Market Data 
Markets
Replies to post #90291 on Tesla Inc (TSLA)
11/25/24 8:23 PM
While most passenger vehicles older than about 15-20 years controlled the throttle with a cable connected directly from the throttle body to the accelerator pedal, most manufacturers have switched to a fly-by-wire system which takes sensor input from the accelerator pedal and sends that position information to the vehicle’s computer which in turn adjusts the throttle position. This might be slightly cheaper to manufacture, but introduces a much larger number of failure modes to a critical system.
[Colin] is recreating one of those failure modes by introducing an electromagnetic pulse at a specific point on the vehicle’s computer. In the real world, this could be caused by certain forms of EMF potentially including cosmic rays. This introduces a memory fault which the computer doesn’t seem capable of recognizing or clearing. With the right set of circumstances that [Colin] can reliably produce, the computer eventually will drive the throttle fully open, and the condition can only be corrected by power-cycling the vehicle’s computer.
The National Highway Traffic Safety Administration (NHTSA) has reopened its investigation into a potential design flaw in Tesla vehicles, which may lead to sudden unintended acceleration. This comes after allegations were made that a voltage spike deep within the control systems could cause the vehicle to incorrectly read an accelerator input, even when none has occurred.
When Voltage Spikes Trigger Unintended Acceleration
Under certain circumstances, such as slow driving, when the power steering requires more power, the draw on the 12-volt battery can cause a significant spike in the system. This voltage surge could lead the inverter to incorrectly conclude that the accelerator pedal has been pressed, resulting in unintended acceleration.
This unexpected acceleration could theoretically happen when a voltage spike, lasting only microseconds, occurs simultaneously as the car performs an ADC check, also lasting microseconds. Belt suggests that the frequency of these events aligns with the 200 or so incidents reported between 2013 and 2019.
Adding complexity to this issue, Belt contends that due to the nature of the fault, it does not get logged as an error. The inverter’s misinterpretation of a voltage spike as a throttle input leaves no trace, leading to discrepancies between Tesla's vehicle data and owners' accounts, possibly explaining why the ODI initially denied the petition.
While Belt's allegations primarily focus on the Model 3, which features a unique inverter design, he notes that similar errors could occur in Model S and Model X vehicles. This opens up the potential for a broader scope in the ongoing investigation.
What's worse is that the incorrectly increased sensor signals will be sent via the CAN bus to the vehicle logs, causing Tesla and NHTSA to conclude that the driver caused the sudden increase in torque by stepping on the accelerator pedal. But in this case, the sudden acceleration was caused not by the driver stepping on the accelerator pedal but by a random superposition of a negative-going voltage spike (which is about 100 microseconds long), and the sampling time of the analog-to-digital converter (which is about 10 microseconds long). This random superposition explains the low occurrence rate of sudden acceleration in Tesla vehicles
E3 can also affect subtransmission and distribution systems by causing harmonic distortion and voltage depression. The voltage regulators at the substation will attempt to correct for low voltage levels on distribution circuits. This attempt can result in overvoltages when the E3 stimulus decays to a low value
4). Among the data records during the accidents according to the background data of the crashed vehicles or the data of on-vehicle terminals, the position values of most accelerator pedals were very high(99%) while the values of brake pedals were 0% or only non-zero in very limited moments (see Fig. 1 and Fig. 2).
In recent years, there have been numerous out-of-control accidents of electric vehicles.
Occasional fault of electronic control unit caused by electromagnetic interference
External electromagnetic interference refers to that caused by electromagnetic radiation of various electrical facilities including the high voltage transmission line, broadcasting TV devices and radio communication equipment as well as natural phenomena such as lightning.
Electromagnetic wave interferes the electric control system of automobile through wiring harness and car body to make it hard to perform or even send wrong instructions leading to wrong actions of various actuators, affecting the safety, reliability and stability of automobile driving. The electromagnetic interference affects the automobile electronic control system mainly in two ways: one is to affect the input signal of the sensor of the electronic control system, causing distortion and resulting in electric control signal where the ECU output does not match the driver's intention, which leads to the wrong operation of the actuator; the other is to interfere the ECU output signal to result in its deviation, misleading the operation of the actuator.
The most common cause of Natural EMI includes:
Lightning
Solar Magnetic Storms
Earth’s Magnetic Field Flux
Cosmic Radiation
When computers go wrong, we tend to assume it's just some software hiccup, a bit of bad programming. But ionising radiation, including rays of protons blasted towards us by the sun, can also be the cause. These incidents, called single-event upsets, are rare and it can be impossible to be sure that cosmic rays were involved in a specific malfunction because they leave no trace behind them.
And yet they have been singled out as the possible culprits behind numerous extraordinary cases of computer failure. From a vote-counting machine that added thousands of non-existent votes to a candidate's tally, to a commercial airliner that suddenly dropped hundreds of feet mid-flight, injuring dozens of passengers
Plus, since giant ejections from the sun can sometimes send huge waves of particles towards Earth, what's called space weather, an unnerving prospect looms: we could see much more disruption to computers than we're used to during a massive geomagnetic storm in the future
Tesla argues it had no control in the crash and death which were "caused by a superseding and/or intervening force."
I'm begging all of you to NEVER get in a Tesla as long as you live. It started accelerating on its own in a parking garage and my dad lost all control of the car and we ran into a wall at 40 mph. Most horrifying experience of my life.
Jain is one of tens of thousands of Tesla owners who have experienced premature failures of suspension or steering parts, according to a Reuters review of thousands of Tesla documents. The chronic failures, many in relatively new vehicles, date back at least seven years and stretch across Tesla’s model lineup and across the globe, from China to the United States to Europe, according to the records and interviews with more than 20 customers and nine former Tesla managers or service technicians.
AI
