Yes, agree with your "man in middle" description, and proprtioning effect.venkyhere wrote: ↑25 Mar 2024, 13:07Right. The intention behind my comparison with road car ABS module was not in terms of functionality, but only in terms of architecture - BBW is like a man-in-the-middle-who-manipuiates-hydraulic-pressure, where driver pedal input, after getting proportioned front v/s back according to his brake-bias setting, the pressure to the rear axle is 'translated' to a different value, according to 'how much' of total "rear braking energy" needs to be shared between electrical loading v/s friction loading. Hope I understood the gist of what you are trying to convey.Farnborough wrote: ↑25 Mar 2024, 12:17Although there's obvious commonality with a brake system for most vehicles, feel there's need to disassociate this with ABS typical system, one that's reactive to wheel speed events.
This in RB 20 (mirrored across all chassis) is primarily led by algorithm determination to maximise recovery of energy by using the MGUK facility to generate high proportion of braking torque, only blending more effort through hydraulic caliper route when the capacity within recovery tapers to below braking demand.
This illustrated by the down sized disc and caliper equipment that effectively provides secondary "top up" torque, but would be completely overwhelmed if used as primary.
Agree that NO modulation of split across the axle (at either end) is the normal arrangement. Indicating that BBW control of that single line out to rear was not the culprit.
Fault seems to exist in the discreet line, after split, out to right rear caliper.
And yes, the problem that Max had is pointing to some fault with the hydraulic line OR the caliper mechanism that went to the right rear wheel, and doesn't look like an issue with BBW itself.
There's not very good public view of these system to concisely evaluate from our perspective.
Something on RB 20 though ... its moved to a single pot fluid reservoir, from a little bath-tub shape previously, with that feeding the two mastercylinder which was visible on bulkhead. This new type is the only component now visible outside bulkhead, so whether it then splits (logical in my view) to still feed two cylinder, we can't see.
Conventional arrangement of mechanical brake bias has two cylinder pushed by rocking lever, moving fulcrum that can be pushed across to one or other in then giving hydraulic pressure bias to either one.
Now you can see them changing bias in software on screen (steering wheel) this should require something like a stepper / servo to accommodate mechanical shift in some way. Wondering if that's present still, the mechanical facility that is.
It COULD though now be just contained in software, potentially. With a fixed bias on hydraulic to give the "emergency" safety link on rear line should that eventuality arise.
But, with software algorithm controlling all of the regen facility in programmed proportion (hence the screen driven command) to give all "race" function bias needs.
This would allow reduction of pedal box complexity, removing component, reduction in brake system hysteris/stiction effect in mechanical control etc etc. The mastercylinder can still have two separate front and rear fluid handling (most road vehicles do this) with integrated front and rear pressure bias internal to that component.
The single fluid reservoir may indicate this in place, or with a simple Y feed inside bulkhead, then nothing of the sort
Iv`e never done it again and always spit on the disc first now if checking.
