Is it enough to have a camera to realize automatic driving?
Many people call 2022 the first year of urban navigation and driving assistance, because a number of production cars equipped with large computing chips, laser radar and high-precision maps have been officially delivered, and driving assistance functions of some urban roads have been opened, but in the future, these seemingly tall terms mentioned above may not be necessary and sufficient conditions for you to choose a car.
Since the second half of last year, two new sounds have appeared in the field of advanced driver assistance. One is "emphasizing perception and ignoring map". The scenery of high-precision maps, once sought after by many car companies, is a little bleak. More and more manufacturers, especially autonomous driving solution companies, have begun to put forward the solution of "emphasizing perception and ignoring maps". The specific change is to use ordinary navigation maps instead of high-precision maps in urban sections that rely more on high-precision maps. Accelerate the coverage of urban navigation and driving assistance functions, improve the freshness of maps and reduce costs. Among them, the missing information compared with the high-precision map is supplemented by the acquisition of airborne sensor.
Speaking of sensing sensors, there is a second sound, which only uses the camera to realize the fully automatic driving function. On Tesla's AI Day last year, they demonstrated the latest network occupation technology. Compared with the widely used BEV, the main improvements are the detection of moving/stationary objects that cannot be judged, the detection of occluded objects and the more accurate estimation of traffic space. Coincidentally, these optimizations are basically the most important functions of lidar for visual sensors at present, and for visual systems, they are promotion.
Coincidentally, in the NIO DAY demonstration video of ET7 high-speed power exchange last year, as well as the introduction of the latest parking schemes of ideal L9 and L8, we also saw the display of the application of network technology. Therefore, before the real fully automatic driving is realized, it is necessary for us and car companies to pay extra and higher costs for lidar.
Average energy consumption is more worthy of attention than the maximum cruising range!
After being promoted as the biggest pain point for electric vehicle owners, endurance anxiety seems to be the sword of Damocles hanging over some car companies. After Weilai released the 150kWh semi-solid battery, the large-capacity battery became a competitive battlefield for some manufacturers. Lan Tu Zhuigong 108.73kWh battery CLTC 730km, OITA 1 1 match1/6.79 kWh battery CLTC 680km, krypton gas 00 1 match/KLOC-0. Large-capacity batteries bring relatively longer cruising range, and larger capacity also means heavier mass, higher energy consumption and more expensive cost. Can we only build an electric car that can drive farther for consumers by stacking?
The answer is naturally no. Looking at several technologies that have been clearly effective, the first one is the 800V platform based on SiC, which brings faster charging speed and motor response, and at the same time reduces the loss by increasing the voltage and realizes lower energy consumption.
Second, it is better energy management. Taking kinetic energy recovery efficiency as an example, thanks to the progress of battery system and electric drive system, the kinetic energy recovery efficiency of BMW i4 can reach 195kW, and the maximum recovery power of Mercedes-Benz EQE can reach 290kW. For reference, the power of the latest fast charging pile in State Grid is 120kW. Higher kinetic energy recovery efficiency ensures that more energy can be converted and stored every time the brake is pressed.
Then there is wind resistance, which is the biggest resistance that vehicles have to overcome at high speed, and it is also the main reason why the cruising range of electric vehicles is greatly reduced at high speed. In order to reduce the impact, we need to work hard on the shape design. For example, the shell modeling of Weilai ET7 roof lidar is blown out in the wind tunnel on the premise of meeting the functional requirements. Similarly, there are many models that use hidden door handles, low wind resistance wheels and active pneumatic kits. At present, Mercedes EQXX is the most extreme in this respect, and the wind resistance is only 0. 17cd. Among the mass production models, the lowest wind resistance is Mercedes EQS 0.2Cd, followed by Weilai ET7 0.208Cd. As a reference, the falling water drop with the lowest wind resistance coefficient is about 0.05Cd, the bird wind resistance is 0. 1 ~ 0.2 CD, the general vehicle wind resistance is about 0.35Cd and the ball is 0.5Cd.
Maybe you will ask, "What if I just want to drive a pure electric car for a long distance without charging?" Back to Mercedes-Benz EQXX, equipped with 100kWh battery, set off from Stuttgart, Germany in 2022 for Silverstone circuit, with a journey of 1202km and an average power consumption of 8.3kWh/ 100km. Up to 95% of the electricity is transferred to the wheels. This run is not a CLTC condition, it is completely completed on an open road. Of course, if you think that the technology represented by Mercedes EQXX is a little far away from you, let's take a look at the next trend.
Large cylindrical battery becomes the "ultimate battery"?
Automobile power batteries are mainly divided into cylindrical batteries, square batteries and soft bag batteries according to the packaging form. Tesla's 18650, 2 1700, 4680 all belong to cylindrical batteries, and the 4680 battery will be on BatteryDay in 2020. Published in the newspaper, because of its large diameter, it is called large cylindrical battery. At the press conference, it was said that the energy and power of the battery could be increased by 5 times and the cost could be reduced by 14%.
After repeated ticket jumps, Sandy Monroe finally dismantled the 4680 battery installed on overseas mass-produced Model Y last year. After testing, it is found that the actual energy density and total capacity of 4680 battery are not behind that of 2 1700 battery, and even the energy density is slightly behind. For such a seemingly completely backward new battery, it is still touted. Both LG and Panasonic said that their 4680 batteries will start mass production in 2023 and 2024, which is by no means brought by the influence of Tesla or Musk.
Cost is the biggest advantage of 4680 battery at present. When the performance is close to 2 1700, the lower cost is very attractive to any car company. For current electric vehicles, the cost of power battery accounts for at least 30% of the total vehicle cost. The smaller the model, the higher the proportion. Combined with what Musk mentioned at last year's earnings conference, the cost of Tesla's new model will be only half that of Model 3. In addition, the performance of the 4680 battery itself, including the electrochemical improvement of cathode materials in the future, will make the 4680 battery have a great room for improvement, because its larger battery capacity, larger stress diffusion area and full-tab design will help it achieve ultra-fast charging and high current discharge.
Like Tesla, BMW Group announced last year that it will take the lead in using large cylindrical batteries in "new generation" vehicles from 2025, and signed a battery production demand contract with two partners, Contemporary Ampere Technology Co., Ltd. and Yiwei Lithium Energy, with a diameter of 46mm and a height of 95mm or120 mm. It can be said that the large cylindrical battery represented by Tesla 4680 meets the current cost considerations of car companies, and there is great room for technological development in the future.
Will electric vehicles become "secondary" products?
At the beginning of 2022, a Tesla Model Y crashed into the wall with a fixed loss of 200,000. The owner lamented that it was better to scrap it directly. I don't know if you still remember, the reason why the maintenance cost is so high is because the rear bottom plate of Tesla Model Y body adopts integrated die casting technology, which turns the original 70 parts into 1 part. The biggest advantage of this technology is that it can improve production efficiency, reduce manufacturing costs, increase body rigidity and reduce vehicle weight. Of course, Tesla's expectation for integrated die casting does not stop there. They also plan to manufacture integral die-casting chassis in the future to further reduce costs and improve efficiency.
For Tesla, you and I may have the same reaction. After all, it is a kind of cost transfer to some extent. However, whether you accept it or not, this manufacturing method may become an irreversible trend. Tesla is not alone on this road. EQXX, which has been mentioned many times before and is equipped with many of the most advanced technologies of Mercedes-Benz, also adopts a similar structure at the rear of the car body and calls it "bionic casting". The back floors of Weilai ET5 and ET7 are integrally cast, while Volkswagen, Volvo and ET7 are integrally cast.
Write it at the end
In 2023, the national new energy subsidy ended. Unlike many people's expectations, the price of new energy vehicles did not rise in an all-round way. After Tesla announced the price reduction, customers and Tucki also joined the price reduction team, giving a lot of concessions. Just like the cost reduction mentioned in the above four points, I believe that with the progress of technology and technology, we can buy products with better and smarter experience at lower prices in the future.