A　parameterized　design　of　universal　motion　controller　is　proposed　in　discrete-time　domain　using　composite　nonlinear　control　approach　for　high-performance　servo　mechanisms　in　industrial　automation.　First,　the　model　of　servo　mechanisms　is　converted　into　discrete-time　state-space　form,　and　a　linear　control　law　is　designed,　consisting　of　state　feedback,　reference　feed-forward　and　disturbance　compensation.　Next,　a　nonlinear　control　law　is　constructed　to　smoothly　modulate　the　closed-loop　damping　as　the　system　output　approaches　the　reference.　To　estimate　the　unmeasurable　velocity　and　disturbance,　a　reduced-order　extended-state　observer　is　adopted.　The　final　controller　is　a　combination　of　the　above　three　parts　and　is　fully　parameterized　in　some　fundamental　tuning　parameters.　The　controller　was　applied　to　a　permanent　magnet　synchronous　motor　(PMSM)　drive,　which　usually　serves　as　the　actuator　for　high-performance　motion　control　systems.　After　MATLAB　simulation,　experimental　test　using　a　digital　signal　processing　board　was　conducted,　to　verify　the　effectiveness　of　the　proposed　design.　©　2020　Elsevier　Ltd