Model-Free Observer for Speed and Acceleration Estimations for Speed Servo System Applications

This brief presents a speed and acceleration estimation mechanism combining a Luenberger-type observer and a nonlinear second-order disturbance observer (DOB) using servo system angle measurements without system parameters and load information. The resultant observer has the following two contributions: (a) the inclusion of a system parameter information-free nonlinear DOB as a subsystem to ensure improved robustness and (b) the capability of performance assignment by tuning the scalar design factor without involving any matrix calculation processes. An experimental study validates the practical advantage of the proposed solution using a prototype 500 W dynamo system as a speed servo system.