On the Strain Feedback Control of a Flexible Robot Arm

We consider a flexible robot arm modeled as a rigid hub which rotates in an inertial space; a light flexible link is clamped to the rigid body at one end and is free at the other. We assume that the flexible link performs only planar motion. We assume that the strain of the flexible link at the clamped end is measurable. We show that suitable control torques applied to the rigid hub stabilizes the system and achieves orientation under certain conditions. The proposed torque contains derivative, proportional and integral terms of the strain. The stability proofs depend on the passivity of the controller transfer function.