TERS : Thermal Energy Recovery System

[subcritical71]

How will the driver be in command and driving the car if his foot demands 50% accelerator pedal travel and the ECU provides 75% or 25% ICE throttles travel?. If that function was allowed by the rules the first thing that will happen is the teams operating launch control and the second after that will be the teams operating traction control to name just two worms.

I don't see this as a workaround for traction control. The pedal is mapped to a demanded torque so as long as the increase in Nm/rpm is respected the 50% pedal position has to deliver the 50% pedal position torque. How that torque is achieved is up to how the engine manufacturer sets it up. It may or may not be a linear ICE or MGU-K map. The driver only controls it indirectly by way of settings on the steering wheel which may change the control strategy.

More curious to me is how the 100% torque is defined in the maps (I know its from a sensor on the crankshaft). Is it at full beans max power or is it at some other setting(?). The reason I ask is that I would think things like ambient temperature and humidity would affect the max torque, so are those part of the maps.

[Tzk]

The ECU does not make decisions on how to mix mechanical and electrical energy to produce the torque level demanded by the accelerator pedal. the ECU Executes the mix level of electric and ICE power/torque as per the selected map from on the steering wheel by the driver. And the driver, according to 5.5 “power unit torque demand” = 5.5.1 “the only means by which the driver may control acceleration torque to the driven wheels is via a single foot accelerator pedal”. What does the driver foot accelerator pedal operates if not the ICE throttles? How will the driver be in command and driving the car if his foot demands 50% accelerator pedal travel and the ECU provides 75% or 25% ICE throttles travel?. If that function was allowed by the rules the first thing that will happen is the teams operating launch control and the second after that will be the teams operating traction control to name just two worms.

Well, the ECU does make these decisions. The input to the whole PU is "torque demand" and the output is "delivered torque on the crankshaft". Everything inbetween is handled as a blackbox for the quoted regulation paragraphs. You can't develop a traction control because that'd require the engine to reduce the output torque for a given pedal position. This has nothing to do with the throttle body position though.

But if the ICE delivers 20, 50 or 100% of the requested torque and the MGU-K 80, 50 or 0%, this isn't covered by the regs and the driver basically doesn't care. As long as the requested torque matches the delivered torque everything's fine

I don’t think a simple offset would work. They still need to map maximum PU torque to 100% accelerator demand.

This raises the question if 100% pedal position must always match 100% torque output. I'd say no, because the pu is ran in a far lower mode in the race than in qualy. Thus race map isn't matching qualy map in terms of power and torque. I conclude that the same applies for a wet/rain mapping.

[saviour stivala]

The ECU does not make decisions on how to mix mechanical and electrical energy to produce the torque level demanded by the accelerator pedal. the ECU Executes the mix level of electric and ICE power/torque as per the selected map from on the steering wheel by the driver. And the driver, according to 5.5 “power unit torque demand” = 5.5.1 “the only means by which the driver may control acceleration torque to the driven wheels is via a single foot accelerator pedal”. What does the driver foot accelerator pedal operates if not the ICE throttles? How will the driver be in command and driving the car if his foot demands 50% accelerator pedal travel and the ECU provides 75% or 25% ICE throttles travel?. If that function was allowed by the rules the first thing that will happen is the teams operating launch control and the second after that will be the teams operating traction control to name just two worms.

Well, the ECU does make these decisions. The input to the whole PU is "torque demand" and the output is "delivered torque on the crankshaft". Everything inbetween is handled as a blackbox for the quoted regulation paragraphs. You can't develop a traction control because that'd require the engine to reduce the output torque for a given pedal position. This has nothing to do with the throttle body position though.

But if the ICE delivers 20, 50 or 100% of the requested torque and the MGU-K 80, 50 or 0%, this isn't covered by the regs and the driver basically doesn't care. As long as the requested torque matches the delivered torque everything's fine

I don’t think a simple offset would work. They still need to map maximum PU torque to 100% accelerator demand.

This raises the question if 100% pedal position must always match 100% torque output. I'd say no, because the pu is ran in a far lower mode in the race than in qualy. Thus race map isn't matching qualy map in terms of power and torque. I conclude that the same applies for a wet/rain mapping.

“if the ICE delivers 20,50, or 100% of the requested torque and the MGU-K 80,50 or 0%, this isn’t covered by the regs”.
The driver’s foot (accelerator pedal) travel 0 to 100, will request a mix of electrical (MGU-K) and ICE power/torque the level of which is as per the selected from on the steering wheel by the driver power/torque map. The level of the output to the driven wheels of this selected map of power/torque mix goes to the driven wheels monotonically (increases or decreases) in accordance with the monotonically increase or decrease travel of the accelerator pedal. The power/torque delivered level will increase or decrease as per the increase or decrease of ICE rpm, with the ‘k’ following suit, it being fixed gear ratio to the crank. The increase or decrease of ICE rpm depends on the travel position (0 to 100 travel) of the ICE throttles butterflies, these ICE throttles butterflies travel position (0 to 100 travel) are as per the accelerator pedal travel position (0 to 100 travel).

[henry]

I don’t think a simple offset would work. They still need to map maximum PU torque to 100% accelerator demand.

This raises the question if 100% pedal position must always match 100% torque output. I'd say no, because the pu is ran in a far lower mode in the race than in qualy. Thus race map isn't matching qualy map in terms of power and torque. I conclude that the same applies for a wet/rain mapping.

I don’t think they would forego the ability to make 100% potential torque if there is sufficient traction to deploy it. So it would depend on the circuit. Maybe on circuits with low full throttle %age, Monaco, Singapore, maybe Mexico but even in the wet many circuits will be 50% full throttle. And in the wet braking distances will be longer and so more basic energy recovery providing plenty of energy for full power deployment.

But there again maybe drivers can make more time with a low power setting and long pedal travel than can be made up on the high speed sections, particularly straights. Teams no doubt run simulations to find out although they will have very little data to work with.

[Dr. Acula]

Implying that a can of worms is indeed available to the PU design team to play with is relegating the rule makers into a very bad light indeed. And in my opinion that is just not right and neither is it fair.
The ECU does not make decisions on how to mix mechanical and electrical energy to produce the torque level demanded by the accelerator pedal. the ECU Executes the mix level of electric and ICE power/torque as per the selected map from on the steering wheel by the driver. And the driver, according to 5.5 “power unit torque demand” = 5.5.1 “the only means by which the driver may control acceleration torque to the driven wheels is via a single foot accelerator pedal”. What does the driver foot accelerator pedal operates if not the ICE throttles? How will the driver be in command and driving the car if his foot demands 50% accelerator pedal travel and the ECU provides 75% or 25% ICE throttles travel?. If that function was allowed by the rules the first thing that will happen is the teams operating launch control and the second after that will be the teams operating traction control to name just two worms.

Well mechanically speaking, the throttle padle in any modern car does operate absolutly nothing.

First of all, the throttles are not the only way to change the power output of a petrol engine. For instance the ignition timing has also a massive influence and the driver in any modern car has no way to change the ignition timing by himself but the ECU is perfectly capable of doing it if it "thinks" it's necessary. Also the PU's have variable lengt intake runners. Does the driver change the length? No of course not, the ECU does it for the driver if it "thinks" it's necessary.

The ECUs used in F1 today are very similar in their capabilities to a FADEC used in aeronautics. It takes all available data into account like pressures, temperaturs, state of charge, rpm and so on and based on all that it "decides" what to do to meet the drivers demands in the best way possible. This also means the solution can change if the input data changes. For instance if the intake charge temperature is to high, the ECU will give a warning out to the display on the steering wheel but it propably will also retard the ignition timing to prevent excessive knock whitout any input from the driver, which also means it reduces peak power of the ICE completly by itself.

[gruntguru]

His interpretations are indeed correct and there is indeed a "can of worms" available for the PU design team to play with. This is the case with any modern hybrid transmission where an Electronic Control Unit makes the final decision on how to mix mechanical and electrical energy to produce the torque level demanded by the accelerator pedal.

How can it be any other way? With accelerator position and the ICE rpm at a given setting, the command torque output might be say 300 Nm. This could be ICE 250 + MGUH 50 = 300 Nm. Under different circumstances the same accelerator/rpm setting might be ICE 300 + MGUH 0 = 300 Nm or ICE 350 + MGUH (-50) = 300 Nm. Without the "can of worms" to play with, the hybrid PU cannot be operated in the way the rules intend.

Implying that a can of worms is indeed available to the PU design team to play with is relegating the rule makers into a very bad light indeed. And in my opinion that is just not right and neither is it fair.
The ECU does not make decisions on how to mix mechanical and electrical energy to produce the torque level demanded by the accelerator pedal. the ECU Executes the mix level of electric and ICE power/torque as per the selected map from on the steering wheel by the driver. And the driver, according to 5.5 “power unit torque demand” = 5.5.1 “the only means by which the driver may control acceleration torque to the driven wheels is via a single foot accelerator pedal”. What does the driver foot accelerator pedal operates if not the ICE throttles? How will the driver be in command and driving the car if his foot demands 50% accelerator pedal travel and the ECU provides 75% or 25% ICE throttles travel?. If that function was allowed by the rules the first thing that will happen is the teams operating launch control and the second after that will be the teams operating traction control to name just two worms.

There are two possibilities here. Either you are not thoroughly reading posts from the people trying to help you or you have an issue which prevents you from understanding.

1. The control system has the ability to make very large adjustments to the PU torque output WITHOUT MOVING THE THROTTLES. Examples are MGUK braking, fuel reduction, boost reduction (MGUH braking or wastgate opening), cylinder skipping, timing retard.

2. Because of 1. above it is impossible to stop teams implementing traction control by simply mandating a relationship between accelerator pedal position and ICE throttle position.

3. For this reason, the rules specify a relationship between accelerator pedal position and PU TORQUE OUTPUT. The means by which this relationship is maintained is entirely up to the team.

4. This relationship is how the driver "will be in command". He moves his foot - the torque changes.

[subcritical71]

One of the published challenges for the AMG One road car was dropping the idle speed from ~5k to 1.5k for emissions (and NVH as well, I'd guess) reduction. I've seen no traditional throttles in published photos of the Merc F1 turbo-hybrid engine nor it's road car derivative. They have variable stator vanes before the compressor with an annular control ring--perhaps this can function as a throttle.

Renault have used ITBs in the past. I surmise from photos which show a bearing intersecting the center of an intake runner. Each bank looks linked i.e. not independently controlled. Note the shared linkage, second photo below--gold colored bellcrank. These throttles are downstream from the VIR mechanisms and just ahead of the intake valves.

https://cdn-6.motorsport.com/images/amp ... 036678.jpg

https://cdn-2.motorsport.com/images/mgl ... plenum.jpg

https://cdn-1.motorsport.com/images/mgl ... plenum.jpg

@MtthsMlw posted some better pictures on the Renault PU thread (viewtopic.php?p=830469#p830469). You can see the linkages a bit more clearly and they look to now be unlinked(?)




@NicolasF1i

[saviour stivala]

So because no traditional throttles can be seen in photos of the Mercedes F1 turbo hybrid engine the engine have no throttles but have a variable stator vanes before the compressor with annular control ring, and perhaps this can function as a throttle!.
But on the other hand because traditional throttles can clearly be seen in photos of the Renault, the Renault have traditional throttles.
(IN F1) Throttles are an important component in an F1 engine, the throttles controls the power of an engine that is send to the driven wheels. The throttle valves are controlled via the accelerator pedal.
Since the 1990 3 types of throttles has been used in F1. Guillotine valve, Butterfly type and the barrel valves. Generally F1 engine manufacturers go for butterflies in F1.
There was a time when the rules or the spirit of the rules were so flagrantly being abused that the FIA had to urgently step in and get things back under control, as it was getting to the point of the teams being able to do away with throttles, throttles were being left fully open for virtually the whole lap especially when slowing down for cornering.

[henry]

So because no traditional throttles can be seen in photos of the Mercedes F1 turbo hybrid engine the engine have no throttles but have a variable stator vanes before the compressor with annular control ring, and perhaps this can function as a throttle!.
....

Technical Regulations 2019

5.9.1 With the exception of devices needed for control of pressure charging systems, variable geometry exhaust systems are not permitted. No form of variable geometry turbine (VGT) or variable nozzle turbine (VNT) or any device to adjust the gas throat section at the inlet to the turbine wheel is permitted..

[gruntguru]

(IN F1) Throttles are an important component in an F1 engine, the throttles controls the power of an engine that is send to the driven wheels.

Not correct. As shown in my previous post, the power of the engine can be controlled almost entirely by other means.

The throttle valves are controlled via the accelerator pedal.

Not correct.

1. This is not mandated by the rules.

2. The hybrid energy management system cannot operate effectively without computer control of the engine throttles.

[gruntguru]

So because no traditional throttles can be seen in photos of the Mercedes F1 turbo hybrid engine the engine have no throttles but have a variable stator vanes before the compressor with annular control ring, and perhaps this can function as a throttle!.
....

Technical Regulations 2019

5.9.1 With the exception of devices needed for control of pressure charging systems, variable geometry exhaust systems are not permitted. No form of variable geometry turbine (VGT) or variable nozzle turbine (VNT) or any device to adjust the gas throat section at the inlet to the turbine wheel is permitted..

This would not rule out use of variable compressor inlet vanes.

"Vortex throttling" was a technique used by Rolls Royce in the Crecy and I believe also in the V16 BRM where RR assisted with the supercharger design.

Crecy quote from https://en.wikipedia.org/wiki/Rolls-Royce_Crecy

Supercharger throttling was used as well to achieve idling. The supercharger throttles were novel vortex types, varying the effective angle of attack of the impeller blades from 60 to 30 degrees. This reduced the power required to drive the supercharger when throttled, and hence fuel consumption at cruising power.

[saviour stivala]

So because no traditional throttles can be seen in photos of the Mercedes F1 turbo hybrid engine the engine have no throttles but have a variable stator vanes before the compressor with annular control ring, and perhaps this can function as a throttle!.
....

Technical Regulations 2019

5.9.1 With the exception of devices needed for control of pressure charging systems, variable geometry exhaust systems are not permitted. No form of variable geometry turbine (VGT) or variable nozzle turbine (VNT) or any device to adjust the gas throat section at the inlet to the turbine wheel is permitted..

I was quoting what has been pushed out, and included an exclamation/surprise mark. I also actually refrained/decided not to, post "5.9.1" as a reference.

[Tommy Cookers]

the Crecy had a vastly oversized compressor to give it a vast surplus of air to stop it melting itself
of course this vast oversize was constantly being justified
the French had a Polish inventor of vortex throttling just before WW2 -this throttling presumably was known to RR

the V16 BRM throttling was a development idea in large part to make a useable power curve
otherwise the centrifugal compressor is useless for GP racing when driven at a fixed multiple of engine speed

most 1930-1950s aircraft had throttles partly closed much of the time so it would be interesting to know the effects of this

the 1975 California-spec Saab Turbo had a throttle that partially closed at full power

[saviour stivala]

"The power unit must achieve the torque demanded by the FIA standard software".
"Power unit actuators may not be used to artificially control the power unite speed or alter the power unit response in a rev range more than 750rpm from below the final rev limit".
"The maximum delay allowed, computed from the respective signal as recorded by the ADR or ECU, between the accelerator pedal position input signal and the corresponding output demand being achieved is 50m/s".

[subcritical71]

"The power unit must achieve the torque demanded by the FIA standard software".
"Power unit actuators may not be used to artificially control the power unite speed or alter the power unit response in a rev range more than 750rpm from below the final rev limit".
"The maximum delay allowed, computed from the respective signal as recorded by the ADR or ECU, between the accelerator pedal position input signal and the corresponding output demand being achieved is 50m/s".

Are you still trying to prove that ICE throttle must be directly related to accelerator pedal?

These rules you quoted do not prevent a non-linear application of throttle position.
The first one you quoted is applicable but still does not disallow a non-linear map. The second rule you quoted deals with over-rev protection. And the third quoted regulation is also not disputed nor does it preclude a non-linear throttle map and deals with the torque demand needing to equal the output of the PU, not the ICE.