Application of Automotive Electronic Control Technology in Automotive Safety

Abstract: With the improvement of people's living standards and the maturity of automobile production and assembly technology, cars have gradually entered the ordinary family. As the most important means of transportation in modern society, the automobile not only brings speed, but also gives people the respect and pursuit of quality life. At the same time, it also brings many security risks. The data shows that in 2011, the number of deaths caused by traffic accidents in China was 62,000, and the death rate from traffic accidents ranked first in the world. Therefore, car safety is becoming more and more important.

1 Introduction

With the rapid development of electronic information science and technology in recent years, intelligent electronic technology has been promoted from the field of traditional household appliances to the field of automotive intelligent control, greatly improving the comfort, operability and safety of automobiles. Since the German Carl Fritridge Bentz invented the world's first three-wheeled car in 1886, car safety and car development have followed. The safety of car driving in today's society is the most concerned issue for consumers. A Visteon company conducted a survey that showed that car safety is at the core of customer demand for cars. Most consumers believe that car safety is more important than car power, comfort and economy. Focus on car safety, not only for drivers and passengers, but also for more people on the road. This article will introduce the application of in-vehicle intelligent electronic control technology to improve the safety control technology of car safety with easy-to-understand text.

2. Automotive electronic anti-skid control system

The automotive electronic anti-skid control mainly includes three aspects of control: anti-skid, anti-skid and anti-skid. The car anti-skid control system is a safety accessory on the car that protects passengers and vehicles from side slip, deviation, loss of steering and slippage during braking, starting, acceleration and steering. The role of greatly reducing the probability of traffic accidents caused by braking, driving, etc.

2.1 Anti-lock Braking System (ABS)

When the car is braking, the tires provide friction to stop the car. And because the static friction (tire rotation) is much greater than the sliding friction (tire slip), the ABS system allows the car to get more friction to stop it faster. The anti-lock brake system (ABS) of the automobile brake is used when the vehicle is in emergency braking on any road surface. The intelligent electronic system of the vehicle receives the signal of the wheel speed sensor, automatically controls and adjusts the braking force of the wheel, so that the wheel is in rotation and sliding. The critical state prevents the wheels from being completely locked, so that the wheels get the maximum braking friction and get the best braking effect. In this way, the deviation, side slip, and loss of steering ability during braking are avoided, and the handling performance and stability performance of the automobile are improved (as shown in FIG. 1). At the same time, the car can also obtain the maximum braking force, shorten the braking distance by 30%, improve the braking performance of the car, and is of great significance to ensure the safety of the car.

In short, the era of “artificial brakes” has passed, and the highly intelligent ABS gives us a lot of protection in driving safety. Shortening the braking distance by 30% will undoubtedly become a life-saving straw in many cases. The brakes ensure that the direction is controllable and provide driving protection.

2.2 Drive anti-skid system (AcceleraTIonSlip RegulaTIon, referred to as ASR)

When the car starts or accelerates, especially when driving on special roads with less friction such as rain, snow, hail, road freezing, etc., the driving wheel slipping often occurs, which is very dangerous on the mountain road. In order to ensure the safety and stability of the car, the control wheel does not slip, mainly receives the wheel speed sensor signal through the vehicle vehicle intelligent control unit, controls the electronic ignition part of the engine and the oil supply, usually by changing the throttle opening and the ignition advance angle. The way to adjust the output torque of the engine to ensure maximum adhesion and traction between the wheel and the ground, so that the slip rate of the wheel reaches the optimal range (15% ~ 20%). If the wheel slips out of control, the car will lose control. Therefore, don't think that the wheel will be dangerous when it is braked. The wheel will slip when it starts.

2.3 Vehicle Electronic Stability System (ESP)

Vehicle Electronic Stability System (EPS) When the vehicle is turning, braking or slipping, the electronic control unit ECU receives the steering angle sensor (the steering angle for detecting the steering wheel), the wheel speed sensor (monitoring the rotational speed of each wheel), G (Skip) sensor (monitoring the state of the car body rotating around the vertical axis), yaw rate (lateral acceleration) sensor (measuring the centrifugal force when the car turns), deceleration sensor, analyzing, calculating and judging the running state of the vehicle Then, an instruction is issued to transmit the hydraulic pressure generated by the pressure pump in the brake actuator to the wheel cylinder of the corresponding wheel brake. Thereby, the control of the front wheel side slip and the rear wheel side slip is realized, so that the vehicle does not deviate from the correct travel track. For example, when the rear wheel of the car is skidding, the ESP system immediately applies the braking force to the outer front wheel that is turning, and quickly braking the front wheel to produce an opposite torque to ensure that the car is in the original lane. Driving; when the front wheel of the car is "floating". The ESP system applies braking force to the two rear wheels and quickly brakes the rear wheels to keep the car in the original lane. It is not difficult to see that the vehicle electronic stability system (EPS) is a further extension of the traditional ABS (anti-lock braking system), ASR (drive anti-skid system), the most important feature of ESP is its initiative, if ABS is passively reacting Then ESP can prevent it from happening. More intelligent to improve the stability and safety of the car.

2.4 Emergency Brake Aid System (ElementalBattle Academy, referred to as BAS)

Since a large number of drivers will be indecisive in an emergency, braking measures cannot be effectively taken. Braking system performance can not be effectively played, the braking distance is significantly extended. In order to shorten the braking distance in the case of emergency braking, Mercedes-Benz has developed a brake assist system (BAS). Since 1997, this system has become the standard assembly for all Mercedes-Benz cars. The specific workflow is shown in Figure 2.

Mercedes-Benz has thoroughly tested the function and mode of operation of the Brake Assist System (BAS). For example: in the driving simulator: here, the driver will encounter a dangerous situation without warning, at which point they must implement emergency braking. On dry roads, if the brake assist system is not used, most testers need a braking distance of up to 73 meters to completely stop the car with a speed of 100 kilometers per hour. With this system, the car stopped completely after only 40 meters. This is equivalent to a braking distance reduction of approximately 45%.

The new car equipped with this system reduced the frequency of accidents by 8 percent in the event of a crash and reduced the frequency of accidents by 30 percent in the case of pedestrian accidents.

3.Airbag protection system (Supplemental InflatableRestraintSystem, SRS for short)

The impact of the car and the obstruction is the first collision. The impact of the person and the corresponding component on the car is the second collision. Generally, the collision occurs in the first 60 ms of the collision, and the casualty is caused by the second collision. After the first collision of the car occurs, before the second collision occurs, the sensor senses the collision strength of the car and transmits it to the controller. The ECU of the SRS receives and processes the signal of the sensor. When the ECU of the SRS determines that it is necessary to open the airbag, The ignition signal is immediately triggered to trigger the gas generator. After the gas generator is ignited, a large amount of gas is quickly generated and the airbag is quickly deployed. The entire inflation process of the airbag takes about 30 ms to complete the entire working process of the airbag, blocking the occupant (mainly front, side, knee) The collision between the part and the head and the corresponding component in the vehicle absorbs the kinetic energy of the occupant through the damping effect of the exhaust throttle on the airbag, thereby hitting the purpose of protecting the occupant.

4. Automotive electronic collision avoidance system

According to the 2012 statistical bulletin published on the website of the National Bureau of Statistics, China’s national civilian vehicle ownership reached 12,089,000 (including 13.45 million three-wheeled vehicles and low-speed trucks) at the end of 2012, an increase of 14.3% over the end of the previous year. Increasingly large, collision accidents are increasing day by day. In order to prevent collision between high-speed vehicles or between vehicles and roadside vehicles, an automatic control anti-vehicle rear-end collision system--automobile electronic collision avoidance system has been developed and developed. When the car is running normally, the system is in a non-working state. When the rear car head is very close to the front car tail and obstacles, the system is equipped with a distance measuring sensor, which uses the light, laser or ultrasonic to measure the car and The distance between the obstacles, the distance signal and the vehicle speed signal and the signal of the wheel angle sensor are sent to the ECU, and the actual distance between the vehicle and the front tail and the relative speed close to each other are calculated by calculation, and a warning car is issued to the driver. The warning of overtaking shows the distance of the object in front; when the vehicle is about to crash, the ECU sends a control command to the brake and the throttle control circuit to brake the car in time, thus effectively avoiding rear-end collision and collision.

5.Electronic Park Brake (EPB)

Most driving beginners will face a very difficult problem when they start uphill. They may fall backwards, sometimes due to insufficient safety distance with the rear car.

The Electronic Parking Brake System (EPB) is effective in preventing such accidents. When the system starts uphill, it mainly monitors the slope by the slope sensor and then transmits the signal to the ECU and calculates to give the accurate parking force. The brake force is intelligently adjusted. When the vehicle is started uphill, the parking control unit passes the clutch distance sensor. The signal provided by the clutch pinch speed sensor, the accelerator pedal sensor, etc., is calculated, and the parking brake is automatically released when the driving force is greater than the running resistance, so that the car can start smoothly. It can avoid unnecessary taxiing of the vehicle. Simply put, the vehicle will not slip and ensure the safety of the uphill start.

6. Tire Pressure Monitoring System (TIRe PressureMonitor System, TPMS for short)

Maybe you will ask, is the ratio of punctures in various traffic accidents really high? We use a set of data to prove to you that between 1998 and 2000, the Guangdong Provincial Communications Department counted 2,484 traffic accidents on the Guangzhou-Shenzhen Expressway, of which 848 had a puncture in a traffic accident and the probability of a puncture was 34.14. %, and all the factors that cause punctures are the primary cause of insufficient tire pressure. Therefore, the majority of car owners, we must always check the tire pressure, TPMS is a system that specifically detects tire pressure to ensure safe driving. One is the Pressure-Sensor Based TPMS (PSB). As the name suggests, this system installs a pressure sensor in each tire to directly measure the air pressure of the tire. The wireless RF transmitter is used to send the pressure signal from the inside of the tire to the inside. On the central receiver, each tire pressure data is then displayed. The system will give an alarm when the tire pressure is below the threshold or leaks. The other is the Wheel-Speed ​​Based TPMS (WSB). This system calculates the tire speed by comparing the tire speed difference between the tires by calculating the tire speed sensor signal of the ABS system. the goal of. There is also a compound (TPMS) system that combines a direct tire pressure detection system (PSB) with an indirect tire pressure monitoring system (WSB) to take advantage of the first two systems to provide greater safety and stability. Tire pressure data.

7. Conclusion

Since the application of electronic technology in automobile safety, the safety performance of the whole vehicle has been greatly improved, but whether it can be safely driven is not only determined by the safety configuration of the car, but if it is drunk driving, it is ridiculous, driving By illegal driving, such as telephones and high-speed trains, even cars with higher safety performance cannot guarantee driving safety. Therefore, the majority of car owners only have a sense of safety, resolutely do not drink and drive, do not fatigue driving, do not speed, do not steal the road, civilized driving can achieve real car safety. Car safety is more for the people on the road and for the most loved ones in the car.