ABB_IRB_120_Model_IK_OK_6_RealParamsLinearization.msim

I did the model of the ABB IRB 120 in MapleSim, but I would like to lock several links but I do not know how to do it.

Also I need the differential equations of the robot, which must be six differential equations but in MapleSim equation extraction page there are lots of equations.

Please can you help me ?

HW5DC.msim

HW5HYD.msim

HW5Pneu.msim

I am trying to (again) extract the equations of the systems which have been done by me, but the equation extraction gave me wrong results.

For example;

The DC motor and the inverted pendulum equation must be 3. (third) order and only a differential equation.

The pneumatic motor and the inverted pendulum must be a differential equation (any order).

Also the hydraulic motor and the inverted pendulum must be a differential equation (any order).

I tried to use "isolate" command but it did not work for me in this case. How can I get the differential equations of the systems ?

I have added the MapleSim simulations and the differential equations that I had.

Please help me for this problem chain.

HW4.msim 

I did the base part of a robot in the MapleSim. I am trying to get the differential equation of the system, but the MapleSim gave me 2 different differential equations. When I use these differential equations, I could not reach to my goal. I think I need only one differential equation whose degree must be 2. The system works well, but the problem is a differential equation of the system. How can I get the correct differential equation? And also, why are there 2 different equations? Which one represents what? Thanks for answering.