Abstract: The ammunition transfer manipulator has low locating accuracy and slow locating speed due to base vibration and payload uncertainty during operating. This study is implemented based on a principle prototype which has the same structure and working principle with the ammunition transfer manipulator. A nonlinear continuous time-varying feedback control method is proposed based on the disturbance compensation of disturbance observer. The control method is PD-like in the form of control law, but its proportional and differential coefficients are determined by system Lyapunov function, which are the differentiable functions of system error variables. To eliminate the nonlinearities caused by base vibration and payload uncertainty, the compensation based on a finite time nonlinear disturbance observer is added to the control algorithm. Experimental results show that the disturbance observer-based compensation can shorten the positioning time by 39.4%, from 2.18 s to 1.32 s. Meanwhile, under all the experimental conditions with base vibration and different loads, the control method can always fast, steadily and precisely achieve the control target，which verifies the effectiveness of the proposed control method.

Key words: ammunitiontransfermanipulator, basevibration, payloaduncertainty, nonlinearcontinuoustime-varyingfeedback, disturbanceobserver, disturbancecompensation