TIP Engineering Forum Index TIP Engineering
Theory In Practice
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Interpreting Dyno Graphs with lots of hysterisis

 
Post new topic   Reply to topic    TIP Engineering Forum Index -> Good Vibrations
View previous topic :: View next topic  
Author Message
swampjam



Joined: 05 Jun 2008
Posts: 1

PostPosted: Thu Jun 12, 2008 12:59 pm    Post subject: Interpreting Dyno Graphs with lots of hysterisis Reply with quote

When looking at a dyno graph with lots of hysterisis, what how do you define your damping coefficients for simulation purposes? That is, do you go off the compression open, rebound open phases, or do you look at the average of compression open/compression close, average of rebound open/rebound close phases?

Does anybody have any experience modelling nonlinear damping in simulink? If so, how are you acomplishing this?

Thanks.
Back to top
View user's profile Send private message
Wiisass
Head suspension nerd


Joined: 09 Nov 2005
Posts: 131
Location: Philly

PostPosted: Tue Jul 29, 2008 11:21 pm    Post subject: Reply with quote

Wow, I need to check this place more often. I have been changing stuff around a lot and have not remembered to check in here in a while, so I'm sorry for the late response.

If the shock has a lot of hysteresis, I would throw it out.

But if you have to use it, it's kind of hard to say. I mean you could use the rebound open and compression open, but that would only tell you how the car is going to behave under compression and rebound from rest. You could average the numbers, but then you could end up with a higher damping coefficient than you will normally see.

What plot are you looking at? Are you dynoing the shock yourself or having someone dyno it? Is there any hysteresis or as much on a 0-3ips plot versus a 0-10 or so ips plot? If so, you can use the 0-3ips plot for low speed and then look at the high speed seperately. You shouldn't see much hysteresis on a lower speed plot, if you are, you should really reconsider your damper choice.

As for modeling, your best bet is a lookup table. Just pull the data off the graph, make a lookup table and have simulink interpolate between points. Or if it were a low speed and high speed slope, you can do switches based on the reference speed and then calculate it based on there. There are a lot of ways to do it, but lookup table is probably the best and most accurate. It is the way I do it when I put in data straight from the Roehrig.
_________________
TIP Engineering
Just put the TIP in.
R&D, damper development and fabrication.

jrud@tipengr.com
Back to top
View user's profile Send private message Visit poster's website AIM Address
Display posts from previous:   
Post new topic   Reply to topic    TIP Engineering Forum Index -> Good Vibrations All times are GMT - 5 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group