Micro-thrust on-orbit calibration method suitable for drag-free control spacecraft

The invention relates to a micro-thrust on-orbit calibration method suitable for a drag-free control spacecraft. The spacecraft comprises a plurality of micro-Newton-level micro-thrusters used for spacecraft attitude control. Comprising the following steps: S1, observing the angular acceleration of a spacecraft by using an angular acceleration observer; S2, calculating a measurement matrix of the spacecraft at the current moment according to the dynamics of the drag-free spacecraft; S3, calculating a gain matrix of the spacecraft according to the measurement matrix of the spacecraft at the current moment; s4, calculating a spacecraft covariance matrix according to the current moment gain matrix of the spacecraft; s5, calculating a micro-thruster calibration value according to the spacecraft gain matrix and the covariance matrix; s6, updating the nominal parameter matrix of the micro-thruster according to the estimated value of the micro-thruster; s7, the nominal force and torque of the micro-thruster are deco