A link position tracking controller is formulated for an n-link, rigid,
revolute, serially-connected robot. The controller generates torque commands to
the individual robot links based on adaptive estimates of the system parameters
and measurements of only link positions. A filtering technique, based on the
link position signal, is used to alleviate the need for velocity measurements. A
complete development of the controller is presented along with a proof of
semiglobal asymptotic link position-velocity tracking performance. Experimental
validation of the proposed controller on the Integrated Motion Inc. (IMI)
two-link direct drive robot is also presented. Several extensions to the basic
controller are described that consider the use of fixed parameter
estimates.