Disturbance observer based control design via active disturbance rejection control: A PMSM example

A new Disturbance Observer Based (DOB) controller design procedure is here obtained via a reinterpretation of the disturbance estimation scheme, present in the Extended State Observer (ESO) based Active Disturbance Rejection (ADR) control scheme. If the reinterpreted disturbance estimation process is explicitly used, now, in combination with an ADR controller, the overall total disturbance effects are substantially diminished in the feedback loop, beyond that achievable by ESO-based ADR control alone. The context is that of nonlinear differentially flat systems, simplified to Kronecker chains of integrations. A Permanent Magnet Synchronous Motor (PMSM) example is examined and its performance is assessed from an experimental setting.