A　control　scheme　is　proposed　to　achieve　fast　and　accurate　set-point　servo　motion　in　typical　double　integrator　systems　subject　to　disturbances　and　speed　constraint.　The　controller　consists　of　a　Proximate　Time-optimal　Servomechanism　(PTOS)　control　law　and　a　compensation　term　for　the　unknown　disturbance.　An　extended　state　observer　is　adopted　to　estimate　the　un-measured　velocity　signal　and　the　unknown　disturbance.　In　the　presence　of　speed　constraint,　a　speed　regulation　stage　is　incorporated　between　the　PTOS　acceleration　and　deceleration　stages.　The　closed-loop　stability　is　analyzed　theoretically.　The　control　scheme　is　then　applied　to　the　position-velocity　control　loop　in　a　permanent　magnet　synchronous　motor　servo　system　for　set-point　tracking.　MATLAB　simulation　has　been　conducted,　followed　by　experimental　verification　based　on　the　TMS320F2812　DSP　controller　board.　The　results　confirm　that　the　proposed　control　scheme　can　track　a　wide　range　of　target　references　fast　and　accurately,　and　has　good　performance　robustness　with　respect　to　the　disturbance　and　parameter　variations.　©　2013　Elsevier　Ltd.