Robotran is designed on the basis of different modules including

1. Model loading : Loading of the model data from the xml description file (.mbs) to a dedicated structure
2. Direct dynamics : Time integration of the system direct dynamics.
3. Inverse dynamics : Computation of the system inverse dynamics.
4. Equilibrium : Computation of the system equilibrium.
5. Modal analysis : Computation of the system eigenmodes.
6. Direct Kinematics : Computation of the direct kinematics of a kinematic chain.
7. Inverse kinematics : Computation of loop kinematics and of the system inverse kinematics (not yet available for MBsysC).
8. Coordinate partitioning : Partitioning of the generalized coordinates into independent and dependent variables (for constrained multibody systems only).

Some modules might be not available according to the used language. For more details, check the appropriate documentation.

Yes, it is. For more details, see here.

• In MBsysPad when creating the model.
  Note: a so-called Tony’s gui option available in MBsysPad allows you to select each joint of your system
  and see the range of motion of this joint
• During the computation using MBsysC (Real-time Flag ON)
• After computation, using the animation panel of MBsysPad

Yes, it is possible to linearize the model thanks to the MODAL module. The way it is generated depends on the chosen programming language. For more information, contact us.

Use the user functions as described in the tutorial, more precisely in the “User derivatives” part.

For each programming languages, two templates are provided : a simple template and a complete template.
In the simple template, the project is loaded, the coordinate partitioning is done if needed and the direct dynamics of the system is computed.
In the complete template, both loading and coordinate partitioning steps are identical. Then, equilibrium and modal analyses are first computed before the direct dynamics. Finally, an inverse kinematics followed by an inverse dynamics are realized.

Some specific templates are also available for courses and research need.

If you select the full symbolic option, the symbolic generator will put a symbol for all parameters of your model, even if they are zero.
If you do not check this option, the parameters with a zero value are not considered in the symbolic equations, leading to less terms in the equations and thus better performances in terms of computational time. For more information, please refer to this article.

For impacts using a penalty approach, contact laws can be implemented in user functions as described in the tutorial in “External forces” part.
For impacts using a non-smooth approach, a coupling with lmgc90 has been developed. More information here (lien web)

The easiest way is to use a user_model, as described in the tutorial in “Tips and tricks > User models” part. User models can be used as variables or parameters in your code.

Note : if you want to integrate a time-variable value, an elegant way is to use the user derivative functionality (see “User derivatives” in the tutorial).

There is no easy way to rename a project. If you want to rename it, change the name file of the .mbs file. In the .mbs file, modify the field “mbsname”. Then, delete the symbolic functions which contain the previous name of your project. Update the project name in the main function. Generate the new symbolic functions.

In Matlab, you can use the function mbs_copy_project that should do all required operations.

It depends on the language you use:

• In Matlab, specific functions to get the id exist. They are explained in the Matlab tutorial, in “Tips and tricks” section.
• In Python, id’s are stored in dictionaries in the mbs structure. For more details, see the Python tutorial, in “Tips and tricks” section.
• In C, a specific c-file called “user_all_id.h” is created when generating the c-specific user files. This file defines id’s of all the elements of your MBS system. For more details, see the C tutorial, in “Tips and tricks” section.

From MBsysPad GUI, there is an animation feature allowing you to visualize the trajectories of your system. More details are available in the tutorial, more precisely in the “Bodies and Joints” section, Step 5.

Whatever the law you want to implement in your joints, it has to be implemented in the user_JointForces function. For more details, see the tutorial, more precisely in the “Bodies and Joints” section, Step 3.