Design And Analysis On The Disturbance Characteristics Test System Of The Two-dimensional Space Steering Mechanism

The micro-vibration of spacecraft is a key factor which affects the performances, such as thepointing precision and imaging quality. There are some disturbance sources to the spacecraft, such asmomentum wheels, control moment gyroscopes, solar wing driving mechanism and two-axis rotatingmechanism, etc. Long-term research has been internationally carried out on the control momentgyroscope and momentum wheel disturbances, and many important results have been achieved. Butthere is little research on the two-axis rotating mechanism disturbance problem and the experimentstudy is not even seen. With the development of the need of high-precision spacecraft, this problemshould be researched deeply. The main works finished in the thesis are as follows.First, according to the scheme of the two-axis rotating mechanism disturbance measuring system,the granite board of the working table, the bracket of the working table, the work-fixture for thesix-component-force sensor, the work-fixture for the calibration system and the work-fixture for thetwo-axis rotating mechanism are designed. The components for a gravity unloading system with airfloat method are designed. The simulated loading structures for the two-axis rotating mechanism aredesigned with the optimal method. The3-dimensional CAD models of the components areconstructed and the simulated assembling check is implemented. The finite element analyses arecarried out for the designed components. The2-dimensional blueprints of the designed componentsare created from the3-dimensional CAD models. The manufacture and assembling are finished.Second, the formulae of the disturbing forces and moments of the two-axis rotating mechanism toits base body are derived and then verified by examples with ADAMS software. Based on theformulae, the different terms of the sum of the results of the two axes rotating alone to the results ofthe two axes rotating simultaneously are obtained. It is the theoretical foundation for the use of singleaxis rotating test instead of two axes rotating simultaneously test on the ground.Finally, the designed two-axis rotating mechanism disturbance measuring system is tested with thecalibration system. The results show the system is reliable and accurate and can meet the engineeringdemands.