"Good rain knows the season, when spring is happening. Sneaking into the night with the wind, moisturizing things are silent", Du Fu's "Happy Rain on Spring Night" can be described as a household name; Lu You also wrote that "Xiaolou listens to spring rain one night, and sells apricot blossoms in the ming dynasty in the deep alley", saying that the second of the twenty-four solar terms - rain.
Every year around February 19, when the sun reaches 330 degrees of yellow longitude, it is the rain of the twenty-four solar terms. At this time, the temperature rises, the ice and snow melt, and the precipitation increases, so it is called rainwater. The rain season generally starts on February 18 or 19 and ends on March 4 or 5.
"The Seventy-two Waiting Solutions of the Moon Order": "In the middle of the first month, the sky is full of water." Spring belongs to wood, but the rain of those who grow wood will also be water, so the rain will follow in the spring. And when the east wind is thawed, it scatters into rain. This means that before and after the rain festival, everything begins to sprout, and spring is coming. For the natural world, rain and water festivals mean the beauty and poetry of the new spring season, but it cannot be ignored that for the traffic travel of the masses, the wet and slippery road conditions and reduced visibility mean the increase in driving safety hazards.
In wet and slippery road conditions, in addition to maintaining good vehicle condition, you also need to be more careful when driving, which requires an understanding of the vehicle's handling stability performance. With the focus on driving safety through rain and solar terms, combined with our research on driving evaluation, we may wish to talk about the topic of car stability performance.
The handling stability of the car refers to the ability of the car to resist interference and maintain stable driving when the driver does not feel excessive tension and fatigue, and the car can resist the interference and maintain a stable driving when it encounters external interference.
So, how to look at the stability performance of a car? What are the main factors that determine the stability performance of the car?
Theoretically, the vehicle's overall weight distribution, chassis suspension, steering, braking, body geometry and aerodynamics, body rigidity, tire equipment, safety configuration (ESP, VSC), etc. all largely determine the handling performance of the vehicle. Of course, vehicles with four-wheel drive, especially full-time four-wheel drive systems, must theoretically have better operating performance, and the driving safety in rain and snow weather and wet and slippery road conditions also has an additional layer of protection.
For the majority of consumers, looking at the user and media's control evaluation of the vehicle, the control performance test, the mechanical structure, and the safety configuration list can also have a general understanding of the vehicle's stability performance to a certain extent. Of course, "paper is finally shallow", the most direct and effective is still related to the professional research and test of stability performance.
Rain and snow weather wet and slippery road conditions are often easy to trigger the vehicle's electronic stability system (ESP, ESC, VSC, TCS, etc.), they are also the most typical active safety equipment of modern cars, in fact, almost all of the vehicle's electronic stability system works the same principle, but its actual working efficiency, and whether the vehicle matching degree is different, but also greatly affects the driving experience of the rain and snow weather vehicle.
Good electronic stability systems are often "silent", bringing silent protection to users, while electronic stability systems that are not well matched are easy to cause or aggravate the tension of personnel in the car, and even lose control of the safe driving trajectory of the vehicle when working. It is mainly reflected in the fact that the trigger is too sensitive and abrupt, and the "rough" intervention brings "interference"; or the reaction time is too slow, or the performance release during work is not up to standard, or it is not reasonable or linear enough. In particular, the novice Xiaobai is relatively unfamiliar with the electronic stability system, and the electronic stability system that is not good enough is a potential danger when driving in rain and snow weather in extreme cases.
To this end, the subjective and objective standard specifications for the verification and calibration of the electronic control system have been studied and formulated by the driving evaluation evaluation, which is suitable for evaluating the operational stability, steering performance and comfort of the model with the control function of the electronic stability system. For example, the impact on TCS on the smoothness of the acceleration process, whether there is resonance or not, the difference in acceleration time of switching TCS, whether there is a large horizontal swing phenomenon, the size of the steering wheel angle correction, the size of the acceleration change; the evaluation of the noise during ESC intervention, the driver's sense of touch (steering wheel, brake pedal, body jitter); the impact of ESC intervention on the driving of the whole vehicle, whether the vehicle can be continuously controlled, whether the driver's input is correctly responded to, and the sensitivity of the ESC (only intervene when the vehicle is unstable or tends to be unstable), Under normal and stable conditions, it will not be sensitive to intervention) and other aspects of verification and evaluation.
In addition, the professional tests that typically reflect the stability performance of the car are mainly directional winding circles, snake-shaped pile piercing, emergency line change/elk test and fish hook test, which is equivalent to a professional test of the stability performance of a car. These tests can deeply consider the stability performance of the vehicle and have typical reference value.
At the same time, the complex road conditions of rain and snow weather, the specific performance differences in vehicle steering, braking performance, etc. also greatly affect the stability performance, such as whether the steering is precise and smooth when driving in rainy and snowy weather, and whether the braking is linear to a certain extent, which affects the active safety performance of the vehicle and the driver's control experience. The more these indicators perform well, the more comfortable and stable the driving experience in rain and snow weather, the driver's control is more relaxed and calm, while the reverse experience is worse, and even brings safety hazards (such as vehicle operation errors and loss of control in extreme cases). In order to more fully reflect the stability performance of the vehicle, the driving evaluation has carried out a more detailed and subdivided disassembly of these indicators in the group standard of the "Automobile Drivability Experience Test evaluation procedures" released recently. as:
Steering
It includes curve steering, steering force feeling, steering force feeling, steering response, steering back positive, steering abnormality, deviation phenomenon, steering wheel vibration, steering power abnormality and other dimensions.
Braking comfort
It includes multiple dimensions such as brake pedal sense, brake pedal force, brake pedal stroke, brake linearity, brake pitch, brake pitch size, brake pitch convergence, and brake pitch abruptness.
Driving evaluation has always been committed to promoting the development of China's automotive industry with technology, when more people understand and pay attention to these professional tests and evaluations, manufacturers will pay more attention to the inherent "real kung fu" of the car, and consumers can enjoy the driving quality and fun of the car more safely.