Few argue that autonomous vehicles (AVs) will need lidar to safely reach higher levels of automation. Radar is well-understood, low-cost and low-power, but lacks the required resolution for object recognition. Stereo camera systems can provide AI-assisted recognition and depth data, but performance is determined by lighting conditions. Only lidar makes its own light while providing depth-mapped resolutions – leaving cost as lidar’s only real drawback, even as more flash-based solid-state options come online. Initial lidar prototypes were thousands of dollars per module, and the descent to less than $1,000/unit is progressing slowly.
Opsys Tech, a company based in Holon, Israel (south of Earth’s startup capital Tel Aviv), claims to have developed a new category of lidar for AVs, a 100% solid-state design it calls Scanning Microflash Lidar (SML). According to Opsys, SML incorporates the solid-state advantages of flash lidar with the range and resolution of mechanical-sweep or oscillating micro-electronic mirrors (MEMs), all in one sensor.
The principals behind Opsys boast extensive laser and optics design expertise, having come from global optical-comm supplier Finisar, and beyond cost, the company’s claims are an intriguing combination of attributes so far unmet in the lidar space. Other lidar technologies support either long range, high resolutions or fast scanning rates, but not all three instantaneously, which Opsys said it delivers in all conditions.
Leveraging existing tech
Extensive integration and recently scaled smartphone technology is leading Opsys to a host of claims for SML: a per-module, mass-produced cost of less than $200; four times the range of flash lidar (>200-meter field of view (FOV)); along with best-in-class resolution (0.1° x 0.1°) and scanning rates (300,000 points/s, per sensor, per module; 16 scans/pixel average within the FOV @ 30 frames per second (FPS)). Opsys also claims its SMLs are 30 times faster than mechanical-sweep or oscillating-mirror (MEM/Galvanometer/rotating prism) lidars and are expected to last the life of the vehicle.
Key to the performance of the Opsys lidar is the VCSEL [vertical cavity surface-emitting laser], a type of semiconductor laser diode. Apple began using similar technology on its iPhone 12 smartphone, helping drive down VCSEL component costs; Opsys is sourcing a VCSEL manufactured to its own specifications. Opsys claims the lidar modules will be factory calibrated, and absent a collision, never require recalibration.
The patented implementation uses a VCSEL array as the pulsed-light source, combined with a single-chip SPAD [Single-Photon Avalanche Diode] solid-state photodetector receiver, enabling the semiconductor-based solution to reside on a single printed circuit board. Opsys describes the setup as using the same amount of light as a typical flash lidar, but narrowed to one pixel, then using multiple detectors and frequencies to give it the required resolution, range and speed.
Opsys recently provided SAE Media with an opportunity to preview the technology in a pilot vehicle outfitted with its SML, spending an afternoon riding with Sunil Kamath, business development manager at Opsys. The setup was described as “version 2.5,” of SML, with version 3.0 set to debut at January’s CES 2022 and be the basis for Tier-1 and OEM integration testing.
“We are focused on creating the best solid-state scanning lidar solution that can be used currently – used now – for manufacturing,” Kamath explained. “Many of the current generations of lidar have their own pros and cons, but they're not able to take that to large scale manufacturing. Our 3.0 production system will be large-scale manufacturable and deployable by automotive manufacturers. An automotive qualified product that can be deployed at mass scale.”
The “in-a-bigger-box” 2.5 demo system was a customer-evaluation generation of product already undergoing review by suppliers and manufacturers. “The big change going from 2.5 to 3.0 is our VCSEL drivers,” Kamath noted. “The laser drivers we're using right now are discrete components, so they're kind of bulky. We're building our own ASICs [application-specific integrated circuits], and these ASICs will be able to drive the VSCEL faster and brighter.”
The evaluation unit was able to provide a real-time display as we moved through suburban-Detroit afternoon traffic, its resolution unnerving in its fidelity, easily picking out hand gestures of pedestrian’s approaching a crosswalk. The 14 Hz refresh rate, faster than most development sensors stacks currently accommodate, easily animated the scenes. Opsys will provide multiple angular resolutions, depending on if the lidars are used for forward-facing (0.1°), offset or rear-facing (0.2°), or on the side of the vehicle (0.4°).
“On the sides where, for example, robot taxis or last-mile delivery vehicles want to be able to see right at, or near the door, they don't need a very high resolution,” Kamath said. “They just want to detect maybe if there's a person walking by.”
Exceeding industry targets
Kamath described the upcoming Opsys Tech 3.0 system as having a 300-m (984-ft) detection range, but noted it’s conforming claims to swiftly forming industry standards. “In the automotive industry they like to specify range based on the performance on a 10% reflective target – roughly, a black car. So we are speccing our 3.0 [system] at 200 meters (656 ft) at 10% reflectivity. That does not mean it cannot see beyond 200 meters. It says that for a 10% reflective target, giving high probability of detection.”
According to Kamath, specifications being requested by the OEMs are varying widely depending on the application. “The trucking companies want to go out further because they want to be able to stop with a full load at highway speeds, so they need longer stopping distances,” he said, but noted the majority of requests reference pricing. “We are really driving down the cost – $200 per module, scaled at maybe 50K or a 100K units.”
The lidar modules output “4D data,” which is three Cartesian coordinates plus intensity. “Most systems are able to provide up to 10 Hertz, and that's what the perception guys are used to, but we can provide much more than that,” Kamath described. “What you saw today was around 14 Hertz, and we can go all the way up to 30 Hertz based on other configurations we can provide. It all depends on whether they'll be able to use it. It's a lot of data and sometimes they are used to creating their software algorithms for 10 Hertz because that's what they had. Now we’re giving them more than that.”
The Opsys units will operate at both 905 and 940 nm, using the two wavelengths in a patented SPAD setup to prevent interference between adjacent lidar modules – a likely packaging scenario on vehicle fascias. “We support two wavelengths, so when you put them side-by-side, they don't interfere with each other because our SPAD receiver has a very narrow band filter. They could have used 1550 nanometers,” he added, “but that really hurts performance when conditions are bad and dramatically raises cost.”
The overall goal, Kamath stressed, was to create a module from available device technology that met manufacturers specifications and could be produced at scale right now. “We’ve tried not to use any exotic technologies,” he said. “We can provide the performance that is currently needed by automotive manufacturers in every spec. No moving parts, no surprises integrating at mass scale, and reliability. It has to operate from -40 to 85 [C]. We can do that without any caveats.”
When can the industry be expected to begin leveraging SML tech? Opsys Tech claims it’s already working with Tier-1 suppliers and OEMs. Shortly after its 3.0 system goes on display at CES in Q1 2022, it’s targeting to have its automotive-qualifiable unit transferred to an off-shore production facility [likely Thailand], with units becoming available shortly thereafter.
“We will have Opsys Tech's automotive-qualifiable Scanning Microflash Lidar unit ready during the first calendar-year quarter of 2022,” said Opsys Tech Chairman Eitan Gertel. “It usually takes one to 1.5 years for automakers to then get that ready for production. Given that timing, we expect Opsys Tech lidar units to be available in vehicles in 2023.”Continue reading »