Honda Power Unit Hardware & Software

[saviour stivala]

the engineers had chosen to have the deployment under the control of an 'imperfect' human being using a stick on the end of a pivot, the accelerator pedal, when they could have it done by 100% repeatable piece of gode, why not with the brake pedalfor harvesting?

Except that code would violate the current technical regulations (section 5.5) in the case of the accelerator pedal.

How would using "a stick on the end of a pivot" for harvesting as a brake pedal violate the current technical regulations (section 5.5)?

[henry]

On this here technical discussion forum I have expressed my personal opinion on the “K” deployment/harvesting function. Am I allowed to do that? It is not like I expressed my opinion as “WE”, it is only my personal opinion.
Reasons as to my personal opinion about the subject at hand: policy of statement of intent and its implementation as a procedure of protocol. “The MGU-K (where the “K” stands for kinetic) converting kinetic energy generated under braking into electricity (rather than it escaping as heat”. In my personal opinion any energy harvested other than by using the brake pedal goes against the above declared policy of statement of intent. Also my opinion, power unit mapping is track dependent and is optimized for given track to minimize lap time, the MGU-K two functions (harvesting and deployment) is mapped into the two driver’s pedals (brake and accelerator pedals). It is these two pedals that triggers both deployment and harvesting, the MGU-K can be used as a generator only while braking.

A policy statement is not a regulation. There is a policy that aerodynamic surfaces should not flex, but they do.

Two questions:

Do you think an engineer would choose to have the harvesting under the control of an imperfect human being using a stick on the end of a pivot, the brake pedal, when they could have it done by a 100% repeatable piece of code? (There is no regulation that requires one or bans the other)

Why does the rain light flash at the end of some straights?

the engineers had chosen to have the deployment under the control of an 'imperfect' human being using a stick on the end of a pivot, the accelerator pedal, when they could have it done by 100% repeatable piece of gode, why not with the brake pedalfor harvesting?

The engineers don’t choose to use the accelerator pedal/human combination. This is the regulation that controls “deployment”:

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 mounted inside the survival cell.

[henry]

and doesn't auto co-ordination of rear brake torque cease at c.110 kph as axle load is insufficient to allow 120 kW generation ?

I wouldn't think so. I would expect that below that speed the braking torque from the K would reduce and not simply be switched off.

[subcritical71]

the engineers had chosen to have the deployment under the control of an 'imperfect' human being using a stick on the end of a pivot, the accelerator pedal, when they could have it done by 100% repeatable piece of gode, why not with the brake pedalfor harvesting?

Except that code would violate the current technical regulations (section 5.5) in the case of the accelerator pedal.

How would using "a stick on the end of a pivot" for harvesting as a brake pedal violate the current technical regulations (section 5.5)?

Don’t think it would be, but as I wrote, for the accelerator pedal it would be.

[subcritical71]

and doesn't auto co-ordination of rear brake torque cease at c.110 kph as axle load is insufficient to allow 120 kW generation ?

I wouldn't think so. I would expect that below that speed the braking torque from the K would reduce and not simply be switched off.

I would think this would be the case (just lowering the generating to reduce braking affect). Road cars do this today, like the Tesla, which brakes as soon as you lift off the accelerator pedal until you are down to a walking pace then you need to actually apply the brakes to come to a full stop. But there shouldn’t be a reason you couldn’t have the MGU-K braking effect until near zero speed.

[Tommy Cookers]

afaik the Honda telemetry showed 120 kW generation from braking point to entering the next straight
so the K was motored by the ICE as necessary for this

afaik and fwiw
the PU is allowed to give up to zero torque at any race rpm with the accelerator at 0% (this NA era rule was retained)
the map can use any throttle and fuelling necessary for this even when driving the K at 120 kW generation

[AJI]

Fully agree that the JB case is a sensitive case and that it strays from the subject at hand, and I apologies for my part in it, but the experts technical findings, and this dates back to quite some time goes to show/validate the use of both feet on both pedals at the same time, the resultant engine cut-off and the intended failsafe system settings which to me seems to have been disputed or doubted.

Not disputed or doubted, simply questioned. There's a difference.

Again apologizes. I did not claim any rules/regulations as regards how harvesting by the ‘K’ is done in fact I quoted “MGU-K (where the ‘K’ stands for kinetic) converting kinetic energy generated under braking into electricity (rather than it escaping as heat” as a policy statement of intent, which in my book is something which is implemented as a procedure or protocol as policies that are adopted by a governance body by an organization. This is my personal opinion and anybody can feel free to disagree with.

If you simply took the time to explain your theories with the extra detail you have used above there would be less questioning and more useful discussion. We're not mind readers...

Also, please don't automatically assume that every reply to your posts are attacks on your intellect.

[subcritical71]

afaik the Honda telemetry showed 120 kW generation from braking point to entering the next straight
so the K was motored by the ICE as necessary for this

afaik and fwiw
the PU is allowed to give up to zero torque at any race rpm with the accelerator at 0% (this NA era rule was retained)
the map can use any throttle and fuelling necessary for this even when driving the K at 120 kW generation

Interesting, so if I follow you correctly you are saying they could do the following. Use K in generating mode during braking from full speed down to some point when the mechanical brakes are no longer providing stopping power and the K is generating at 120kw. To further slow down, they would maintain the 120kw K generating scenario but add fuel to make up the difference until they get to their desired apex speed. This would make torque(demandmap) = torque(engine) + torque(k) where torque(k) is negative when generating. Is that correct?

[henry]

Here’s a really useful post from the Monza 2018 Thread.

Did a little video about the ERS and Overtake button at work, from Monza onboard.

Gasly pressed the overtake button for a better corner exit acceleration. But it can only work for a few seconds, so after that it was back to auto ERS deployment based on the setting. It's also very clear to see the battery bar went down on straights and went back up after braking through corners, which is how MGU-K works.

I enhanced the audio a tiny bit so it's a little easier to hear the sound of the electric boost. The few seconds where Gasly pressed the overtake button is obviously the sound of the maximum ERS boost, but the electric boost was working on all straights during that lap, just not in that extremely-consuming overtaking mode.

https://www.youtube.com/watch?v=xmEZGKfo50o

https://www.youtube.com/watch?v=xmEZGKfo50o

It was made to illustrate the use of the overtake button but it also illustrates the use of ICE at 0 demand.

At the end of braking for turn 1 the ICE runs in a cut cylinder mode to help us hear that it is motoring, thanks Honda. The only place the power can go, under the rules, is to the MGU-K.

Apart from harvesting some extra energy, I’m guessing this helps with driveability and throttle pick up. At the point of throttle pick up the ICE is potentially already producing about 20% of its max, the turbine is providing some power to the compressor, reducing ES drain to the H. As the demand increases the delivery can mix K and ICE to provide a smooth match to the demand curve with no lag, and the turbine can take over full responsibility for driving the compressor early.

This behaviour works well at Monza, and most tracks, where the 2MJ K>ES limit is not satisfied by harvesting under braking over the lap. It would be interesting to find a video of the Singapore to see if the behaviour changes.

[etusch]

Here’s a really useful post from the Monza 2018 Thread.

Did a little video about the ERS and Overtake button at work, from Monza onboard.

https://www.youtube.com/watch?v=xmEZGKfo50o

https://www.youtube.com/watch?v=xmEZGKfo50o

There good comments under the video too. Thank you

[godlameroso]

Here’s a really useful post from the Monza 2018 Thread.

Did a little video about the ERS and Overtake button at work, from Monza onboard.

Gasly pressed the overtake button for a better corner exit acceleration. But it can only work for a few seconds, so after that it was back to auto ERS deployment based on the setting. It's also very clear to see the battery bar went down on straights and went back up after braking through corners, which is how MGU-K works.

I enhanced the audio a tiny bit so it's a little easier to hear the sound of the electric boost. The few seconds where Gasly pressed the overtake button is obviously the sound of the maximum ERS boost, but the electric boost was working on all straights during that lap, just not in that extremely-consuming overtaking mode.

https://www.youtube.com/watch?v=xmEZGKfo50o

https://www.youtube.com/watch?v=xmEZGKfo50o

It was made to illustrate the use of the overtake button but it also illustrates the use of ICE at 0 demand.

At the end of braking for turn 1 the ICE runs in a cut cylinder mode to help us hear that it is motoring, thanks Honda. The only place the power can go, under the rules, is to the MGU-K.

Apart from harvesting some extra energy, I’m guessing this helps with driveability and throttle pick up. At the point of throttle pick up the ICE is potentially already producing about 20% of its max, the turbine is providing some power to the compressor, reducing ES drain to the H. As the demand increases the delivery can mix K and ICE to provide a smooth match to the demand curve with no lag, and the turbine can take over full responsibility for driving the compressor early.

This behaviour works well at Monza, and most tracks, where the 2MJ K>ES limit is not satisfied by harvesting under braking over the lap. It would be interesting to find a video of the Singapore to see if the behaviour changes.

MGU-H in motor mode only operates for a few seconds at a time max. Most of the time, just giving the turbo a kick-start is all that's needed to nearly eliminate lag.

[henry]

MGU-H in motor mode only operates for a few seconds at a time max. Most of the time, just giving the turbo a kick-start is all that's needed to nearly eliminate lag.

I think you meant to say a few fractions of a second?

When I looked at the extra harvest scenario motoring the H inertia set at 120kW increased the speed by 5000rpm in 25msec. To overcome lag the H would also need to provide the shortfall in power needed to drive the compressor caused by the lack of exhaust gases.

So without the sort of off throttle compensation @tommy cookers highlighted the H might have to motor at 150 to 200kW for to speed up from say 50k to 100k rpm in 0.2 seconds.

[saviour stivala]

Before these hybrid power units had even ran on track researched estimations said that ERS-H had to use 60kw of power from the energy store to power the compressor with waste-gates open.

[henry]

Before these hybrid power units had even ran on track researched estimations said that ERS-H had to use 60kw of power from the energy store to power the compressor with waste-gates open.

I think that estimate presupposes that the exhaust turbine contributes a further 30kW or so to provide the total 90kW needed to drive the compressor.

[AJI]

Before these hybrid power units had even ran on track researched estimations said that ERS-H had to use 60kw of power from the energy store to power the compressor with waste-gates open.

I think that estimate presupposes that the exhaust turbine contributes a further 30kW or so to provide the total 90kW needed to drive the compressor.

Interesting that the AMG Project 1 suggests ~90kW for the H.
From the press release...