Chrono help for example file

Comments on CHRONO example robot_stewart_learn.r3d

Actuators which learn motion.

What to do: load the file, open the control panel, press the play button on the animation timeline (watch at least 6 seconds of simulation!). Be sure that time slider is at frame 0 (beginning) when you load the project.

Here you can see the simulation of a typical Stewart platform, that is a 6 degrees-of-freedom (3DOF) device robot which is used mainly for airplane simulators, steel milling, etc.

Note that the robot is in 'learn' mode, that is, its motion does not happen because the 6 linear actuators are moving it, but rather because its end effector (ex.the gripper) is 'pulled' by a reference which moves in space, hence obtaining an inverse-kinematic movement. In fact, if you open the property window of the 6 linear actuators ('linear actuator' objects in 'System' level), you see that their 'learn mode' flag is ON, meaning that they are switched off and they just record their rotation in the 'd(t) extension' ChFunction.

By the way, since motors are in 'learn motion' mode, how is this device moved? Note that there is a lock-link in System level, which constrains the position of the tool tip to a moving marker. Hence the moving marker, performing as a 'teacher' which pulls the robot arm, is in 'ground', and its motion has been created with the default keyframing tools of Realsoft (you can see and edit its choreographies).