Abstract
A mathematical framework is proposed for intelligibility of abilities of acquiring skilled motions through practices and versatile adaptive actions adjusted to changes of the environment. It is pointed out that the passivity property of not only the original robot dynamics but also the residual error dynamics between the desired motion and the actual motion is crucial in learnability and adaptability of skilled motions. By means of such learnability and adaptability, both a simple learning control and a model-based adaptive scheme are proposed for nonlinear mechanical systems with multi joints of revolute-type such as robot arms and mechanical hands. It is also suggested that the present PD or PID servos used in industrial manipulators should be replaced with a linear combination of a saturated position (SP) feedback and the conventional velocity (D) feedback, in order to easily implement the learnability and adaptability in such mechanical systems.
