Let’s talk about what sensor technologies are used in automotive active safety systems

With the development of society, traffic safety issues are becoming more and more prominent, and traditional car safety concepts are gradually changing. Traditional safety concepts are very passive, such as seat belts, airbags, bumpers, etc. Passive methods are not effective. To solve the occurrence of traffic accidents, with the advancement of science and technology, the safety of automobiles has been refined, so the concept of active safety has been gradually formed and continuously improved.

With the development of society, traffic safety issues are becoming more and more prominent, and traditional car safety concepts are gradually changing. Traditional safety concepts are very passive, such as seat belts, airbags, bumpers, etc. Passive methods are not effective. To solve the occurrence of traffic accidents, with the advancement of science and technology, the safety of automobiles has been refined, so the concept of active safety has been gradually formed and continuously improved.

The so-called active safety actually corresponds to the concept of passive safety. Passive safety focuses on reducing injuries to passengers in the car as much as possible in the event of an accident. For example, airbags and caged bodies are typical passive safety categories. Active safety, on the other hand, focuses on detecting the possibility of an accident or loss of control of the vehicle, so as to avoid it through a series of interventions in vehicle control. Such as anti-lock braking system (ABS), Electronic brake force distribution device (EBD), body electronic stability control system (ESP), traction braking system (TCS), and active cruise and yaw warning in today’s mainstream configurations , automatic braking, etc. are all active safety designs. Their characteristics are to improve the driving stability of the car and try their best to prevent accidents. Others like high-mounted brake lights, front and rear fog lights, and rear window defogging are also active safety designs. At present, the security technology is gradually improving, and more security technologies will be developed and applied. Next, I will introduce the sensor technology used in the safety technology in the automotive active safety system.
car active safety system

Braking Anti-lock Braking System (ABS). It uses the rotational speed of each wheel detected by the sensor, and the computer calculates the wheel slip rate at that time, so as to know whether the wheel is locked, and then instructs the actuator to adjust the braking pressure to make the wheel in an ideal braking state ( Locked fast but not fully). Correct understanding of the ABS function: it can keep the vehicle from being locked and out of control, maintain the steering ability, and avoid obstacles under emergency braking conditions. Under normal conditions, it does not shorten the braking distance.

Let’s talk about what sensor technologies are used in automotive active safety systems

ABS function diagram

Electronic Brake Force Distribution (EBD). It must be used in conjunction with ABS. At the moment when the car is braking, it senses and calculates the different grounds attached to the four tires, and obtains the friction force value. Dangers of slipping, tilting and rollover caused by different wheel braking forces.

Body Electronic Stability Control (ESP). It is also actually a traction control system. Compared with other traction control systems, ESP controls not only the driving wheels but also the driven wheels. It enables the vehicle to drive smoothly by actively intervening in danger signals. For example, the rear-wheel drive car often turns too much. At this time, the rear wheel loses control and drifts, and the ESP will slow down the outer front wheel to stabilize the car; when the steering is too small, in order to correct the tracking direction, the ESP will put Slow the inner rear wheel to correct the driving direction.

Adaptive Cruise Control (ACC). The radar sensor is used to monitor the distance between the vehicle and the vehicle (object) in front in real time, and then remind the driver to keep the distance.

Blind Spot Monitoring (BSD). The 24GHZ radar sensor is used to detect whether there are pedestrians or other vehicles in the blind area of ​​the vehicle, and then alarm.

Brake Assist (EBA). The computer judges the driver’s intention to brake according to the braking action detected on the brake pedal. If it is an emergency brake, it will instruct the brake system to generate higher oil pressure to make the ABS work, so that the braking force can be applied more quickly. generated, shortening the braking distance.

Lane Departure Warning System (LDWS). The system provides intelligent lane departure warning. When the driver deviates from the original lane unintentionally (the driver does not turn on the turn signal), it can send an alarm 0.5 seconds before leaving the lane, providing the driver with more reaction time and greatly reducing the risk of lane departure. In addition, the use of LDWS can also correct the driver’s habit of not turning on the turn signal. The main function of the system is to assist the inattention caused by excessive fatigue or prolonged monotonous driving.

Let’s talk about what sensor technologies are used in automotive active safety systems

lane departure warning system

Tire pressure monitoring system. The National Highway Traffic Safety Administration (NHTSA) has mandated that as of 2003 all U.S. passenger vehicles with a product weight of 4,536 kg or less must be equipped with a tire pressure monitoring system, which BMW has since used in in all cars. The driver can judge whether the tire pressure is normal through the in-vehicle warning system. First, it avoids the driving deviation caused by the lack of tire air, and secondly, it is a guarantee for the safety of the occupants when driving at high speed.

Let’s talk about what sensor technologies are used in automotive active safety systems

Tire pressure monitoring sensor

Reverse image. Reverse Warning This technology is used to warn you of cars or objects in your blind spot while driving and while parking. Typically, the system will already respond while you are driving; it may flash a warning sign in the rearview mirror, along with an audible warning, and the system is a short-range detection system. Such as: Shanghai GM Buick LaCrosse interior rearview mirror is equipped with this function, there will be a car body-shaped icon on the left side of the mirror, and the front/rear radar will warn the driver when detecting obstacles. warn. The reversing camera and rearview camera are integrated to not only protect your car, but also prevent accidental injury to children and animals while reversing. Reversing has gone from tilting the mirrors down or sounding an audible warning to Live View. The new generation of technology includes a camera that works in tandem with the navigation system to take a wide-angle shot of everything behind you, which is then reflected on an interior screen to help you back up or hitch a trailer.

Chip anti-theft system. Property safety has also been paid more and more attention by people. The theft of a car with hundreds of thousands of dollars will cause great losses to the owner. Manufacturers are also racking their brains to add more security systems to cars. The GM Buick LaCrosse not only added the Passkey III security anti-theft system to the ignition key, but also improved the structure of the rear trunk, and changed it into a remote-controlled anti-theft mode without a lock cylinder, which greatly reduces the probability of being stolen and pryed, and provides the owner with property damage. Maximum protection.

Auto-sensing headlights. The auto-sensing headlights are affected by the ambient light around the vehicle, and the system will automatically identify and judge. In rainy and foggy weather, the light is not enough, the headlights will automatically turn on to provide the driver with a safer driving environment. Later manufacturers extended to adaptive headlight systems, which are more advanced systems that adjust for direction (turning the lights when the vehicle turns). They can also be speed-sensitive lights (which can change the length or height of the beam), or compensate for ambient light.

Night vision systems can come in different forms, such as basic infrared headlights or thermal imaging cameras. But no matter what technology is used, the effect is the same: at night or when the line of sight is unclear, it helps to see further out on the road and identify animals, people or trees on the road up to 1,000 feet away. The image is formed on the Display screen in the cab, so that the obstacles that are difficult to see with the naked eye are controlled by the driver in advance. At present, the night vision system developed by Bosch has the above functions, but the price is very expensive, even for ultra-luxury cars. It is also basically an optional system. It is believed that this more advanced system will also be used by mid- to high-end sedans in the near future.

The Links:   LTM12C275A CM1000HA-25H