Abstract: A tuning method for a motion simulator embarking a payload. the simulator includes a mechanical device, a mobile plate of which is capable of carrying a payload, and a control unit including a controller capable of position feedback controlling the plate. The method includes: an initial step for the synthesis of a robust controller enabling to control the mechanical device over a range of values of an inertia parameter extending between a minimum inertia parameter and a maximum inertia parameter and, after having positioned the given payload on the plate, a test step during which the mechanical device, controlled by the robust controller, is actuated according to a reference input; an identification step which, on the basis of the data of the test step, enables to determine the value of the inertia parameter; and, a final step of synthesis of an optimal controller adapted to the given payload.