3 crank mechanisms cause kinematic problem in simmechanics

Hi,

the system I want to modell mainly consists of three drive crank mechanisms (with three actuators) which can raise the upper base vertically (roll and pitch angle are free as well). Each drive crank mechanism consists out of a flywheel connected to the drive shaft of the actuator and a connecting rod which is attached to the flywheel by a revolute joint and connected to the upper base by a universal joint. One of the drive cranks rotates in the xz-plane and the other two rotate in yz-plane allowing the 3 DoF in z, phi (tilting in y) and theta (tilting in x).

Without the visualization and only with distances and joints: (see the closed loops)

Basically I want to model movements of the upper base in z, phi and theta. As input I want to acuate the 3 revolute joints of the crank mechanism.

I modeled all that in simmechanics 2nd generation. The model explorer shows everything just great when only updating the diagram. But when I give an input to one of the revolute joints following error occurs:

_* ['ATMOS_MKS_mit_shapes/Solver Configuration1']: Error evaluating equations at time 0.0. Stopping simulation. There may be a singularity in the solution. If not, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances)

• ['']: 'xxxxxxxxxx/Aktor hinten/Universal Joint' has a degenerate mass distribution on its base side.Component: Simulink | Category: Block error_

I already put several additional masses, but it still says "degenerate mass". As I see the model is assembled... I dont know where the problem is since SimMechanics is supposed cut joints automatically. See the this link: https://www.dropbox.com/sh/3xxfo873lwt0vfd/AAADJnbegg3eppKM9kPOB5oKa?dl=0

I hope you can help me.

Thanks.

Answer 1

[tolga ermis]

No one?

Answer 2

[tolga ermis]

push

Answer 3

[waleed niklawy]

please help me to simulate the flowing in matlap simulink

dh/dƟ=rsinƟ + [r^2*sinƟ*cosƟ / L*sqrt(1-(r/L)^2*sin(Ɵ)^2)

where r and L const h displacement Ɵ angle