Adaptive control of a 3-DOF parallel manipulator considering payload handling and relevant parameter models

• Four dynamic reduced models of a robot were evaluated for on-line identification.
• An adaptive control scheme was implemented for 3-DOF parallel manipulator.
• The adaptive controller permits to study the cases in where uncertainties affect.
• The performance of the adaptive control is evaluated with a payload on the platform.
• The on-line update of the relevant parameters minimizes the absolute error.

Model-based control improves robot performance provided that the dynamics parameters are estimated accurately. However, some of the model parameters change with time, e.g. friction parameters and unknown payload. Particularly, off-line identification approaches omit the payload estimation (due to practical reasons). Adaptive control copes with some of these structural uncertainties. Thus, this work implements an adaptive control scheme for a 3-DOF parallel manipulator. The controller relies on a novel relevant-parameter dynamic model that permits to study the cases in where the uncertainties affect: (1) rigid body parameters, (2) friction parameters, (3) actuator dynamics, and (4) a combination of the former cases. The simulations and experiments verify the performance of the proposed controller. The control scheme is implemented on the modular programming environment Open Robot Control Software (OROCOS). Finally, an experimental setup evaluates the controller performance when the robot handles a payload.