9: Dynamics and Control

This chapter considers the dynamics and control of a serial-link manipulator. Each link is supported by a reaction force and torque from the preceding link, and is subject to its own weight as well as the reaction forces and torques from the links that it supports.

The chapter covers:

• independent joint control, effect of gravity and payload
• the equations of motion that describe the joint torques necessary to achieve a particular manipulator state, and the recursive Newton-Euler formulation
• real-world drive train issues such as gearing and friction
• forward dynamics which describe how the manipulator moves, that is, how its configuration evolves with time in response to forces and torques applied at the joints by the actuators
• variation of gravity torque and inertia with robot configuration
• computed torque and feedforward control
• task-space dynamics and control, operational space control, compliance and admittance control
• series-elastic actuation