SimMechanics

Essential Steps to Configure and Run a Model

After you've built your model as a connected block diagram, you need to decide how you want to run your machine, configure global settings, and set up visualization.

• SimMechanics offers four analysis modes for running a machine model. The mode you will probably use most often, at least at first, is Forward Dynamics.

• But a more complete analysis of a machine makes use of the Kinematics, Inverse Dynamics, and Trimming modes as well. You can create multiple versions of the model, each with the same underlying machine, but connected to Sensors and Actuators and configured differently for different modes.

• You can also use the powerful visualization and animation features of SimMechanics. You can visualize your machine as you build it or after you are finished but before you start the simulation, as a tool for debugging the machine geometry. You can also animate the machine model as you simulate.
• Choose the analysis mode and configuring visualization, as well as other important settings, in the Mechanical Environment Settings dialog box. You might also need to reconfigure the Simulink Simulation Parameters dialog for SimMechanics models. See A Four Bar Mechanism in this chapter for an example.

The tutorials of this chapter introduce you to most of these steps.

Caution    You might want to make modifications to these tutorial models. To avoid errors, be sure Not to attempt connecting Simulink signal lines directly to SimMechanics blocks other than Actuators and Sensors To keep the collocation of the Body coordinate system origins on either side of each assembled Joint to within assembly tolerances You should save multiple versions of models as you try different analysis modes and configurations.

The first tutorial in the next section shows you how to configure the most basic blocks in any model: Ground, Body, and a Joint, in order to create a simple pendulum model. The second tutorial explains how to visualize and animate the pendulum.

Creating SimMechanics Models

Building a Simple Pendulum