microcontroller for e-bikes article (attn Joe Perez et al) - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Insert BS here A place to discuss anything you want

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 06-24-2013, 02:47 PM   #1
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default microcontroller for e-bikes article (attn Joe Perez et al)

JasonC SBB is offline   Reply With Quote
Old 06-24-2013, 03:16 PM   #2
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,318
Total Cats: 1,916
Default

Interesting.

The current crop of motor controllers are pretty "dumb." Even though they are programmable for things like speed and phase-current limits, they mostly just translate the throttle input to a motor duty cycle. This works on on low-power units, but is very twitchy at higher voltages. (eg: 10% throttle makes the bike want to wheelie from a stop.)

I'm using a piggyback solution at present, with a device called a CycleAnalyst. This computer sits between the throttle and the controller, and takes in data from motor temp and battery current. In addition to various logging and display functions, it also allows you to implement a closed-loop throttle rescaling mode, which turns the throttle into a "current request" function, similar to how a Subaru DBW system works. It generates a synthetic throttle output (to the controller) which aims to achieve a specific amount of current for a given throttle input. Works quite well, and is something which ought to be a part of all current-gen controller ICs.

No reason this couldn't all be integrated into a single box, I'm just not aware of anyone who has done it yet. This looks like a step in the right direction.
Joe Perez is offline   Reply With Quote
Old 06-24-2013, 04:13 PM   #3
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

"Current request" is approximately equal to "torque request".

I considered it really dumb to do a fixed duty cycle which translates to motor speed - ergo at low speed and you open the "throttle" slightly you get full torque until the motor is at the target speed.
JasonC SBB is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
CAS weirdness Asx MEGAsquirt 5 12-15-2015 12:14 PM
Worm drive clamps are better than t-bolt clamps aidandj Insert BS here 80 09-18-2015 08:19 PM
ME221 Now has Autotune and Long Term Fuel Trim Tables Motorsport-Electronics ECUs and Tuning 0 09-05-2015 09:02 AM
My G-Man Tank, Remote Filler, and Pump Mount. Mechazawa Methanol/Water Injection 22 09-08-2007 03:17 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 07:03 PM.