Radar, lidar, camera
I can see what you can’t see
Audi A8 is the first automobile to achieve level 3 automated driving. For that it is rigged with multiple sensors — ultrasonic sensors, laser scanners (lidar), cameras, radar sensors — to span and monitor vehicle surroundings.
Ultrasonic sensors, cameras and radar are meanwhile in many cases basic equipment. In the case of lidar the picture is still something quite different. In a blog Audi reasons the use of lidar or laser scanners as follows: “What’s important is that the various sensors are able to validate their data by interchange. Their specific characteristics in range and speed of detection must complement one another, and be able to compensate them if a sensor malfunctions. Add the information of a laser scanner and it not only improves redundancy but also recognition of the details of static and dynamic objects. The automobile will perceive its surroundings more widely, measure distances more precisely, and make out obstacles more reliably.”
According to Audi, long-range radar (LRR) detects objects almost 250 meters away, the cameras span 150 meters to the side. The laser scanner can only detect objects at a range of 80 to 100 meters, but — the big advantage — the sensor multiplies the previous 35 degrees narrow field of vision of the LRR more than four times to 145 degrees. Plus, lidar improves nighttime orientation, detects objects in fractions of a second (the light pulse of only 0.004 µs travels to and back from an object 100 meters away in less than 0.7 µs), and can determine the exact distance to the object.
Market research forecasts good growth for all “vehicle eyes”
No matter whether lidar, camera or radar — market prospects are excellent. Grand View Research in a market study of August 2017 predicts that the worldwide automobile radar market is likely to reach a volume of $12.16 billion by 2025. That would be average annual growth (CAGR) of 20.8 percent. The analysts explain that the increasing focus on active safety features, innovations in radar technology, sinking component prices, and more automobile purchases are the driving factors behind the market growth. Turning to the camera market in the automobile segment, here the analysts of Grand View Research expect the world market to chalk up substantial growth between 2015 and 2022 on the strength of further advances in camera-based driver assistant sensors, automotive safety systems, and the aftermarket sale of parking cameras. Market Research Future states concrete figures: the worldwide automobile camera market will probably grow to some $19 billion by 2023, meaning a CAGR of 19 percent between 2017 and 2023.
Looking at the worldwide demand for lidar, the figures of Transparency Market Research indicate that the market will hit the $2 billion barrier in 2026. That in turn means a CAGR of more than 35 percent between 2018 and 2026. The increasing use of intelligent active safety systems in vehicles, given the strengthening trend to autonomous driving, should lend impetus to the automotive lidar market in the period forecast. Analysts are convinced that increased testing of autonomous vehicles by large OEMs worldwide, especially in the USA and Germany, offers the automotive lidar market substantial growth opportunities in these years.
And what does industry say?
In radar you must differentiate clearly between 24 and 77/79 GHz. In the opinion of Ovaldo Borghetti, head of the radar product group/sense and control in the ATV division of Infineon Technologies, 24-GHz systems have reached the zenith of their use for applications like blind-spot detection (BSD). And after the zenith things tend to go downhill, for 24-GHz radar too. Dr Steffen Heuel, technology manager radar at Rohde & Schwarz, explains why. Although 24-GHz radar solutions are still being produced in series, and offer sensor solutions for BSD and other driver assistant systems, “the 24-GHz frequency band is subject to changes in legislation.” Until now industry has used 24-GHz ultra wideband (UWB), with a bandwidth of 5 GHz covering the frequencies 21.65 through 26.65 GHz. “Because of specifications and standard amendments by the ETSI (European Telecommunications Standards Institute) and the FCC (Federal Communications Commission) the use of UWB for new vehicles will end by 2022.”
Borghetti adds, “Radar is a global market and bidders attempt to serve a global market with global specifications. But there’s only a global standard for 77 GHz. The lack of large bandwidth in the 24-GHz band, plus the level of maturity that 77 GHz has reached and a smaller antenna form factor are a clear advantage for the latter over 24 GHz, so that 77-GHz variants will replace 24 GHz step by step.” Similar arguments come from Kishore Ramaiah, product manager in the automotive millimeter wave sensors group of Texas Instruments (TI): “The narrow 200-MHz band does not give adequate resolution to be considered for applications in automotive engineering, especially as we enter the era of self-driving.” For which reason tier 1 manufacturers would ramp down the production of 24-GHz radar systems, and ramp up on 77-GHz radar. But Heuel does point out that the narrower 200-MHz band in the 24-GHz range will continue to be developed — despite bandwidth restrictions — for applications outside the automobile.
77 GHz receives much more positive judgment on all sides. On one point the statements from the semiconductor manufacturers differ: in their assessment of the basic process technology. Infineon has had 77-GHz radar transceivers on the market for a number of years, on the basis of SiGe. Borghetti: “We’ve just completed development of a fully integrated radar transceiver based on a 130-nm SiGe technology. The transceiver comes with three transmit channels, four receive channels, low-noise PLL, loop filter, baseband functions, A/D converter, DC offset suppression, and so on — all on a single chip.” This device is combined with the Aurix microcontroller of the second generation and the TLF30684 power supply IC to create a radar chip set of the next generation, he says, with ramp-up due to start in the first half of 2019.
- I can see what you can’t see
- Cameras — developments continue
- Lidar
