As a means of transportation for modern humans, cars have changed people's lifestyles, promoted the development of social economy and the progress of human culture, and become an indispensable means of transportation in society. However, with the increasing number of automobiles, automobiles also bring about social problems such as environmental pollution, energy consumption, and traffic safety. Among them, automobile road traffic safety issues are particularly prominent. There are about 1.2 million deaths from road traffic accidents in the world each year. In China, about 100,000 people died in road traffic accidents each year, and the direct economic losses amounted to several billion yuan.
As automobile accidents continue to occur, causing major social harm, which has attracted the attention of all countries in the world, automobile safety has become a global social problem. Countries have adopted a series of measures to reduce traffic accidents and casualties, and achieved good results. Especially in recent years, electronic technology has been widely used in automobiles, equipped with electromechanical products such as ABS, ASR, ESP, SRS and VDC. The safety performance of automobiles has been greatly improved. Although the number of automobiles in China is increasing, traffic accidents have caused death The number of people is declining, which shows that advanced automotive electronic technology can improve the safety performance of automobiles and reduce the occurrence of traffic accidents.
1. The content and influencing factors of automobile safety
(1) The content of automobile safety
Automobile safety is generally divided into active safety, passive safety, post-accident safety and ecological safety.
1. Active safety of the car
The active safety of a car refers to the ability to control the braking or steering system to prevent accidents when an accident is about to occur, and the ability to ensure the power, stability, driving comfort, and normal information of the car during normal driving. It can be divided into driving safety, environmental safety, perceived safety, and operation safety.
2. Passive safety of cars
Passive safety of cars refers to the ability to protect occupants and pedestrians in the event of an accident and minimize direct losses. It can be divided into external safety and internal safety.
3. Post-accident safety
Post-accident safety refers to the ability of a car to mitigate the consequences of an accident. Refers to whether the consequences of the accident can be quickly eliminated and new accidents can be avoided.
4. Ecological security
Ecological safety refers to the impact of engine exhaust pollution, automobile driving noise and electromagnetic waves on the environment. Its content is shown in Figure 1.
(2) Factors affecting automobile safety
Automobile road traffic accidents are a worldwide disaster, so automobile traffic safety is also a worldwide problem. Road traffic accidents have caused casualties and property losses, and have also caused huge losses to the national economy. However, the factors that induce traffic accidents are multi-faceted. It is affected by factors such as vehicle speed, road conditions, vehicle conditions, driver behavior, driver's cultural quality, and natural environment. Among them, people, cars, roads, and environmental conditions are the main factors affecting road traffic safety. The relationship between them is shown in Figure 2.
In the road traffic system, people are the core of the system, and roads are the foundation of the system. The influence of human factors mainly refers to the personality, experience or status of direct traffic participants. The influence of road factors refers to the direction of the route, the condition of the road surface, the arrangement and clarity of traffic signals, as well as traffic rules and traffic management measures. The influence of the car itself refers to the vehicle structure and technical status. The influence of environmental condition factors refers to the mental influence of the environment on people (fatigue, reaction ability), the influence on road factors (rain, snow, wind, fog) and the physical influence on cars (road attachment conditions, steering characteristics, etc.). If the environmental conditions are included in the range of road influence factors, it can be considered that road traffic safety is mainly related to the "driver-car-road" system. The automobile is the most potentially critical part of the system, so applying advanced electronic technology to improve the safety of the automobile is an effective way to reduce road traffic accidents.
Second, the application of electronic technology in car driving safety
In recent years, car ownership has increased rapidly, and car safety has become a matter of greatest concern to people. In order to protect the safety of people ’s lives and property, government departments have formulated relevant road traffic safety regulations. In order to meet safety regulations and consumers ’requirements for automobile safety, automobile manufacturers have taken various measures to improve the safety performance of automobiles. Played a great role. Electronic technology to improve car safety is mainly manifested in the following aspects.
(1) Active safety electronic technology
The typical electronic control devices of modern automotive active safety electronic technology include anti-lock braking system (ABS), electronic braking force distribution device (EBD), drive anti-skid system (ASR), electronic stability program system (ESP), electronic Controlled suspension system, electronically controlled power steering system, active collision avoidance system, vehicle dynamics control system (VDC), information display system, etc.
1. Automobile anti-lock brake system
AnTI-LockBraking System (ABS) is an active safety device that prevents the wheels from locking during the braking process. During braking, the ABS system senses the slip between the wheels and the road through sensors, and the ABS electronic control unit makes the judgment, and adjusts the braking force through the solenoid valve to keep the tire slip rate in an ideal range (10% ～ 20%), to ensure that the vehicle has a large longitudinal braking and anti-side force, to prevent possible rear wheel slip, tail flick, improve the direction of the car during braking and steering The ability to manipulate and improve the utilization of the adhesion coefficient, shorten the braking distance and reduce tire wear. Electronically controlled automobile anti-lock brake system is one of the effective measures to improve vehicle safety.
2. Automobile anti-skid system
Automobile anti-skid system (ASR) is to control the slip rate within a certain range (5% ~ 15%) when the car starts and accelerates, to prevent the driving wheel from slipping quickly and improve the driving force of the car. In ASR control, the signal fed back through the wheel speed sensor is processed by the control unit to issue a command to adjust the output torque of the engine, thereby adjusting the driving torque of the driving wheels. At present, most of the ASR equipment is realized by adding some components to the ABS system, which can be regarded as the improvement and supplement of the ABS system.
3. Automotive electronic braking force distribution system
When a car brakes, the ground conditions where the 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 ground, while the right front wheel and the left rear wheel are attached to the water or muddy water. This situation will cause the four wheels to contact the ground when the car brakes The friction force is different, and it is easy to cause slip, tilt and vehicle rollover accidents when braking. The electronic braking force distribution system (EBD) can automatically adjust the ratio of the braking force distribution of the front and rear axles according to the difference in axle load transfer when the car brakes, improve braking efficiency, and cooperate with the ABS system to improve braking stability.
4. Automotive electronic stability program system
ESP is the abbreviation of Electronic Stability Program in English, and translated into "electronic stability program" in Chinese. This system usually supports the functions of the anti-lock braking system and the drive anti-skid system. It analyzes the vehicle driving status information transmitted from each sensor, and then sends correction instructions to ABS and ASR to help the vehicle maintain dynamic balance. ESP generally requires the installation of steering sensors, wheel sensors, side slip sensors, lateral acceleration sensors, etc. It can monitor the driving status of the car and automatically apply braking force to one or more wheels to keep the car running in the normal lane.
5. Automotive electronically controlled suspension
Different driving conditions of automobiles have different requirements for suspension. In general, a softer suspension is required for comfort when driving, and a harder suspension is required for stability when cornering and braking. There is a contradiction between the two. In addition, the requirements for the height of the car body are also different in different environments in which cars are driven. Suspension with constant rigidity cannot meet this contradictory demand. The ideal suspension should have different spring stiffness and resistance shock absorption under different conditions, which can not only meet the requirements of ride comfort and handling stability, but also achieve the purpose of safe driving. The development of electronic technology has made it possible to design a suspension that can be adjusted within a certain range. This type of suspension is called an electronically controlled suspension. At present, the more common form is an electronically controlled air suspension. A typical electronically controlled suspension system consists of an electronic control element (ECU), air compressor, vehicle height sensor, steering angle sensor, speed sensor, brake sensor, air spring element, etc. The system can automatically adjust the performance of the suspension assembly according to the instantaneous driving conditions of the car, that is, the running status of the car is detected through various sensors. When the suspension electronic control component receives the steering and braking status signals detected by the sensor, It can adaptively handle the vehicle's roll, forward and backward, and automatically adjust the damping force of the shock absorber, which can prevent the vehicle body from tilting and improve the ground adhesion of the wheels. The system makes the car easier to control and has better handling stability.
6. Automotive electronically controlled power steering system
The electronically controlled power steering system (EPS Electronic Control Power Steering for short) is designed to realize that the force required on the steering wheel under various driving conditions is the optimal value, and the electronic control system is adopted in the steering system. The system automatically adjusts the steering wheel's steering force through an electronically controlled steering microprocessor under various speed conditions. At low speeds and when the vehicle is placed, the driver can flexibly steer with less force, and at high speeds, the force for steering the steering wheel can be automatically increased.
EPS not only improves the driving comfort and steering sensitivity, but also overcomes the disadvantages of "fluttering" in high-speed steering, ensuring the stability and safety of high-speed driving.
7. Automobile active collision avoidance system
The system is to assist car drivers in real-time monitoring of people, vehicles, and road environments that affect the safety of highway traffic. In a critical situation, the system actively intervenes in driving operations, assists the driver in emergency treatment, prevents car collision accidents, and guarantees Driving safety.
8. Automobile integrated chassis control system
Automobile Integrated Chassis Control System (UCC) is an advanced integrated system that connects control systems such as braking, suspension, steering and drive train through a central chassis microprocessor. The chassis microprocessor can accept each sub The data sent by the system sensors coordinate the control of each subsystem to optimize the overall level of the vehicle and ensure the safety of the vehicle.
9. Car tire monitoring system
Automobile tires are the contact parts between the car and the ground, which affect the driving force and braking force of the car. It plays a very important role in safety. If the tire pressure is insufficient during driving, it will cause uneven tire wear, increase fuel consumption, and deteriorate stability and maneuverability. It is easy to burst tires and cause traffic accidents. Automobile tire monitoring system (TMPS) can realize real-time monitoring of automobile tires, and will give an alarm when the pressure is below the safe range.
10. Other safety control systems
In order to meet the needs of high-speed, safety and comfort of cars, more and more advanced electronic technologies are applied to cars, such as sleep driving warning systems, driver distraction monitoring systems, visual enhancement and night vision systems, navigation systems, etc Provides safe driving.
(2) Passive safety electronic technology
With the development of automobile technology, automobile active safety technology has played an increasingly important role in traffic safety, effectively reducing the occurrence of traffic accidents. But in reality, many traffic accidents still inevitably occur, so modern cars also need to be equipped with passive safety systems. The representative electronic device of passive electronic technology for automobiles is an airbag.
The airbag is generally composed of a sensor, an electronic control unit, a gas generator, an airbag and a freewheel, etc. Usually, the gas generator and the airbag are made together to form an airbag module. When the sensor senses the collision intensity of the car, it transmits the sensed signal to the controller. The controller receives the signal from the sensor and processes it. When it judges that it is necessary to open the airbag, it immediately sends out an ignition signal to trigger the gas generator. After the ignition signal is reached, a large amount of gas is quickly generated in the ignition well to inflate the airbag. At this time, on the one hand, the occupant's head and chest are pressed against the air bag to separate it from the object in the front of the car. It can absorb the kinetic energy generated by the occupant's inertial force and protect the occupant. The composition of the airbag system is shown in Figure 3.
Airbags are the most effective passive safety devices that have been developed recently. They show great protection for occupants in collision accidents. With the development of electronic technology, airbags are gradually developing in an intelligent direction.
(3) Post-accident safety electronic technology
The post-accident safety technology is to ensure the timely rescue of occupants and reduce post-accident losses, to avoid further injuries. Typical electronic devices include door lock emergency release system and GPS rescue system.
1. Door lock emergency release system
The door lock emergency release system should be able to be opened easily in order to enable the occupants to be quickly rescued from the impacted vehicle after the vehicle has a collision accident. The working principle is that when the collision sensor confirms that a collision has occurred, the system immediately releases the door lock.
2. GPS rescue system
After a vehicle collision, in order to quickly rescue the injured, the location of the accident vehicle must be accurately determined. The GPS rescue system uses satellite navigation and positioning, which can quickly determine the vehicle's position, shorten the rescue time, and reduce the degree of occupant injury.
3. Conclusion
With the development of automotive technology and electronic technology, automotive safety technology has gone through a development process from easy rescue after collision to damage reduction, to accident avoidance and prevention, and gradually changed from passive safety to active safety to a more humane and intelligent Direction development. The car of the future will become a comprehensive platform for electronic products, and electronic technology will make the car safer, more comfortable, and more convenient.
Accessories for cameras are mainly for care, protection, special effects and functions.
Lens hood: used on the end of a lens to block the sun or other light source to prevent glare and lens flare (see also matte box).
Lens cap: covers and protects the lens during storage.
Lens adapter: sometimes called a step-ring, adapts the lens to other size filters.
Lens filters: allow artificial colors or change light density.
Lens extension tubes allow close focus in macro photography.
Flash equipment: including light diffuser, mount and stand, reflector, soft box, trigger and cord.
Care and protection: including camera case and cover, maintenance tools, and screen protector.
Large format cameras use special equipment which includes magnifier loupe, view finder, angle finder, focusing rail /truck.
Battery and sometimes a charger.
Some professional SLR could be provided with interchangeable finders for eye-level or waist-level focusing, focusing screens, eye-cup, data backs, motor-drives for film transportation or external battery packs.
Tripod, microscope adapter, cable release, electric wire release.
Dew shield - Prevents moisture build up on the lens.
Camera Accessories,Selfie Stick Adaptor,Smartphone Selfie Stick,Threw Hold Camera Accessories
GUANGZHOU WEWOW ELECTRONIC CO., LTD. , https://www.stabilizers.pl