812c steer by wire?

Can the following indicate the 812c no longer has steering linkage to the driver and instead steering is 100% controlled by electronics???

https://corporate.ferrari.com/en/812-competizione-and-812-competizione-two-interpretations-ferraris-racing-soul

specifically this from the link above:

The independent rear-wheel steering features a new electronic management system that enables the right and left actuators to be actioned individually rather than synchronised. This evolution yields a significant boost in performance in relation to the control of the position demanded of the individual actuators, and quicker response times.

This system emphasises the front axle’s response to steering wheel commands, maintaining the feeling of grip from the rear axle, which responds promptly to front inputs, and also manages the car’s lateral dynamics response more efficiently as a function of the actuation frequency of the steering wheel angle.

The new solution has resulted in the evolution of the SSC system which brings together all of the control systems developed in-house and uses a shared dynamic control language to integrate the actions of all of the systems to improve efficiency. The Side Slip Control 7.0 spans the electronic differential (E-Diff 3.0), traction control (F1-Trac), SCM-Frs magnetorheological suspension control, brake pressure control when driving on the limit (FDE) available in Race and CT-Off Manettino settings, and the Virtual Short Wheelbase 3.0 which integrates the electric front steering with the electronically controlled independent rear-wheel steering.

 

more:


http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220190126970%22.PGNR.&OS=DN/20190126970&RS=DN/20190126970

STEER BY WIRE ROAD VEHICLE STEERING SYSTEM PROVIDED WITH A MECHANICAL LIMIT STOP DEVICE FOR THE STEERING WHEEL

Abstract

A steering system for a road vehicle; the steering system comprises: a steering wheel provided with an outer ring, which is mounted so as to rotate around a rotation axis and has no connection to steering wheels; a position sensor, which is designed to detect the angular position of the outer ring of the steering wheel around the rotation axis; and a mechanical limit stop device, which is coupled to the outer ring of the steering wheel and limits, in both directions, the maximum angular width of the rotation of the steering wheel around the rotation axis, so that the steering wheel can make, on the whole, a rotation around the rotation axis that is greater than 360.degree..

Inventors: Cimatti; Franco; (Pavullo (MO), IT)
Applicant:
Name City State Country Type

Ferrari S.p.A.
Modena
IT
Family ID: 61581436
Appl. No.: 16/171445
Filed: October 26, 2018

 

Components "by wire" rarely have the same feel/feedback as those mechanically connected. If so, not good.

 

Maybe @Marcel Massini can help clarify if the 812c is steer by wire or not?

 

From the wording it is pretty clear that only the rear wheels steer independently, which is the logical thing as well.

 

@JTSE30 they did seem to labour this and I'm also now quite intrigued as to why the rear wheels can now be "actioned individually rather than synchronised....".

Normally they move with the front wheels for stability, or against for tighter steering/virtual SWB. Mmhhh!

 

It seems to me the rear wheels which can be steered independent of each other, and perhaps independent of the front?!

I would not want steer by wire either, but the current EPAS setup isn’t the most feelsome so I dont know if we’d even notice the difference.


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Feeling the difference isn't the issue, it is 100% loss of steering control if the electronic system fails (because there is no mechanical linkage to the steering wheel)

 

That's just downright scary.

 

And that is why I am wondering if the 812c is using steer-by-wire....without mechanical linkage

still not 100% confirmed, but it appears as if that could be the case...

 

Sort of an important "minor detail" isn't it

 

From this it is obvious that only the rear wheels steer independently, whereas the front use the typical EPAS rack. Also, it is mandatory in the EU to have a mechanical linkage to the front wheels, even as a back-up (Infinity had such a system).

 

Thank you, could you send the reference link for the EU mandatory mechanical steering linkage.

Especially because the Ferrari patent referenced at the top of this thread indicates no mechanical linkage..curious why Ferrari would endeavor to create such an invention if specifically disallowed...

 

If left/right steering actuators function independently, how could the fronts be mechanically tied together via traditional rack?

 

Used to be like this:

"Traditionally the major requirement has been that the main steering system contains a positive mechanical link between the steering control, normally the steering wheel, and the road wheels in order to determine the path of the vehicle. The mechanical link, if amply dimensioned, has been regarded as not being liable to failure.

Advancing technology, coupled with the wish to improve occupant safety by elimination of the mechanical steering column, and the production advantages associated with easier transfer of the steering control between left and right hand drive vehicles, has led to a review of the traditional approach and the Regulation is now amended to take account of the new technologies."

It seems that this stipulation has been altered as follows:

"3.4.3. The Manufacturer shall provide the technical authorities with an explanation of the design provisions built into ‘The System’ so as to generate safe operation under fault conditions. Possible design provisions for failure in ‘The System’ are for example:

(a)
fall-back to operation using a partial system;

(b)
change-over to a separate back-up system;

(c)
removal of the high level function."

https://eur-lex.europa.eu/legal-content/en/ALL/?uri=CELEX:42008X0527(01)

The steering actuators you are referring to are those of the rear wheels. Thus, the two rear wheels can steer independently, but the fronts are coupled via the traditional steering rack.

 

What happens if the computer fails which is managing the by wire throttle in every modern Ferrari? I can imagine a situation when you need to drive away from danger and you go no where in a failure. Has any TDF owner (just for an example) worried about this? What about the newer cars with electronic parking brakes? The TDF features one of these. Worse yet, what if the computer decides to clamp the e-brake while in motion (!!!) What happens if it decides to let go of the brake while your precious is sitting on a hill. What happens if the system managing the EPAS in all these new cars fails? (812, Roma, PF- supposedly when EPAS fails the steering is incredibly difficult to manipulate). And then how about independent brake force distribution? The computer can adjust brakes independently.. what if it decides to grab, for instance, the drivers side front while you are motoring down the auto strada? You can just add this to a list of things which could be issues.

 

You are over-thinking this. Computer failures can lead to lot's of problems, not the least of which is a car wreck.

 

Agreed, but @JTSE30 was concerned about there being no mechanical link between the steering wheels and the rear wheels and my point is there is already for almost 20 years (!!) NO mechanical link between many critical systems.


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What if a wheel falls off? Or the engine falls out? Or the windscreen explodes in your face?
I dont know anyone that has had any electrical failures that caused life dangering issues but i know several that had wheels come off driving (not ferraris)

 

When the EPB/AVH fails it locks, it does not fail in the open position... And it can fail and some have but only have heard (and seen) of it failing while the car is standing still, not in motion, but have been cases where it fails (i.e. it locks) when driving, but at a stopped position. There have been software updates but requires a new EPB module to receive (only have seen/heard of EPB failures in the LaF system also used on the 458S and 488GTB/Spider; the 488 Pista uses the system that the 812SF uses which is an improved design).

If the EPAS fails you still have mechanical steering linkage, not impossible to steer such as a system devoid of any such linkage.

And yes, those are considerations, most definitely, but completely different than dealing with a car with no mechanical steering linkage.

 

Real world experience: my wife’s Range Rover EPAS failed and turning it was very difficult- fortunately it was at low speeds- I wonder if it would be easier at high speeds but other accounts suggest its also difficult there- its not like HPAS.

I dont think Ferrari has yet explained exactly how their independent rear steer system works so we are speculating. At this point I think the concerns are overstated. My point is simply, there are other systems with no direct mechanical connection and I haven’t heard much concern over those.

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It's not that complicated. Instead of the two rear wheels doing exactly the same thing, they just move independently.

 

The base 812 was already full electric steering. As is the f8, sf90, roma etc.

 

I think F8 is still HPAS


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I agree, but I think the questions being raised here are

1- is it purely electronic control with no mechanical connection whatsoever to other systems? And, if so;
2- should we be worried? (2a- if we should be worried, how worried should we be?)

I am very curious to learn what they are doing with this system. To my mind it could be used in amazing ways that enhance the driving experience, such as variable altering of the rear toe depending on situation (turn in, track out etc) and maybe more.


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