The situation before the incident: How do you think that a female car owner in Henan took the Tesla roof to defend her rights, and the loudspeaker played “Model 3 brakes failed, and a family of four nearly died”?

Previously, it was mentioned in other answers that “if the car owner now agrees with the appraisal agency, there is a high probability that Tesla will have no problem in a short time.” Sure enough, before the appraisal agency came out, many people began to scold the car owner. The owner of the car could not take out anything except a mouth and a mobile phone. And Tesla can not only take out the data, but also take out all the bad habits and *** during your M3 period. At that time, the appraisal agency can only refer to the information provided by Tesla “voluntarily” to prove that Tesla no problem. Because Tesla is not stupid, there is definitely no problem with what you can get. You can’t get the others if you want. Is there any relevant agency that can force Tesla to provide true and complete back-end data? Of course, let’s not say who is right and who is wrong. Everyone still doesn’t understand. However, one party must be lying, the owner of the car was not the driver and was in panic, and the non-professionals’ statements must not be completely accurate. Tesla is very professional, shrewd and tough, and what it provides is not necessarily true. The owner can’t get anything out and is still in custody. She is now a passive receiver. Let’s not talk about her. Let’s talk about the data provided by Tesla. You don’t need to look at the data provided by Tesla to know that there is definitely no problem, but from the incomplete data sheet, you can still learn a little bit of Tesla braking system information. 1. From 118.5 to 109.5, only 9 is provided on average in 2 seconds. /3.6/2=1.25m/s², I haven’t tested the deceleration provided by Model 3 kinetic energy recovery at about 118, but I just measured the deceleration of about 1.6m/ when the switch is released at about 60km/h. s², of course, I don’t have the specific logic for the kinetic energy recovery of the M3 at different speeds, but I think the kinetic energy recovery deceleration should be greater at 118 hours. But the kinetic energy recovery of 118kph at the time of the accident plus brake pedal force and wind resistance provide a deceleration of 1.25m/s², which is not as good as the single kinetic energy recovery deceleration at 60kph. I don’t quite understand this. I hope someone can help. Interpretation, thank you first. 2. In addition, from (94-48.5)/3.6/(27.45-25.41)=6.3m/s², this data is not ideal. According to the M3 100kph braking distance of 35m, the deceleration is about 11m/s². The accident data is obviously much worse. 3. Some people may have doubts that the above calculation is not all the maximum brake. Then I want to say that this data is incomplete and I have no choice. But we will also do the math. At 74kph, it is considered full braking, from this moment on. (74-48.5)/3.6/(27.45-26.43)=6.9m/s², I didn’t want to understand, the difference between full braking and not full braking is not obvious, is it due to the steering effect or something else? It can’t be seen from the data now. Well, when it comes to this, I’m the same as everyone, but I can see that the braking effect of the M3 in this accident does not seem to be very good, and it is certain that the owner’s father did not get the “Electric Gate Star” like other owners. title. But who is lying is still unknown, maybe neither can be trusted. Or is there no lie between the two phenomena during braking? The pedal feel calibration curve should be in the middle of the upper limit and the lower limit. Because I feel that the M3 pedal is indeed hard and fails to provide pedal stroke signal data, so boldly guess if the M3 curve is as follows. The driver may indeed depress the pedal forcefully, but the result is that, as in Tesla’s data, it failed to generate enough master cylinder pressure to provide sufficient deceleration. Does this possibility exist? There is also a conjecture, ibooster has signal loss or bugs and other faults, even though the pedal is stepped on, it cannot provide assistance, which affects the braking efficiency. Correspondingly, Tesla believes that the driver did not pedal vigorously. Not to mention that the deceleration at 6 o’clock is almost the same as the full braking deceleration when there is no assist. The relationship curve between pedal force and deceleration is based on the current situation. Even if the appraisal agency intervenes, it is difficult to prove that Tesla has a problem. Therefore, it is estimated that the probability of failure of the owner is relatively high. Tesla also pointed out that it has exceeded 100kph many times before. Then please help the government to find the dash cam and previous intersection data. If there is speeding, end the farce early. If there is no speeding, although you may not be able to pay you justice, everyone will still support you.


By zhiwo

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7 months ago

This data, for the engineer, looked lonely. 1. Lack of key signals. According to the following draft of the GBXXX “Automobile Incident Data Recording System”, the draft to explain the requirements of the Ministry of Industry and Information Technology for EDR is as follows EDR can automatically record the vehicle operation and vehicle safety system status during a period of time before and after the occurrence of a vehicle collision Information, such as: vehicle speed, steering angle of the steering wheel, engine operating status, vehicle stable status, seat belt use status, airbag status, vehicle braking system (ABS, etc.), driving assistance system, occupant distribution, driver in a collision event Important information such as the reaction to the time. When a vehicle has a collision event, by collecting and analyzing the vehicle state and driver’s reaction actions recorded by the collision event data recording system, the actual operating parameters of the vehicle before and after the collision event can be inferred for the analysis and identification of the collision event Provide objective and fair technical support. According to data released by Tesla, there is only a brake switch and no brake stroke. Therefore, it is difficult to be used as a basis for judging the “driver’s reaction behavior when a collision occurs.” Such a system design obviously does not meet the national standard. So I prefer to believe that Tesla has a record of the brake pedal travel data, but it has not been intercepted. 2. The data collection frequency is low, and it is difficult to judge what happened within tens of milliseconds. 3. The ABS is triggered, and the deceleration is only 0.6 g? If the road is dry, this data is abnormal. But we don’t know the road conditions at the time and cannot judge. In summary, it is really difficult to come to any conclusions. Does Tesla really want to clarify the problem? As far as I know, Tesla also has dash cam records and real-time data uploaded. For example, this shadow mode Tesla is already an old player in the field of autonomous driving, but Tesla’s official road test is really very few, most of which rely on Tesla owners to contribute data on autonomous driving. Previously, Tesla released the “shadow mode” in April 2019, hoping to make a large number of Tesla cars’ self-driving hardware work while the vehicle is driving to achieve the purpose of machine learning. The principle of “shadow mode” is to enable the autopilot software of the Tesla car, and the sensors detect the data around the road on which the vehicle is driving, but the driving operation is completely completed by humans, and the machine does not participate in driving. In the process of human driving, the machine can learn the human driving operation, so as to achieve the purpose of improving the ability of automatic driving. If you want to restore your innocence, you might as well make the rest of the data public. Since there is no problem, why conceal it?

7 months ago

A table with only a few rows of seemingly critical data. Isn’t this complete data? ? ? Even if it is not complete, please publish more objective data. Do not selectively use part of the truth to bring rhythm. The braking process requires the participation of multiple systems, at least including brake pedal switch sensors, pedal depth sensors, motors, and the entire vehicle. The controller, ESP system (including ABS), the AEB emergency braking is activated, and the forward radar is involved. As a result, only a few seemingly professional data such as vehicle speed, pedal switch signal, and brake cylinder pressure were given. The pedal depth data, motor speed signal, and forward radar data are all given to fully restore the process of the car owner’s braking, motor speed and vehicle speed verification, and forward radar to see the distance of the vehicle ahead… Does it better reflect the real situation at the time? ? Since you have said that the driver increases the amount of brake pedal, you must have this data, right? Announce it. The data of the brake pedal depth sensor can truly reflect whether the owner has stepped on the pedal violently, and whether the pedal cannot be stepped on due to the increased resistance of the pedal. Take a closer look at the name of the pedal column is the physical movement signal of the brake pedal. Movement is not a switch. Is there any movement? Why is it blank? In addition, it clearly stated that the data was half an hour before the accident, and the investigation has not yet started. As a result, it was the first to publish several data to the media (China Market Supervision News is a media, not a regulatory bureau, and it is also very high here). , The Internet has already begun to attack female car owners and lie. Tesla wants to prove that it is okay. Even though it will provide more data, the Municipal Supervision Bureau cannot analyze it. Auto experts can analyze it. Don’t just take a few editable forms to prove your innocence.

7 months ago

Some comments prove that the data is incomplete based on the time interval of the data, and one says that this is not a problem technically. Because the car bus data is different from the network data we understand, not all data is time stamped. The CAN bus sends some data cyclically, and stops sending after the information receiver feedbacks. So the time may be a common time on the bus. In addition, the bus has multiple transmission frequencies according to the priority of the signal, and the bus will have a congestion delay, so some data intervals of 1s are also possible (the key high-priority signals, such as braking and acceleration, will not be so long). Also, there is a national standard GBT32960 for Internet of Vehicles data upload, but this national standard only requires part of the data and data format, at least that part of the data is not that simple. Moreover, Tesla has always claimed to be using car owner data to optimize the intelligent driving algorithm, so if the data it collects by itself is so simple, it certainly cannot be done.

7 months ago

One! point! Sincerity! No! An empty table does not even have the most important brake pedal stroke signal, so that there is no reference for the driver’s braking behavior. How to analyze the accident, it is better to listen to the owner of the accident. In addition, there is no energy recovery signal, nor is there any drive motor torque signal. But in spite of this, you can still have a conversation with Tesla and ask everyone together. Borrow the complete form Round oneLeech: I see that most of the form is empty, especially when there is no brake pedal displacement signal. How can I judge the driver’s operating behavior like this? Tesla: This signal should not be recorded. Leech: The electric vehicle monitoring platform should be required to record information such as the torque of the driving motor. This information is directly related to the acceleration and deceleration of the vehicle. Tesla: Yes, but uploading to the platform The data is only uploaded once for a long time. It is meaningless. Leech: The vehicle itself will definitely record these data. Why did you not disclose it. Tesla: If you keep recording, the controller storage capacity will be insufficient. Leech: But a few minutes before the collision. The data recording and proper storage should play a positive role in the tracing of accidents. This is not difficult in itself, and it is also a necessary safety strategy. Tesla: In theory, this is the case, but we may not currently have Leech: As far as I know, Tesla has a “safety” strategy that deletes the dash cam images from a period of time before the collision in the event of a collision. Why is it important? Did this one? (See @三青 Deleting driving records after Tesla Model Y accident) Tesla: I don’t understand what you said. Round twoLeech: I noticed that the car triggered ABS from 25.4 seconds to 26.4 seconds, and it was judged from the master cylinder pressure that the owner did not release the brakes, but the car speed only dropped by 20km/h in this one second. That is, when the ABS is triggered, the average braking deceleration is only 0.55g, which is far from the normal standard of about 1g, and the weather is clear that day. This is a bit beyond my imagination. Tesla: The road conditions are particularly complicated, and the ground adhesion coefficient may be Will be very low Leech: There is also the same situation from 26.4 seconds to 27.4 seconds. The car ran for more than 40 meters in these two seconds, which means that the adhesion coefficient is not very good for such a long road. Have you investigated the road conditions of the accident section? If not, we can collect evidence together, such as section characteristics, drainage capacity, and whether there is silt. Tesla: The road conditions are actually difficult to reproduce. Leech: You can roughly judge by looking at the time and frequency of the driving records. First Tesla: The owner’s car does not have a driving record. Leech: I strongly request to do some reproducibility tests, of course, to use other brands of cars. Round threeLeech: Then who do you think is responsible for the accident and whether the vehicle is faulty. Tesla: We have issued a statement and will fully cooperate with the investigation. Leech: I think you wrote “In summary, the vehicle is running at a higher speed When driving, the driver began to depress the brake pedal lightly. After that, the automatic emergency braking function was activated and played a role, which increased the braking force and reduced the impact of the collision. The braking system was normally intervened and reduced the vehicle speed. “At the beginning, when the driver stepped on the pedal lightly, how did you judge Tesla: The master cylinder pressure is not high. Leech: The degree of pedaling in the ibooster system has nothing to do with the master cylinder pressure, so the master cylinder pressure you said is ESP. The pressure of the front master cylinder or the pressure after the pedal putter Tesla: This is not clear Leech: I think you reminded everyone that, “In addition, regarding the condition of the vehicle 30 minutes before the accident, Tesla said this: In the 30 minutes before the vehicle accident, the driver drove the vehicle normally and had more than 40 records of depressing the brake pedal. At the same time, the vehicle had multiple times of exceeding 100 kilometers per hour and multiple stops.” This Is it a dangerous driving reminder? If so, what does it have to do with vehicle performance? Tesla: This is a statement. The above conversation only exists in the truth of all data.

7 months ago

Please give me a copy of Tesla’s DBC, and then give me all the definitions, and then send me a copy of the data, either in asc format or BLF format. I have Canoe here. I’ll see for myself, so that everyone can argue .I stepped on the brake more than 40 times in half an hour. This is nothing to me. There is still a motorbike on the road that does not loosen the brake. Otherwise, the driver deliberately kept on the brakes so that the brakes overheated, and finally could not stop the car. Without the brake pedal depth signal, I don’t know if the driver has stepped on the brake. I tested a test car a few days ago, and the ibooster car should not have been fully calibrated at that time. I immediately released the brake pedal after I stepped on it, but within 0.5 seconds after I released the brake pedal, the car still maintained the deceleration before I let go of the pedal, so I can’t tell whether it’s stepped on by the pressure of a master cylinder. For the sampling frequency, I found the frequency of the bus data analyzed before. The first line is the time, but it is not converted to Beijing time. Look at this frequency. This is the data about 5 years ago. Check it out. To be honest, I don’t understand his data… The data that is usually exported into EXCEL is not the same as this, and I don’t see what the image of his data playback looks like, so I still want to be myself See how clear I look like, how many brakes I have stepped on, how deep I have stepped on it, and how long I have stepped on it, the corresponding vehicle speed can be seen at a glance.

7 months ago

I firmly oppose the statement that “frequent braking causes heat exhaustion, which leads to brake failure”. The object of heat exhaustion is the brake pads. This is indeed possible, but it has nothing to do with the pressure of the brake master cylinder. If it is because of heat exhaustion, the final curve should be a very high brake master cylinder pressure, but the acceleration is very small. Unless there is a scene I encountered in previous competitions, the competition was too intense and the pipeline was not properly emptied, causing the trace water in the oil to evaporate and evaporate, occupying space in the pipeline. The specific manifestation is the pedal. Very soft (because the water vapor in the pipeline is compressed but the oil is not pushed), the brake master cylinder pressure is small, the braking force generated by the piston is extremely small, and the braking performance is greatly reduced. But according to the use scene of the civilian car, I very much doubt whether it can achieve the same intensity as the racing car, which will eventually lead to this scene…

7 months ago

Deeply doubt the authenticity of the data, the following points: by taking the difference of the time stamp, the sampling interval of the brake master cylinder pressure is 0.20-0.22s. The speed sampling is 1.01-1.02s. Doubt 1: The sampling frequency of vehicle speed . This channel has data as long as the car is moving. The sampling frequency is actually 1/5 of the braking force master cylinder channel (used only part of the time). Is this setting method really okay? And, is the refresh rate of the vehicle speed on the dashboard really only 1Hz? Doubt 2: For the sampling frequency, there is no reason to use non-conventional frequencies (for example, often take 1, 2, 5, 10, 20, 50, 100 Hz…), even if you consider the error of thousandths, it should not be 1.01 -1.02, 0.21-0.22 this kind of percentile fluctuation. For a channel that does not require any calculation, you also need to take a 4.76Hz, 0.98Hz, is this method really okay? Doubt 3: There are a lot of timestamps in the cells of speed and active master cylinder pressure. Even if it is reluctant to think that other channels are sampling, the difference of the timestamps is found to be irregular, so even if it is because other channels are in Sampling at the same time, is this kind of irregular timestamp really not deleted (for whatever reason)? 2. The brake pressure of the master cylinder, first of all, is not a difficult term, it can be directly understood as a braking force, and it must have a linear relationship with the braking force on the caliper (F=ps, the total piston area s remains unchanged). Since it is a rear-end collision, we first assume that the maximum pressure of the brake master cylinder is around 140. This is in line with the common sense of life of “a rear-end collision scenario, where the car brakes fully in the final stage” and the “emergency” stated in the Tesla statement. The brake function was activated and worked”. And there was no known weather or other reasons that caused the road to be slippery on that day. If there were any, news reports had already said that from the value of the pressure of the master cylinder, it can be seen that at 26.58 and 27.21, the pressure of the master cylinder experienced two significant downward movements. Polyline. Doubt 4: What is this? Did the driver release the pedal? Is there anything happening in the brake line? Is the data recording error? Design the “brake establishment speed” index, the algorithm is (next brake pressure-previous brake pressure)/(next time stamp-previous time stamp), and the graph is shown in the figure. This kind of jitter can be understood as a situation where you tremble when lifting a heavy object and finally still pick it up. In the calculation, the two reduced values ​​in Doubt 4 were removed. If they are not removed, the jitter will be greater. Doubt 5: Why is there such a big jitter before braking? If it is the driver’s input, is it because the driver can’t apply the brakes? That’s why the brakes are trembling? If it is the intervention of ABS, do you really need to intervene when the acceleration is only -0.1g? If it is the input of other electronic control system, is the calibration really okay?
Doubt 6: Final acceleration The final acceleration calculation result is shown in the figure (for convenience, G takes a positive number). It can be seen that even before the final collision, the maximum braking force is only 0.709. Directly search Model3 brake evaluation, there is an article clearly written that during the evaluation process, when the driver fully depresses the brake, the acceleration is about -1g~-1.2g. Did the driver not apply the brakes fully? Or the driver can’t step on it? Even if according to Tesla, “the emergency braking function was activated and worked”, your emergency braking system finally created a deceleration of -0.7g. Is this calibration really reasonable? Or did it really work? Or… is your data really real? I hope that some engineers in the industry can overcome my six doubts one by one.

7 months ago

According to the data given by Tesla itself, from a speed of 94 in 25.41 seconds to a speed of 48.5 in 27.45 seconds, the vehicle speed is reduced by 45.5 kilometers per hour when the ABS is triggered in 2 seconds. The total is 12.63 meters per second, and the average acceleration is 6.3 meters per second. This braking ability really proves that Tesla can’t stop. The ABS is only about 0.63g. Normal family cars are close to 1g, right? Is this wave of Tesla data surely self-defeating? Knocking on the blackboard, this “China Market Supervision News” is a media that has obtained Tesla’s exclusive first-hand news, so these data and reports cannot be regarded as the official conclusions of Tesla or the national supervisory agency. All in all, when you read this report, you still have to use your brains and discern it carefully. However, judging from the media’s statement, this data table is indeed given by Tesla. There is a question that is worth pondering. It can be seen from the data that the driver depresses the brake pedal from 23.17 seconds, the pressure of the master cylinder gradually increases, and then triggers abs at 25.74 seconds (at this time aeb does not start, indicating that the driver has already done so without the help of aeb The maximum deceleration capacity of the vehicle was reached by stepping on the brakes), and then the pressure of the master cylinder continued to rise, until it reached the peak value in 27.63 seconds (maybe aeb, or it may be a miracle of the owner’s life and death). However, Tesla’s own text stated that within 2.7 seconds of stepping on the brake, the pressure of the master brake cylinder was only 45.9 bar. Please, did you step on the abs at that time? What does it mean? How many people can step on abs when driving? Then Tesla himself said that the brake pressure gradually increased to more than 90. Anyone who knows a car knows that once the ABS is started, it has basically reached the maximum braking capacity of the vehicle, and then it will not work if it is stepped on. Tesla also said that aeb played a role and successfully helped slow down, excuse me? This wave of data actually proved that the driver stepped on the brake hard enough. After all, it was the abs that was stepped on by others. Then even if the aeb system intervened, it did not help to decelerate. If you can’t stop it, you can’t stop it. Tesla’s intention was to use the media to prove that the owner did not apply the brakes too hard. Unfortunately, the data after the ABS trigger happened to prove that there was a problem with Tesla’s brakes. As for how the driver stepped on the brakes at the time, Tesla can only say with one mouth, after all, people have “data” in their hands. In addition, it is strongly recommended that the majority of Tesla owners buy two sports cameras, one before taking pictures of the car and the other taking pictures of their feet, to avoid wrangling afterwards. After all, Tesla’s own driving recorder is also suspected to actively delete the images before and after the collision. At the same time, all the operating data information is also held in Tesla’s hands. The owner is afraid that it is not a dumb to eat Huanglian. If it is true that there is a problem with the Tesla car, using the data given by Tesla under pressure to prove that it is because of the problem with the Tesla car and not because of the owner’s operation error, this logic is too magical, I I believe that Tesla should not make such a mistake.

7 months ago

I’m very curious about why a group of people are so anxious to scold the owner of the car, will it be impossible to let the bullet fly again? The owner did not clearly say that it was between the two traffic lights and the evening rush hour, so there was no speeding. Tesla also said that there were more than 40 records of depressing the brake pedal in the 30 minutes before the accident. At the same time, the vehicle exceeded 100 kilometers per hour and stopped repeatedly. Then compare who is true and who is false in these 30 minutes. After all, there are so many cameras on the national highway, there is always a time to take pictures. In addition, the distance between the two cameras is fixed, the data provided by Tesla is also fixed, and the required time can also be calculated. Regarding whether the car owner is speeding or not, a mathematical model can be established based on Tesla data to verify the correctness of the 30 minutes before the incident. There is another doubt about this incident. The car owner received a call from Tesla at 18 points, which is a clear record of the call. Tesla claimed that the collision occurred at 14 minutes, which is also recorded. This of course contradicts Tesla’s call within one minute of the accident. I don’t know how to explain it (of course I haven’t bought Tesla and I don’t know their rules).

7 months ago

Tesla is worthy of being a U.S. company. Even the published data report exudes a strong American style. What is good for you is released, and what is bad for you is hidden…The time point where the red line is drawn lacks the master tank Is the pressure value deliberately hidden or not recorded? If it is deliberately hidden, does it mean that the data at these points in time will subvert Tesla’s rhetoric? If there is no record, then there is a problem with your hardware and the master cylinder pressure cannot be collected in real time! 25 seconds after the master brake cylinder pressure reaches 45.9, 87 front wheel ABS triggers, and 25 seconds after the master brake cylinder pressure reaches 61.2, 87 rear wheel ABS triggers. As a result, the subsequent master cylinder pressure increases rapidly, but ABS does not Haven’t been triggered?
Dare the driver lightly step on the brake to trigger ABS, but hardly stepping on the brake is not enough to trigger ABS. Is this logical? In the last paragraph of the data, under the condition that the brake master cylinder pressure is already large enough, the vehicle speed ranges from 74Km/h in 26 seconds 43 to 48.5Km/h in 27 seconds 45. For a full period of 1 second 02, the speed only dropped. 25.5Km/h, one has to doubt the braking ability of this car under full braking! As for the issue of speeding attacks mentioned by special fans, even if there is a speeding in front of it, it is under the control of traffic safety regulations. What Tesla has to do is to be able to stop even if it drives fast, otherwise you will kill you! Cao sir is still the same sentence. If a brand highlights its acceleration performance on the product homepage, but does not talk about the braking distance, then this acceleration performance is more like a reminder! In short, I don’t understand whether Tesla is releasing data or releasing conclusions? It’s just a matter of declaring that Tesla is right, it’s all the driver’s pot~ This is very American, but the Chinese people do not eat this set…

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