Time
Models of TuSimple's solution involve an array of four to five cameras precisely retrofitted to a Peterbilt truck. “We just can't trust one signal unit, so we have to think about what we need and have a series of different cameras,” Hou said. “We use cameras with different lens sets and orientations and it's sufficient for the entire system to work. We also use radar for backup in severe weather. But relying on radar doesn't support full automation.”
|A corporate video from TuSimple gives an overview of its autonomous trucking technology.|
While the cameras used in TuSimple's system are off-the-shelf models with some proprietary modifications, TuSimple is not a hardware company. Rather than build its own truck, the company aims to supply the AI and software for trucking manufacturers to build their own self-driving trucks.
With that, however, comes concerns over meeting manufacturer specifications—particularly around additional power consumption. Hou laughed that TuSimple's engineers are always asking for more power consumption, but understand they have to work within limits. “We currently consume about 2000 watts just for computation. Aside from that, there's very little retrofitting on the truck,” he said. “We don't want to build something in a very hacky way because then it won't be very safe or reliable. What we want is a production level system. In order to do that, we have to buy parts from Tier 1 suppliers because they can guarantee the parts are production-level quality. We don't need to rebuild the power steering system or build our own braking system. All of those components are there. We just need to talk to the right people and collaborate with them in the right way.”
Chuck Price, VP of Product at TuSimple, told Design News that things such as changes to the power system are steps toward working with TuSimple's trucking partner, Peterbilt, to realize a truck design that can come off the assembly line ready for full autonomy. “A large part of our business is providing a reliable autonomous service,” Price said. “We're licensing our technology to OEMs and other Tier 1s that will be building the long-term production platforms that we'll require. It's not our preference to be in the hardware business directly, but to be more in the technology business for that part of the system.”