1. Road test process
test site
1. What are the test sites?
For some less demanding/simple test scenarios, you can find some closed sites, such as dead end roads or test roads provided by the local government of the city, such as special roads for intelligent network connections. For complex or relatively demanding The test scene can be tested at a professional national intelligent networked vehicle pilot test field. The following provides a demonstration area commonly used in China:
① Closed test area of National Intelligent Connected Vehicle (Shanghai) Pilot Demonstration Area
② National Intelligent Commercial Vehicle Inspection and Testing (Taixing) Base
③ China Automobile Center (Yancheng) Automobile Test Site
④National Intelligent Transportation Comprehensive Test Base (Wuxi)
⑤Zhejiang 5G Internet of Vehicles Application Demonstration Zone (Hangzhou Yunqi Town & Tongxiang Wuzhen)
⑥ China Automobile Center Intelligent Connected Vehicle Test (Beijing) Base
⑦ China Automotive Research Institute Intelligent Connected Vehicle (Chongqing) Test Base
⑧National Intelligent Connected Vehicle (Wuhan) Test Demonstration Zone
⑨National Intelligent Connected Vehicle (Changsha) Test Area
⑩National Intelligent Connected Vehicle Closed Test Base (Hainan)
2. What types of roads are there in the test site? How long is the field? How wide is the driveway? Charges?
Commonly used test field types are: straight line performance road, dynamic square
The length of the site is usually 2km-3km and above
The standard width of a single lane is 3.75m
Charges are usually charged by the hour, 1 hour is ￥2000+
CAN related
1. What is the difference between CAN, CAN-FD, FleyRay, and LIN bus communication distance and speed?
2. What are the classifications of CAN?
Drive CAN
Body CAN
Chassis CAN (chassis CAN)
Instrument CAN
Infotainment CAN (entertainment CAN)
Diagnostics CAN
3. Which analysis windows does CANoe use?
Analysis（Measurement Setup/Trace/Graphics/Statistics）
Simulation（）
Diagnostics
Environment（System Variables）
Hardware
Tools（CAPL Browser/Panel Designer）
Actuator Performance Test
1. What is the actuator test?
Example: accelerate(throttle);
decelerate (brake);
steering (steering wheel)
2. What are the working conditions of the actuator performance test?
Slope input, sine input, step input
state machine test
1. How does the CAN bus transmit signals?
differential signal
2. What are the logic signal values corresponding to the dominant/invisible levels of the CAN signal?
Dominant level corresponds to logic "0", invisible level corresponds to logic "1"
3. What are the transition conditions between ACC states?
data collection
1. Introduction to the data acquisition system?
The data acquisition system mainly collects data related to autonomous driving (including raw data) through test vehicles equipped with various visual sensors, such as cameras, radars, lidars, GNSS, etc. These data can be used to accurately simulate certain traffic conditions in the laboratory to test ADAS perception algorithms and control logic, which can save a lot of road testing and validation time.
2. What is the work content of data collection?
Data collection is divided into driving and parking data collection
Daily work content: digital acquisition equipment debugging
Learning and using data acquisition software
Post-processing of acquired data
3. How is data post-processing handled?
First, the data collected on the real vehicle (WinDows system) is converted into a rosbag package through software in the Linux system, and then the rosbag is generated through a script to generate a result result, which includes information such as objects, lane lines, etc. txt, etc.)
After importing into the software by re-injection, you can see the visualized target, lane lines and other information.
4. What is the accuracy of the time synchronization of the data acquisition equipment?
Example: The synchronization accuracy of 500 microseconds to 1 millisecond is in the leading position in the industry.
5. What are the commonly used Linux commands for data acquisition?
Example: ①sudo su//obtain administrator privileges
②df-h//Check whether the hard disk is mounted successfully
③rm-rf//Delete files in the specified folder
④poweroff/shutdown/halt//shutdown command
⑤ssh[user name]@IP address//Switch to another host
⑥sudo./start.sh[path]//run the sh script with administrator privileges, and store the result in the specified path line
6. What is the main type of data collected? What format data does the ros package for data post-processing contain? What are the final processed data formats?
The collected data are mainly engineering documents
The ros package mainly includes bag and xml files
The final processed data is mainly csv and txt, such as truth data (.csv), lane line data (lane.csv)
7. What technology is used to transmit the video stream between the ECU and the camera?
Usually using SerDes
8. How much data is collected?
From software algorithms to hardware devices, the field of autonomous driving will naturally generate a lot of data. A car that meets or is capable of autonomous driving has various sensing devices such as cameras, radars, and positioning systems. These sensing devices run for 24 hours and collect about 4 TB of data.
9. Data storage (data bandwidth estimation)?
Example: ① 8MP front-view camera data volume (RAW14):
3840*2160*14bit*30Hz=3484Mbps
②3MP surround view camera data volume (RAW12):
1920*1536*12bit*30Hz=1062Mbps
③Total data volume of 1 channel forward view + 4 channel surround view camera:
3484+1062*4=7732Mbps=7.55Gbps=0.94GB/s=3398GB/h=3.32TB/h
④ 1 channel front radar data volume:
3.3GB/h
⑤ Data volume of 4-way corner radar:
700MB/h*4=2800MB/h=2.8GB/h
10. What is the principle of data acquisition time synchronization?
Since each sensor has its own time stamp, in order to ensure the time synchronization of each sensor, it is necessary to time the sensor and the acquisition system. The whole system obtains the GPS time by the integrated inertial navigation, and provides time to the time synchronization server; then the time synchronization server provides time to the lidar and the acquisition host through the PTP gateway, so that the whole system uses the same time source (GPS time); at the same time, the time synchronization server Output the trigger signal to trigger the camera, control the exposure time of the camera, so as to realize the data synchronization of all sensors.
11. What is data recharge?
Reinjection equipment is very important in intelligent driving simulation, because some scenes that are difficult to reproduce, it is difficult to reproduce the second time after sending it once in the real vehicle test, such as animals running around on the road and restoring traffic accidents , traffic lights behind trucks, blocked vehicles, dark driving scenes, backlighting caused by sunlight on snow, etc. The intelligent driving re-injection device can make the material of these corner cases form a data prototype and inject it into the domain controller, and then the domain controller can use these data to output an open-loop perception result.
12. What are the data failure simulations?
In addition to re-injection of real scenes, fault simulation can also be performed, involving fault simulation of video frames, such as setting some mosaics at random or fixed positions during the test, or adding some abnormal images to destroy the authenticity of the original video properties, to verify. At the same time, it can simulate underlying faults, such as simulating frame loss and simulating delay.
13. What is data annotation?
Manual labeling is time-consuming and laborious, and semi-supervised learning (pseudo-label learning/automatic label learning) can be used
Principle: first train a model on manually labeled ground-truth data, and then use the trained model to predict labels for unlabeled data, thereby creating pseudo-labels.
Furthermore, the labeled data and newly generated pseudo-labeled data are combined as new training data. Heavy use of automatic or pseudo-labeling is semi-supervised learning.
Advanced testing
Today, with the development of intelligent driving in full swing, the software testing industry has also derived job requirements for vehicle testing. Compared with other positions being recruited, the salary of vehicle testing is also more impressive.
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