Honda Power Unit Hardware & Software

[saviour stivala]

"the failsafe system is the system that was out of order and so not functioning on Jules B Marussia in Japan" "I have heard nothing of this, but are you suggesting that this was a contributing factor in JB's death?". refer to: FIA ten men expert accident panel findings 03-12-2014.

[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?

[Jokeri]

[/quote]

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?
[/quote]

Turbo is harvesting?

[saviour stivala]

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?

[Dr. Acula]

"the failsafe system is the system that was out of order and so not functioning on Jules B Marussia in Japan" "I have heard nothing of this, but are you suggesting that this was a contributing factor in JB's death?". refer to: FIA ten men expert accident panel findings 03-12-2014.

Well, that's not exactly what they found.
The failsafe system didn't react, yes. But this doesn't mean i didn't work. The failsafe system is a bit more sophisticated than "if you press the brake and accelerater pedal at the same time the engine will cut off." The teams are allowed to setup up the system by them self to a certain degree. The so called "overcut" where a driver presses the accelerator and brake pedal at the same time isn't something unusual in racing.

[dren]

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?

Perhaps the engineers should add a third pedal for the MGUH? The driver could initiate the extra harvest mode the Honda PU uses by quickly pumping the brake and MGUH pedal back and forth. They could bring back a lever on the steering wheel for spark advance, too. No sense in letting the ICE mapping do that.

[saviour stivala]

DR. ACULA. The following is what they found: "During the 2 seconds JB's car was leaving the track and traversing the ru-off area, he applied both throttle and brake together, using both feet. the failsafe algorithm designed to over-ride the throttle and cut the engine (like what happened to Vandoorne in Hungary free practice this year) was inhibited by the torque coordinator, which controls the rear brake-by-wire system. Bianchi's Marussia has a unique design of BBW, which proved to be incompatible with the failsafe system settings. the fact that the failsafe did not disqualify the engine torque requested by the driver,,,, .

[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?

Perhaps the engineers should add a third pedal for the MGUH? The driver could initiate the extra harvest mode the Honda PU uses by quickly pumping the brake and MGUH pedal back and forth. They could bring back a lever on the steering wheel for spark advance, too. No sense in letting the ICE mapping do that.

the engineers had chosen to add a button for the 'H' instead of a third pedal and in so doing avoided the need for pumping said pedal, this for deployment, for harvesting and control of turbo speed the 'H' is mapped into the power unit turbo control system. something that there is no way the driver can control.

[turbof1]

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.
Vandoorne Hungary free practice driver to pit/pit to driver radio: “I have no deployment, no power” “do not press the brakes to hard under throttle” his rear brake-by-wire failsafe system was triggered and the engine was cut, this while he was trying to get some extra harvesting.
Jules Bianchi: for detail about the contribution of the Marussia failed rear brake-by-wire failsafe system to the accident refer to FIA panel of experts report findings of 03/12/14.

Yes, it goes against the statement of intent. However, F1 regulatory authority does not originate from intent. It originates from the written regulations in the fia pdf files, and their technical directives. We have to clearly distinct intent and reality from one another, especially in such a competitive environment where intent is usually stepped on in favour of a competitive advantage.

Just so you know: I didn't think myself harvesting was possible without touching the brake pedal. I did know about software mapping predicting in which corner the driver is (yes, those mappings are on a circuit to circuit base). I did not know it effectively can do the harvesting completely separate from the braking.

As regards for brake/throttle overlap: That's technically possible. I certainly would not exclude it. I think it can for instance be useful in a chicane where you simply cannot increase speed before exiting. So you effectively burn fuel to increase battery power. Theoritically. Of course, accurate mappings can make the practice redundant.

I also agree the driver probably does not have a control turbo button. That's wonky stuff for just a human brain to control.

Here is why I’m skeptical on the driver needing to press the brake pedal to get K to generate. Say they have the DRS open and get to the point where they have attained their top speed (either physically or by their rnerfy strategy) and now want to generate with the K. If they then have to push the brake to do this the DRS wing returns to its normal position. I would think a better way to do the K strategy is via track position vs speed vs brake position and not relying on driver input for normal usage scenarios. If they want to give the driver an override mode that would also make sense, be it a push button or similar.

That's only true if DRS is open though. Usually that is accompagnied with overtaking or full attack modes. I think using to brake pedal on the straights can be effective in lift and coast operations.

Also please people, the case of JB is sensitive. Stay within the constraints of the relevant discussion. Let's not start to appropiate blame to these systems in regard of JB's injuries.

[rogazilla]

One thing A lot of people spent a lot of time practicing when I was doing track day on bike is trail braking. Most people think brake is only used to slow down but it can help you change the balance of the bike by weight transfer and change suspension geometry. I never do this in car but I do think car racing this technique is used too. Does it not apply to F1 car?

[Tommy Cookers]

......trail braking. .....Does it not apply to F1 car?

only blatantly ever since the late 1950s

TB is inevitable where corner radius is not constant (unless the driver is stupid and content to throw away laptime)
any car trackday will give this experience
this is basic stuff not clever stuff
if you don't TB then you must brake to the apex speed before you start to turn the corner
so the start of the corner is being driven slower than it could be driven
(only a constant radius corner has the same speed at starting to turn as at the apex)

the clever stuff ....
we've seen telemetry showing that Schumacher fellow braking under power eg in high speed corners to alter the balance
(brake torque goes to both axles but drive torque only to the driven axle)

[saviour stivala]

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. 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.

[Tommy Cookers]

the telemetry shows eg K generation throughout some slow corners and during upshifts in the lower gears
(despite DC line seeing only the part of an upshift generation pulse that isn't held in capacitive storage onboard the controller)

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 ?

[subcritical71]

Here is why I’m skeptical on the driver needing to press the brake pedal to get K to generate. Say they have the DRS open and get to the point where they have attained their top speed (either physically or by their rnerfy strategy) and now want to generate with the K. If they then have to push the brake to do this the DRS wing returns to its normal position. I would think a better way to do the K strategy is via track position vs speed vs brake position and not relying on driver input for normal usage scenarios. If they want to give the driver an override mode that would also make sense, be it a push button or similar.

That's only true if DRS is open though. Usually that is accompagnied with overtaking or full attack modes. I think using to brake pedal on the straights can be effective in lift and coast operations.

I would agree that is can be accompanied by overtaking or full attack mode, but this is where I would implement an OT button to override the feature that would be for ~80% of its usage. For normal usage I would make it automated that at a certain speed to no longer motor the MGU-K and instead generate. I've seen it done numerous times at the end of a long straight where you see before the braking zone a slight reduction in speed and also the rain light flash. If you need the speed to complete the overtake then hit the OT. This makes sense because motoring the MGU-K at 330kph brings a smaller gain than doing it out of the next corner.

[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.