Study on disturbance rejection of four-axis turntable in coaxial work mode

Four-axis turntable, as a novel form of motion simulator with redundant structure, can overcome the weakness of traditional three-axis turntable that one degree of freedom may lose when the table simulates large angle motion. This paper focuses on the disturbance rejection of four-axis turntable in coaxial work modes including horizontal mode and vertical mode. Based on disturbance mechanism analysis and modelling, a compensation method based on the motor reaction force is designed to reject the disturbance from active axis to static axis in the horizontal mode and a simplified feedforward controller with the command of active axis as input is developed to improve the tracking performance of static axis in the vertical mode. Both simulations and experiments are conducted to verify the effectiveness and feasibility of the proposed methods.