Active brake/active safety system

[WapCar] The active braking function refers to the normal driving of the vehicle under non-adaptive cruise conditions. For example, when the vehicle encounters a sudden dangerous situation, it can actively generate a braking effect to slow the vehicle, thereby improving the safety of driving. (But a vehicle with this function may not be able to stop the vehicle completely).

According to different names of each car manufacturer, there are also the Pre-crash System, the Forward Collision Warning System, the Collision Mitigating System, and the Pre-Collision System, Collision Mitigation Brake System, etc.

Working Principle

Active brake safety technology is mainly composed of three modules, including control module (ECU), distance measurement module and brake module. The core of the ranging module includes microwave radar, face recognition technology and video system, etc., which can provide safe, accurate, real-time images and road condition information on the road ahead.

First use radar to measure the distance to the vehicle or obstacle in front, and then use the data analysis module to compare the measured distance with the alarm distance and safety distance. If the distance is less than the alarm distance, an alarm will be given. When the distance is less than the safety distance, even if the driver does not have time to step on the brake pedal, the system will start to make the car brake automatically, thus escorting the safe travel.

Measured active brake

Standard introduction

After referring to the relevant experimental standards of international safety testing agencies and combining some common accident cases on the road, we divided the active emergency braking test into two major items: the anti-collision braking test and the pedestrian detection test, and the vehicle AEB system is considered separately The ability to recognize the vehicle ahead and pedestrians crossing the road, and the ability to control the speed of the vehicle.

In addition, many brands or models currently have high-end driving assistance systems, such as Tesla’s Autopilot, etc. These systems integrate multiple driving assistance functions including AEB, and can reach the second-level autonomous driving level in accordance with relevant industry standards. It should be noted that these systems can only be used as an aid and supplement to the driver's operation during driving. In order to achieve the uniformity of test standards and ensure fairness and impartiality, we only test the Active Emergency Braking System (AEB) and will not turn on other driving assistance systems.

-Anti-collision braking test

In this test session, we use an inflatable model as the "target vehicle" in a rear-end collision, that is, the party being rear-end collision. The test vehicle will drive from directly behind the model at a speed of 10-50km/h to investigate the whether the car can recognize obstacles ahead, issue warnings and apply braking. We will test the performance of the vehicle at six sets of speeds of 10km/h, 20km/h, 30km/h, 40km/h, 45km/h and 50km/h. Each set will be tested 5 times to determine whether the system can avoid or effectively reduce the collision as an evaluation conclusion.

-Pedestrian detection test

In this test session, we set up three scenes: 1. The dummy is standing still in front of the vehicle's driving route to check whether the vehicle can recognize stationary pedestrians and issue warnings and apply braking; 2. If the first scene passes successfully, it will enter the test of the second scene, that is, the dummy props cross the vehicle movement route horizontally, simulate the scene of pedestrian crossing the road, and examine the detection range and reaction speed of the system.

If the test car successfully passes the tests of the first two scenes, then the third additional scene will be tested, the "ghost probe" scene. The difficulty of this scene is relatively high, so it serves as a "plus point" for the entire test. The test speed of all scenes is 30km/h, each scene is tested 5 times, and the evaluation conclusion is based on whether the system can avoid or effectively reduce the collision.