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10-21-2019, 11:37 PM
Boring Stuff Unless You're an Engineering Nerd...
I found this site when I was researching what my Land Rover was capable of. The user
handbook claims an approach angle and slope of 45º or 100% which I find hard to believe,
and I've certainly never attempted anything like that.
The Slope of a Road
There's also a Slope, Distance and Equation Calculator HERE.
You can catch 40 winks now folks—no Z-drugs necessary. And you're welcome.
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10-22-2019, 01:44 PM
Boring Stuff Unless You're an Engineering Nerd...
You didnt know that 100% is 45°? You didnt know that at 45° the hypothenuse is sqrt(2)?
<-- is an engineering nerd
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10-22-2019, 03:59 PM
Boring Stuff Unless You're an Engineering Nerd...
It's 100% slope at 45º because the tangent (sine/cosine) of 45º is 1. Straight up is not defined for the tangent, as cosine is zero at 90º, and we may not divide by zero.
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10-22-2019, 04:16 PM
Boring Stuff Unless You're an Engineering Nerd...
Falls of bicycle.
Damn you lot!
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10-22-2019, 04:33 PM
Boring Stuff Unless You're an Engineering Nerd...
Most drivers in Oz are so fuckin' thick they cant cope with any maths involving road slopes.
So this is all we get...
And the vehicle graphic appears to have been modelled on a UK Standard Eight from 1947.
And if an Aussie bogan saw this...
... he'd think it was some new sort of hashtag.
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10-22-2019, 04:42 PM
Boring Stuff Unless You're an Engineering Nerd...
Little tip:
tangent 30° = 1/sqrt(3)
tangent 45° = sqrt(2)
tangent 60° = sqrt(3)
On an (un?)related note: You know how your ABS/ESC measures the angle/slope of the road when you, like, have your car parked uphill?*
It doesnt measure the angle at all. Its the longitudinal acelerometer (that is already in, because of ABS/ESC). The accelerometer measures the 1g reduced by the above rules of trigonometry. At 45° it would measure 0,5g
IPB = Integrated (electric, the one with the single button instad of the classic lever) Parking Brake is part of the ESC usually. Not many people may know this. IPB (as well as a couple of other functionalities like HDC = Hill Descent Control ) needs info about slope of road.
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10-22-2019, 04:48 PM
Boring Stuff Unless You're an Engineering Nerd...
(10-21-2019, 11:37 PM)SYZ Wrote: I found this site when I was researching what my Land Rover was capable of. Actually i think Land Rover has one of our CONTI ESC systems. What Model year is it? I could ask the application engineer across my desk and tell you exactly what your ESC can do. You would be surprised about how many functions are provided by it. It starts with ACC (Adaptive Cruise Control) and only stops at ABS/ESC. Its up to 50 functionalities.
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10-22-2019, 04:58 PM
Boring Stuff Unless You're an Engineering Nerd...
(10-22-2019, 04:48 PM)Deesse23 Wrote: Actually i think Land Rover has one of our CONTI ESC systems. What Model year is it? I could ask the application engineer across my desk and tell you exactly what your ESC can do. You would be surprised about how many functions are provided by it. It starts with ACC (Adaptive Cruise Control) and only stops at ABS/ESC. Its up to 50 functionalities.
MY2000 Land Rover Discovery II, TD5, auto, with hill descent mode.
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10-22-2019, 11:28 PM
Boring Stuff Unless You're an Engineering Nerd...
(10-22-2019, 04:42 PM)Deesse23 Wrote: Little tip:
tangent 30° = 1/sqrt(3)
tangent 45° = sqrt(2)
tangent 60° = sqrt(3)
In new-maths tangent 45° = 1
No gods necessary
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10-23-2019, 06:09 AM
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(10-22-2019, 11:28 PM)brunumb Wrote: (10-22-2019, 04:42 PM)Deesse23 Wrote: Little tip:
tangent 30° = 1/sqrt(3)
tangent 45° = sqrt(2)
tangent 60° = sqrt(3)
In new-maths tangent 45° = 1
You guys are cracking me up. I was totally confused about the term "tangent". A tangent in german is, well, the tangent, to a circle i.e. What you are calling "tangent" is "tangen s" in German. Had to google that shit myself yesterday, but thats one of the reasons i am here, to learn (english primarily).
I was wrong, as i didnt give the tangen s, but lenght of hypothenusis for 45°. I am simply getting too old for this shit.
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10-23-2019, 06:31 AM
(This post was last modified: 10-23-2019, 06:37 AM by Deesse23.)
Boring Stuff Unless You're an Engineering Nerd...
(10-22-2019, 04:58 PM)SYZ Wrote: MY2000 Land Rover Discovery II, TD5, auto, with hill descent mode. MY2000 thats pretty ancient. I started working for Conti in 2002 and many people from back then have retired until now.
We always had the Land Rover projects ( f.u. BOSCH ) Your car should have our Mk60 (or Mk25, bigger hydraulics, usually for SUVs n stuff) system. We currently are at least 3 generations ahead of that now (Mk60E, Mk60A, Mk100). I just searched our intranet databases, but its so ancient we never carried over our Mk60 specs into the new tools and databases. So heres off the top of my head what your ESC system can so.
ESC: Control of yaw axis (drifting off the road in a turn)
ABS/TCS: Longitudinal acceleration control
OHBV: Safety function. Once your vacuum booster fails, you would severly lack brake pressure to stop your car. Mk60 can detect this (driver hits brake pedal like mad, but no hydrulic brake pressure) and actively turn on its hyd. pump and provide the needed pressure. Vacuum bossters rarely fail, and you never want to run into this scenario anyway, trust me.
EBD: electronic brake force distribution. Essentially preventing the rear axle from lock up. Rear axle lock up is making the car inherently unstable and uncontrollable, its feking dangerous it has to be avoided. This is particularly a concern on vehicles with a high center of gravity and high weight, or uneven weight distribution. Once you brake hard, your vehicle tends to pitch forward, thus reducing weight on rear axle and making it prone ot lock up. Mk60 reduces pressure on rear axle in such a scenario. In case of undervoltage this is the very last function we keep alive on the system (down to ca. 7V, after that the coils of the electronic valves wont work).
Hill Holder: Temporarily keeping pressure in the brake, assisting drivers to stop on an upwards slope
HDC Hill descent control. When slowly rolling downhill, Mk60 controls the speed by applying a small brake pressure to avoid acceleration dowwards. Also an assisting function.
HSA: Hill start assist: Driving off from an upward slope can be difficult for drivers, especially with manual gearbox, due to need to control clutch, brake and accelerator at the same time. Mk60 keeps brake pressure for 1 or 2 secs after brake pedal release, giving the driver time to get into 1st gear and drive off.
For SUVs there is also a function to control the tentency to roll in tight turns (due to high center of gravity and high suspension). Engine management will be ordered to decel and slight diagonal brake force will be applied to stabilize vehicle.
Some of these functions my not already be included in Mk60 but only Mk60E, but you can easily check those assistant functions yourself if you pay attention to what happens.
P.S.: All the functionalities related to "hill" will determine the slope by using the longitudinal accelerometer (used for ABS/TCS anyway) and trigonometry.
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10-23-2019, 11:51 AM
Boring Stuff Unless You're an Engineering Nerd...
I joined the Navy right out of high school, didn't go to college for decades after high school. But I was an "engineering rating" in the USN, meaning I worked on the guts of a carrier or such lesser beasts as the Navy so ordered. I worked hard to understand the technical aspects of the 70,000 shp turbines that were my responsibility. I like to think I had more fun that I would have sitting in an office. I know it was more exciting in a shit-your-pants WTF fashion.
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10-23-2019, 01:49 PM
Boring Stuff Unless You're an Engineering Nerd...
(10-23-2019, 06:31 AM)Deesse23 Wrote: (10-22-2019, 04:58 PM)SYZ Wrote: MY2000 Land Rover Discovery II, TD5, auto, with hill descent mode. MY2000 thats pretty ancient. I started working for Conti in 2002 and many people from back then have retired until now.
We always had the Land Rover projects ( f.u. BOSCH ) Your car should have our Mk60 (or Mk25, bigger hydraulics, usually for SUVs n stuff) system. We currently are at least 3 generations ahead of that now (Mk60E, Mk60A, Mk100). I just searched our intranet databases, but its so ancient we never carried over our Mk60 specs into the new tools and databases. So heres off the top of my head what your ESC system can so.
ESC: Control of yaw axis (drifting off the road in a turn)
ABS/TCS: Longitudinal acceleration control
OHBV: Safety function. Once your vacuum booster fails, you would severly lack brake pressure to stop your car. Mk60 can detect this (driver hits brake pedal like mad, but no hydrulic brake pressure) and actively turn on its hyd. pump and provide the needed pressure. Vacuum bossters rarely fail, and you never want to run into this scenario anyway, trust me.
EBD: electronic brake force distribution. Essentially preventing the rear axle from lock up. Rear axle lock up is making the car inherently unstable and uncontrollable, its feking dangerous it has to be avoided. This is particularly a concern on vehicles with a high center of gravity and high weight, or uneven weight distribution. Once you brake hard, your vehicle tends to pitch forward, thus reducing weight on rear axle and making it prone ot lock up. Mk60 reduces pressure on rear axle in such a scenario. In case of undervoltage this is the very last function we keep alive on the system (down to ca. 7V, after that the coils of the electronic valves wont work).
Hill Holder: Temporarily keeping pressure in the brake, assisting drivers to stop on an upwards slope
HDC Hill descent control. When slowly rolling downhill, Mk60 controls the speed by applying a small brake pressure to avoid acceleration dowwards. Also an assisting function.
HSA: Hill start assist: Driving off from an upward slope can be difficult for drivers, especially with manual gearbox, due to need to control clutch, brake and accelerator at the same time. Mk60 keeps brake pressure for 1 or 2 secs after brake pedal release, giving the driver time to get into 1st gear and drive off.
For SUVs there is also a function to control the tentency to roll in tight turns (due to high center of gravity and high suspension). Engine management will be ordered to decel and slight diagonal brake force will be applied to stabilize vehicle.
Some of these functions my not already be included in Mk60 but only Mk60E, but you can easily check those assistant functions yourself if you pay attention to what happens.
P.S.: All the functionalities related to "hill" will determine the slope by using the longitudinal accelerometer (used for ABS/TCS anyway) and trigonometry.
All that tech, wow! My big dumb 1970 truck gets higher pressure in the rear tires to correct for over steer from the large camper on the back. I'll eventually put a rear stabilizer bar on it to reduce the effect even more, especially when pulling my 6k pound trailer.
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10-23-2019, 03:53 PM
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(10-23-2019, 01:49 PM)Fireball Wrote: All that tech, wow! My big dumb 1970 truck gets higher pressure in the rear tires to correct for over steer from the large camper on the back. I'll eventually put a rear stabilizer bar on it to reduce the effect even more, especially when pulling my 6k pound trailer. Modern ESC systems are correcting for a lot of bad (chassis and brake) design of modern cars. Of course your local car dealer wont tell you....
Modern diesel engines offen dont provide enough vaccum for the (vacuum) brake booster. The ESC has to provide extra *oomph* in case your pedal starts feeling funny.....although (and the OEMs ar well aware!) an ESC is a driver asisstant system and its architecture not fit for providing base brake function.* The ice the OEMs are walking on is sometimes pretty thin, legally speaking.
Most famous was the so called "Elk test" of the Daimer A-class in the 90s, where the vehicle had a ridiculously high center of gravity (and soft suspension afaik) and tended to flip over when confronted with a scandinavian "Elk crossing road" scenario. The only thing that prevented a major desaster for Daimer was the ESC. Thats when our sales were sky rocketing.
There are also a lot of cars with other design issues. Automotive business is a real swamp i tell ya, and diesel-gate is just the tip of the iceberg.
*because of lack of redundancies. ESC systems are fail-silent, not fail-safe.
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10-23-2019, 05:24 PM
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I have a couple of KIA econoboxes that we use for base commuting. I can still stop and steer them if the assist quits, but I'm not so sure about the wife being able to do it. Though she did manage to do so when the fuel pump quit on our Chevy Astrovan and no steering or brake assist was available. Up until I got married, I had manual shift vehicles with manual brakes and steering. The minor increase in effort wasn't an issue for me. The big dumb truck has power steering and brakes, but I'm still able to control it if it stalls. I hope I never (literally) run into an elk, though. They do live here in the higher elevations and the northern parts of the country.
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10-24-2019, 02:43 AM
Boring Stuff Unless You're an Engineering Nerd...
(10-23-2019, 06:31 AM)Deesse23 Wrote: (10-22-2019, 04:58 PM)SYZ Wrote: MY2000 Land Rover Discovery II, TD5, auto, with hill descent mode. MY2000 thats pretty ancient. I started working for Conti in 2002 and many people from back then have retired until now...
Thanks for all that info mate! Much appreciated.
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