At the 5th ADAS and Autonomous Driving Forum in 2021, Mr. Dao Liyang, the high-precision product manager of Hexinxingtong, gave a speech titled “Beidou High-precision Chips Empower Intelligent Vehicle Applications”. This speech mainly focused on three aspects. Introduce the latest product technology and application of Hexinxingtong.
(1) Product development process and market position
Founded in 2009, Hexinxingtong is a technology enterprise under Beidouxingtong, which specializes in the design, research and development of GNSS satellite positioning and navigation chips, high-precision positioning algorithms, multi-source fusion core algorithms, and GNSS data service provision. Since its establishment 12 years ago, it has released more than ten satellite positioning and navigation chips.
In 2010, the first domestic Beidou-compatible multi-system and multi-frequency high-performance SoC chip and Nebulas were released. In 2013, it released China’s first 55nm Beidou chip and Humbird, a GNSS chip for in-vehicle navigation and T-Box vehicle applications. In 2017, it released the first 28nm smallest chip and core firebird Ufirebird that supports Beidou global signals; in the same year, Beidou Skycom acquired Canadian RX Networks to build a cloud + IC business sector. In 2020, the 22nm RF baseband and high-precision algorithm integrated GNSS SoC chip NebulasIV was released, which is oriented towards the future market directions of intelligent driving, drones, and robots.
The GNSS satellite positioning and navigation chip developed by Hexinxingtong is the first to pass the AEC-Q100 vehicle standard certification, and is the first to be commercialized in the vehicle pre-installation, and the domestic chip pre-installation shipment is No.1. Beidou’s high-precision centimeter-level products are the first to achieve batch applications in the fields of drones, robots, and locomotives, and the drone market shipment volume is No.1.
In 2015, the Beidou satellite positioning chip technology designed by Hexinxing was the only one that independently won the second prize of the National Science and Technology Progress Award.
(2) Intelligent vehicle applications and Beidou positioning products
In recent years, the precision, reliability, and driving comfort of Beidou satellite positioning for in-vehicle navigation applications have been increasing, which has significantly improved the positioning accuracy, quality, and craftsmanship of Beidou satellite positioning products. The in-vehicle navigation application module supports single GPS satellite system from the beginning, to today’s multi-system joint positioning solution, and supports multi-system multi-frequency signals; the positioning accuracy is from the initial single-point positioning accuracy of 3 meters to 5 meters. It has risen to centimeter-level RTK positioning accuracy, meeting the requirements of intelligent driving and autonomous driving applications. In the automotive application market, Hexinxingtong Beidou satellite positioning module is used in V2X, T-Box, navigator, monitoring and other fields, followed by corresponding products in L3 and L4 autonomous driving scenarios.
The figure below shows the application mode of Hexinxingtong’s standard precision positioning module products, which are mainly used in large-scale T-Box and IVI installed in the front of passenger cars.
With the continuous improvement of vehicle satellite positioning experience requirements, in order to meet the needs of continuous positioning without satellite signals in tunnels, viaducts and other scenarios, UM220-INS integrates MEMS devices and has GNSS+INS integrated navigation function, allowing vehicles to enter In heavily occluded scenes such as tunnels, bridges, and even urban canyons, it can also achieve continuous and accurate vehicle positioning.
On the other hand, in scenarios with high accuracy requirements, such as automatic driving of agricultural machinery, automatic driving of passenger cars, shuttle buses, and high-precision map collection, the Beidou satellite positioning module is required to be able to achieve centimeter-level positioning accuracy. In the above application scenarios, Hexingtong has mature products.
According to different vehicle application modes, Hexinxingtong has defined the following 2 products:
The first UM4B0
In the past, products with centimeter-level accuracy of satellite positioning only existed in surveying and mapping. Now, the Beidou satellite positioning module UM4B0 with centimeter-level positioning accuracy can be used on high-precision vehicles. UM4B0 is a full-system full-frequency RTK positioning module developed based on NebulasII high-performance high-precision chip, supporting BDS B1I/B2I/B3I/B1C/B2a, GPS L1/L2/L5, GLONASS L1/L2, Galileo E1/E5a/E5b, QZSS L1/L2/L5 and other satellite signals, support narrow-band anti-jamming, mainly for high-precision map acquisition, intelligent driving and drones and other application fields.
The second UM482
For in-vehicle high-precision applications, some modes not only require centimeter-level position information, but also require accurate determination of the vehicle’s heading in real time, even in a parked state. Hexinxingtong has developed a system-wide multi-frequency high-precision positioning and orientation module – UM482 for such needs. The product supports two antenna signal inputs, and outputs RTK positioning and Heading heading information at the same time.
UM482 is a full-system multi-frequency high-precision positioning and orientation module developed based on NebulasII high-performance high-precision chip. It supports satellite signals such as BDS B1I/B2I, GPS L1/L2, GLONASS L1/L2, Galileo E1/E5b, QZSS L1/L2, etc. For agricultural machinery automatic driving, intelligent driving and other application fields.
However, for mass production vehicle applications, the module size of 30×40mm is still large. Therefore, Hexincom released a GNSS SoC chip, NebulasIV, which integrates 22nm RF baseband and high-precision algorithms last year. The NebulasIV chip adheres to the design concept of All in One, and integrates all RF information processing, baseband signal capture and tracking, high-precision centimeter-level algorithms, and anti-jamming algorithms into the chip, truly realizing on-chip high-precision centimeter-level Beidou satellites. GPS.
NebulasIV has both high integration, high reliability, RTK fix accuracy rate > 99.9%; high quality meets automotive-grade AEC-Q104, and meets the application requirements of vehicle pre-installation, drones, and agricultural machinery; unique device ID and RSA digital signature, It has the characteristics of low power consumption and small size, and is suitable for many high-precision applications such as precision agriculture, intelligent driving and telecommunication timing.
In vehicle applications, in addition to chips, different car manufacturers have different solutions and application modes, and there are some differences in the form requirements of GNSS satellite positioning products. For example, some car factories use 17×22 surface mount modules, while some car factories use equipment that directly integrates GNSS chips. Based on NebulasIV chips, CoreStar has developed a series of high-precision centimeter-level RTK positioning modules in different product forms.
The picture above is a positioning module with a size of 17×22mm and 12×16mm. Provide different product forms for high-precision automotive applications. Take the UM960 as an example, the size is 12×16mm, and the size is compatible with mainstream GNSS module products in the vehicle market. It has on-chip RTK positioning and solution functions, and can reach centimeter-level positioning accuracy. The UM960 module can achieve high precision and small size, mainly from the information processing of the radio frequency part, baseband signal capture and tracking, high-precision centimeter-level algorithm, and anti-jamming algorithm in the GNSS SoC chip that integrates the 22nm RF baseband and high-precision algorithms. Wait for the effect of effectively integrating into a chip.
(3) “Cloud” service solutions enable smart vehicle applications
In order to better Display the ultimate positioning accuracy on the terminal, Truepoint Technology, a subsidiary of Beidouxingtong, integrates the data of its own reference stations with the data of its partners nationwide, and accesses the truepoint cloud data service platform to provide 7*24h for users across the country. centimeter-level data services.
The vehicle only needs to connect to the cloud service platform through the on-board terminal to obtain service data and transmit it to the terminal’s built-in GNSS chip or module to achieve centimeter-level high-precision positioning on the terminal side.
The following figure is the architecture diagram of the cloud service platform. After the data is collected by the base station, the data is returned to the platform, and the positioning error parameters are analyzed and calculated on the platform side, and the service data broadcast is completed. After the autonomous vehicle receives the service data, the high-precision positioning solution is completed. to improve the positioning accuracy.
For the “cloud” + “terminal” integrated solution, the data services provided by Truepoint Technology mainly include the following:
One is the A-GNSS assisted positioning data service. It includes real-time ephemeris services and predicted ephemeris services, which are mainly used for rapid positioning of vehicles and other carriers to improve user experience. Among them, the real-time ephemeris service can shorten the positioning time from tens of seconds or even tens of seconds to less than 3 seconds, and the predicted ephemeris service can provide up to 14 days of ephemeris prediction data for fast positioning in a weak network environment.
The second is the GNSS enhanced positioning data service, which mainly includes D-GNSS, RTK data service, PPP and PPP-RTK data service, etc. The most important one is RTK data service. Benefiting from the large-scale deployment of reference station networks and the performance advantages of RTK algorithms, RTK data services have been widely used in industries such as smart agriculture, drones, and smart driving. Other types of services have gradually begun to be applied in different industries and scenarios.
In addition, TruePoint can provide high-precision RTK algorithm services, supporting two modes of cloud deployment and device-side integration. Provide integrated high-precision positioning solutions for monitoring industries such as shared bicycles and intelligent driving industries.
The picture above is the test data based on the UM220-INS product in the Bird’s Nest Tunnel and Zhongguancun in 2019. The product is mainly for V2X or in-vehicle navigation application scenarios. The latest test data shows that the positioning efficiency of this product reaches 100%.
For the automatic driving of agricultural machinery, China basically has the automatic driving of agricultural machinery in the four links of farming, planting, management and harvesting. Beidou high-precision satellite positioning products play an important role in the cultivation, planting, management and harvesting of smart agriculture. From 2019 to 2020, the demand for autonomous driving of agricultural machinery has increased by more than 45%. Therefore, there is also a large application demand for Beidou satellite positioning in the field of automatic driving of agricultural machinery.
The picture above is the autonomous driving farming scene of agricultural machinery. Agricultural machinery also relies on precise positioning to achieve autonomous driving in multi-machine collaborative operation and different operation modes. The multi-machine cooperative operation has been realized in the market, which requires precise control of the position and distance between vehicles and precise matching of the forward speed, so that multi-machine cooperative operation can be realized.
The above picture is a real shot of the application of the product on the self-driving vehicle in the closed park. For low-speed unmanned autonomous vehicles, they basically operate in a closed park, but the scene is more complex, such as tall buildings, shade, etc., which have a greater impact on satellite signals. Therefore, there are not only satellite positioning on such vehicles, but also a series of sensors such as radar and cameras to assist.
The calibration of the sensor relying on the GNSS satellite positioning results can accurately locate the starting position of the vehicle, so the efficiency, accuracy and precision of the GNSS positioning are very important for the vehicle. The above picture shows the driving path of the product in the closed park, the two pictures on the right show the self-owned product above, and the following is the trajectory of the internationally renowned product. The place for comparison and annotation is the lack of trajectory.
As we all know, the realization of autonomous driving is inseparable from high-precision maps. The collection of high-precision maps requires Beidou high-precision satellite positioning as a base station. At the same time, combined with other sensors, it can realize the perception of road signs, roads and scenes to form accurate and high-precision maps.
The above picture is the application scenario and Display for L3 and above autonomous vehicles. We integrate high-performance inertial navigation devices into high-precision GNSS positioning. To meet the application requirements of the vehicle at the L3+ level, the actual test vehicle remained in the lane after driving through a 2.8-kilometer tunnel. The picture above is the test map in Chongqing. The vehicle has passed through a 2.8-kilometer tunnel and its display line is still very coherent.
In the future, Hexinxingtong will continue to focus on building the core sensor of autonomous driving – satellite positioning chip, to provide accurate time and space information for autonomous driving.
Q1. In addition to the impact of occlusion, does the application of satellite positioning in autonomous driving face other challenges?
Dao Liyang: In addition to occlusions and tunnels, which have a relatively large impact on satellite positioning, they will also be interfered by signals from TV stations and high-power radio stations. These interference signals may cause the GNSS positioning module to fail to locate properly. This is mainly because the satellite signal is sent to the ground from more than 20,000 kilometers of outer space. After the ionosphere and troposphere delay, the satellite signal reaches the earth’s surface very weakly, and the satellite signal is submerged in the noisy radio signal, so the satellite signal is also easy to Affected by surrounding electromagnetic waves. But the reason why the satellite signal can be identified is because the satellite signal is based on the pseudo-random code (PRN code) encoding method, which has its particularity. In addition, spoofing signals can also affect the use of GNSS satellite positioning modules in vehicles.