[YesAuto Test Drive] BMW driving training activities have been held many times so far, but this time it is a bit special, because MINI COUNTRYMAN has joined the driving training family as a training car for the first time. Compared with the commonly used 1 Series 3 Series and other rear-wheel drive models, this MINI COUNTRYMAN 1.6T COOPER S ALL 4 model will provide more powerful grip and controllability, and at the same time, for this model that is biased towards SUVs. , Desert driving training was also introduced for the first time, let’s follow us to experience it.
This training course is divided into two parts, road driving and desert driving. Of course, the purpose is to help everyone control their vehicles more safely. We also hope to share the safe driving skills learned in the training and apply them to daily Driving.
Training vehicle: MINI COUNTRYMAN 1.6T COOPER S ALL 4
The training vehicles all use MINI COUNTRYMAN 1.6T COOPER S ALL 4, which uses a timely four-wheel drive system. From the structural point of view, the application of the four-wheel drive system can more effectively improve the driving performance of the vehicle on the paved road, while taking into account the driving performance in some poor road conditions, but for the harsh off-road project, I am afraid that it is a little powerless. But this is not contrary to his positioning, after all, the city is his main “battlefield”.
Preparation: Adjust the seat and rearview mirror/select the appropriate driving mode
Regardless of whether we are in driving training or not, when we drive a car for the first time, the first task is to adjust the seat, rearview mirror angle, etc., to avoid the embarrassment of stopping and adjusting again during driving.
In addition, the driving mode can be adjusted according to personal preferences, such as trying to manually shift gears and so on. At the same time, it is recommended to turn on the sport mode. In this mode, the throttle response is more aggressive and sensitive, and the direction becomes heavier. The overall change is more suitable for relatively intense driving behavior.
● Curve braking
Simulation scenario: We drove off the ramp from the expressway or ring road, and drove downhill at a high speed in the bridge of the curve. There was a blind spot in the line of sight of the curve. At this time, an accident car appeared not far away. We need to stop the vehicle as soon as possible. under.
Project content: We will drive along a downhill curve at a speed of 100km/h, brake with full force at the blue pile bucket, and keep the vehicle moving along the curve during the braking process.
Correcting a misunderstanding: Before introducing the main points of the project, I must first correct a misunderstanding that has stayed in my mind for many years. Maybe many friends and I have the same view, that is, braking in a curve is a very dangerous behavior, even if you brake, you can’t brake quickly. Even some coaches in driving schools also teach the students this way, but this is not the case. The center of gravity of the vehicle in the curve is affected by the centrifugal force, and the center of gravity will be shifted. If you tap the brake lightly, the center of gravity will move forward and the rear wheel grip will be greatly reduced. At this time, the vehicle may have a tail-flick. If you brake fully, the body will press down rapidly, giving the front wheels great downforce in the corners, greatly increasing the front wheel adhesion, reducing the probability of sideslip caused by centrifugal force, and the overall depression of the body's center of gravity will also cause The rear wheel has a certain degree of adhesion, which can more effectively help the driver to control the vehicle.
Of course, everything mentioned above must be within the comprehensive limits of the vehicle's turning speed and turning angle. In other words, if your driving speed is extremely fast or the corner angle is extremely small, which exceeds the vehicle's tolerance limit, any driving skills will be useless.
Project experience: First, we accelerate the vehicle to a speed of 100km/h on the straight line section before entering the bend, and maintain this speed to enter the bend. At this time, the huge centrifugal force will push the vehicle to the outside of the bend, and the wheels will creak. The call, obviously this speed is close to the tire grip limit. When the braking point represented by the blue pile barrel appears, press the brake with full force. At this time, the jitter of the ABS will be directly transmitted to the whole body, and the direction is most likely to shift at this time. In addition, the braking force reduces the rolling speed of the wheels instantaneously. Even if the direction is maintained, the vehicle will still slide along the outside of the curve in the direction of centrifugal force. Therefore, during the braking process, a larger angle is required to turn into the curve to control the vehicle to hug the curve as much as possible. heart.
Project summary: There is no difficulty in controlling the process, and correcting people's misconceptions is the biggest gain of this project. Some people may ask, in many accidents in daily life, why do vehicles or objects on the outside even when the speed is not fast and the angle is not too large? Is their technology inadequate? In fact, it is not. What is reflected here is a stress response of human beings: wherever you look, your body will manipulate the body. When there is an accident on the road, your sight is more focused on the broken car or object parked on the outside. According to this theory, the vehicle you drive will also rush there. So after the project was over, the trainer told us that if some obstacles were placed outside the corners, many people would have run into them. It does make sense to think about it.
● Emergency avoidance
Simulation scene: Speaking of the scene simulated in this project, the safety trainer from BMW described to us vividly, when we were driving on a two-lane road, we lowered our heads to change the CD or look at the mobile phone, and found when we raised our heads The vehicle in front stopped unexpectedly and it was too late to brake at this time. What we have to do is to make an emergency avoidance.
Project content: We will drive the vehicle at a speed of 100km/h, keep the speed in the blue zone without braking, rely on the steering wheel control to avoid the car to the left red zone lane, when the vehicle enters the left lane, fully brake and Return the car to the blue area.
Project experience: This project can consist of two actions, the first is to avoid, and the second is to brake and merge at the same time. The first link mainly examines the experiencer’s ability to control the distance of obstacles and avoidance points in high-speed driving. In a 100km vehicle, the lanes and avoidance areas laid out by the pile buckets look very narrow, so they have a grasp of the avoidance points. It is indeed very challenging. Turning the direction early or late will roll the pile barrels on both sides. In the first few attempts, the phenomenon of rolling the pile barrels is very common.
Of course, the situation will get better after many attempts, and there are many skills in it. When we drive a vehicle at high speed, if we focus too much on the stationary point, the timing of avoidance will be difficult to grasp. An error of a few tenths of a second will cause the avoidance to fail. At this time, if you can try to look farther, the overall route planning can more easily find the right time, and it is more effective to judge the time of avoidance by feeling.
When the first evasive action is completed, it is followed by full braking and evasive action. At this time, you need to quickly return the body to the center, and then fully depress the brake, and at the same time grasp the avoidance point to avoid. The success or failure of this link depends on the completion effect of the previous link. The difficulty lies in the rapid adjustment of the body direction after the first action is completed. It is the key to make the vehicle return as soon as possible. After full braking, the vehicle speed is significantly lower than before, so the second Second avoidance is not a difficult task.
Project summary: It should be noted that the effect of the first link of the whole set of actions is crucial to the completion of the whole set of actions. At the same time, the force control of the direction is also very important. The angle is sufficient to ensure the success of the vehicle avoidance, and the action must be done as much as possible. Smooth, control the body attitude as smooth and stable as possible. Too blunt and sudden steering will cause the body to swing violently, especially when driving at high speed, which will directly cause the body to take a long time and distance to adjust, and in severe cases, it may even lose control of the direction.
● Desert experience/driving skills
Friends who follow Dakar should not be unfamiliar with the scene of driving in the desert. Many people know some driving knowledge such as fast walking in the sand and slow walking in the water. However, there may be very few people who have tried desert driving in person. Taking advantage of such a rare opportunity today, we also share some learning experiences about desert driving.
Compared with ordinary paved roads in deserts, the essential properties of roads are much different. Before entering the sandy land, we need to do the following preparations.
1: Reduce tire pressure
Driving in the desert, because the sand is soft and hard to eat, the adhesion of the wheel will be severely reduced. For this reason, we need to reduce the tire pressure of the wheel to about 1 bar to increase the contact area between the tire and the ground, thereby reducing the adhesion. Drain.
2: Turn off the body stability system:
As an important safety system in driving, DSC can reduce the power output to the slippery wheels when the wheels slip during daily driving, which is exactly contrary to the needs of driving in the desert. The adhesion of the four wheels in the desert is reduced as a whole, and the slipping wheels need continuous power supply. At this time, the intervention of the stabilization system will reduce the power output of the slipping wheels, slowing down the vehicle speed and increasing the probability of sand trapping, so sand driving is closed Various body stabilization systems are very important.
3: Choose the right gear
We recommend driving in 1 gear for hand-geared models, and manual 1st gear for manual-automatic models. This can be more controllable for gears and power output, and is more helpful for desert driving.
In daily life, the simpler truth that you need to step on the brakes to stop is believed to be unknown, but the theory in the desert does not apply. Because the sand is soft, stepping on the brake pedal will cause the body to press down and the center of gravity will be lowered, which greatly increases the risk of sand trapping. Therefore, the correct way to stop in the sand is to release the accelerator pedal and rely on the resistance of the sand to let the car slip to a stop slowly.
In addition, stop in the sand as far as possible and choose to stop in the downhill section, which will be very helpful for starting again. If there is no downhill section, you can choose a horizontal section. Don't park your car in an uphill section, otherwise you will most likely get sand trapped when you start again.
When you start, step on the accelerator as much as possible. When the vehicle moves forward, refuel slowly. Do not start with a big accelerator. Not only will the fast-spinning wheels not help you move forward smoothly, but the loose sand will completely trap your wheels in the sand. in.
Try reversing first
When the vehicle is stuck and cannot move forward, don't try to refuel blindly, it will make you sink deeper and deeper. First try to reverse the car to get out of trouble, because compared to the sand and stone resistance encountered when going forward, the rutted route that the car will go through is relatively flatter and has a greater chance of getting out of trouble.
Finally try to dig sand and trailer
If reversing still can't help you out of trouble, then you have to shovel sand with your hands, and this shoveling sand is not without skill. First shovel out the sand on the front and rear of the four wheels, and then observe the condition of the chassis, because when the sand is severely trapped, the sand around the four wheels will be shoveled out, the sand under the chassis will lift up the vehicle, and the four wheels are almost completely lost. Grip, so getting out of trouble is bound to fail.
Therefore, at this time, the sand under the chassis should be shoveled out as much as possible. If none of these can get your vehicle out of trouble, there is only a tow truck.
Driving in the desert with soft and undulating materials, no matter how powerful the four-wheel drive system is, it is difficult for all wheels to lose adhesion one after another, so the only way at this time is to keep the vehicle at a higher speed. Once the vehicle slows down or even stops There is a danger of sand sinking at any time, so climbing in the desert may be more appropriate to be called rushing.
When you are ready to climb the slope, please leave a certain distance on the gentle road in front of the slope. At this time, manually lower the gear to first gear while holding the direction to increase the throttle to allow the vehicle to accelerate and rush up the hill. It should be noted that when the vehicle is approaching the top of the slope, the oil should be collected a little, not only to prevent the vehicle from rushing out due to inertia, but also to allow the driver to observe the downhill road conditions.
When going downhill on a general small ramp, we only need to grasp the direction and refuel steadily. But when the slope is steep, the direction is the most important point. Keep the vehicle perpendicular to the slope. Except for the head down that must be lowered when going downhill, try to prevent the vehicle from tilting laterally, otherwise it is easy to cause rollover and other situations.
Summary of this article:
No matter what kind of driving training, the goal is safety, and the same is true for MINI driving training. There is an old saying that you can sail boats carefully for thousands of years. However, under the background of complex and changeable traffic conditions and people's uneven driving skills, being careful alone may not be enough. Emergency response and safety Common sense of driving skills is what we need to continuously improve and learn, and this is what we hope to convey to everyone through this type of driving training.