Is SimMechanics suitable for models with a lot of collission force calculation?

[TheBeard]

Hello,

I tried to build a model of a walking apperatus in SimMechanics but the simulation is extremely slow so I can't use the model properly.
It assume the reason why it is so slow is that there is a lot of contact force calculation going on.

At some times there is simulatanious contact force calculation of two objets against the floor and calculation of three revolute joint limits. All these restrictions to keep the object falling through the floor and keep rthe joints from going over their limits are implemented with spring-damper-systems.


Did I just build a poor model or is it so slow because SimMechanics isn't made for such models with a lot of contact force calculation?

Greetings,
The Beard

 

[GregLocock]

how slow is slow?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[TheBeard]

It was about 5 Minutes for 2 Seconds of simulation time (if it didn't get stuck before it finished)

But I just found out yesterday by accident that I had a fault in the calculation. It#s much smoother and faster now. For 2.7 Seconds Simulationtime it takes about 28 Seconds real time. I can live with that.

Thanks anyway for reading this!

 

[GregLocock]

10:1 is actually pretty quick for a sim with contacts, 25:1 to 100:1 is not unusual, depending on model complexity.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?