3D GPS, Cruise Control

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douglasteeple

New member
Joined
Sep 11, 2011
Messages
2
First, apologies if my suggestions overlap existing entries, I have read the forum ad did not find exactly these points.

First, I would realy like a more accurate % of charge display. The bars are too course-grained and I find a whole bar drop near the lower end of charge somewhat disturbing.

I live in a very hilly (actually mountainous) area, thus prompting the next suggestions.

GPS maps show the world as flat, something I think was disproved some time ago. The range of the LEAF is very dependent on hills. I have observed that climbing 0.5 miles up (and 10 miles forward) is about equivalent to 50 flat miles. 3D GPS maps would permit better estimates of range, taking in to account the vertical component.

Cruise control could be hooked into regeneration. When I am going down that steep hill, and I ask the cruise control to hold me at 45, it could push hard on regeneration to keep me at 45. At the moment there is no connection between cruise control and regeneration, so even with cruise control my speed creeps up beyond what I have set it at.
 
the GPS issues will be self resolved as you learn your Leafs capabilities and limitations. as far as a CC setpoint, you can only do so much against gravity. regen helps but it is limited.

for the range; there are solutions like Garygid's SOC meter that breaks estimated charges into a 281 point scale. the latest firmware update from Nissan is also supposed to make the range estimates more accurate as well.

i do have the former, have not done the latter yet
 
1. the SOC-Meter gives about 280-step "fuel" resolution instead of the LEAF's 12-step resolution.

2a. The data for 3D GPS is available, but few "need" it, so only a few have written suitable programs. Elevation gain/loss is only one of many "Range" variables.

2b. 10 miles up 2600 feet equal to 50 flat miles? I suspect that around 20 or 25 miles is closer.

3. The CC does slow the LEAF using Regen, I believe. Perhaps you need more Regen due to steep grades? Can one use ECO mode's greater Regen with CC?
 
Nissan is working on integrating elevation into their range algorithm. I personally spoke with one of the engineers working on the project. It won't help current LEAFs much, however.

I don't use the GuessOmeter at all, and whatever improvement would be (potentially) just less wrong. I'm scheduled to have my car updated Monday.

Have you had a chance to check out the range chart linked on my signature line?
 
garygid said:
3. The CC does slow the LEAF using Regen, I believe. Perhaps you need more Regen due to steep grades? Can one use ECO mode's greater Regen with CC?

Yep, sadly the regen available in CC mode is tied to driving mode. So shifting to eco will give the CC more regen to work with.

In my opinion, CC should be able to command all the regen possible, regardless of driving mode.
 
CC setpoints are tied too much to the setpoint itself.

regen will slow you down but common sense is what is needed here. if you know you are starting a steep decent and you want to average 45 mph then you need to set CC to 40 mph or less.

CC will not let you go below your setpoint but gravity can push you beyond regen's ability to slow you down TO YOUR SETPOINT

i see this on the Oly hills which are not steep by any real sense nor are they very long. the road to downtown has a decent grade, steep enough to run you 5-10 mph past your set point.

now braking occasionally will slow you down or increase regen but then you have to restart CC.
 
I think it is good that ECO gives the CC more Regen to work with.

Unless it turns on the brake lights, you probably should
not have the use of Strong Regen.

But, it would be nice for CC to have the ability to do more Regen
(with brake lights), for long, medium-speed, downhill stretches.
 
garygid said:
I think it is good that ECO gives the CC more Regen to work with.

Unless it turns on the brake lights, you probably should
not have the use of Strong Regen.

But, it would be nice for CC to have the ability to do more Regen
(with brake lights), for long, medium-speed, downhill stretches.

feedback i have received from driving in Eco mode is that brake lights do not come on unless you engage the brake pedal. have had dozens of co-workers tell me i should check my brake lights.

i normally drive all the way to work without touching the brake pedal except to stop when pulling into my parking space.

this could be construed as a safety issue on flat ground but anyone going down a steep hill who is not paying very close attention to the speed of a car in front of him... either way, maybe having brake lights come on at a certain level of regen might not be such a bad idea ?
 
garygid said:
I think, for better Safety, the EV should turn ON
the brake light at ANY Regen level.
That would mean brake lights on the whole way down a hill. Doesn't having brake lights on all the time lose the startle factor that warns the following driver of a speed decrease?

Using mild regen going down a hill is similar to descending a hill in a lower gear in an ICE car, the usual technique used by any competent driver on hills. (The rule-of-thumb is that one descends the hill in the same gear as is used to climb the same grade.) As it happens, the Eco regen slows the LEAF quite a bit less than third gear on my ICE cars; I wish it could be dialed up a bit so I can reduce my speed going down those grades without having to use brakes.

Descending a grade in a lower gear or using regen doesn't involve slowing if the grade is relatively constant, so there is no need to warn following drivers with brake lights. It is only the sudden change in speed that needs brake lights, IMHO.
 
dgpcolorado said:
garygid said:
I think, for better Safety, the EV should turn ON
the brake light at ANY Regen level.
That would mean brake lights on the whole way down a hill. Doesn't having brake lights on all the time lose the startle factor that warns the following driver of a speed decrease?

Using mild regen going down a hill is similar to descending a hill in a lower gear in an ICE car, the usual technique used by any competent driver on hills. (The rule-of-thumb is that one descends the hill in the same gear as is used to climb the same grade.) As it happens, the Eco regen slows the LEAF quite a bit less than third gear on my ICE cars; I wish it could be dialed up a bit so I can reduce my speed going down those grades without having to use brakes.

Descending a grade in a lower gear or using regen doesn't involve slowing if the grade is relatively constant, so there is no need to warn following drivers with brake lights. It is only the sudden change in speed that needs brake lights, IMHO.
Agreed, I see no need whatsoever for linking regen to brake lights, no matter how high the regen is (and the Leaf definitely needs a 'B' mode). When you get on the brakes it should be a relatively rapid but short-turn decel, which is different from descending a hill with a steep grade in a lower gear. In the latter, you use the brake pedal only when the speed has crept up faster than you want and you need to slow for a turn or what have you. I'm often amused, occasionally alarmed, to see someone riding their brakes all the way down a long hill instead of shifting to a lower gear and letting engine compression (in an ICE) slow them; even if their brakes aren't smoking at the bottom, you can usually smell them. As my dad (a truck driver) taught me, "use your brakes intermittently so they can stay cooler, and save them for emergencies; always use primarily engine braking for any long or steep descent. If your transmission fails, you can replace it. If your brakes fail, you can't replace you!"

If you need brake lights on to maintain a safe distance behind someone while descending a hill you shouldn't be driving a car in the first place, because your head isn't in the game.
 
1. Down-shifting and using engine-compression for braking ...
does not really apply to a LEAF.

One's head must be in the game called: "Regen or Brake".

And, when Regen is not available, the "game" has few options.

2. Any action that will "noticably" reduce the car's speed should turn on (or flash) the brake lights.

Perhaps just starting to reduce pressure on the "Go-Faster" (pedal) should flash the brake lights as an early warning of possible impending slowing.

I think that extra (roughly) half-second warning (of a sudden slowing) would save some lives, much inconvenience (having the rear end of your car repaired), and a lot of insurance dollars!
 
jkirkebo said:
garygid said:
3. The CC does slow the LEAF using Regen, I believe. Perhaps you need more Regen due to steep grades? Can one use ECO mode's greater Regen with CC?

Yep, sadly the regen available in CC mode is tied to driving mode. So shifting to eco will give the CC more regen to work with.

In my opinion, CC should be able to command all the regen possible, regardless of driving mode.

I can see a possible safety issue. The max regen is variable based on SOC and (iirc) temperature. If you were going down a steep descent and gotten comfortable with CC using strong regen for speed control... and the computer decided to greatly reduce regen, it could lead to a startling "runaway" situation. By forcing the driver to use the brake pedal to get strong regen, they are ready to react.
 
garygid said:
1. Down-shifting and using engine-compression for braking ...
does not really apply to a LEAF. Not really true. Descending a hill on regen is analogous to engine braking on an ICE car, which is why we mention it.

One's head must be in the game called: "Regen or Brake". Although it was a bit unclear, I believe that GRA was referring to the driver of the following car, not the EV using regen.

And, when Regen is not available, the "game" has few options. In that case brakes are used, complete with brake lights.

2. Any action that will "noticably" reduce the car's speed should turn on (or flash) the brake lights. Agreed. What I was referring to was driving on regen at a relatively constant speed. Brake lights in such a situation don't make sense. I encounter this situation every time I leave my house, so it isn't some sort of "special case".

Perhaps just starting to reduce pressure on the "Go-Faster" (pedal) should flash the brake lights as an early warning of possible impending slowing.

I think that extra (roughly) half-second warning (of a sudden slowing) would save some lives, much inconvenience (having the rear end of your car repaired), and a lot of insurance dollars! What I would like to see is brake lights tied to deceleration. For example: lights come on at -0.2g and go off when deceleration is reduced to -0.1g. (Those numbers are just guesses on my part, I don't know what really good figures would be.)
The reason I mentioned all this is that my impression is that flatlanders are completely unaware of the use of regen to descend hills at constant speeds and that they assume that regen=braking=rapid slowing. This is not true when going down hills of significant grade; in that case regen is used to offset the acceleration of gravity. I do not want my brake lights to come on unless I am slowing at a significant enough rate to present a hazard to the following driver.
 
dgpcolorado said:
garygid said:
1. Down-shifting and using engine-compression for braking ...
does not really apply to a LEAF. Not really true. Descending a hill on regen is analogous to engine braking on an ICE car, which is why we mention it.

One's head must be in the game called: "Regen or Brake". Although it was a bit unclear, I believe that GRA was referring to the driver of the following car, not the EV using regen.

And, when Regen is not available, the "game" has few options. In that case brakes are used, complete with brake lights.

2. Any action that will "noticably" reduce the car's speed should turn on (or flash) the brake lights. Agreed. What I was referring to was driving on regen at a relatively constant speed. Brake lights in such a situation don't make sense. I encounter this situation every time I leave my house, so it isn't some sort of "special case".

Perhaps just starting to reduce pressure on the "Go-Faster" (pedal) should flash the brake lights as an early warning of possible impending slowing.

I think that extra (roughly) half-second warning (of a sudden slowing) would save some lives, much inconvenience (having the rear end of your car repaired), and a lot of insurance dollars! What I would like to see is brake lights tied to deceleration. For example: lights come on at -0.2g and go off when deceleration is reduced to -0.1g. (Those numbers are just guesses on my part, I don't know what really good figures would be.)
The reason I mentioned all this is that my impression is that flatlanders are completely unaware of the use of regen to descend hills at constant speeds and that they assume that regen=braking=rapid slowing. This is not true when going down hills of significant grade; in that case regen is used to offset the acceleration of gravity. I do not want my brake lights to come on unless I am slowing at a significant enough rate to present a hazard to the following driver.
Yes, In the situation described, if you tied brake light activation to decel rate I could see it. I think that's what Dave was referring to, a situation of rapid decel in a car with high regen and doing single-pedal driving, such as stop-and-go traffic. The question is whether this is worth the extra cost and complexity of providing an extra circuit to the lights and some kind of decel sensor.

And yes, in my earlier post I was referring to the driver of the car following the one using regen.
 
i know a lot of drivers around here that will frequently hit the brakes hard enough to engage brake lights without actually engaging the brakes just as a courtesy just to let someone in the back there might be a need to slow down soon

in the Prius i have done it as well since i have a tendency to slow down way in advance if i see brakes lights up ahead.
 
DaveinOlyWA said:
i know a lot of drivers around here that will frequently hit the brakes hard enough to engage brake lights without actually engaging the brakes just as a courtesy just to let someone in the back there might be a need to slow down soon

in the Prius i have done it as well since i have a tendency to slow down way in advance if i see brakes lights up ahead.
I'm the same (or I turn on the emergency flashers briefly, if I can see a rapid slow-down ahead), which is why I question the need for a special circuit. Ultimately, any need for one won't be settled until the IIHS has gathered enough data from cars with and without such a circuit, and the latter show a statistically significant increase in getting rear-ended.
 
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