Research of the feedforward control system of 3-axis stable platform based on disturbance observer

In order to improve stability and capability of rejecting disturbance of the platform, the feedforward controller and disturbance observer (DOB) are used in angular loop of the 3-axis stabilized platform. This method can effectively avoid the conflict between stability and rapidity of system. Using the error signal as the evaluation index, the DOB can accurately track external disturbances, such as constant, periodic and random disturbance signal, eliminate model mismatches and improve the stability and robustness of the inner loop. Finally, the simulation result shows that the composite control method has better dynamic performance and smaller steady-state error than cascade lead-lag compensation.