I’m not talking about limiting current so the acelleration is less but the ramping of the acceleration over a time period, maybe a second or two so the rider can brace for it.
I’m running a 5500W board and it can be jerky if I’m not careful. I’m building a 6200W hill climber and I’d love to ramp the acelleration / beaking on the Vesc. It’s would be nice to limit sharp changes in acceleration to suit the rider and make a safer board more ridable board. Maybe like this:
When you pin it forward the acceleration or currently will increase over a short time period.
When you reduce the throttle or release the throttle, acceleration will ramp down to a coast over a short time period.
When you brake it would ramp to the negative acelleration. You may want this to have a shorter ramp for braking responsiveness but to still be ridable.
When you release brakes, it would release over a time period vs that jerky feeling when you let go from braking.
Sounds like your talking about some type of response delay. Kinda like when your driving a car with stick shift and your in a high gear cruising and you stomp the gas pedal but the car increases speed slowly.
Ugh. I absolutely hate that.
I recommend playing around with the throttle curve maybe? I’m not sure how commands work on the vesc but if it’s a PID then you could definitely tune it to be mushier
Yeah. That’s it. @PXSS. If you wanted it mushy, you could; I don’t but you could do that. I’m talking about much shorter ramps where you could tune the ride to be less jerky, more glide, but still responsive with no power limitations. I’m talking about powerful boards here.
Imagine driving a car and you take your foot off the gas quickly, you don’t have a jerk as the acceleration stops. Now it would be different if you were surfing on the roof and feel it as you adjust your stance.
Since some if us are surfing these really powerful boards, I think some acceleration ramp would help over powered machines be much more approachable yet still responsive. More refined.
Well, my firmware mod changes the throttle curve. What you want is a throttle ramping. But it’s already there in the Nunchuk controls.
@mainstreet So best for you is to get a nunchuk or a nrf controller.
Ok. So not quite. I get the throttle curve and how the position of the controller throttle can be calculated to mean an Esc throttle value based on a curve or slope/ramp.
Please allow me to add context.
The main issue I’d like to solve, when I ride my powerful board, is I have to slowly let go of the throttle or it feels jerky. Like when I pin it and I let go of the throttle. I’m used to it but it’s not what I want people to experience when they ride my boards.
It is a throttle state change with time variable. If you let go of the throttle the motors freewheel, the rider stops accelerating and it feels like the brakes are tapped. It can be unnerving for a rider at high speeds.
If you ramp or curve the throttle with a time variable say 1 sec or so the feeling of stopping accelerating would be smoothed out to the coast.
In the automation world I work in, we use these functions to make motors move smoothly. When the program calls for MAX speed, we adjust the acceleration of the motor gradually over a short period of time. Not to be confused with the speed or rpm but the value of the acceleration; the rate at which the speed increases or decreases.
Yeah - you are describing what I mean by throttle interpolation. You don’t want to go instantaneous from one to the other but smooth the transition.
This is not an acceleration curve so the title is still misleading for me.
I do have to add that letting go of the throttle does result in no jerking on my board - maybe you should also look into the efficiency of your gear setup. On my hub motors I just coast.
Just let us know what motors you are going to use for your hillclimber and what remote you are using. And as i said already. The Nunchuk has the function of ramping.
But to me it sounds like you might overstress your batterys and that could be a reason for the jerky feeling. Or you have a bad setup for the VESC. Because when the VESC starts to limit the power and you give full power those little jerky situations can happen.
I have been looking for that sort of thing as well so you are not alone, mainstreet.
I wish to build a board that is capable massive wattage by using VTC6 in 10s6p or 12s5p configuration and VTC6 has 15c and max of 30c with 80 degrees cutoff meaning it could peak as much as 7,560 watts. ( not sure if I can use “c” as amps in the v*a=w equation? )
you have the numbers right, but the wrong units. vtc6 and most 18650 have output in Amps. 15a and 30a max current. but you end up with about half the capacity at those rates.
why do you guys want that much Power? theres no torque increase past the saturation point.
just stressing your batteries…
half the power is enough to scare you and embarrass any complete…
Thanks for clearing that up. Was just talking about how it is possible to crank out that much wattage with VTC6, but I do not intend to push it that far up.
I plan to cap the absolute limit to 80 amps thus each motor gets maximum of 40 amps each.
The reason why I know that is more than enough power for me is that I have an Evolve GT Bamboo and also I know that the GT peaks out at 1100 watts meaning max of only 550 watts each motor and we know how strong GT mode is ( Found that info on Evolve forums )
My board will be more powerful than that obviously, so still interested in ways of making control buttery smooth!!
Hi @mainstreet, VESC-Tool has some more settings to allow more control over the throttle. In some cases you would want to be able to react fast to unforeseen obstacles. A delay would not help in that case.
If I read your post correctly, you want to use a VESC, right? You may want a VESC 6 in that case, running the all new firmware and being adjusted by VESC-Tool. My personal V6 board rides very smooth - but its a beast at the same time.
Truth is: If you gear down a lot, brakes get more effective.
Some people like it ultra direct and others like the butter.
I can let go the throttle without the board trying to throw me off.
LiFePO4 8s2p Prismatic Pouches
30C Discharge at 16Ah
My 6364 motors are the limiting component in my system protected by the VESC current settings.
Who knows what the real current is in the system when the board runs but I weigh 260lbs and it has no problem on steep hills. I tried to over spec as much as I could.
I had a 10C Lipo pack on this same board and it was gnarly in comparison.
I have 2x VESC that I am contemplating a mineral oil bath for cooling. I wanted to see how the temp runs before going to all that trouble. From a fabrication-porn standpoint I like it.
Here is my current battery pack spec I did a few months ago.
This. Pulley ratio and wheel height have at least as much to do with the feel of braking and acceleration as VESC settings do.
Taller wheels on smaller pulleys make the brakes smooshy and the acceleration smoother, where smaller wheels on larger pulleys make the acceleration harder and the brakes stiffer.
You can of course make noticeable differences with VESC settings, but there is also a lot of magic in the gearing and wheel height.
( Found that info on Evolve forums )