Aiming　at　the　influence　of　nonlinear　friction　characteristics　on　position　tracking　accuracy　in　harmonic　drive　servo　drive　system,　a　method　of　nonlinear　friction　modeling　and　compensation　was　proposed,　and　the　control　accuracy　of　the　system　was　improved　combined　with　fuzzy　active　disturbance　rejection　control　(ADRC).　Firstly,　the　mathematical　model　of　permanent　magnet　synchronous　motor　in　electromechanical　actuator　was　given,　the　dynamic　model　of　harmonic　drive　was　constructed,　and　the　relationship　between　friction　torque　and　control　current　was　deduced.　Then,　the　corresponding　torque　currents　at　different　speeds　were　obtained　by　wavelet　de-noising　and　Kalman　filter,　and　the　speed　torque　curve　was　obtained.　The　functional　relationship　between　speed　and　control　current　was　obtained　by　cubic　Gaussian　fitting.　Then,　according　to　the　principle　of　ADRC　and　fuzzy　control,　the　fuzzy　rules　were　formulated　and　the　Fuzzy-ADRC　was　designed.　Thirdly,　according　to　the　fitted　function,　feedforward　compensation　was　added　to　the　Fuzzy-ADRC　to　suppress　the　nonlinear　friction　in　the　harmonic　drive　and　improve　the　control　accuracy　of　the　system.　Finally,　the　experimental　results　show　that　the　root　mean　square　value　of　position　tracking　error　under　no-load　state　and　load　state　is　reduced　by　about　180　and　176　compared　with　PI　control　method.　©　2023　Editorial　Department　of　Electric　Machines　and　Control.　All　rights　reserved.