The automotive safety system is mainly divided into two aspects: active safety system and passive safety system. Simply put, active safety refers to its role in preventing accidents from occurring; Passive safety, on the other hand, refers to the protection provided by a car to its occupants in the event of an accident, or to the protection of a crashed vehicle or pedestrian. If subdivided, the safety of the vehicle body is also included in the aspect of active safety - that is, the resistance of the materials used in the design of the vehicle body structure to external hazards.automotive industry supply So the quality of active safety determines the probability of accidents occurring in a car, while the quality of passive safety mainly determines the severity of injuries to members inside the car after an accident.
The safety design adopted to prevent car accidents and avoid personal injury is called active safety design, such as ABS, EBD, TCS, etc. Their characteristic is to improve the driving stability of cars and do their best to prevent accidents. Other active safety designs include high mounted brake lights, front and rear fog lights,automotive industry services and rear window fog lights.
ABS (Anti lock Brake System)
It detects the rotational speed of each wheel through sensors, and calculates the wheel slip rate by the computer at that time to understand whether the wheel has locked up. Then, it commands the actuator to adjust the brake pressure to make the wheel in the ideal braking state (fast lock but not fully lock).
Correct understanding of ABS function: able to maintain the vehicle from being locked and losing control in emergency braking situations, maintain steering ability,automotive industry solution and avoid obstacles. In general, it cannot shorten the braking distance.
EBD (Electronic Brake Force Distribution System)
It must be used in conjunction with ABS. At the moment of car braking, different ground surfaces attached to four tires are sensed and calculated to obtain friction values. The corresponding braking force is distributed based on the different friction values of each wheel to avoid dangers such as slipping, tilting, and rollover caused by different braking forces of each wheel.
TCS (Traction Control System)
When a car brakes on a smooth road surface, the wheels may slip and even cause direction loss. Similarly, when a car starts or accelerates rapidly, the driving wheels may also slip, and on smooth roads such as ice and snow, it can cause direction loss and become dangerous. TCS is designed to address this issue. It relies on electronic sensors to detect that when the speed of the driven wheel is lower than the driving wheel (which is a characteristic of slipping), it will send a signal to adjust the ignition time, reduce the valve opening, reduce the throttle, downshift or brake the wheel, so that the wheel no longer slips. TCS can improve vehicle driving stability and avoid the danger of excessive acceleration and tailspin loss.
ESP (Electronic Stability Program)
It is actually a traction control system, and compared to other traction control systems, ESP not only controls the driving wheel, but also the driven wheel. It achieves smooth driving of vehicles by actively intervening in danger signals. If rear wheel drive cars often experience excessive steering, and the rear wheels lose control and spin, ESP will slow down the outer front wheels to stabilize the car; When steering too little, in order to correct the tracking direction, ESP will slow down the inner rear wheel, thereby correcting the driving direction.
EBA (Emergency Brake Assist System)
The computer determines the driver's intention to brake this time based on the brake action detected on the brake pedal. If it is an emergency brake, it instructs the brake system to generate higher oil pressure to enable ABS to function, resulting in faster braking force and shorter braking distance.
The safety design adopted to avoid or reduce injuries to personnel in car accidents is called passive safety design, such as seat belts, airbags, front and rear energy absorption zones of the vehicle body, and collision resistant steel beams of the door. They all come into effect after a car accident.
safety belt
It is designed to fix the body of passengers to avoid collisions. There are mainly two types of two-point and three-point styles. The two-point style only fixes the waist of passengers and cannot fix the upper body. Generally, it does not need to be in the front seat. The three-point style adds a diagonal strap to the shoulder to fix the upper body on the basis of the two-point style. There are three fixed points for the strap, which can fix the upper body of passengers and improve safety.
Pre tensioned seat belt: At the moment of a car collision, when the passenger has not yet moved forward, it will first tighten the webbing, immediately tie the passenger tightly to the seat, and then lock the webbing to prevent the passenger from leaning forward, effectively protecting the safety of the passenger. It not only has the function of retracting and retracting the webbing of a regular seatbelt retractor, but also has a control device and a pre tensioning device. Their function is to strengthen the restraint force on passengers in about 0.1 seconds when there is a sharp change in vehicle speed, fix passengers in their seats, and minimize injuries. It can also be classified as active safety.
Airbag (SRS)
When a strong collision occurs at the front of the vehicle, the airbag will instantly "jump" out of the steering wheel and cushion between the steering wheel and the driver, To prevent the driver's head and chest from colliding with hard objects such as the steering wheel or dashboard (airbags do not come out in all sizes of collisions, but have requirements for the force and contact area of frontal collisions. Generally, they only react when a frontal collision occurs at a speed of 40 kilometers per hour or above, as well as when a frontal collision occurs at an angle of approximately 30 degrees to the left and right of the vehicle center).
Working process: When the sensor detects the intensity of the collision, it transmits a signal; The gas generator generates an ignition action based on the signal indication, igniting solid fuel and generating gas (mostly nitrogen) to inflate the airbag, causing it to rapidly expand. When it expands, the airbag immediately deflates, preventing secondary injuries caused by passengers bouncing back after colliding with it. However, it must be noted that the bursting of the airbag has a very short duration, generally speaking, it will only pop up when encountering severe impacts and cannot be retracted. From a practical perspective, the protection of airbags is far inferior to that of seat belts. Moreover, without the use of seat belts, airbags are generally useless in the event of an accident. So the airbag must be used in conjunction with the seat belt to function properly
Side door anti-collision steel beam
When a car is hit by a side impact, the doors are easily deformed due to the impact, directly harming the occupants inside the car. In order to improve the safety performance of the car, one or two very sturdy steel beams are placed in the middle of the door interlayer on both sides of the car. Its function is to: when the side door is hit, the sturdy collision bar can greatly reduce the deformation of the side door, thereby reducing the damage to the passengers inside the car caused by car collisions.
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