Liu Jida of Tsinghua University: Building a technical barrier with algorithms as the core around in-vehicle UWB applications

In addition to digital keys, UWB technology has more potential applications in automobiles.

Two years ago, Xiaomi released a black technology called "One-finger connection". In the demonstration video, the demonstrator only pointed the phone at a certain device, and the corresponding control card popped up on the phone interface, making it convenient for the user to take the next action.

At that time, Xiaomi also stated that in the future, users will not even need to take their mobile phones out of their pockets to open smart door locks seamlessly.

Now, two years have passed, and although UWB technology has not yet realized the above smart home vision, it has taken the lead in landing in automobiles and becoming a form of digital key.

The first "adopter" of UWB car digital keys was BMW. In January last year, BMW announced that it would introduce "enhanced digital car keys" for its 2022 models, and this function was realized based on UWB technology.

However, "it was not until July last year that UWB technology was announced as a relevant standard for digital keys. So it was from the second half of last year that UWB digital keys really received a lot of attention from car manufacturers, and they began to actively promote the implementation of this technology." said Liu Jida, product director of Tsinghua University Intelligent Driving.

Figure | Liu Jida, Product Director of Tsinghua Research Intelligent Driving

Qingyan Zhixing is a subsidiary of Qingyan Xunke, which was officially spun off at the end of last year. "Our parent company has been in the field of UWB positioning for 8 years and is also the first UWB solution provider in China."

At the same time, he also pointed out that, as of now, there are no truly mass-produced models around UWB technology worldwide, and they are still in the stage of promotion, positioning and implementation. "UWB mass-produced models will only be launched at the end of this year and next year."

When it comes to the application of UWB technology in automobiles, in addition to digital keys, Liu Jida also mentioned many other potential directions and markets to Magnetron.

Digital key is the fastest application of UWB technology in automobiles

It can be said that digital keys are the product direction where UWB technology is applied to automotive scenarios the fastest.

Before this, digital keys were mostly realized through NFC and BLE (Bluetooth Low Energy), such as the digital card and mobile phone (Bluetooth) key of Tesla Model 3. The former embeds the radio frequency chip into the card to achieve touch unlocking, while the latter achieves unlocking by authenticating the Bluetooth pairing between the mobile phone and the car.

However, the three major characteristics of strong anti-interference ability, high positioning accuracy, and strong coexistence also allow the digital key solution that incorporates UWB technology to be further improved.

For example, Bluetooth and WiFi both use the 2.4 GHz frequency band, so signal interference has become a "common occurrence." In comparison, "UWB in cars uses the 6-8 GHz frequency band, so it has a strong ability to coexist with other signals."

At the same time, in principle, UWB uses ToF flight time to accurately measure the distance between the vehicle body anchor point and the digital key, providing 0.1-meter-level high-precision position perception capabilities. This is also the core function of the technology in automotive scenarios.

With the addition of UWB technology, the digital key solution has also been upgraded from the second generation to the third generation - three wireless communication technologies, UWE, BLE, and NFC, coexist.

Under this solution, BLE will be used for long-distance sensing, authentication and interaction between the vehicle and the authentication device, while UWB will be responsible for distance measurement between the vehicle and the authentication device. As for NFC, it is Plan B. Once BLE and UWB fail at the same time, users can also choose to unlock with NFC.

In Tsinghua Zhixing's UWB digital key solution, UWB technology can accurately locate the authentication device (mobile phone/smart watch) within a 20-meter radius circle with the car as the center; 3-10 meters is the welcome area, and the vehicle will turn on the lights after the UWB system locates and identifies the authentication device; 1-3 meters is the unlocking area, and the vehicle will automatically unlock after accurately locating the authentication device, and the turn signal will flash and the horn will prompt; inside the car, the vehicle can be started/shutdown with a one-touch start button.

Beyond digital keys, UWB has more possibilities

As mentioned earlier, position perception is the core function of UWB. Based on this, "UWB also has motion and micro-motion perception, and UWB radar can be used to detect some movements and micro-movements in the environment." Liu Jida said.

In response to this, Tsinghua Research Institute has already developed two solutions, namely kicking the box open and in-vehicle liveness detection.

Taking in-car liveness detection as an example, "the tiny changes in the chest and abdomen when a person breathes can be detected by UWB radar, and this micro-movement perception can be used to determine whether there is a live body in the car, etc." Liu Jida went on to say, "These two solutions already have very mature technical solutions and should be able to be implemented in the car soon."

At the same time, based on location perception capabilities, UWB technology can also be used to assist in precise positioning of autonomous driving.

Liu Jida explained, "Precise positioning is one of the important parameters for autonomous driving. Under outdoor conditions, Beidou and GPS can provide a relatively accurate position for the car, but underground garages, tunnels, overpasses, and points in cities where buildings are densely packed are actually blind spots for satellites."

In other words, in the above scenarios, it may be difficult for the car to obtain satellite signals, and the inability to obtain signals means that real-time positioning cannot be provided, which is not conducive to functions such as path planning of the autonomous driving system.

"Using the UWB modules already installed on the vehicle and the UWB base stations installed in the above locations, our vehicles can obtain an accurate position with an accuracy of 0.1 meters even in such blind spots, providing a feasible technical path for scenarios such as autonomous driving and indoor navigation."

Liu Jida said that in order to achieve this capability, Tsinghua Research Institute is also carrying out cooperation projects with some OEMs and research institutes. However, because the infrastructure construction of UWB micro base stations is still not perfect, the application is still in its early stages.

In addition, he also suggested that UWB technology can also be used in convenient payment scenarios.

At that time, taking the refueling scenario as an example, based on the UWB technology's perception of the car's location and the amount of refueling, the financial system can automatically deduct the relevant fees based on this data. "Some of the current ETC functions may also be replaced by UWB payment. There are already many organizations and institutions actively exploring this application."

Algorithm directly determines the overall positioning performance of UWB

Currently, Qingyan Zhixing's business is mainly based on digital keys, and it also provides UWB in-vehicle radar and intelligent location services. In product delivery, it focuses more on a complete set of module hardware (hardware + algorithm) on the vehicle side, and most of them are customized deliveries.

Of course, "we also have a set of benchmark solutions. If car manufacturers can accept this universal solution, it will be implemented more quickly."

Looking at the UWB in-vehicle solution market, "In the early stage, the market share of foreign Tier 1 manufacturers was higher." Liu Jida said, "But in the past year, domestic manufacturers have also developed very rapidly, and many solutions have emerged. Relatively speaking, the momentum of domestic midstream solution manufacturers is even faster."

In his opinion, domestic manufacturers also have more advantages in terms of cost and service because they can meet the differentiated needs of different customers with faster response speeds and more personalized support.

In addition, from the perspective of Tsinghua Research Institute, Liu Jida also said that the company's current focus is on building a barrier with algorithms as the core. "The algorithm will directly determine the overall positioning performance, especially in driving in complex scenarios."

Regarding this area, "First of all, in terms of technology, our parent company has accumulated 10 years of technology, and the core positioning algorithm continues to lead the industry by one or two generations. Secondly, our algorithm has been applied and verified in thousands of projects in other fields. There are more than 3,000 cases in UWB positioning alone. Therefore, in terms of algorithm stability, we are very advanced in the industry, if not the best."

According to him, Tsinghua Research Institute of Automotive Science and Technology has connections and in-depth communications with more than 50 mainstream automotive industry customers around the world, and currently has designated projects.

at last

Data from Gaogong Intelligent Automobile Research Institute shows that from January to November 2021, the number of new domestic cars equipped with digital keys such as remote control keys, Bluetooth/NFC, etc. as standard was 18.0427 million. At the same time, major automakers are also accelerating the speed of digital key installation. Among them, UWB technology solutions are increasingly attracting the attention of leading automakers.

Just this year, the NIO ET7 model equipped with UWB technology officially started delivery, and the BMW ix 2022 xDrive50 adapted to the UWB digital key function has also been launched one step earlier. In addition, Tesla, Hyundai Motor, Great Wall, etc. have all taken action on UWB technology.