Introduction to Dynamics#

Main problem types in mechanism and machine theory#

  • Kinematic analysis: Known positions, velocities, and accelerations in some degrees of freedom => Positions, velocities, and accelerations of the rest of degrees of freedom.

  • Direct dynamics problem (“Simulation”): Known forces and masses => Positions, velocities, and accelerations.

  • Inverse dynamics problem: Known masses, positions, velocities, and accelerations => Forces. Useful for example in robot trajectory control.

Where we are?#

Classification according to constraints#

The existence of more constraints normally implies harder-to-solve problems. Listed below in order of increasing complexity below, these are the kinds of problems we want to find out how to write their equations of motion:

  1. Free rigid solids (🡆 The aim of this lesson 🡄):

 

  1. Links in an open kinematic chain:

 

  1. Links in a closed kinematic chain: