A precise three-dimensional profile of a vehicle’s surroundings is a fundamental prerequisite for automated driving. A new high-resolution 3D flash lidar (HFL) sensor developed for use at close range – 50 m (164 ft) or less – delivers on this capability, according to Thomas Laux, head of business development and sales for HFL segment in Continental’s Advanced Driver Assistance Systems (ADAS) business unit.
“This is automotive grade and solid state, meaning no moving parts. It’s a bunch of semiconductors, which is ideal for commercial vehicle and even more so for the off-highway environment – they don’t have a lot of hours [of operation] but their environments can be pretty rigorous,” said Laux. The IP6K9K packaging is very important for these applications, he said, as is a 3D Global Shutter feature that eliminates motion distortion and enables persistence mode and geo-registration of point cloud.
Laux, who is located in Carpinteria, Calif. as part of Continental Advanced Lidar Solutions U.S., LLC, was working for a Tier-2 supplier acquired by Continental a few years ago. “We started off with 22 engineers and now we have 300, working across domains on everything from the software to the test and validation, which is one of the most crucial pieces,” Laux said. About 25% of the activity in developing its automotive-grade lidar sensor is devoted to test and validation, he added.
“For this sensor we designed short range first. We thought this was a bigger issue, which turned out we’re right,” Laux said. The supplier is providing samples of its HFL110 lidar sensor to commercial vehicle (CV) and off-highway manufacturers for evaluation. Application areas include agriculture, construction, mining, UAV delivery, and precision infrastructure inspection. Continental’s patent-protected flash lidar is expected to be in mass production by the end of 2020. The supplier already has launch customers for automotive and off-highway, Laux said, but not yet on the CV side.
Particulars of flash lidar
Complementing the supplier’s existing ADAS sensor suite including radar and 2D color sensors, the HFL110 sensor delivers a detailed 3D profile in 330 nanoseconds per frame, regardless of lighting or weather conditions. The sensor generates a high-res 3D point cloud 25 times per second within its 120° x 30° field of view. Its multiple distance measurements capture 4,096 contiguous pixels (128 x 32 pixels) of depth data in real-time across the field of view.
“We flash a laser pulse for 4 nanoseconds to illuminate all of those pixels, 4,096 pixels with a single flash. We use something called ‘engineered diffuser’ that spreads the light,” Laux said, adding that the unit has up to four returns to counter impediments such as rain, spray, dust, smoke or fog. Built-in heater and blockage detector, and an optional washer system, also ensure reliable imaging.
The contiguous pixels tolerate nearby high or low reflectivity surfaces, producing a point cloud and/or an object list to define and track the vehicle’s surroundings and moving objects within it. The sensor’s range is 22 m (72 ft) at 10% reflectivity. The sensor operates at 1,064 nm in the near-infrared range, which is Class 1 eye-safe, and the unit weighs approximately 700 g (24.7 oz).
“It doesn’t replace a 2D sensor, we can’t see color with this,” Laux explained. “As a human you have ears, eyes, nose, that’s how we interact with the real-world environment. Similarly, with vehicles we need lidar, radar, 2D – a full sensor suite.” So, lidar is a must to achieve SAE Level 4 autonomy? “I know Elon Musk might have a different opinion, but why would you cripple yourself and operate either without eyes or without ears,” Laux said. “I think the more redundancy you have in different wavelengths, where if one doesn’t work you’ve got a fall back, is critical for Levels 3 and 4.”
For dense urban environments, two HFL110 units can be mounted to provide imaging with overlap in the middle. “You can get really good geometry, you can read the FedEx on a delivery truck,” he said. “That kind of geometry is necessary for merging environments, when things are whipping by really fast when it’s raining or you get truck spray.” The new sensors currently are “a bit expensive,” which is typical with a launch product, Laux noted, referencing the high cost of radar over a decade ago. “Volume and manufacturing enhancements will bring cost down. It will happen.”
Off-highway machine vision
The HFL110 3D flash lidar featured prominently at Agritechnica 2019 in Hanover, Germany. In the John Deere innovation section of its booth, the HFL110 was demonstrated on a concept tractor, and a large wall-mounted monitor displayed what the lidar sensor detected on the OEM’s stand. Continental received strong interest from a number of equipment manufacturers, said Laux, noting that several initiatives are under way but they cannot be commented on at this time.
An agricultural robot concept, the Continental Contadino, also employs the HFL110 sensor. Introduced at Agritechnica, the fully electric and autonomous Contadino features a modular design that allows exchangeable implements and different track widths. The implement carrier can be used for different light-duty tasks such as seeding, weeding, spraying, fertilizing and monitoring. Smart farming is possible with precise application of pesticides and fertilizers or a selective sowing process.
The robot is equipped with lidar scanner, radar, real-time kinematic GPS, camera and ultrasound to ensure accurate object detection and classification, tracking and a global navigation satellite system (GNSS) accuracy of 3 cm (1.2 in). The tools are connected to the robot via open interfaces. This connection provides the implement with electric power and acts as a data line enabling access to sensor data and cloud communication.
Several robots can work collaboratively in the field in fleet operation. A trailer that transports the autonomous machines to the field also functions as a charging and refill station for seeds, fertilizers, etc. Automatic recharging allows 24/7 operation. A cloud connection of the fleet allows mobile monitoring and a constant overview of the process. Contadino is currently in prototype phase. Continental is looking for partners in the agricultural sector to realize first field applications in 2020.Continue reading »