[YesAuto technology] At the Guangzhou Auto Show that just ended, Jiangling released its 2016 JMC Yusheng S350. The main improvement of the new car is the addition of a 2.0T engine with ZF’s 6-speed automatic manual transmission power system. The engine is derived from Ford, and is also the latest version of its 2.0T engine. However, any model equipped with a new power system needs to be re-calibrated and tested. The engine calibration of a new car is a system engineering that involves various complex projects. It needs to be tested in various extreme environments. This time we are introducing high temperature and plateau tests. Among them, the high temperature test will go to Turpan, the place with the highest average temperature in the country, which is also the location of the Flame Mountain in “Journey to the West”; the plateau test will go to the Hoh Xil Reserve, which is 4700 meters above sea level. This article will introduce what kind of tests manufacturers will conduct in order to test the performance and quality of vehicles in extreme environments, and see how automotive engineers usually work.
■ Model introduction
The 2016 Jiangling Yusheng S350 2.0T (hereinafter referred to as S350) of the vehicle tested by Jiangling Motors. The 2.0T engine used in this car is from Ford and is produced by Jiangling by CKD (Completely Knock Down) assembly method. It is the latest version of Ford's 2.0T engine. It matches the 6-speed automatic manual gearbox provided by ZF. The power system is completely new. This time, the new power system will be tested at high temperatures and plateaus. Since the car was still in the confidential stage during the test, we photographed models with camouflage or old models.
■ High temperature test
The high temperature test, as the name implies, is to test the adaptability of the vehicle in a high temperature environment. This is also an important item in the vehicle “three highs” test. The location of the test is related to the area where the vehicle is sold. The S350 is a model sold nationwide. It is natural to find the hottest place in the country for testing. The test items cover almost every function of the vehicle. We will select some of them below. The project is introduced.
● Site selection: The most important requirement is high temperature. Go to the hottest place in the country during the hottest season.
Many domestic manufacturers choose Turpan for high temperature testing. This is one of the hottest places in the country. It is known as “Fire Island” in history. Turpan's daily maximum temperature is higher than 35 degrees Celsius and the average annual average is more than 100 days. , The average annual temperature is 35-40 days when the temperature is higher than 40℃. The absolute maximum temperature measured in history is 49.6℃ (July 13, 1975), and the surface temperature can reach 83.3℃, which is a veritable “Chinese hot spot”. According to my personal experience, the most uncomfortable thing in this place is not the hot air temperature, but the really high intensity of light. Although the Turpan Basin is the lowest inland basin in China, the amount of solar heat radiation here is per square centimeter. Up to 139.5 cards, up to 9.8 trillion cards in the city.
Except in the same city, the major manufacturers even tested the same roads. They were all on the S202 provincial highway next to the Turpan high-speed railway station. The road is surrounded by deserts on both sides, and occasionally there are several small factories in the surrounding area. There are no vegetation and buildings, the sunshine is very strong, and people are usually sparsely populated. Basically, all the test vehicles from major manufacturers are seen on the road. Pedestrians or other social vehicles are basically not visible. The test here can reach the temperature required for the high temperature test. It will not be disturbed by other pedestrians.
The high temperature test is different from the high temperature test. The high temperature test requires low temperature, which often takes place in the early morning or late at night to reach the required temperature. Testers are required to get up early to test different items in the dark. High-temperature projects require high temperatures, and generally do not reach the required temperature until the afternoon. Therefore, most of the various tests are conducted in the hottest afternoon, so engineers often work in the afternoon.
● Engineer introduction
In this high temperature test, we will come into contact with the four engineers in the picture. Two of them are engineers from Jiangling, and the other two are engineers from United Automotive Electronics Co., Ltd. (UAES). The engine calibration work is performed by UAES engineers. And Jiangling’s engineers will check and accept the calibration results.
It is a common practice in the industry to invite professional companies to perform new car calibration. United Automotive Electronics Co., Ltd. (UAES) is a joint venture in China between China United Automotive Electronics Co., Ltd. and Robert Bosch Co., Ltd. of Germany. The company is mainly engaged in the development, production and sales of gasoline engine management systems, transmission control systems, body electronics, hybrid and electric drive control systems. In the field of new car calibration, many domestic first-tier brand manufacturers are their customers. They list 40 brand customers on their official website, including joint venture brands such as Mercedes-Benz, BMW and Volkswagen, as well as Chinese brands such as FAW, Geely and JAC .
● Introduction of test equipment
Let me introduce the related equipment used by the engineers in the plateau test. Since this time is mainly to collect data and verify the previous data model, the tools used by the engineers are mainly notebook computers and various sensors, which will be introduced one by one below. In terms of software, INCA software is mainly used for engine calibration system.
Laptops have long been an indispensable tool for engineers. This time, the models of engineers’ laptops are different. As long as they can run INCA software, they don’t require high hardware performance. I have made a rough statistics and basically use them. Lenovo and Hewlett-Packard brands account for the majority.
At present, most automobiles use electronic control systems. Engineers need to calibrate the electronic control of the engine. The software systems include INCA, CANape, ATIVISION, etc. This time, Jiangling engineers use the German ETSA company. INCA calibration software. The software can detect various data of the vehicle in real time, adjust the parameters of the ECU at the same time, and calibrate the vehicle according to different environments.
In terms of hardware, it mainly includes various calibration communication tools, such as ES630 air-fuel ratio analyzer, temperature, pressure and speed data acquisition module, etc. By connecting sensors and trip computers everywhere in the vehicle, engineers can use INCA calibration on a laptop computer The software works.
● Test items
After introducing the relevant tools for testing, let’s take a look at the specific calibration items that engineers will do in the high temperature test. Since we only have 4 days and cannot fully demonstrate the whole process of the high temperature test, here are a few of the items to be selected. Introduction.
◆ OBD monitoring model calibration of turbocharger vacuum controller
Project introduction: Since mass-produced commercial vehicles will not install numerous sensors, the trip computer ECU will adjust the different parameters of the power system when encountering different road conditions, which requires engineers to establish a correspondence for the ECU in advance According to the data collected in advance under these conditions, the power system is adjusted. This item will have an impact on the power experience during actual driving.
The whole project is to collect the data of the vacuum controller of the turbocharged engine at different altitudes to establish a data model. In the production car, the ECU will adjust the engine according to the data model without the need for numerous sensors. It can be seen from the figure that the model requires the collection of 10 sets of duty cycle pressure values of different vacuum controllers under 10 different pressure values (the lower the pressure value, the higher the altitude).
In actual operation, it is actually relatively simple, that is, when idling, use the computer to adjust different duty cycle data, and then record the corresponding pressure data. This process is actually very simple, but all the data of 10 different pressure values must be collected. Complete, it really needs to be collected at different altitudes all over the country. Traveling Wanli Road is only for collecting 10,000 sets of data.
◆ Calibration of fuel temperature OBD monitoring model
This project is somewhat similar to the previous project. It is also based on collecting data to build models. This time, it is collecting fuel temperature data. Since the fuel injection quantity of the engine is measured by volume, the density of the fuel will change according to the change of temperature. After the density changes, the fuel of the same quality will have a different volume, so the ECU must always follow the change of the fuel temperature. To determine the fuel injection volume, this test is to verify whether the actual fuel temperature is the same as the previous preset value in a high temperature environment. This project will mainly affect the daily fuel consumption and power performance, and it can be regarded as a project that has a relatively large connection with the owner's car.
This project will have an impact on the fuel consumption and power performance of the vehicle. It should be said that it is a more important subject in engine calibration. Engineers spend relatively more time on this project. In actual operation, engineers need to collect fuel temperature data at different vehicle speeds, such as fuel pumps, fuel pipes, and fuel pump outlets. Test whether the data at different times and speeds is the same as the preset value, and then make corrections.
◆ Hot start test
This project is mainly to test the engine's hot start in a high temperature environment. In addition to the high ambient temperature, the engine itself must also reach a certain operating temperature, so that it can be tested under extreme conditions where the internal and external temperatures of the engine are relatively high. Whether it can start smoothly. The tested items include the time of starting, whether the engine is running smoothly after starting, and whether the torque output will fluctuate.
In actual operation, the engineer will ask the driver to simulate extreme driving conditions, for example, let the vehicle use 1 gear, maintain a high speed of 4500 rpm, continue to run for a period of time (about 15 minutes), and then stop in a place where there is no wind, and test separately. After stopping for 5 minutes, 10 minutes, 15 minutes and 30 minutes, the situation of hot start. Make adjustments based on the measured data. For example, if the fuel temperature is too high, adjust parameters such as fuel injection volume and fuel injection time.
◆ Fan detection
This project is mainly to detect the influence of the fan switch on the engine idling stability in a high temperature environment. Starting the fan will affect the load of the generator, which will affect the engine speed. The engineer’s goal is to make the influence of turning on the fan on the speed in Within 30rpm, if the impact on the speed exceeds 50rpm, the driver and passengers can feel it.
The detection method is that when idling, the engineer will control the ECU to manually switch the primary and secondary fans through the laptop computer, and record the impact on the idle speed. If the impact range exceeds the requirements, the engineer will adjust the throttle and ignition angle and other parameters to deal with it. The effect of switching the fan on the engine speed.
In actual operation, the engineer basically adjusts various parameters to the computer. The vehicle only needs to stop in place, start and maintain the idling state. From the outside of the vehicle, it is not obvious that the vehicle is undergoing testing. Automobile technology has developed to today’s level, and many things are processed by computers. The “three highs” test is more of a verification work, which is to see whether the previous preset values are correct in different environments and based on the actual situation. Make adjustments.
■ High temperature test summary:
The report in just a few days cannot summarize the entire content of the high temperature test, but most of the project test procedures are similar, and we select individual items to introduce. To put it simply, the most important thing for high-temperature testing is that the ambient temperature here is high enough to verify whether the vehicle's performance under such extreme conditions meets expectations. The high temperature and hot sunlight here are not only a test for the vehicles, but also for the engineers. Sometimes in order to collect a set of data, the test needs to go back and forth on the same road several times, and run back and forth on the S202 highway in Turpan. It's really not a casual thing, even if the air conditioner is turned on, the sun outside the window can also make the human body hot. It is the strict requirements of the engineers behind these on performance and quality that can ensure that the cars finally delivered to consumers are safe and reliable in various environments. Next, you will see the report of my colleague Tang Chao conducting a plateau test in Golmud.
■ High altitude test
When Liang Haiwen returned home after being baptized in high temperatures in the Turpan Basin, the test car did not “rest”. They were loaded on a transport vehicle and sent to Golmud, Qinghai, in the starry night. Here, they will face a plateau test at high altitude and low oxygen content. Following this test, I first flew from Beijing to Xining, which is more than 700 kilometers away from Golmud and just over 2,000 meters above sea level, and we finally need to go to the Hoh Xil Nature Reserve at 4,700 meters above sea level, a journey of more than 700 kilometers. So I, who has lived for a long time at an altitude of less than 100 meters, have a body to adapt.
In the vehicle plateau test, oil is also the top priority of the test. Throughout the test, gas stations will be randomly selected for refueling to test the adaptability of the engine to oil products. On the plateau, not only is the oxygen content in the air lower, but the air humidity is lower than in low-altitude areas, which means that the air here is drier. For vehicle engines, the combustion chamber has a higher temperature and is prone to pre-ignition.
Before entering the test area, the tester will reconfirm the state of the vehicle, because most of the test area is in a deserted area, it is very difficult to repair problems, and the progress of the test project will inevitably be affected.
The entire test process is very similar to our previous trip to the Chongqing Dianjiang Proving Ground to experience the vehicle durability test, all of which are repeated tests on the road to observe the results. The same gear, the same throttle depth, and repeated observation of the speed, the work of a test driver in the real world is so boring. There are no supercars and beauties, only the rustle of the radio signal after the vehicle enters the hinterland of the plateau.
Are you asking about the results of the test? From the Q&A between Xiaoan and his colleagues, I only got the answer that everything is in the design. This may be good news if there is no news.
Even if you are at an altitude of 4110 meters, it still takes at least 2 hours to completely cool the engine. Since the vehicle is in a confidential stage, Xiaoan and his colleagues must be near the vehicle at all times. Between meals, I asked Xiao An how he spent this time every time, and he replied slightly shyly, “Look at the test procedures or miss home.”
We could not fully experience the time and physical relationship in the follow-up tests. As I panted and climbed up and down the mountain, the work of Xiao'an colleagues had just begun, and the Yusheng Plateau test project had just begun.
● Postscript of Altitude Test
One month after returning to Beijing, Xiaoan posted a circle of friends, again in a snow-capped mountain. I sent him a WeChat message, asking him to summarize what his work contains. The dialogue is as follows:
“Is the job of a test driver really always sleep and eat?”
“Of course not, in addition to testing outside, I will write a report in the office to prepare for the next test!”
“Uh, then I'll give you another chance, will you still choose this job?”
“Of course, but to be honest, sometimes it's a bit boring. It may be aware of the car problem before everyone, I think it's worth it!”
■ Summary of the full text:
Through the double-high test of the new Yusheng 350 2.0T model, we can see that in order to verify the performance and quality of the vehicle under extreme conditions, the manufacturer’s engineers will conduct tests all over the country. Not only is it a test for the car, in fact, It is also a test for people, and it is also a physical exercise. In terms of working methods, most of the work today is done on the computer. Whether it is to verify the feasibility of the data model or calibrate the power system, it is adjusted through the corresponding software, and there is almost no need for hardware. The changes are completely brain-intensive tasks. In general, the calibration of the vehicle must be done well. Without a good body and strong professional knowledge, it is really not done well. Take a look at the new Yusheng 350 2.0T model tested this time. Whether it is a high temperature test or a plateau test, it can be said that it has shown good adaptability. For its performance after the market, please pay attention to our subsequent tests. article. (Photo/Text/Photo by Liang Haiwen/Tang Dynasty)