  In this work, an advanced motion controller is proposed for buck
converter-fed DC motor systems. The design is based on an idea of active
disturbance rejection control (ADRC) with its key component being a custom
observer capable of reconstructing various types of disturbances (including
complex, harmonic signals). A special formulation of the proposed design allows
the control action to be expressed in a concise and practically appealing form
reducing its implementation requirements. The obtained experimental results
show increased performance of the introduced approach over conventionally used
methods in tracking precision and disturbance rejection, while keeping similar
level of energy consumption. A stability analysis using theory of singular
perturbation further supports the validity of proposed control approach.
