Text: "Autobots" Wu Yu.
A few years ago, I took an old friend's ride, and sighed together that my friends and good cars had to accept the baptism of time.
The old friend drove a BMW 535li, the car was more than 10 years old, but it did not drift at high speed, did not wait for overtaking, did not breathe, the seat was supported, and there was no noise in the ears......The winter night is warm, and it warms people's hearts and hearts.
After the year, I went north to visit BMW's Tiexi Plant and Dadong Plant. One day is just a matter of sightseeing, but you can experience the inclusion, the triviality, the high investment, and the difficult ...... behind building a good car
EMC EMC Electromagnetic Compatibility TestingBuild strong immunity
If high-strength steel and laser welding are shaping a strong body, EMC electromagnetic compatibility test is to improve immunity.
The so-called EMC electromagnetic compatibility test is mainly to improve the ability of vehicles or equipment to resist electromagnetic interference EMI, and avoid electromagnetic induction and electrostatic coupling leading to system transmission or performance degradationAt the same time, it reduces the strength of the vehicle's own electromagnetic signal to avoid potential damage to the "young", "sick" and "pregnant".
Since the 80s of the last century, the growth of mobile communication and broadcasting has affected vehicles and mobile devices not only on short circuits and noise, but also on signals interfering with each other and even accidental spark dischargeAs switching faster (more radiated) and lower voltages (increased sensitivity), the negative effects of RF interference, broadband noise, and electromagnetic pulses increase by a logarithmic scale. If Marconi, Faraday, and Lenz were reincarnated, I am afraid that their jaws would drop in shock.
In contrast, digital systems can indeed rely on software for protection and error correction, but the interference caused by conduction and coupling cannot be completely eliminated. Bluetooth headsets and mobile ** can restart the system to correct errors, but the moving car cannot, you can't press the pause button, you can't wait for OTA, and you don't have time to carefully check and double check, especially when the intelligent driving curtain is slowly opened.
Standing in an inconspicuous workshop of the Tiexi factory, the giant door more than ten meters high moved silently like a mountain, and the shock and sense of ceremony felt at the scene were far from being comparable to the collision of the whole vehicle. Along the pneumatic track at the top, the screen door retreats and then slides to the right, revealing not a cave filled with gold and silver, but a flat, wide 10-meter anechoic chamber filled with wave-absorbing cones.
Flat and wide, there are data to prove it: 27 meters long, 22 meters wide and 13 meters high – equivalent to the volume of 3 standard swimming pools, providing a measuring space with a clean electromagnetic background and good field uniformity.
For EMC experiments, "big" is king. Here, not only the anechoic chamber structure is "large", the turntable diameter and load are "large", but also the antenna layout is "flexible", the test quiet area is wide, and the dynamic experiment with a speed of 120 kilometers per hour can be done, and the V2V scene of different angles can be accommodated by two vehicles.
The most important thing is that this huge measurement space not only makes the electromagnetic "immunity" of the new generation 5 Series close to 5 times that of the national standard, but also can be used to verify the vehicle's autonomous driving ability in complex electromagnetic environments, which is of forward-looking significance for future travel.
There is "zero tolerance" cubing firstOnly then is there a 5 series that is close to perfection
If all automobile products have to go through the college entrance examination, then BMW's products have to pass the test of the Olympiad.
Ordinary people expect a perfect world with zero gaps, but engineers have to face an ordinary world full of deviations, and even a miserable world where tolerances turn into errors.
With the manufacturing capacity of human beings, it is indeed possible to produce products with close to "zero tolerance", but the cost is expensive, and only the dragon who explores the sea and Zhu Rong who surveys the sky are qualified. Large-scale industrial production uses only "economic machining accuracy" - machining accuracy that can be guaranteed without additional processing conditions (costs).
This may be a common standard in the industry, but it is by no means a standard for BMW.
Ordinary people will use "chassis whole" and "ten-year-old car is still as new" to describe the feeling of driving BMW, but few people know that BMW's secret ** is to provide a cubing with magic for each car - tighten the economic processing accuracy, reduce the cumulative error of assembly, and make the ordinary world close to perfection.
CUBING is a high-grade inspection tool that is manufactured at a scale of 1:1 according to the digital model of the car body, and is infinitely close to zero tolerance. It is named after the gauge, but it is not comparable to ordinary calipers and gauges.
It is made of forged aluminum alloy that is only used in aircraft structural parts, and the manufacturing cost of a single unit is more than 8 million yuan. It "holds the balance high" in a constant temperature and humidity room, and in the 5 months before the SOP (mass production), thousands of spare parts are matched to the accuracy verification of the dimensions up to 100 times ......
With cubing, it is equivalent to having a ruler. From design to process, from body to **, all manufacturing problems can be answered by comparing CUBING, and the standards are clear at a glanceFrom the first business to the assembly line, from the interior and exterior decoration to the connectors, whose deficiencies are rectified, they are strictly treated equally.
The most important progress is that because CUBING tends to be close to zero tolerance, based on its corrected part tolerance, it is equivalent to being "five folds", so that the cumulative error of the body ** is greatly reduced, and the driving pleasure and luxury quality are also laid.
100,000 without makeup**Just for the perfect experience
No one may believe it when you say it, but the high quality of the BMW 5 Series actually comes from "love" and the kind that does not open the beauty.
Stamping is the first process of vehicle manufacturing, and it is also the place where the 5 series begins. In the stamping workshop of BMW's Dadong plant, under the 18-minute production cycle, the parts with cracking and pit hazards are eliminated.
In order to meet this challenge, 40 industrial cameras were set up to shoot the finished stamped parts at a speed of 200 frames per second, pointing at different positions and presetting different angles**After uploading, the AI algorithm detects stamping defects. Compared with manual detection, the detection speed of AI algorithm is faster, reaching 001 seconds, the recognition rate is closer to 100%.
With **0With 5Mbit of computing (compressed), a press line can store more than 10 tbits of data per day. That sounds like a staggering amount of data. But in fact, the inspection of the body paint is the high-incidence scene of the 5 series.
In the paint inspection process, the paint scanning robot with a unit price of more than 10 million yuan is busy, a manipulator grabs the lamp head to move diagonally and flashes at high speed, and a manipulator grabs the lens to move in parallel and take pictures at high speed - the former keeps flashing, the latter keeps shooting, and the number of bicycle shots can reach 100,000.
Under the illumination of high lumens, the raised frontal side of the paint surface is brightened and the backlit side is darkened (the opposite is true for the paint surface).Through the contrast between light and dark on **, AI can accurately determine that all the diameters on the paint surface exceed 001 mm of blemishes or impurities. Finding a single defect is not the goal, the AI will continue to determine whether the painting process needs to be adjusted and optimized, and feed the results back to the system.
Whether it's 001 second check speed, still 0The diameter of the imperfections of 01 mm is all about finding and eliminating those imperfections. But what BMW is pursuing is not one TBIT after another, nor is it one laboratory after another, AI algorithms;It's about making products that can stand the test of time, providing experiences that can be built over time.
The luxurious heritage is not cultural feelings, nor is it cost craftsmanship, but the awe of time. All those equipment and processes, dreams and efforts are in awe of time, and will eventually be rewarded by time. 【Copyright Notice】This article is the original manuscript of "Autobots", and it is not allowed to be unauthorized **.