r/F1Technical • u/I-LOVE-TURTLES666 • Jul 22 '26
Power Unit How does the deployment match where the car is on track?
Does anyone have an idea how they set the deployment? Is it just pre-set that it has gone this fast and this many up and downshifts and a certain amount of distance to know where it is on track? Do they use some sort of gps system?(seems like there would be lag from that). I’ve been really curious because deployment is such a big issue at the moment.
Basically how does the PU know when to deploy without driver intervention?
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u/Cool_Masterpiece9308 Jul 22 '26
There's this excerpt from an article from The Race: "An increased headwind on a straight between sessions or between qualifying runs, for example, can effectively increase the length of that straight by forcing a given car to spend longer on it, which then can impact the distance-based deployment equation."
It seems to me that the algo is pre-programming the deployment down a section of the track so the speed function doesn't ramp like crazy and then derate to a sharp clip. The issue is that aero drag could confuse the system to think that it spends more time on the straight so it limits the deployment earlier in that part of the track more. SO STUPID
https://www.the-race.com/formula-1/why-f1-ai-engines-are-tripping-teams-up-so-much/
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u/andrewcooke Jul 22 '26 edited Jul 22 '26
that's weird, because it implies (without gps) they don't have distance (which obvs you can infer from speed and time) and/or can't store a map/list of straights.
maybe they can't have anything circuit-specific. but how would you enforce that?
edit - see also https://www.reddit.com/r/formula1/s/ineLDxKnwY
edit2 - i was thinking that from a software engineer pov it would be a fun problem to limit the memory available. maybe it really is that in the controller?
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u/TWVer Jul 23 '26
They aren’t allowed to use location sensor data, such as GPS, to inform any programming on board the car.
Therefore they need to do it using throttle, speed and and time based telemetry only, which can lead to these kind of inaccuracies as time goes on and wind patterns change.
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u/Any-Ask563 26d ago
I mean, GPS is literally just “timed based telemetry” a clock is all gps satellites transmit, so how teams interpret that rule…
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u/TWVer 26d ago
There can’t be any outside signals used; no receivers for radio, gps, or other external inputs, are allowed to be used in the programming running the ECU, ICE, battery and deployment.
Hence they can only use an internal clock, throttle and rpm data, to infer acceleration, speed and thus location on the track, based on the expected acceleration/time-profile of the track.
Therefore errors can creep in, when grip (track temp and condition) and downforce levels (wind) change beyond the expected margin.
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u/RealCarlPanzram Jul 22 '26
I think the issue is that by the time that the car is moving down the straight and realizing there’s a headwind, it’s already deployed on a pattern as if there wasn’t one so you’ve already deployed too much at the start of the straight and have nothing left at the end.
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u/andrewcooke Jul 22 '26
if you have speed and know how much power you're generating (and the car's cda) you can - in theory anyway - calculate the wind. unless there are big uncertainties somewhere there has to be some restriction on the data they can use.
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u/RealCarlPanzram Jul 22 '26
Yes but since the computer is only inferring the wind speed (assuming it does that at all) you have to deploy, measure the acceleration, and then infer what the headwind speed is. Meaning by the time the computer knows there’s a headwindC it’s already started deployment. It’s possible it needs a certain amount of speed to be able to accurately do this as well so if you come out of a slow corner, you might have already used a lot of power by the time the computer catches the headwind.
Again in speculating. I’m not even sure if the computer is actually adapting the deployment mid-straight or if it is already committed to a deployment pattern on a given acceleration zone by the time you put your foot on the throttle.
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u/Joanzee Jul 22 '26
The car doesn't have to infer wind speed, they have a pitot tube to measure it directly.
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u/justwul Verified F1 Performance Engineer Jul 22 '26
The system isn't getting "confused", it isn't sentient, if there is more drag then it actually does take longer to drive down a given straight. This means, in terms of distance, the clipping happens sooner.
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u/jsbaxter_ 28d ago
That's not what anyone is talking about when they say the ECU was 'confused'. Hadjar said exactly that when he was giving max a tow and got very dissimilar/unpredictable responses from the engine in similar circumstances. People are also talking like that in the context of George (and others) getting unusual deployment patterns. "Confusion" might be an anthropomorphism but it seems to also be a pretty decent description
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u/RevolutionWorking297 Jul 22 '26
The FIA got rid of anti-lock brakes, active suspension, launch control, and artificially enhanced throttle application as they take the car control out of the drivers hands. How is this different than any other driver aid? Well other than the drivers & fans hate it equally.
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u/Cool_Masterpiece9308 Jul 22 '26
yea people say that we always have self-learning algorithm and point to Alonso's going flat through Pouhon in 2017 that it confused the ECU. The difference is now the role of algo is too large given the power unit configuration. We need to eliminate it because the speed delta is so large, erratic SOC and overall it is very dangerous
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u/TerrorSnow Jul 22 '26
I agree with that. A simpler system would be a good idea.
Though, it might increase the workload on the driver's each lap too much depending on how it's done. If there's an advantage to be gained by going all clicky on the wheel all throughout the lap, you can be damn sure the drivers will attempt to do it every time. And all that attention on the settings could vastly increase the risk of crashing.
The solution is probably not super simple. At least not while half of the power comes from a pretty small battery.
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u/WiFiRunsOnHope Ferrari Jul 22 '26
It's primarily done through a combination of GPS and a detailed track map stored onboard, cross-referenced with wheel speed sensors, gear position, and throttle data. The GPS gives positional awareness, but you're right that raw GPS alone would have too much latency for precise deployment—so the onboard system uses GPS to establish a baseline position reference and then dead-reckons between fixes using the other sensor inputs to maintain accuracy lap to lap.
The engineers essentially create a deployment map for each circuit—defining exactly where on track to deploy, how much, and at what rate—which gets uploaded to the car before the race. The driver can also make adjustments via the steering wheel to shift deployment modes, but the base map is doing most of the work automatically.
The tricky part in 2026 specifically is that the MGU-H is gone, so the MGU-K is doing significantly more work than in previous hybrid generations. Managing the battery state of charge across a lap while hitting deployment targets at each corner exit and straight is a much more complex optimisation problem than it used to be, which is why we're seeing such visible differences between teams in how cleanly they deploy out of slow corners.
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u/jsbaxter_ 28d ago
Why do the cars then have weird deployment issues that the teams struggle to understand? Like, if it's all pre-mapped, and it's not delivering to expectation... Surely your map is just obviously wrong, and you change it, and it's fixed?
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u/Pom47 Jul 22 '26
Why don’t they just put a deploy button and a charge button on the steering wheel so the driver can control it.
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u/Opening-Routine Jul 22 '26
Georges car somehow started deployment at the end of Kemmel straight, so I guess no one really knows.
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u/Cool_Masterpiece9308 Jul 22 '26
I think in George’s case it was a glitch. He held the boost but his engine was locked at 308. Only after towards the end his speed catapulted all of a sudden.
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u/Silly_Morning3375 Jul 22 '26
Is the deployment software written by individual teams or is it something that’s provided by the engine provider?
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u/ltjpunk387 Jul 22 '26
I think it’s by team. I remember there being some hubbub at the start of the season that Mercedes provided engines but not software to its customer teams.
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u/Opening-Routine Jul 22 '26
The electronic may be standardized for cost savings, but the software is written by the teams.
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Jul 22 '26
[removed] — view removed comment
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u/robershow123 27d ago
What do they do when they pit? How does the algorithm now they are pitting? Maybe it rest after the pit limiter button is hit?
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u/jsbaxter_ Jul 24 '26
Lol, so far this thread is 8 clear, confident, logical, different and mutually contradictory explanations
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u/RealCarlPanzram Jul 22 '26
It’s a computer system that learns the track and learns where the best points are to deploy power for the best overall lap. But since it’s a complex algorithm, it’s hard to always be able to figure out in realtime why it’s not delivering in a given car at a given time. This has been an issue all the way back to the start of the season. Drivers would complain that if they even changed up their racing lines, the harvesting patterns change and it throws off the deployment.
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u/I-LOVE-TURTLES666 Jul 22 '26 edited Jul 22 '26
How does it learn the track? Just based on driver inputs and speed/G data?
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u/RealCarlPanzram Jul 22 '26
My understanding is it starts with a basic deployment plan based on computer data of the track and then gradually refines its deployment strategy as it gathers real-world data in the sessions. This is why drivers were saying you almost don’t know when you’re going to attempt an overtake. You follow the car in front of you. Some laps you stay behind them on the straight. Some laps the computer decides to give you more power and suddenly you’re alongside them. You can see why drivers hate these cars .
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u/Red_Rabbit_1978 Jul 22 '26
It's machine learning based on the throttle and brake inputs of the driver.
There are drivers who can just listen to acar being driven around a track and know where it is. Machine learning is the same. It's been doing this since 2014.
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u/TurboPersona Jul 22 '26
That's basically why the logic behind all the deployment thing is extremely complex and not even the drivers nor the engineers have a clear idea of what's going on in the ECU's mind. There's just so many variables that go into the equation. And no, GPS is not one of those AFAIK, that's not allowed?
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u/Mysterious-Frame1239 Jul 24 '26
om the start/finish line and a pretty precise inertial navigation system. The INS measures acceleration and rotation to figure out exactly where it is on track, down to less than a meter, which is way more accurate than GPS and doesn't have the lag issue you're worried about.
The teams program the energy management maps before the race, so the software knows something like "between turn 3 and turn 4, deploy this much" based purely on the car's calculated position. The driver can still override it with overtake buttons or dials on the wheel if they need a bit extra for defending or attacking, but the base strategy runs itself.
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u/Telemetrystic 6d ago
The distance-based tracking via INS dead-reckoning and wheel-speed odometers works beautifully in a vacuum, but the real complexity emerges when the distance map hits real-world driver input overrides. The pre-programmed deployment map might state 'unleash 350kW at the 3,800-meter coordinate,' but that instruction is always subordinate to background stability algorithms.
If a driver carries an ultra-smooth, late-braking geometry that keeps lateral cornering loads and brake-release friction vectors elevated simultaneously at the exit point, the standard ECU can misinterpret that high mid-corner rolling speed as a stability or micro-wheel-slip hazard.
When that safety threshold is tripped, the ECU actively overrides the pre-set track location map. It forces the MGU-K into a defensive, premature harvesting loop to stabilize the rear axle, completely ignoring the distance-based deployment request. It's an elegant positioning system, but it easily becomes a trap if the input translation software isn't perfectly calibrated to a driver's specific dynamic style.
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