Inner axis control with friction compensation for high precision flight motion simulator

A new approach combined advance equivalent control voltage fiction compensation upon Stribeck mode with compound control based on input feed-forward and close loop PID control was presented to enhance the low speed servo performance for DC torque motor driven inner axis of a high precision flight motion simulator. Firstly, compound controller was designed to meet the requirements from the inner axis low speed servo analysis. Secondly, equivalent control voltage Stribeck model was established with its parameters directly acquired just with the available components of simulator itself, thus avoiding the shortcoming of conventional Stribeck model based method and the difficulty in determining parameter values for the model, and the ways how to access three key parameters were specified. Lastly, experiments were carried out to verify the approach on the inner axis servo control, with a triangle wave tracking with amplitude of 0.03° and frequency of 0.0005 Hz, 95% time the tracking error is within 0.0001°, tracking of other signals was also with high precision. The results show the scheme can accomplish sound low speed servo for the plant under the nonlinear friction leading disturbances.