Modifying to be illegal?

[bigothunter]

kambites said:

bigothunter said:

Change parameters beyond a vehicle's limited calibration tolerance and it no longer functions properly. This becomes even more critical with increasing autonomy.

Do you have a citation for that statement? Because I think it's entirely factually incorrect. I could be wrong, but I'm guessing you don't have a background in real-time embedded systems?

I have direct experience of base engine calibration (ECU on engine dyno) and how that's tuned for each vehicle application. Also I have experienced how sensitive calibration of Dynamic Stability Control is to brake package changes. Even fitting different tyres can have an adverse effect.

Why do you think my previous statement is entirely factually incorrect?

[kambites]

bigothunter said:

Why do you think my previous statement is entirely factually incorrect?

Because the embedded systems I work on (which admittedly aren't automotive related) simply don't work that way. They're based on feedback loops - they don't make blind assumptions about how the hardware they're interfacing with will respond, they react in real time to how the hardware responds to their requests.

Assuming that analogue components and sensors will react to a particular degree due to control inputs would be utterly idiotic. Firmware obviously has to make a baseline guess, but it should take no more than a few milliseconds for it to make corrections if that guess turns out to be wrong.

Obviously there are limits, but as long as everything is within the correct order of magnitude the systems should... must... be able to deal with things differing from expected parameters if they're ever going to be safe to trust to drive a car.

ETA: If nothing else, things like differences in road surface will have far more effect on how a car behaves than the vast majority of mechanical modifications.

Edited by kambites on Saturday 25th December 21:41

[D4rez]

Oilchange said:

D4rez said:

For example if you moved the front radar forward, backward or up and down then that would significantly disrupt that allows your car to brake automatically if a pedestrian steps out. Similarly if you put a big front tea tray splitter underneath it. Go have a conversation with any big supplier of these and they’ll tell you the same.

If a pedestrian steps out and the driver is relying on anything other than their right foot on a brake peddle then they are entirely to blame, not some added splitter they chose to bolt on. It won't stop the brakes working as they should.

Nice idea but that safety system is mandatory from next year. Point is it shouldn’t be disabled by some stick on bits because it does actually work as intended.

[Oilchange]

Maybe mandatory but nothing stopping a load of mud or leaves from blocking sensors or a bird hitting and redirecting the beam, all without the driver knowing, is there?
If the law said the driver could not bother braking and rely on this stuff AND the manufacturers would be culpable for all the deaths caused then I would be with you. But it isn't going to happen that way.

Good luck in court when you run down a child and your defence is ' the car should have stopped on its own, I shouldn't have to rely on the brake peddle and actually pay attention to the road'

[D4rez]

Oilchange said:

Maybe mandatory but nothing stopping a load of mud or leaves from blocking sensors or a bird hitting and redirecting the beam, all without the driver knowing, is there?
If the law said the driver could not bother braking and rely on this stuff AND the manufacturers would be culpable for all the deaths caused then I would be with you. But it isn't going to happen that way.

Good luck in court when you run down a child and your defence is ' the car should have stopped on its own, I shouldn't have to rely on the brake peddle and actually pay attention to the road'

Not really the point in the context of the thread. Point is - system is a legal requirement. System will not work if you change the bodywork in that area. Therefore change to the bodywork shouldn’t be allowed as safety system is legal requirement.

[bigothunter]

kambites said:

Because the embedded systems I work on (which admittedly aren't automotive related) simply don't work that way. They're based on feedback loops - they don't make blind assumptions about how the hardware they're interfacing with will respond, they react in real time to how the hardware responds to their requests.

Assuming that analogue components and sensors will react to a particular degree due to control inputs would be utterly idiotic. Firmware obviously has to make a baseline guess, but it should take no more than a few milliseconds for it to make corrections if that guess turns out to be wrong.

Obviously there are limits, but as long as everything is within the correct order of magnitude the systems should... must... be able to deal with things differing from expected parameters if they're ever going to be safe to trust to drive a car.

ETA: If nothing else, things like differences in road surface will have far more effect on how a car behaves than the vast majority of mechanical modifications.

Initially I was surprised that base engine ECU calibration did not read straight across to multiple vehicle and driveline applications. But much effort is made to tune these specifically, especially to optimise driveability.

Sensitivity of DSC calibration to component change, is alarming. When pushing hard on race circuits, a previously stable DSC system invoked violent yaw instability making driver control difficult. This was caused by changes to the brake system

Clearly adaption through feedback control was not adequate in these cases.

Unless autonomous vehicles adopt much more effective feedback control, I suspect changing fundamental parameters or components would be unwise. Authorities are likely to take the same view and legislate accordingly.

Edited by bigothunter on Saturday 25th December 22:55

[DodgyGeezer]

otolith said:

Most of the troublesome sensors now are parts of the emissions control system, and at least the ECU usually tells you when they fail via a cheap obd reader - easier than sorting misbehaving carbs, as I recall. We could do without them if we decided we didn’t care about breathing clean air. As for all the fluff, the toys and features - if it breaks, and you don’t care about it - ignore it?

I'll put not be surprised if the 'toys' and 'fluff' will be fully integrated and if they don't work (for whatever reason) nor will the car until the manufacturer approved specialist has resolved the issue (it's allowed to not work for, say, 50/75/100 ignition cycles then the car will be immobilised)

[bigothunter]

RoadsterAlex said:

bigothunter said:

DodgyGeezer said:

this is quite funky & modified:

- engine
- body
- exhaust
- wheels
- suspension
- interior
- colour

Certainly funky and fine for running on the track. But it's not a road car...

If it can be driven on the road it’s pretty much a road car ?

What makes you believe this Supra is road legal, even in the States where authorities tend to be more lenient towards modified cars ?

[otolith]

DodgyGeezer said:

I'll put not be surprised if the 'toys' and 'fluff' will be fully integrated and if they don't work (for whatever reason) nor will the car until the manufacturer approved specialist has resolved the issue (it's allowed to not work for, say, 50/75/100 ignition cycles then the car will be immobilised)

Doesn’t do that now. If my bluetooth phone integration or radio or CD changer or satnav fails, the car still works. If it doesn’t, don’t buy that car?

[Oilchange]

D4rez said:

Not really the point in the context of the thread. Point is - system is a legal requirement. System will not work if you change the bodywork in that area. Therefore change to the bodywork shouldn’t be allowed as safety system is legal requirement.

Not true. System works fine, just that view might be impeded. Note ‘might’. And mud/leaves or an impact could do the same.
System when tested shows no errors. System has not been removed, switched off or tampered with.

[anonymous-user]

bigothunter said:

I have direct experience of base engine calibration (ECU on engine dyno) and how that's tuned for each vehicle application. Also I have experienced how sensitive calibration of Dynamic Stability Control is to brake package changes. Even fitting different tyres can have an adverse effect.

Why do you think my previous statement is entirely factually incorrect?

This doesn't make any sense. If fitting different tyres causes instability in the control then how can it possibly cope with different road surface conditions ambient or tyre temps? Sounds like a very poor system that can't cope with feedback it's not expecting or isn't actually using any feedback.

[Kawasicki]

fblm said:

bigothunter said:

I have direct experience of base engine calibration (ECU on engine dyno) and how that's tuned for each vehicle application. Also I have experienced how sensitive calibration of Dynamic Stability Control is to brake package changes. Even fitting different tyres can have an adverse effect.

Why do you think my previous statement is entirely factually incorrect?

This doesn't make any sense. If fitting different tyres causes instability in the control then how can it possibly cope with different road surface conditions ambient or tyre temps? Sounds like a very poor system that can't cope with feedback it's not expecting or isn't actually using any feedback.

It can cope with different road surfaces because it’s been developed to deal with different road surfaces. Similarly tyre temps.

Bigothunter is correct. Look at simple ABS braking. Not every aspect of the slip control is based on feedback of what is happening at the tyre. Some parameters pre-control… some parameters expect certain hydraulic stiffness in the system… some parameters expect certain tyre rolling circumference. Change them enough (and it might not take much) and you can drop quite quickly from impressive stopping distances to a situation where the ABS system might actually perform worse on one occasion than a car without ABS.

[Oilchange]

But it wouldn't -stop- working though and you'd never know the difference between the stopping distance changes on differing road surface and changes in conditions anyway. Those changes in conditions might make more of a difference on any other occasion. Plus, tyres wear out and their performance degrades over time so there's another of the seemingly endless parameters.

[Kawasicki]

Oilchange said:

But it wouldn't -stop- working though and you'd never know the difference between the stopping distance changes on differing road surface and changes in conditions anyway. Those changes in conditions might make more of a difference on any other occasion. Plus, tyres wear out and their performance degrades over time so there's another of the seemingly endless parameters.

It could stop working, it could also switch into a fail safe mode where it would have less braking performance.

There are endless situations where the braking performance could be degraded. Why make the situation even worse?

[Oilchange]

Could.
A great word that. It 'could' have absolutely no affect whatsoever.
Likewise, a blob of mud could block it or break it.

Edited by Oilchange on Sunday 26th December 15:16

[D4rez]

Oilchange said:

Could.
A great word that. It 'could' have absolutely no affect whatsoever.

Well, if you’re upgrading the performance of tyres, brakes and suspension then you would hope it knocks on to better roadholding and braking. Wouldn’t you rather have a verified modification that checked all of that put though? I’d rather know ABS, ESC and safety systems still work.

[M4cruiser]

bigothunter said:

craigjm said:

Personally, I quite like the idea of an autonomous pod thing that I can summon using my phone or watch to come and collect me from the pub and take me home. Much more useful than uber etc and can still have the garage with fun cars for whenever you want one. Oh, and you can still modify your autonomous pod if you wanted to

... and it will never crash, just like an Airbus.

[vaud]

M4cruiser said:

... and it will never crash, just like an Airbus.

No-one has said they won't crash but there is a good indications that there will be fewer incidents per 1m miles for fully autonomous, with the rate improving as the % of cars that are autonomous increases.

Car to car data, multiple cameras, ML, sensors, knowledge of speed limits etc.

It's not tomorrow but the direction is firmly set for incremental autonomy of the car.

[craigjm]

M4cruiser said:

bigothunter said:

craigjm said:

Personally, I quite like the idea of an autonomous pod thing that I can summon using my phone or watch to come and collect me from the pub and take me home. Much more useful than uber etc and can still have the garage with fun cars for whenever you want one. Oh, and you can still modify your autonomous pod if you wanted to

... and it will never crash, just like an Airbus.

How much more likely will it be to crash than any other solution?

[Oilchange]

D4rez said:

Well, if you’re upgrading the performance of tyres, brakes and suspension then you would hope it knocks on to better roadholding and braking. Wouldn’t you rather have a verified modification that checked all of that put though? I’d rather know ABS, ESC and safety systems still work.

I do. I simply don't trust the government to police it. I trust my own judgement.
And I can usually tell if an oem part or an aftermarket part has been designed with a lifespan on it so when the government tells me I must have a part from xyz manufacturer I am instantly suspicious they will abuse the position, overcharge and underperform. And since when do governments not ever give contracts to their mates? Plenty of scope for corrupt back handers as well.