LiDAR enters the 4D era, Volkswagen and Porsche are making early preparations-EEWORLD

Collect

Autonomous driving technology is inseparable from the 3D information of the surrounding environment obtained by LiDAR, but have you heard of "4D LiDAR"? For driverless cars, in addition to the 3D information of the surrounding environment, another very important factor is the speed of the surrounding moving objects and the direction of the objects' movement. Real-time acquisition of the overall data of "three-dimensional information + speed" has become the research and development technology route of many companies.

For example, Aeva, a lidar manufacturer, has just received investment from Porsche, a major shareholder of Volkswagen. It is the only lidar company invested by Porsche. In April this year, Aeva announced that it had established a partnership with Audi. In this way, the company has the support of two high-end brands of Volkswagen.

FMCW technology behind 4D LiDAR

Why do we need to obtain the speed of surrounding objects? Because the three-dimensional map generated at a certain point in time is a relatively static data after all. Is each point on the three-dimensional data stationary or moving? Which direction will the object move in the next second? This is very important for judging surrounding objects (such as walking pedestrians and stationary trees). If the speed data can be successfully obtained, the sensor can help the self-driving car determine whether the object hundreds of meters away is a stationary tree or a walking pedestrian, so as to make the right decision.

LiDAR can be roughly divided into two categories: pulsed LiDAR and continuous wave LiDAR. Pulsed LiDAR is the technology adopted by most LiDAR companies at this stage. It uses the principle of "time of flight (ToF)" to emit discontinuous light pulses to calculate the round-trip time and obtain the distance of the target. The second technology is to emit continuous waves to detect objects, and thus measure the frequency of the returning photons. This method is also called frequency modulation continuous wave (FMCW), which can successfully detect the speed of surrounding objects.

Point cloud image generated by LiDAR

The reason why this technology can detect speed is that FMCW laser radar generally uses the so-called "coherent detection", which can perform Doppler measurement on moving targets. We all learned the "Doppler effect" in high school physics. The frequency of waves increases when the wave source moves toward the observer, and the receiving frequency decreases when it moves away from the observer. Through Doppler measurement, it is possible to accurately distinguish between moving and stationary objects, thereby measuring speed data.

Universities and industry continue to invest

FMCW technology is considered by many to be a very promising LiDAR technology. For example, in 2017, the U.S. Army Geospatial Laboratory published a paper comparing the 3D imaging effects of two types of LiDARs, proving that FMCW technology can see richer details than light pulses. Because it can measure speed, it helps self-driving cars make predictions and improves driving safety. Other benefits are that it greatly eliminates the impact of external radiation, and its power is lower than that of light pulse LiDAR, and its hardware performance requirements are relatively low, so it can be integrated into smaller chips.

Due to these advantages and application prospects, many universities and institutions with R&D functions are conducting relevant research on FMCW technology. I know that the US Naval Laboratory and Montana State University are researching FMCW technology with higher resolution and clearer imaging. In addition, integrating FMCW technology into miniaturized chips is also one of the research directions. Since 2014, the University of California, Berkeley, California Institute of Technology, and MIT have all made FMCW technology a research focus and carried out related research. In addition to academia, in the industry, a large number of companies are conducting R&D based on the FMCW technology route and have achieved some phased results, such as France's Thales, Blackmore acquired by Aurora, and Strobe acquired by Cruise, an autonomous driving company under General Motors.

Because of these advantages, Aeva mainly conducts research and development related to the FMCW technology route, integrating all the key components of the sensor into a miniaturized chip. The latest chip is only the size of a finger, which is equivalent to a quarter coin (24.26 mm in diameter). When an autonomous vehicle uses this sensor, the space occupied will be very small, and there will be more space for other hardware, and the energy consumption of the lidar sensor will also be significantly reduced.

On the eve of marketization

In an interview with the media, Aeva announced that their "4D LiDAR" can identify objects 300 meters away, which has reached the detection limit of LiDAR on the market. The company's head said in public that this LiDAR can also detect objects that reflect 10% of the incident light and can identify lane markings or traffic signs.

More importantly, the 4D lidar developed by Aeva costs no more than $500. We know that the key factor in whether lidar can be widely used in driverless cars is cost. This product can scan 120 degrees horizontally and 30 degrees vertically. Ideally, 1-2 lidars can meet the needs of an autonomous vehicle; to achieve true driverless driving, 3-4 radars are required. However, even if 3-4 lidars are used, the cost of each car is only about $1,500-2,000, which is still far lower than the price of Velodyne, the leader of lidar. It is said that Volkswagen Group also took a fancy to the cost advantage of Aeva lidar.

Technology competition is like this. No matter how early you start, as long as you don’t achieve large-scale production and bring it to the market, you are always at risk of being surpassed by newer technologies. Aeva was founded in 2017. Although the amount of this round of financing was not disclosed, the amount of financing in 2018 was US$45 million, which is not a large amount of financing in the field of lidar, and it should still be far from mass production. However, another lidar company Luminar raised another US$100 million in the second half of this year, and the cumulative financing has reached US$250 million. It is striving for mass production (but they originally announced that they would achieve mass production by the end of 2018, but now it seems to be postponed). Faced with more and more pursuers, Velodyne has been slow to mass produce and the price has not come down. It really needs to be vigilant!

Although Aeva's LiDAR technology route still has disadvantages such as long measurement time and large data processing volume compared with other competitive technologies, as mass production scale expands, technology iteration improves, costs continue to decrease rapidly, and LiDAR is also developing towards miniaturization, low power consumption, and ASIC integration. You see, miniaturization is the development direction of LiDAR, and it is even possible to introduce such high-precision 3D imaging functions into the consumer electronics field in the future.

Let's take a look at the team. Aeva has two founders. The first one, Soroush Salehian, is a former Apple executive who served as a product development manager for four years. He participated in the product development of iPod, Apple Watch and iPhone, and was responsible for sectors including LED systems and sensor systems. Before joining Apple, he founded a company called bluelibris, which made continuous real-time health monitoring wearable devices, sold more than 300,000 units, and was eventually acquired by Numera Health. From founding the company to joining Apple, and now continuing to start a business, he has accumulated a lot of industry experience and industry understanding. With his background as a Stanford University alumni, he has also accumulated a lot of connections.

The second co-founder, Mina Rezk, is more inclined to the role of CTO. She worked in hardware development at Nikon for 11 years, responsible for all R&D tasks of the LiDAR product line. Later, she worked in sensor R&D at Apple for more than a year. In 2017, the two founders started a business together and established Aeva.

Co-founder Mina Rezk publicly stated that this lidar is in mass production, and some OEM manufacturers have begun to purchase and use their products and put them into testing. In fact, the experimental version of Audi E-Tron has begun using this lidar since April this year. Volkswagen's autonomous driving department is planning to use Aeva's lidar in future cars. The latest news is that the Volkswagen ID Buzz electric car, which will be launched in 2022, will use this lidar.

Although Aeva has good technology in hand, this does not mean that it will be able to kill other lidar manufacturers in the future. In fact, the world's first FMCW lidar system for self-driving cars was developed by Blackmore, which was acquired by Aurora. However, compared with Aeva's 300-meter detection distance, the data we learned is that Blackmore's measurement range is much shorter: 200 yards (about 184 meters). Before Blackmore, this technology was more used in aerospace (NASA developed the first Doppler lidar for automatic lunar landing missions), and heavy industry (such as measuring wind speed and turbulence, Mitsubishi uses it for wind power generation and detecting air traffic safety).

Reference address：LiDAR enters the 4D era, Volkswagen and Porsche are making early preparations

Previous article：The world's first and smallest ultrasonic sensor can penetrate metal door handles to open/lock car doors
Next article：Taking over low-speed parking tasks – 360-degree surround view and automatic parking system

Popular Resources
Popular amplifiers