The power of ESP is not so simple, it also derives these functions.
[Pacific Auto Network Technology Channel] Automobile safety systems are mainly divided into active safety systems and passive safety systems. When it comes to the former, I believe that most consumers will think of ESP body electronic stability system for the first time, because it is one of the most important safety functions, which can effectively prevent vehicles from losing control and greatly reduce the accident rate. Nowadays, the popularity of ESP body electronic stability system in domestic private cars has reached a high level, and even many models within 80,000 yuan are equipped.
The principle and importance of ESP body electronic stability system has long been a commonplace topic, but its practical application scope has been underestimated by many ordinary consumers. In fact, the power of ESP body electronic stability system is not so simple, because many functions, such as HAC uphill auxiliary control, HDC steep slope descent control, AUTOHOLD automatic parking, AEB active braking system, RSC anti-rolling stability system, etc., are derived from it, and without it, these functions cannot be realized.
HAC uphill auxiliary control
As we all know, it is a technical test for a vehicle to start on a steep slope or a gentle slope with smooth road surface (especially manual gear). The driver’s right foot needs to be switched from the brake pedal to the accelerator pedal. If the action is not fast and accurate enough, the vehicle may slide down the slope. The birth of Hill-start Assist ControL (HAC) is to solve this problem.
In fact, uphill auxiliary control can be called an extended function of ESP, because it is controlled by ESP system. When the vehicle starts on the ramp, even if the driver does not step on the brake or pull the hand brake, EPS will apply braking force to the four wheels at the same time and keep it for 2-3 seconds. This time is enough for the driver to step on the accelerator calmly and improve the driving force without worrying about slipping back. With the increase of accelerator pedal stroke, the braking force of uphill auxiliary will gradually fade, so the vehicle can easily start on the ramp.
The auxiliary control of uphill does not need high cost, but its function is not small, so the popularization rate is already very high. Nowadays, most models equipped with ESP have uphill auxiliary control, and it does not need the driver to set it manually, and it will work by itself when necessary.
HDC steep slope descent control
The Hill Descent Control (HDC) is opposite to the uphill auxiliary purpose. In the steep downhill section, it can automatically control the vehicle at a lower speed to ensure a safe downhill. In the process, the driver only needs to focus on observing the road conditions and controlling the direction, without pedal operation.
In principle, steep slope descent is more complicated than uphill assist, because it is the joint action of engine braking and ESP. This function generally needs to be turned on manually before entering the steep slope. When the vehicle enters the steep slope, the gearbox will remain in the first gear, and the speed will be reduced by engine braking. If the ramp is too steep and the engine braking is not enough to control the vehicle speed, then ESP will intervene and reduce the vehicle speed to a safe range through high-frequency automatic "point brake", which is more delicate than the manual foot brake, so it has higher reliability. It is particularly important to note that if you step on the clutch, brake or accelerator pedal in the process of using steep slope descent, it will immediately fail.
Compared with uphill auxiliary control, the average cost of steep slope descent control is higher, because it is often used in off-road conditions, and the specifications will be different for different off-road vehicles. Steep slope descent control is basically used in SUV models, and now even many domestic SUVs below 80 thousand yuan are equipped.
AUTOHOLD automatic parking
In the city’s congested roads, vehicles often stop and go, and drivers often need to step on the brakes or use the handbrake frequently. After a long time, they will feel very tired, and sometimes carelessness will cause unnecessary accidents. So, is there any way to simplify this process of frequent starting and braking?
Based on the above requirements, automotive engineers have developed AUTOHOLD automatic parking. When the driver steps on the brake, this function will automatically maintain the appropriate braking state, without the driver continuing to step on the brake or pull the hand brake; When the vehicle needs to continue driving, it will automatically sense the throttle action, thus releasing the brake.
The premise of automatic parking is also ESP, because automatic parking is also controlled by ESP components. Its basic principle is to measure the levelness of the car body and the torque of the wheels through a series of sensors, and then the ECU makes a judgment on the slipping trend of the vehicle and issues an execution command. Finally, ESP performs the automatic braking operation, which is similar to the electronic slip-limiting function between wheels of some timely four-wheel drive systems.
It should be noted that the operation methods of different brands of vehicles to perform this function are not uniform. Some of them are automatically performed after stopping completely for about 1 second, while others have to step on the brakes again after stopping.
AEB active braking system
Automatic emergency braking (AEB) is one of the most popular driving assistance functions at present. It can automatically brake the vehicle in an emergency, avoid some collision accidents, and make driving safety more secure.
Compared with the previous functions, the principle of active braking is more complicated and the technology content is much higher. After all, it is a safety function triggered in an emergency. Active braking consists of three parts: perception, decision-making and execution. As the sensing parts, radar and camera are responsible for detecting whether there is a risk of collision with cars or pedestrians in front. ECU electronic control unit analyzes whether it is necessary to send a reminder or take braking measures; Finally, if emergency braking is needed, the actuator will take the initiative to operate. At present, the actuator of active braking is usually ESP, and a few of them are brake-by-wire systems or independent high-voltage accumulator controllers.
In recent years, the active braking function is accelerating its popularization, and many brands have equipped it to models of about 100,000 yuan, taking it as a publicity point. However, it is particularly important to emphasize that with the current technical conditions, active braking can’t guarantee that drivers won’t rear-end vehicles or hit pedestrians in front, so even with it, they can’t relax their attention when driving.
RSC anti-roll stability control
Rollover RollStabilityControl (RSC) is an active safety function for many people, because it is basically applied to off-road SUVs to prevent vehicles from rolling over.
Anti-roll stability control can calculate the roll degree of the vehicle by the signal sent by the wheel sensor when the vehicle is turning on the off-road road surface, and carry out additional control on the middle and outer wheels in the curve. When the vehicle has a serious roll at any time, the anti-roll stability system will quickly adjust the braking force distribution of the wheels on both sides through ESP, and at the same time reduce the torque output of the engine, so as to restore the balance of the vehicle in the shortest time, reduce the risk of body shaking and rolling, and ensure the safety of the vehicle occupants.
summary
After the above analysis, I believe everyone has a deeper understanding of ESP body electronic stability system, which can not only prevent out of control, but also play an auxiliary role in many daily car scenes. In addition to the five functions introduced in this article, it has other functions, and even more and more in the future. You can wait and see. (Photo/Text/Photo: Pacific Auto Network Zhu Shiyong)
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