Model toppling when velocity is given
Model toppling when velocity is given
(OP)
Hi,
I have a simple design..6 wheels, links connecting them and a carrier box on top.
2 wheels in front, middle and rear.
The problem is my whole model is toppling or jumping too much (don't know why). I gave angular and transverse velocity for the wheel parts.
The rear wheels jump high sometimes, sometimes it is the front, while the rest are on ground pulling them down.
It is so happening that for a given velocity the jump is less (it is coming to ground with a little detour) but sometimes the whole body jumps and as a result the model is upside down.
Is it that there is a fixed ratio of angular : transverse velocity. Please help me with this problem.
I have a simple design..6 wheels, links connecting them and a carrier box on top.
2 wheels in front, middle and rear.
The problem is my whole model is toppling or jumping too much (don't know why). I gave angular and transverse velocity for the wheel parts.
The rear wheels jump high sometimes, sometimes it is the front, while the rest are on ground pulling them down.
It is so happening that for a given velocity the jump is less (it is coming to ground with a little detour) but sometimes the whole body jumps and as a result the model is upside down.
Is it that there is a fixed ratio of angular : transverse velocity. Please help me with this problem.
Talk To Other Members
RE: Model toppling when velocity is given
To be honest your problem description is lousy, but there are several things you can look at. have you set the initial velocity of each part, both translational and rotational? Alternatively what does your model do if you start with it stationary?
Next, how are you modelling the tire to ground interface?
Next, do you have any compliances and damping in the model?
is your ground surface smooth?
if you export your model as an adm file and post it I may take a look a look at it.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Model toppling when velocity is given
Sorry for the description..to answer you
I am using ADAMS View, I have set both the translational and rotational velocities but only for the tires. I used 'fixed joint' to join other links.
Under special forces I used 'contact force' between the wheel and ground. There is no compliance or damping and the surface is smooth (negligible friction)
Just to be a little more clear I did not use the tire option..I used the extrude command for wheels (extruded a circle I drew).
Sorry but I did not understand what you meant by starting it stationary. Anyway I removed all the velocities and simulated. It just remains in its position.
I want to basically move my body forward so gave some velocity to the wheels which will inturn pull the whole body forward. (I used right click < modify < initial velocity conditions).
I am an amateur so please bear with my questions and description. I am only able to upload a screenshot
RE: Model toppling when velocity is given
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?