Brammo Owners Forum

General => Off Topic => Topic started by: implovator on April 18, 2013, 09:32:12 AM

Title: Paddle Shifters on E-Autos?
Post by: implovator on April 18, 2013, 09:32:12 AM
I was watching the the video on the Cadillac ELR's "Paddle Shifters". Seems they're trying to put a little more control on the driver's hands. They took away the transmission, so this is a way of giving back a tool to the driver (as Brammo might say). Mercedes is doing something similar with their electric SLS. I can't help but think that they have it all wrong. Empulse owners have something way better. Firstly, we've got six regen settings over two modes yielding 12 total settings. Furthermore, the computer-controlled regen resembles actual engine braking dynamics, which many people are already very familiar with.

Is it just me, or are cars getting boring? I'm so glad that I'm a motorcyclist.

Cadillac ELR Puts Energy Control at Driver's Fingertips (http://www.youtube.com/watch?v=dlrC1h64gJQ#ws)

OK, so this SLS isn't that boring, but still... :)

Mercedes SLS Electric Drive. Can Volts Ever Match Pistons? - CHRIS HARRIS ON CARS (http://www.youtube.com/watch?v=IElqf-FCMs8#ws)
Title: Re: Paddle Shifters on E-Autos?
Post by: flar on April 18, 2013, 04:57:57 PM
It seems that these are workarounds for providing selective regen in a car.

With Tesla's pedal design and the Brammo (and Zero?) grip design you get regen as you release the control, but this means that coasting requires maintaining a particular constant pressure on the control.  That's fine for short periods, but long periods of coasting can get tiring.  (With the Empulse you can use the clutch as well, but that also uses energy for long periods of coasting.)

With a motorcycle twist grip you can have both pull and push actions (due to "gripping" the control rather than resting on and pushing against it) so that you can set it up so that coasting happens at the rest point and regen is chosen by pushing on it, but you can't do that in a car and people keep saying that there is a patent for doing that with a twist grip that manufacturers are trying to avoid.

With a car, there is no "pulling" on the pedal in the first place so if you want totally optional regen then you can tie the selective regen into the brakes or you need another control for coasting.  I believe that Prius does tie regen into the brakes, but I don't think you get pure regen that way and it adds complexity into a safety mechanism that should otherwise be very simple and foolproof.  These cars are using an existing standard car control (steering wheel shifters) to repurpose them for selective regen.

Personally, I'm happy with the "release partially to get regen" concept.  It ties into existing expectations of engine braking and simplifies the controls.  My need for coasting is rare.

I'm not sure cars are getting boring, the dynamic behaviors on that Mercedes seem pretty exciting to me... ;)  (Of course, I'm already driving a torque vectoring car - Acura's SH-AWD - though it is not nearly as sophisticated as the Mercedes mechanism.)
Title: Re: Paddle Shifters on E-Autos?
Post by: flar on April 18, 2013, 06:55:51 PM
Not sure if you can read this if you are not a forum member over at Tesla, but they discussed these regen controls in a thread there:

http://www.teslamotors.com/forum/forums/paddle-shifters-model-s (http://www.teslamotors.com/forum/forums/paddle-shifters-model-s)