"Discrete-Time Analysis and Synthesis of Disturbance Observer-based Rob" by Emre Sariyildiz, Satoshi Hangai et al.
This paper analyses Disturbance Observer-(DOb-) based robust force control systems in the discrete-time domain. The robust force controller is implemented using velocity and acceleration measurements. A DOb is employed in an inner-loop to achieve robustness, and another DOb, viz. Reaction Force Observer (RFOb), is employed in an outer-loop to estimate interaction forces and improve the performance of force control. First, the inner-loop is analysed. It is shown that the DOb works as a phase-lead/lag compensator tuned by the nominal design parameters in the inner-loop. The phase margin of the i...
Source: uow.edu.au