Automotive Active Safety Equipment and Passive Safety Equipment

Active Safety Equipment for Automotive Safety

Disc brakes

Disc brakes, also called disc brakes, are named after their shape. It is controlled by hydraulic pressure. The main components are brake discs, sub-pumps, brake calipers, tubing, etc. The brake discs are made of alloy steel and are fixed to the wheels and rotate with the wheels. The sub-pump is fixed on the bottom plate of the brake, and the two friction plates on the pliers are respectively installed on both sides of the brake disc. The piston of the sub-pump is acted on by hydraulic pressure from the tubing to push the friction plate to the system. The frictional brakes of the moving discs act as if they were used to clamp the spinning plate and force it to stop.

Disc brakes provide fast heat dissipation, light weight, simple construction, and easy adjustment. In particular, the high-temperature performance at high load is good, the braking effect is stable, and the mud is not afraid of attack. In winter and bad road conditions, the disc brake is more likely to stop the vehicle in a shorter time than the drum brake. Some disk brakes also have a number of small holes in the brake disk to accelerate ventilation and improve braking efficiency.

Anti-lock brake system (ABS)

ABS is an acronym for Anti-lockBrakingSystem. The earliest ABS system in the world was first applied to aircraft and later became standard equipment for limousines. Nowadays, most cars are equipped with ABS. As we all know, you can't step on the brakes when you brake, but you should brake step by step, step on and off until the car stops, but when it comes to emergency braking, you often need the car to stop and you really want to stop the car. At this time, because the wheels are prone to lock up and do not rotate, so that the car has a dangerous working conditions, such as the front wheel locking caused the car to lose the ability to turn, the rear wheel locking and easy to flick tail accidents. The installation of ABS is to solve the problem of locking the wheels when braking. The car equipped with ABS can effectively control the wheels to remain in the state of rotation without locking, which greatly improves the stability of the car when braking and the poor road surface. Car braking performance under conditions. ABS continuously detects the rotation speed of each wheel through a speed sensor installed on each wheel or drive shaft, and the computer calculates the wheel slip ratio at that time (it is known from the slip rate whether the wheel of the car is locked). The slip ratio is compared to make a decision to increase or decrease the brake pressure, and the command actuator adjusts the brake pressure in time to keep the wheel in an ideal braking state. Therefore, the ABS device can always maintain the wheel in a rolling state with slight slip, and does not lock, so as to improve the braking performance.

Electronic brake force distribution system (EBD)

EBD can automatically adjust the braking force distribution ratio of front and rear axles based on the difference in axle load transfer caused by the braking of the vehicle to improve the braking performance and to improve the braking stability with ABS. When the car is braking, the ground conditions on which four tires are attached are often different. For example, sometimes the left front wheel and the right rear wheel are attached to the dry concrete floor, while the right front wheel and the left rear wheel are attached to water or muddy water. This will result in the four wheels and the ground when the car is braking. Friction is not the same, which can cause slipping, tilting, and rollover accidents when braking. EBD uses a high-speed computer to sense and calculate the different grounds on which four tires are attached at the moment of vehicle braking. Different friction values ​​are obtained, so that the braking devices of the four tires are used in different ways according to different situations. The power is braked and constantly adjusted at high speed during the movement to ensure the smoothness and safety of the vehicle.

Traction Control System (TCS)

TCS is also called tracking control system. When the car is braking on a smooth road, the wheels can slip and even lose direction. Similarly, when a car starts or accelerates rapidly, the driving wheels may also slip, and on a smooth road such as ice and snow, the direction may be out of control and dangerous. T<蹯÷ is designed for this problem. When the TCS relies on an electronic sensor to detect that the speed of the driven wheel is lower than the driving wheel (this is a characteristic of slip), it will send a signal to adjust the ignition timing, reduce the valve opening, reduce the throttle, downshift or brake the wheel. So that the wheels no longer skid. TCS can improve the car's driving stability, improve acceleration, and improve climbing ability. The original mining only installed TCS on limousines, and now also on many ordinary cars. If TCS and ABS cooperate with each other, it will further enhance the safety performance of the car. TCS and ABS can share the wheel speed sensor on the axle and connect with the driving computer to constantly monitor the rotation speed of each wheel. When the slip is found at low speed, TCS will immediately notify the ABS to reduce the slipping of this wheel. If slippage is found at a high speed, TCS immediately sends instructions to the trip computer to command the engine to slow down or the transmission to downshift, so that the slipping wheels no longer skid and prevent the vehicle from running out of control.

Electronic Stability Device (ESP)

The Electronic Stability Device (ESP) was first applied by Mercedes-Benz to its A-Class. ESP is actually a traction control system. Compared with other traction control systems, ESP not only controls the driving wheels, but also controls the driven wheels. If rear-wheel drive vehicles often experience excessive steering, then the rear wheels will lose control and flick their tails, ESP will brake the outer front wheel to stabilize the car; when the steering is too little, the ESP will brake to correct the tracking direction. Slow the rear wheel to correct the direction of travel.

Smart Air Conditioner

The intelligent air conditioning system can analyze, judge, and automatically turn on cooling, heating, dehumidification, and air in accordance with the external climate conditions, according to preset indicators, signals sent from the temperature, humidity, and air cleanliness sensors installed in the vehicle. Purification and other functions. In advanced safety vehicles, the air-conditioning system is also combined with other systems (such as the driver's doze alarm system). When the driver is found to be insane and there are signs of dozing, the air conditioner can automatically emit a sober scent.

smart key
Mercedes-Benz CLK has adopted a smart key, which can emit infrared signals, can open one or two doors, trunk and fuel filling hole cover, but also can manipulate the car's windows and skylights, more The advanced smart key is like a credit card. When the driver touches the door handle, the central lock control system starts working and sends a wireless inquiry signal. After the smart key card responds correctly, the lock is automatically opened. The engine will only start when the CPU senses that the key is stuck in the car.

Anti-glare rearview mirror

The anti-glare rearview mirror is generally installed in the carriage. It consists of a special mirror, two photodiodes and an electronic controller. The electronic controller receives the forward and backward light signals sent by the photodiode. If the illumination light shines on the interior rearview mirror, if the rear light is larger than the front lighting, the electronic controller will output a voltage to the conductive layer. The voltage on the conductive layer changes the color of the mirrored electro-chemical layer. The higher the voltage is, the darker the electro-deposition layer is, and even if strong illumination light shines on the rear-view mirror, it is reflected by the anti-glare interior rearview mirror to the eyes of the driver. On the display is dark, not dazzling. The mirror electro-active layer causes the reflection i11 to automatically change continuously to prevent glare, depending on the incident intensity of the rear light. When the vehicle is reversing, the glare-proof function of the anti-glare interior mirror is released and the right exterior mirror automatically illuminates the ground.

High brake lights

The general brake lights (brake lights) are installed on both sides of the rear of the vehicle. When the driver depresses the brake pedal, the brake light is on and a red light is emitted to remind the rear vehicle to pay attention and not to rear-end. The brake light goes out when the driver releases the brake pedal. The high brake light is also called the third brake light. It is usually installed in the upper part of the rear of the car so that the rear vehicle can detect the vehicle ahead of time and apply braking to prevent car rear-end accidents. Since the car has two left and right brake lights, it is customary to also refer to the upper brake light installed in the upper part of the rear of the vehicle as the third brake light.

Rain sensor

The rain sensor is concealed behind the front windshield. It can adjust the action of the wiper according to the amount of rain falling on the glass, thus greatly reducing the troubles of the driver.

The rain sensor does not change the speed of the wiper with a few limited gears, but adjusts the speed of the wiper steplessly. It has a light emitting diode called LED that is responsible for sending far-infrared rays. When the glass surface is dry, the light is reflected almost 100% back, so that the photodiode can receive a lot of reflected light. The more rain on the glass, the less light is reflected back and the faster the wiper moves.

Passive Safety Equipment for Automotive Safety

Side door bumper

As we all know, when the car is hit by a side impact, the door is easily deformed by impact and directly injure the occupants in the vehicle. In order to improve the safety performance of automobiles, many automobile companies place one or two very strong steel beams in the middle of the door sandwich layer of the car. This is the so-called side door anti-collision bar. The anti-collision effect of the anti-collision bar is: when the side door is impacted, the solid anti-collision bar can greatly reduce the degree of deformation of the side door, thereby reducing the impact of the car impact on the occupants in the car.

Safety body
In order to reduce the occupant’s casualties in the event of a car crash, the body of the passenger compartment is designed to reinforce the passenger compartment and weaken the head and tail of the vehicle. When the car collides, the head or tail is flattened and absorbs the collision energy at the same time, and the cabin is not deformed to ensure the safety of the occupants.

Safety glass

Safety glass has two types of tempered glass and laminated glass. Tempered glass is a high-strength glass in which glass is rapidly cooled to produce pre-stress when the glass is in a hot state. When the tempered glass is broken, it is broken into many small pieces without sharp edges, which is not easy to hurt. There are three layers of laminated glass. The middle layer has strong toughness and adhesion. When it is destroyed by impact, the inner layer and the outer layer still adhere to the middle layer, making it difficult to hurt people. Laminated glass for automobiles has been doubled in thickness and has been widely adopted because of its better safety.

Preloaded seat belt

Preloaded seat belts are characterized by the fact that when a car crashes, if the occupant has not moved forward, it will first tighten the webbing, immediately fasten the occupant tightly to the seat, and then lock the webbing to prevent the occupant from getting in front of the body. Dump, effectively protect the safety of the occupants. The retractor, which plays a major role in the pre-tensioned seat belt, is different from an ordinary seat belt. In addition to the retracting and retracting function of an ordinary retractor, it also has the effect of restraining the occupant at around 0.1 s when the speed of the retractor changes abruptly. Force, so it also has control devices and pre-tensioning devices.

There are two types of control devices: one is an electronic control device and the other is a mechanical control device. Pre-tensioning devices come in a variety of forms. The common pre-tensioning device is an explosion-ignition type consisting of a gas initiator, a gas generating agent, a conduit, a piston, a rope, and a drive wheel. When the pre-tensioning device is activated when the car is impacted, the gas initiator in the bottom of the sealed pipe immediately ignites spontaneously and detonates the gas generating agent in the same sealed conduit. The gas generating agent immediately generates a large amount of gas expansion, forcing the piston to move upward to pull the rope. The rope drives the driving wheel to rotate the number driving wheel to rotate the retractor drum, the webbing is wound on the drum, and the webbing is pulled back. Finally, the retractor locks the webbing in an emergency and secures the body of the occupant, preventing the body from leaning forward to avoid colliding with the steering wheel, dashboard, and glass windows.

Airbag (SRS)

Airbags are an attractive high-tech device on modern cars. The car steering wheel with the airbag device installed is usually no different from the ordinary steering wheel. However, once a strong collision occurs at the front of the car, the airbag will instantly “snap” out of the steering wheel and place it between the steering wheel and the driver. The driver's head and chest hit a hard object such as a steering wheel or dashboard. Since the advent of airbags, many lives have been saved. Studies have shown that frontal cars with airbag installations have suffered a frontal collision, the driver’s death rate has been reduced by 30% for large cars, 11% for medium-sized cars, and 14% for small cars.

Airbags mainly consist of sensors, microprocessors, gas generators, and airbags. The sensors and microprocessors are used to determine the degree of collision and transmit and send signals. The gas generator generates ignition action according to the signal indication, ignites the solid fuel and inflates the gas to the airbag to rapidly inflate the airbag. The capacity of the airbag is approximately (50-90)L. . At the same time, the air bag is provided with a safety valve. When the air bag is over-inflated or the pressure in the bag exceeds a certain value, part of the air is automatically vented to avoid crushing passengers. The gas used for airbags is mostly nitrogen or carbon monoxide. In addition to airbags on the driver’s side, some passenger cars have airbags installed in the front row (ie, dual airbags). Passengers use similar airbags, but the airbags are larger. The gas is also more. In addition, some cars also have side airbags installed on the side of the seat on the side of the door.

Smart airbag

The smart airbag is based on the common type of sensor to detect whether the occupant of the seat is a child or an adult. What is the height of the seat belt and the position of the seat belt? By collecting these data, the expansion of the airbag is analyzed and processed by the computer software to make it function optimally to avoid unnecessary expansion of the airbag, thereby greatly improving its safety. Smart airbags have two more core components than the common ones, namely sensors and their associated computer software.

Currently used sensors mainly include: weight sensors, based on the perception of the weight of the seat, whether adults or children; electronic area sensors. Can produce a low-energy electronic zone in the cab, measure the current through the area to determine the presence and location of the occupant; infrared sensor, according to the heat detection of human presence, to distinguish from inanimate things; optical sensors. If the same camera looks at the seat and compares it with the stored image of the empty seat to discriminate between the presence and the position of the human body; the ultrasonic sensor, which detects the occupant’s Presence and location.

Another important task in the design and development of smart airbags is the development of computer software. In general, computer software should be able to react to changes in the moment of the occupant’s size, body weight, seatbelt position, position of the person in the seat, vehicle speed at the time of the collision, and the degree of impact. The time, speed, and degree of inflation of the airbag allow the airbag to provide the passenger with the most reasonable and effective protection, and in particular, to reduce injuries to children, such as short persons.

Occupant Head and Neck Protection System (WHIPS)

WHIPS is generally installed in the front seats. When the car is impacted by the rear, the head and neck protection system will quickly inflate and inflate. The entire backrest will lean back with the occupant. The occupant's entire back and backrest will be securely close together, and the backrest will lean back to maximize the backrest. Reducing the force of the head forward and backwards, the seat back and headrest will move horizontally backwards, so that the upper body and head can be supported and protected softly and evenly to reduce the impact on the spine and neck. Force and prevent the head from throwing back.