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BMW F Series Gear Selector, Part Two: Breakthrough

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Re: BMW F Series Gear Selector, Part Two: Breakthrough

#101

Post by stefanve »

rconti wrote: post #64
phkahler wrote: post #44

A lot of the complexity here is because the gear selector is considered a safety-critical part. They may also consider LED indicators on it as safety-critical information to the driver. Those two things - is the transmission receiving the real intent of the driver, and is the driver being told the actual state of the system - are just the top level. Security is also starting to be a concern, though I think there is r…

Yup. Bad Things can happen: https://money.cnn.com/2016/06/20/autos/jeep-recall-anton-yel... I absolutely hate stateless switches on automotive stuff. Why can't I tell that my turn signal is on by 'feel'? Why do I have to rely on a (too quiet) clicking, or a (too hidden) indicator light? I have an E70 X5 with the "new style" transmission selector, as well as a Tesla 3 that replicates it on the right side of the column…

I owned a 325xi e91 and didn't experience any turn signal problems, same for my current 420i F36. Lot of German cars (VW, Audi etc) have a two stage turn signal. A light bump will do 4 or so signals and automatically stops if you move the stalk all the way it wil stay there until you move it back.

to me the sound is loud enough to hear it but not so loud it is annoying

Re: BMW F Series Gear Selector, Part Two: Breakthrough

#102

Post by stefanve »

speed_spread wrote: post #95
userbinator wrote: post #89

Earlier quoted context omitted.

The E90 and newer BMWs seem to have indicator clicks that are almost inaudible That's very odd, given how much emphasis they have (or used to?) about road-feel and other forms of feedback while driving, and BMW's slogan is "the ultimate driving machine".

BMW has lost much of its driving mojo in the last decade. The quest for more customers has eroded a lot of the car's character.

e91 was a very nice car to drive the f36 is the first car that I modified because it didn't driver that well. changed the suspensions and now drivers in some ways nearly as good as the e91 and in other ways better

Re: BMW F Series Gear Selector, Part Two: Breakthrough

#103

Post by climb_stealth »

smilekzs wrote: post #83
rconti wrote: post #64

Earlier quoted context omitted.

Yup. Bad Things can happen: https://money.cnn.com/2016/06/20/autos/jeep-recall-anton-yel... I absolutely hate stateless switches on automotive stuff. Why can't I tell that my turn signal is on by 'feel'? Why do I have to rely on a (too quiet) clicking, or a (too hidden) indicator light? I have an E70 X5 with the "new style" transmission selector, as well as a Tesla 3 that replicates it on the right side of the column…

Fortunately, G20 onwards have returned to a mechanically latching turning signal stalk design. Unfortunately, ZN8/ZD8 Toyota GR86 / Subaru BRZ (the new ones!) have regressed to the dreaded mechanically momentary (non-latching) turning signal stalk design.

Noooooo! I have been following the new GR86s for a while. Hearing this makes me actually reconsider whether I really want one.

Re: BMW F Series Gear Selector, Part Two: Breakthrough

#104

Post by wolrah »

stefan_ wrote: post #87
wolrah wrote: post #6

Earlier quoted context omitted.

> Makes me want to go out and hug my truck, whose gear selector consists of metal sticks and pins. If it's a manual transmission or an ancient automatic, sure, but manual transmission trucks basically haven't existed for a decade or so and every automatic since the mid 90s has an electronic gear selector of some variety. Somehow the world keeps working just fine. The biggest problem that's come up with them has been…

I think the first part of this blog series had the gear selector sending it's state every 30ms - so you are looking at some averaged ~15ms of latency just from this thing.

> I think the first part of this blog series had the gear selector sending it's state every 30ms - so you are looking at some averaged ~15ms of latency just from this thing.

For reference purposes at the standard gaming benchmark of 60 FPS a single frame is 16.666_ ms, so you're looking at the equivalent of a frame or two of delay.

That could be critical for a CRT-era fighting game that requires frame-perfect inputs, but as a controller for a traditional automatic transmission it doesn't matter in the slightest.

Re: BMW F Series Gear Selector, Part Two: Breakthrough

#105

Post by wolrah »

thescriptkiddie wrote: post #49
wolrah wrote: post #6

Earlier quoted context omitted.

> Makes me want to go out and hug my truck, whose gear selector consists of metal sticks and pins. If it's a manual transmission or an ancient automatic, sure, but manual transmission trucks basically haven't existed for a decade or so and every automatic since the mid 90s has an electronic gear selector of some variety. Somehow the world keeps working just fine. The biggest problem that's come up with them has been…

> manual transmission trucks basically haven't existed for a decade That might be true of pickup trucks, but commercial trucks are virtually all manual.

> That might be true of pickup trucks, but commercial trucks are virtually all manual.

I don't have much experience with the big trucks, but my understanding is that most fleets are leaning towards automatic these days because it's easier to get drivers, they can enforce shifting policies for fuel economy, and there's less a bad/aggressive driver can screw up. I'd totally believe owner ops still stick with three pedals for the most part though.

In the medium size truck world it's been ages since I've seen a stick, everything has an Allison with that same janky '80s seven-segment LED control panel.

Re: BMW F Series Gear Selector, Part Two: Breakthrough

#106

Post by wolrah »

throwaway0a5e wrote: post #18
wolrah wrote: post #6

Earlier quoted context omitted.

> Makes me want to go out and hug my truck, whose gear selector consists of metal sticks and pins. If it's a manual transmission or an ancient automatic, sure, but manual transmission trucks basically haven't existed for a decade or so and every automatic since the mid 90s has an electronic gear selector of some variety. Somehow the world keeps working just fine. The biggest problem that's come up with them has been…

I'm very familiar with EEC-IV era Fords. If you want to have this debate I am very much down. Your 1993 Crown Vic may as well be a 1980s toaster over compared to the 2010+ cars being discussed. The only digital electronics are in the ECU and for the display on the radio. There is a huge difference between a 90s Ford style lever position sensor and the BMW stuff. If the computer doesn't do the right gear for what you…

> There is a huge difference between a 90s Ford style lever position sensor and the BMW stuff. If the computer doesn't do the right gear for what you want you just move it until it does. The BMW will spit error messages at you.

You have missed the point. Yes, in that one particular failure mode if the calibration is off on the shift lever itself you can usually fiddle with it to at least end up in a gear. The point was that the transmission doesn't work unless the computer thinks everything's OK. It's not like a mechanical automatic where you can climb under the car and fiddle some levers to force it in to gear. The computer controls everything, just like in the BMW and just like basically every other automatic transmission from the late '80s/early '90s and beyond.

The fact that the BMW shift lever separates the part deciding what gear you've selected from the part actually controlling the gearbox and connects the two over CAN doesn't seem like a significant difference to me from a functionality or reliability standpoint.

The Ford is more or less a classic "game port" joystick where the BMW is the equivalent of a USB HID joystick.

Re: BMW F Series Gear Selector, Part Two: Breakthrough

#107

Post by numpad0 »

asciimike wrote: post #13

I've spent quite a bit of time hacking my own F-Series BMW, and I can confirm it's a _huge_ pain in the ass, mostly because there is basically zero documentation on how to do it. IMO BMW also occasionally makes some bizarre engineering decisions, for instance, connect one long wire from an internal switch console to the DME unit (engine controller) rather than connect directly to an adjacent CANBUS that already went…

> wire from an internal switch console ... rather than connect directly to an adjacent CANBUS that already went there

This type of design was not straightforward for me as well, but in the end this is because a car is topologically not an integrated machine with centralized control like a PC, but more like a network rack kitted with various systems, with user interfaces at the front and networking at the back.

We tend to look at a driver's seat of a car and understand it as an equivalent to VT100, and that is not what it is; the controls in a car are for each discrete systems that shares a chassis. Therefore the control goes to respective systems and communications goes through the network.

Re: BMW F Series Gear Selector, Part Two: Breakthrough

#108

Post by stefan_ »

wolrah wrote: post #104
stefan_ wrote: post #87

Earlier quoted context omitted.

I think the first part of this blog series had the gear selector sending it's state every 30ms - so you are looking at some averaged ~15ms of latency just from this thing.

> I think the first part of this blog series had the gear selector sending it's state every 30ms - so you are looking at some averaged ~15ms of latency just from this thing. For reference purposes at the standard gaming benchmark of 60 FPS a single frame is 16.666_ ms, so you're looking at the equivalent of a frame or two of delay. That could be critical for a CRT-era fighting game that requires frame-perfect inputs,…

Yes, exactly, that is terrible latency if you want to use it as an input device.

Re: BMW F Series Gear Selector, Part Two: Breakthrough

#109

Post by smilekzs »

simondotau wrote: post #90
quarantaseih wrote: post #61

Im currently renting a BMW with this gear selector. In fairness, I throughly hate the car (an X1). Terrible lag, awful throttle response, terrible steering, unpredictable brakes, etc. But the two candidates for worst feature of the car are 1. The gear selector 2. The indicator lights Every time I have to engage one of the two I let out a little curse. I driven stick shifts, autos, rear wheel drive cars, trucks, front…

Pretty much everything you’ve said is the exact opposite of my experience (BMW 1-series F20 125i). Great throttle response, minimal turbo lag, precise steering, and highly controllable confidence inspiring brakes. I can see why someone might not like the shifter and indicator stalk, but they simply haven’t been an issue for me. In fact there’s aspects of them which I prefer.

I have driven the X1 and various other BMWs. The X1 is indeed horrible, and there is a reason:

For handling / lateral dynamics: The X1 is derived from essentially a MINI platform which is FWD-based (transverse engine), compared to the rest of the BMW lineup which is RWD-based (longitudinal engine).

For power / longitudinal dynamics: If GP happened to be driving a 3-cylinder, then of course the turbo lag would be high. OTOH, the 4-cylinder B48 is a venerable engine with negligible lag (again used all across the BMW lineup).

Re: BMW F Series Gear Selector, Part Two: Breakthrough

#110

Post by smilekzs »

harryha11er wrote: post #97

German here: Startled by your use of the word "Gangwahlschalter" (I had never heard the word before) I did a quick google search and apparently there is a German Dictionary company that actually tracks use of words and its synonyms. A query to their database confirmed my intuition that "Schalthebel" would be the word people would use. (src: https://www.dwds.de/r/plot/?view=1&corpus=zeitungenxl&norm=d... )

On surface this sounds like refrigerator vs fridge ;)
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