User`s guide

MADYMO Coupling Manual Release 7.5

Figure 9.4: Example of the pendulum model

9.4 Conditions

Accessing MADYMO from MATLAB/ Simulink via the S-function madymo3d_server is straight

forward if the following is taken into account:

• MATLAB executes the m-ﬁle ’startup.m’ when starting. The minimum list of commands

is listed below.

• The coupling can run only if the MATLAB variable runmad is set and the search path

includes the S-function madymo3d_server, version 7.5.

9.5 Miscellaneous

Using the coupling gives some side effects, mainly in the area of numerical stability. Most of

the side effects concern the availability of the time integration and the computer platforms.

Here are some MATLAB/ Simulink remarks:

• Development and testing takes place on the MATLAB Service Pack which was available

at the MADYMO release date. It is most likely that newer Service Packs are working,

where older Service Packs might not work on some platforms.

• Either ode1 (Euler) or ode2 (Heun) is the best MATLAB solver to start with for multi-

body models. In some cases problems with ode4 are noted.

• The selection of the discrete (e.g. no continuous states) solver is the preferred choice to