Control of two-link flexible manipulator using disturbance observer with reaction torque feedback

We propose a simple and easily implementable controller for a planar type two-link flexible manipulator. Due to the neat property of the disturbance observer, each flexible link can be considered as just two lumped masses with a spring between them, which is called a two-mass resonant model within the selected frequency range. For such a system, we design a controller which is simple to implement and robust for uncertainty using feedforward disturbance cancellation through the disturbance observer. The performance of the proposed method is verified by simulation and experiments.