This paperfocusesonhigh-precisiondivingandlevelingcontrolofanunderwatertensionlegplatform,
which useshydraulicwinchesastheactuationmechanism.First,dynamicmodelisestablishedbasedon
joint space.Then,decoupleddoubleclosed-loopcontrolstrategiesfordivingandlevelingareproposed
and internalclosed-loopcontrollersaredesignedandtestedbasedonbacksteppingslidingmodecontrol
(BSMC) method.Finally,winchtestsand field trialsarecarriedouttoverifytheefficacy ofourapproach.
Simulation andexperimentalresultsshowthatthecontrollersdesignedinthispapercanachievespeed
control anddisplacementcontrolwithhighprecisionandstrongadaptability,thusleadingtosuccessful
diving andlevelingcontroloftheunderwatertensionlegplatform.