How to create a suspension model with 2 springs?

ravel · 2014-05-25T18:54:01

Basically I want to create a suspension that has 2 springs with 2 seprate compressions, one spring is actually for the tire. I am keeping things simple, so its only the vertical action(raycast for example) As far as I know and wich works quite well, is this method: create a raycast with a length of: rayLength = suspensionTravel + radius; // (so it's basically something like 0.2 + 0.3 = 0.5) rayHit = CreateRay(rayLength,suspensionPosition); calculate the compression like this: prevCompression = compression; compression = (suspensionTravel - (rayHit.distance - radius)); calculate vertical force like this: springVelocity = (compression - prevCompression)/timeStep; springForce = springRate * compression; // springRate is something like 50000 damperForce = damperRate * springVelocity; // damperRate is something like 2500 totalSpringForce = springForce + damperForce; Now I'd like to know how I'd add a secondary spring to the same raycast? The difficult part for me, is to know how to calculate the secondary compression(tire deflection in this case) ? And how to combine these 2 compressions, so that they would have theyr seprate functionality? Thanks in advice!

Math and Physics Programming

Started by vadevaman May 21, 2014 08:35 PM

20 comments, last by Dirk Gregorius 9 years, 10 months ago

Buckeye

10,754

May 23, 2014 02:51 PM

Note that the algorithm I posted has a possibility of incorrect behavior. I wrote it for compression only, assuming that (L1-x1) would always be a positive value. That is, I didn't look at the possibility that the the spring/tire would be stretched. That could occur if the car goes airborne and the suspension stretches where D > sum of static lengths.

However, looks like you're getting something useable.

Please don't PM me with questions. Post them in the forums for everyone's benefit, and I can embarrass myself publicly.

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