5 ms·

Vehicles doing unpredictable things are simply broken. The 04 R1 I used to ride had a goofy double throttle system where the cable directly drove the first set

Vehicles doing unpredictable things are simply broken. The 04 R1 I used to ride had a goofy double throttle system where the cable directly drove the first set of intake butterflies, but a duplicate set downstream was computer controlled via servo. This was the generation that introduced catalytic converters to bikes, and I presumed the intention was to limit throttle opening rates via computer overriding what the rider had done when opened too quickly. Conventionally that transient pressure drop situation is handled by throwing a bunch of excess fuel into the air stream to not hesitate and stumble from most the fuel falling out of suspension and clinging to the walls, i.e. they were cleaning up emissions. Even this seemingly benign and dead-stupid bit of a computer override almost caused me to crash on multiple occasions. If the rider opened the throttle aggressively far beyond where the servo operated throttle was at, and immediately began dialing it back to reduce the acceleration, the servo operated throttle would continue opening to meet the still more open cable operated throttle's position. So rider is telling bike to accelerate less, and bike is accelerating more in a game of computer catch up. This is not only very unexpected on a naturally aspirated ICE, but outright dangerous on a nearly 200HP sportbike. At least it was relatively trivial to remove the plates from the servo actuated throttle shaft and let the computer keep pointlessly twisting a bare shaft.

rconti 5y ago
Ugh. I had a bike that liked to stumble when cold, and it's exciting when leaned into a corner to leave the traffic lights and lose most of your power. These things are kind of important.
- pengaru 5y ago
  Yeah that's problematic. A 500cc track bike I had came with primitive slide carburetors lacking any sort of accelerator pump by design. Cold or hot that thing would fall on its face if you were too ham-fisted with the throttle at low RPMs. But at least it was deterministic at this, and you quickly learned to not do that. On the track you're never down so low in RPMs so maybe it even made sense from a KISS perspective.
function_seven 5y ago
That sounds like a nightmare. What was the rationale for having a split control system like that? If preventing snaps of wide open throttle were the goal, then having the butterflies both servo controlled would accomplish that right? Wait, when you say "downstream" do you mean the butterflies were in series on the same intake path? I'm trying to visualize what a small time delay and rate mismatch would look like here.
- pengaru 5y ago
  > when you say "downstream" do you mean the butterflies were in series on the same intake path? Yes, in series, literally redundant throttle plates on a common set of ITB runners: \ / \ / \ / \ / | | | | | | | | |/|-|/|-|/|-|/|-cable/rider-operated | | | | | | | | |/|-|/|-|/|-|/|-servo/ecu-operated | | | | | | | | * * * *
  - function_seven 5y ago
    Top notch ASCII art there, thanks. Yeah, I'm no combustion engineer or anything, but I just can't see what would motivate a system like that. I suppose the rider has the ability to snap the throttle shut instantly, but you could achieve the same with a limit plate on the same set of butterflies that are servo-controlled. So when you open it up, you're both electonically telling the ECU what you want, and mechanically allowing the range of motion. When you snap the throttle shut, you're forcing the intakes closed. Computer gets to limit the rate of opening and coordinate the fuel, rider still gets to close it as fast as they please.
    - pengaru 5y ago
      What you're describing would still suffer from the same "catch-up" problem though, assuming the same control software. It's worth noting later versions of YCC-T are servo-actuated using a single throttle shaft. This early version was probably just something slapped on at the last minute using off-the-shelf components, and they didn't refine the control software enough to do things like at least resync the logical servo position with the cable throttle position when the rider has started closing the throttle from an overshoot position. It was just a very naive rate-limiting filter of sorts where the servo is continuously chasing the actual throttle's instantaneous position. The experience occasionally resembled a laggy high boost turbo car where tq keeps increasing despite a shrinking throttle open %. Kind of amusing in a car, Tesla FSD levels of idiotic on a ~1000hp/ton bike.
jeffbee 5y ago
Yamaha for some reason can't get the fueling right, even to this day. Kawasaki gets it right and meets the same emissions standards. It's not a fundamental issue with ride-by-wire, it's quality of implementation.
- pengaru 5y ago
  There's a reason Rossi insisted on his M1 stay carbureted for years while Yamaha was shipping the ycc-t junk on the R1. It was quite public and controversial at the time. Obviously Yamaha was pressuring him to market their ycc-t by winning races with it, but he kept rejecting it after testing and kept dominating motogp using carbs instead.
  - pengaru 5y ago
    Out of curiosity I tried digging up information surrounding the continued use of carburetors on the M1 while the R1 was shipping w/EFI, considering there were multiple articles written at the time including quotes from Rossi. But this was all I could find: https://www.motorcycledaily.com/2002/02/27february02yamahamotogp/ https://www.motorcycledaily.com/2002/02/27february02yamahamo...
kube-system 5y ago
Some early traction control systems in cars used the same double-throttle setup. I presume this is just the simplest way to slap a feature like that on as an afterthought.
- pengaru 5y ago
  At least on cars there's usually so much mass and aggregate mechanical sloppiness present you probably wouldn't notice. The R1 didn't so much as accelerate as it teleported at wide throttle angles in 1st gear, combined with no squishy rubber isolation bits adding mechanical latency to the system. The phenomenon was very apparent and nerve-wracking in the right conditions.
  - kube-system 5y ago
    The cars I've driven with this feature have also been quite quick to retard the throttle and quite slow to advance it. But things like this are certainly just one more reason that I do not ride liter bikes.
- KennyBlanken 5y ago
  Traction control happens via braking (especially in AWD vehicles), fuel and ignition cut per-cylinder, or via drive-by-wire throttles. I've never heard of a car with a second throttle for traction control. You might be confusing variable intake geometry vanes.
  - kube-system 5y ago
    I am not confusing anything. The system I describe was used, for instance, in several BMW models from the 1990s. It’s sucks and it disappeared fairly quickly, in lieu of the other much better systems you list. See: http://www.eatsleeptinker.com/2014/06/02/asc-throttle-body-delete/ http://www.eatsleeptinker.com/2014/06/02/asc-throttle-body-d...
    - PhantomGremlin 5y ago
ClumsyPilot 5y ago
"Vehicles doing unpredictable things are simply broken." They should result in corporate manslaughter charges ahainst the manufacturer. If we let this slide, a JavaScript library with 100 known vulnerabilities will be running on 10 year old kernel controlling your breaks and then you will get 'oops, something went wrong!' Message and die because you car started mining buttcoin
- paulmendoza 5y ago
  But if these systems are saving lives compared to driving without them then it is better to keep them even if they are a bit buggy.
sidewndr46 5y ago
The 2012 Kawasaki ZX14-R had an identical system, but it was non problematic. It would artificially limit throttle opening below 3500 rpm but I didn't mind that. The idle speed of the motorcycle was 35 mph, so I just used the clutch only at low speed to control the vehicle. This was much safer and the engine wouldn't get over 200 F even in stop and go traffic.
14 5y ago
That's just crazy, motorcycles require smooth and predictable acceleration. I like to rip on my bike but a sudden surge of power could really screw you up in certain conditions. That is why I always say when you get a new bike ride it like a beginner for a long time and slowly build up how aggressively you ride it. They all seem to have slight personalities so going slow is the way to go at first.
mattalex 5y ago
I still think it's absolutely insane that for aviation we require everything to be formally verified, while cars don't have any such thing and can brick themselves via over-the-air updates at any time. And that ignores the even more complex problem of self-driving which is something even aviation, which has a lot less opportunities for external errors, doesn't even try to tackle.
- qualudeheart 5y ago
  The two biggest problems are unsafe languages and memechine learning. We need a new paradigm for secure software.

rconti 5y ago

Ugh. I had a bike that liked to stumble when cold, and it's exciting when leaned into a corner to leave the traffic lights and lose most of your power. These things are kind of important.

pengaru 5y ago
Yeah that's problematic. A 500cc track bike I had came with primitive slide carburetors lacking any sort of accelerator pump by design. Cold or hot that thing would fall on its face if you were too ham-fisted with the throttle at low RPMs. But at least it was deterministic at this, and you quickly learned to not do that. On the track you're never down so low in RPMs so maybe it even made sense from a KISS perspective.

function_seven 5y ago

That sounds like a nightmare. What was the rationale for having a split control system like that? If preventing snaps of wide open throttle were the goal, then having the butterflies both servo controlled would accomplish that right? Wait, when you say "downstream" do you mean the butterflies were in series on the same intake path? I'm trying to visualize what a small time delay and rate mismatch would look like here.

pengaru 5y ago
> when you say "downstream" do you mean the butterflies were in series on the same intake path? Yes, in series, literally redundant throttle plates on a common set of ITB runners: \ / \ / \ / \ / | | | | | | | | |/|-|/|-|/|-|/|-cable/rider-operated | | | | | | | | |/|-|/|-|/|-|/|-servo/ecu-operated | | | | | | | | * * * *
- function_seven 5y ago
  Top notch ASCII art there, thanks. Yeah, I'm no combustion engineer or anything, but I just can't see what would motivate a system like that. I suppose the rider has the ability to snap the throttle shut instantly, but you could achieve the same with a limit plate on the same set of butterflies that are servo-controlled. So when you open it up, you're both electonically telling the ECU what you want, and mechanically allowing the range of motion. When you snap the throttle shut, you're forcing the intakes closed. Computer gets to limit the rate of opening and coordinate the fuel, rider still gets to close it as fast as they please.
  - pengaru 5y ago
    What you're describing would still suffer from the same "catch-up" problem though, assuming the same control software. It's worth noting later versions of YCC-T are servo-actuated using a single throttle shaft. This early version was probably just something slapped on at the last minute using off-the-shelf components, and they didn't refine the control software enough to do things like at least resync the logical servo position with the cable throttle position when the rider has started closing the throttle from an overshoot position. It was just a very naive rate-limiting filter of sorts where the servo is continuously chasing the actual throttle's instantaneous position. The experience occasionally resembled a laggy high boost turbo car where tq keeps increasing despite a shrinking throttle open %. Kind of amusing in a car, Tesla FSD levels of idiotic on a ~1000hp/ton bike.

jeffbee 5y ago

Yamaha for some reason can't get the fueling right, even to this day. Kawasaki gets it right and meets the same emissions standards. It's not a fundamental issue with ride-by-wire, it's quality of implementation.

pengaru 5y ago
There's a reason Rossi insisted on his M1 stay carbureted for years while Yamaha was shipping the ycc-t junk on the R1. It was quite public and controversial at the time. Obviously Yamaha was pressuring him to market their ycc-t by winning races with it, but he kept rejecting it after testing and kept dominating motogp using carbs instead.
- pengaru 5y ago
  Out of curiosity I tried digging up information surrounding the continued use of carburetors on the M1 while the R1 was shipping w/EFI, considering there were multiple articles written at the time including quotes from Rossi. But this was all I could find: https://www.motorcycledaily.com/2002/02/27february02yamahamotogp/ https://www.motorcycledaily.com/2002/02/27february02yamahamo...

kube-system 5y ago

Some early traction control systems in cars used the same double-throttle setup. I presume this is just the simplest way to slap a feature like that on as an afterthought.

pengaru 5y ago
At least on cars there's usually so much mass and aggregate mechanical sloppiness present you probably wouldn't notice. The R1 didn't so much as accelerate as it teleported at wide throttle angles in 1st gear, combined with no squishy rubber isolation bits adding mechanical latency to the system. The phenomenon was very apparent and nerve-wracking in the right conditions.
- kube-system 5y ago
  The cars I've driven with this feature have also been quite quick to retard the throttle and quite slow to advance it. But things like this are certainly just one more reason that I do not ride liter bikes.
KennyBlanken 5y ago
Traction control happens via braking (especially in AWD vehicles), fuel and ignition cut per-cylinder, or via drive-by-wire throttles. I've never heard of a car with a second throttle for traction control. You might be confusing variable intake geometry vanes.
- kube-system 5y ago
  I am not confusing anything. The system I describe was used, for instance, in several BMW models from the 1990s. It’s sucks and it disappeared fairly quickly, in lieu of the other much better systems you list. See: http://www.eatsleeptinker.com/2014/06/02/asc-throttle-body-delete/ http://www.eatsleeptinker.com/2014/06/02/asc-throttle-body-d...
  - PhantomGremlin 5y ago

ClumsyPilot 5y ago

"Vehicles doing unpredictable things are simply broken." They should result in corporate manslaughter charges ahainst the manufacturer. If we let this slide, a JavaScript library with 100 known vulnerabilities will be running on 10 year old kernel controlling your breaks and then you will get 'oops, something went wrong!' Message and die because you car started mining buttcoin

paulmendoza 5y ago
But if these systems are saving lives compared to driving without them then it is better to keep them even if they are a bit buggy.

sidewndr46 5y ago

The 2012 Kawasaki ZX14-R had an identical system, but it was non problematic. It would artificially limit throttle opening below 3500 rpm but I didn't mind that. The idle speed of the motorcycle was 35 mph, so I just used the clutch only at low speed to control the vehicle. This was much safer and the engine wouldn't get over 200 F even in stop and go traffic.

14 5y ago

That's just crazy, motorcycles require smooth and predictable acceleration. I like to rip on my bike but a sudden surge of power could really screw you up in certain conditions. That is why I always say when you get a new bike ride it like a beginner for a long time and slowly build up how aggressively you ride it. They all seem to have slight personalities so going slow is the way to go at first.

mattalex 5y ago

I still think it's absolutely insane that for aviation we require everything to be formally verified, while cars don't have any such thing and can brick themselves via over-the-air updates at any time. And that ignores the even more complex problem of self-driving which is something even aviation, which has a lot less opportunities for external errors, doesn't even try to tackle.

qualudeheart 5y ago
The two biggest problems are unsafe languages and memechine learning. We need a new paradigm for secure software.