What are the two manifestations of light and backlight？ Measuring Geely Xingrui Active Braking

　　[car home Active Emergency Braking Test] Looking back on this year, although the number of new cars tested in our program Active Emergency Braking Test declined slightly due to the epidemic situation, several cars tested this year are quite representative, such as the Weilai ES8 with a three-eye camera and millimeter-wave radar, and the brand-new Honda Fit with only a monocular camera. Originally, I thought this year’s test was over, but in last week’s test, the test results of a brand-new Geely (|) surprised me, and almost all of them failed in the rear-end static fake car project. What was the situation? Now listen to me slowly.

◆ Benchmark Civic, Geely Xingrui on the same platform as Volvo XC40.

　　This car of Geely Xingrui was mysterious at first, but it has been in a half-hearted situation in the second half of this year. After the official appearance at the Beijing Auto Show, his fame soared, and he once entered the top ten in car home’s attention ranking.

　　The driving quality is excellent, and the technology is also very interesting. From the price point of view, from the official price of 139,700 sub-top models to the top model of 149,700, the driver assistance function has been configured.

　　In terms of configuration coverage, the mainstream L2 driver assistance functions are all configured. Compared with overseas brands, L2 driver assistance functions are generally configured above 200,000, which is full of sincerity.

◆ Introduction of Geely Xingrui Driver Assistance Function

　　At present, Geely Xingrui has not given a unified name to its driver assistance function, so we will describe Xingrui’s active safety system with driver assistance function below.

　　From the technical route, this is a very obvious route of sensor fusion. Theoretically speaking, this technical route is more costly than the pure monocular camera route that is common in the middle and low-priced market at present, and at the same time, it has stronger ability to cope with bad weather, and the misjudgment will be reduced because of the double comparison between radar and camera, thus improving the accuracy of judgment.

　　Let’s take a look at the actual test.

◆ Simulated rear-end static fake car test

　　　According to the test flow, we drive the test vehicle to 10km/h, 20km/h, 30km/h, 40km/h and 50km/h respectively, and then keep a certain constant speed to see if the vehicle can stop in front of the simulated vehicle to avoid collision. In the test, below 30km/h simulates the reaction ability of the system in the low-speed driving stage of the community, while above 30km/h tests the system reaction in the daily driving process. Below, let’s learn about the whole test through a video.

　　We first test according to the normal scene in the past. During the test, it was in winter in Beijing, the closed test site was in the north-south direction, and the vehicles were driving from north to south. Therefore, during the test (in the morning), the actual scene would be backlit. In fact, all our previous tests were conducted on sunny mornings, so the light environment of different models was roughly the same.

More exciting videos are all on the car home video platform.

　　After continuing to improve the test speed, Xingruika finally reached 30km/h, and when the speed exceeded 30km/h, the system could not effectively identify the obstacles ahead.

　　Immediately, I consulted the electronic manual of Xingrui. We found that the working range of AEB (active emergency braking) is 4 km/h-150 km/h. Among them, when facing the stationary front vehicle, the working speed is 4-85km/h, and when facing the moving vehicle in front, the working interval can be expanded to 4-150 km/h. Therefore, from the working range, our test conforms to the working range of Xingrui active emergency braking.

　　Then, considering the weather conditions of the day, we think it is possible that the angle of direct sunlight (equivalent to the backlight scene) has an impact on the forward-looking camera.In order to verify this conjecture, we conducted a smooth test.

More exciting videos are all on the car home video platform.

　　First of all, at low speed, it is still impossible to judge at 10km/h, but since 15km/h, Xingrui’s active emergency braking system has started to work stably, from early warning to automatic braking.

　　In the rear-end collision test, we can obviously find that the light has a great influence on the camera. In the case of backlight in the morning, there is a great chance of "blindness". When facing static objects, camera recognition is the main judgment basis of the system, so the system will default to the obstacle-free vehicles in front, and the automatic braking will not start at this time.

　　In the case of smooth lighting, the system will operate well, and the working logic of the whole system is also very clear, and repeated tests have not affected its functional performance. We preliminarily judge that Xingrui has no problem in the algorithm of driver assistance system, but the performance of monocular camera may have a certain drag on the system.

◆ "Pedestrian" collision test article

　　In addition to vehicles, Geely Xingrui’s active emergency braking system also introduces the judgment of pedestrians. Compared with vehicles on the road, pedestrians have greater flexibility, smaller size and complex shape, so they have higher requirements for the computing performance of the system and the capture of the camera. The system can neither misjudge the sudden braking nor "turn a blind eye", which will be more difficult. Because the pedestrian test was carried out after the rear-end stationary fake car was completed, the lighting environment of the test site was noon and afternoon, and the backlight situation improved. Therefore, we think that the "pedestrian" test will be relatively stable. The following test results are indeed as we expected:

Write at the end:

　　After this test, we make an analysis and guess on the active emergency braking function of Geely Xingrui. From the overall configuration, Geely Xingrui’s active safety system is rich in functions, and the common L2 driver assistance functions have been covered, which is worthy of recognition. But many functions do not mean that each function can reach a good level, such as active emergency braking function.

　　Although this function of Xingrui adopts the technical route of camera+millimeter wave radar with higher cost and higher technical requirements, the function is too sensitive to light, and the backlight scene during the day may cause the camera to be "blind" and the system has no corresponding prompt at this time, which leads to a decrease in the degree of obstacle recognition. On the other hand, the visual range of the camera to the environment also has room for upgrading, and there is a certain chance that the dummy will not be recognized in the ghost probe test.

　　Generally speaking, at present, the active emergency braking function of Geely Xingrui has room for upgrading from algorithm to hardware, and it is hoped that Xingrui can continuously improve this system and bring consumers a better product experience. (Photo/Text Photo by car home Leng Xiaoyang/Tang Dynasty)