Many friends in the industry are discussing that the electrical architecture and integrated form of Tesla Model 3 are very different from traditional cars. Friends who are inclined to outside the industry think that Tesla is 1-2 generations ahead of traditional companies. In fact, we can discuss in detail,
How did this feeling come about?
In fact, facing this problem, we look at it from different angles. Is this true?
What exactly is the core change in electrical architecture from Model S to Model X to Model 3?
I think we can discuss this issue in detail, because everyone does not know enough information, especially Tesla’s technicians rarely talk about their own software and EE content, and we have no way of in-depth understanding Its in-house engineering and technical personnel design concepts. So I think it is still necessary to think, interpret and form your own independent views from various angles.
1) Mainly due to differences in OS systems
We look at these three evolutionary versions, Model S and Model X to Model 3. In terms of network architecture, if we don’t consider Tesla’s self-developed car-machine system, a large number of components are combined according to the supplier’s situation. We can see a lot of simplification of electronic components from Model S to Model X. Merge and integrate to remove those general-purpose components, and gradually increase the functional authority of the Linux system developed by myself in the original possibility.
I think Tesla’s EEA level is similar to traditional car companies here. It does not involve the core area of its own system and uses a large number of CAN networks; The common practice of these companies is to start talking about the car body, air conditioning, etc. first.
The big differences in the long run are:
In a place far away from security, through integration and simplification to get rid of the shackles of suppliers, Tier1 leads the door, and then simplifies the design by intervening
Breaking away from the original function setting, it is a system design based on virtualization from the very beginning. The most typical one here is still our design idea of switch => ECU => actuator, which becomes the system interface => Linux system => actuator, and a lot of things are done completely around the signal. Then, the information collection of the system itself is added, and functions that are not easy to implement in the original ECU can be designed in a wider dimension around the non-real-time system
Remarks: We consider a hard real-time system, and it is okay to make a window of 1s or 60s. When looking at the problem in terms of hours or days, the original consideration is not appropriate. I think this lead is due to the limitations of the original automotive electronics.
Remarks: I can’t see clearly the pictures I posted before, I try to enlarge some pictures as much as possible
2) Consideration of reliability and maintenance cost
If we compare several parts of the body of Model X and Model 3, we can also see that this change is also necessary. In the past, the design of BCM was not very different from that of other car companies. According to the wiring harness diagram, the entire function was classified as follows:
The body management system inherits the full functionality of Bluetooth, LF antenna and LIN communication as well as CAN communication
The interior lights and alarms are also included.
External perception sensors, including temperature and rain sensors
Processing involving direct regulation is also done here
When it comes to Model 3, we can see that the functions are more integrated, and the functions other than a few core design parts are reduced as much as possible. We can see that this seems to be a process of combination, combining many things together. There are several conditions for doing this:
These design circuit modules need to be very reliable, otherwise the failure of a single component will cause functional problems and the maintenance cost will be relatively high
The cycle of test verification is relatively long, because there are more functions covered, and there are more test cases and actual conditions under various interference and combined functions.
In the later stage, you have to follow this centralized path. The cost of engineering changes is not low, and you have to go through the whole thing to make some changes.
The left body controller mainly covers the following functions: front seat control, front door control, air conditioning system, ultrasonic sensor and TPMS interface.
The big difference between the right controller and the left controller is the addition of R7F7015483, which is the controller sequence of Renesas RH850 Series Body Control Module, 3072K bytes + 64K bytes, this chip and three NCV74244 channel LIN communication controllers, It is used to process and read the signals of all ultrasonic sensors as a reading of a sensing signal.
We can understand that these external changes like Model 3, the manufacturability of components, the scope of EOL off-line, and QRD (Quality, Reliability, and Durability) will make the cost of changes very high. In the past, there was a method of accumulating modules at one level, which was to process a lot of things through artificial division, and it was also a way to share risks.
Summary: I think many things are not as smooth as they seem on the surface. The statement made by the CEO of Volkswagen still shows an attitude. In the short term, it must be sacrificed in the non-safety field (increasing costs and QRD is not good-looking) in exchange for long-term Transformation, the so-called advanced nature of the surface, we realized that it will actually take a lot of pain to transition to the past.