A brief analysis of automotive radar and driving safety

What is Automotive Radar

Automotive radar is the core sensor of the driver assistance system (detection distance, speed). The long-range radar (LRR) is used to realize automatic cruise control (ACC), the medium-range radar (MRR) is used to realize side vehicle warning and lane change assistance, and the short-range radar (SRR) is used to realize parking assistance, obstacle and pedestrian detection.

In the intelligent transportation system, automotive radar detects vehicle speed and distance through radio waves. It can stably detect targets even in adverse weather conditions such as rain and snow. It is usually installed at the front and rear ends of motor vehicles to implement functions such as adaptive cruise control (ACC) and vehicle collision avoidance warning. It can help drivers better perceive and understand the situation around the vehicle, thereby improving driving safety.

The role of automotive radar

(1) Improve driving safety.

(2) Inform the driver of surrounding obstacles by sound or more intuitive display.

(3) It relieves the driver from the trouble of looking around when parking, reversing and starting the vehicle, and helps the driver eliminate blind spots and blurred vision.

Radar technology, committed to improving driving safety

Automotive radar and driving safety

At present, there are three main types of radars used in automobiles: lidar, ultrasonic radar and millimeter-wave radar. It is one of the auxiliary means for safe driving of automobiles and plays an important role in automobile driving safety.

For example, reversing is an inevitable thing in our lives, and every successful reversing is inseparable from the reversing radar. What does the reversing radar help us with?

It will inform the driver of surrounding obstacles through sound or more intuitive display, relieving the driver of the trouble caused by looking left and right when reversing, and helping the driver to eliminate blind spots and blurred vision, thereby improving reversing safety.

The reversing radar is composed of an ultrasonic sensor (commonly known as a probe), a controller, and a display (or buzzer), as shown in Figure 1. The reversing radar generally uses the ultrasonic ranging principle. The sensor emits an ultrasonic signal under the control of the controller, and generates an echo signal when encountering an obstacle. After the sensor receives the echo signal, the controller processes the data, determines the location of the obstacle, displays the distance, and issues other warning signals, thereby achieving the purpose of safe parking. Figure 2 is a working principle diagram of the reversing radar.

Some time ago, the first low-speed collision test of LiDAR by BAIC Research Institute under BAIC Group was successfully completed, providing technical support for the safety verification of BAIC's high-end intelligent driving vehicles.

The main working principle of LiDAR is to emit a laser beam (single-line/multi-line) to the target, then compare the reflected signal with the transmitted signal, and analyze the signal's return time (TOF) or frequency difference (Doppler shift) to obtain relevant parameters such as target distance, and even derive target posture, shape and other information. It is widely used in autonomous driving, smart cities and other fields.

LiDAR is an important component of the perception system of high-end intelligent driving vehicles. The installation points of the front perception radar are located in the middle and on both sides of the vehicle bumper. Daily collisions and extrusions may cause the LiDAR carrier components to deform, resulting in reduced test accuracy, or even direct damage to the radar body, seriously affecting driving safety. In combination with the vehicle usage scenario, in order to verify the reliability of LiDAR under low-speed collisions, the test verification team of BAIC Research Institute conducted in-depth research on the low-speed collision test method of the LiDAR system, and fully carried out verification preparations such as designing and manufacturing pendulum tooling, loading measurement, setting collision speed and position calibration. During the collision, the vehicle was equipped with 3 LiDARs, 7 millimeter-wave radars and 4 surround-view cameras to fully perceive and identify the surrounding environment, speed and other information. After the collision, the intelligent driving performance of the vehicle was intact.

The success of the lidar low-speed collision test is a small step in verifying the quality of product design and development, and a big step towards the goal of high-safety driving.