Motion Driver for SimMechanics

A block to generate velocity and acceleration from a position signal.

One way to actuate a SimMechanics model is by providing its Actuator blocks with 'Motion' signals. The input to a 'Motion' actuator is a three-element vector containing position, velocity and acceleration signals.
In many applications, the only data that is available is the position. This raises an interesting question: how can we calculate consistent velocity and position signals? One way to actuate a SimMechanics model is by providing its Actuator blocks with 'Motion' signals. The input to a 'Motion' actuator is a three-element vector containing position, velocity and acceleration signals.

In many applications, the only data that is available is the position. This raises an interesting question: how can we calculate consistent velocity and position signals? Differentiating the position signal sometimes works, but the velocity and acceleration signals tend to become very noisy. A better - though less intuitive approach - is to create a second-order tracking filter and use its position, velocity and acceleration signals to drive the actuator.

This file contains a small Simulink library, motdrv_lib and an example file, mech_motdrv. To use these, copy the files to your computer, add the directory to the MATLAB search path (see addpath for help) and type mech_motdrv in the MATLAB Command Window.