Design and control of a planar two-link manipulator for educational use

Abstract

This paper proposes a new robotic planar two-link manipulator design for educational use. Planar two-link manipulators are among the most accessible two-degree-of-freedom robots for students because they function like human arms. As a result they are ideal for laboratory teaching environments. While previous designs using belt-driven arms served adequately, this new design possesses a number of features that were not possible with the previous design, including more intuitive simplified dynamics, an expanded workspace allowing multiple full rotations, and the ability to be easily reconfigured into an acrobot (an underactuated double-pendulum which can be stabilized in a vertical configuration while being actuated only at the middle joint). The governing equations of the system are derived and an analysis of velocity control in the xy plane is perform and a control methodology is also presented by which the arm can be stabilized vertically while in its acrobot configuration. A Discussion of tradeoffs relevant to the future design of similar systems is also presented.