Chevy Bolt with new regenerative braking

[HTSS_TR]

Quote:
While EV watchers are eagerly awaiting its EPA certifications, dealer ordering to open for the $37,500-before-subsidy EV, and more definitive details, the automaker today is teasing out previously announced info about one-pedal driving with the Bolt.

A novel feature, the 2017 Bolt EV permits this via a regenerative braking paddle on the back of the steering wheel to enable four different operating modes.

The “regen on demand paddle” lets the driver slow the car at varying rates – and simultaneously the motor-generator feeds current back to the battery, increasing range.

“Using a vehicle simulation model, engineers compared regen performance on a testing cycle that simulated heavy stop-and-go traffic in Drive and another using one-pedal driving while in Low and also the Regen on Demand paddle,” said Chevrolet. “The engineers found that the one-pedal driving can add up to 5 percent of range to the Bolt EV.”


Quote:
The regen paddle has evolved since it was first featured on the now-discontinued Cadillac ELR, then second-generation 2016 Chevy Volt, and the Bolt does them one better by even enabling a complete stop.

The effect is not unlike how hand brake controls would work for a handicap-enabled vehicle, and it can be easily adjusted on the fly to be progressively stronger in the following modes:

• Operating in Drive and easing off the accelerator.
• Operating in Drive and using the Regen on Demand paddle on the back of the steering wheel.
• Operating in Low and easing off the accelerator.
• Operating in Low and using the Regen on Demand paddle in tandem.

The first mode is standard with any EV, as all provide a bit of regenerative braking on decel, and coasting is still easy. The second through fourth add regen effect, and using another corollary, it is something like shifting an automatic transmission in Low – and feeling the drag in forward momentum – and then if there were an extra-low, the drag effect is felt more and more.


Quote:
Reports have been that the Bolt will come to a complete stop even on a decline meaning the regen paddle can be used like a brake.

In actual use, the system will likely be easy to adapt to, and become an extra means to control the car. Drivers will be able to time stops to a light or slow the car without having to touch the brake pedal in many circumstances.

It is not actually a replacement for the brake pedal though, and when faster stops are needed, that will be the one to use.


http://www.hybridcars.com/chevrolet-teases-2017-bolt-ev-regen-on-demand-paddle/

Possible more rear-end collisions with unfamiliar drivers ? But for experience drivers this feature can add power to battery and rarely use the brake so no need to replace pads/rotors for long time.

 

[Traction]

The Tesla Roadster I drove had a progressive lift off the pedal. Lift all the way off the pedal and it was like hitting the brakes. Turns out the brake lights come on just by lifting off the go pedal. Brilliant.
The original brake pads on my 2007 Camry hybrid were not even 1/2 worn at 200,000 miles.

 

[1000MPH]

Yep, AC Propulsion had this in '92. Long before it became the Tesla.

 

[oil_film_movies]

Originally Posted By: HTSS_TR
Possible more rear-end collisions with unfamiliar drivers ? But for experience drivers this feature can add power to battery and rarely use the brake so no need to replace pads/rotors for long time.


Yes, more controllability human factors issues here. Bad move on GM's part. ((((In aviation, you have to pass human factors tests to get it certified. With cars, you can put anything out there and just see what happens.))))

In reality, a human controls speed using whatever you've got. So the speed profile shouldn't really change, only your foot (and now hand!!) movements. And the brake pedal on hybrids and EV's already automatically monotonically blends in motor regen drag for light braking and brake pads for heavier braking anyway. It's already done. See the comment above from the older Hybrid Camry driver on how he has been doing regen and staying off the pads naturally with light braking. This paddle thing is just stupid. Stick to the braking method people are used to and don't confuse them with toys.

 

[sciphi]

This will be useful in hilly areas or in the mountains. Might as well recover some of that kinetic energy when needing to stop at the bottom of a long hill. Or at the bottom of an off-ramp.

5% for an average driver is a pretty big accomplishment. Even if that's just an extra 10 miles of range, that's still nothing to sneeze at. It goes to show that the easiest ways of increasing efficiency are retraining the humans, not spending zillions of dollars on fancy-schmancy new technology.

 

[oil_film_movies]

When it saved "5% range", as claimed, they are referring to the different speed profiles people fell into while doing one-pedal operation (mostly), compared to normal brake usage speed profiles.

You don't want to be behind someone one-pedaling it with too much slowing, as it means they are creeping up to stop signs/lights excessively and slowing traffic.

The truth is a good driver is already using brakes normally, and hybrids/EVs already phase in brake pedal motion for regen and harder braking naturally. No re-training of drivers required.

 

[veryHeavy]

Originally Posted By: 1000MPH
Yep, AC Propulsion had this in '92. Long before it became the Tesla.


You mean they were FOUNDED in 1992. The first electric car to use regenerative braking (via the throttle pedal) was the GM EV1 in 1997, and they hold the patent on it.