Research On Compound Loading Control Technology For Passive Multi-dimensional Force-torque

The space station transfer mechanism is a fundamental yet important component of space station.Before to conduct the transfer operation,the transfer mechanism would firstly complete the capture and connection procedures to ensure the rigid connection between the arm and base structure of the transfer mechanism.During the process,the transfer mechanism is required to overcome the connection force/torque constraints between the cabins.This thesis carried out a systematic research on the dynamics modeling and multi-dimensional loading control technology.The main research contents and results are as follows:Firstly,the dynamics of the passive multi-dimensional servo platform was analyzed and a systematic study about the influence of friction to low speed operation condition was carried out based on the LuGre model.Due to the slip constraint of the guide plates is difficult to analytic described,a numeric study based on ADMAS was conducted to analyze the position-force coupling effect for the procedure of capture and connection.Secondly,to deal with the nonlinear effect caused by friction in low speed operational condition of servo platform,this paper proposed an nonlinear disturbance compensation control algorithm,based on the framework of Immersion and Invariance,to adaptive estimate the LuGre model parameters,which enhances the smoothness and dynamic performance of the platform in low speed operational conditions.The superiority of the position servo control performance of the proposed method is demonstrated.Finally,in order to solve the problems of multi-dimensional force/torque coupling caused by slip constraint of the guide plates and cannot eliminate the excess force by the motion track of the arm during the capture connection process,a virtual reference feedback decoupling loading control algorithm is proposed based on online data-driven,which can complete automatic decoupling between multiple channels to achieve force/torque servo loading.Simulations and experiments show that the proposed algorithm is able to track instructions with high loading accuracy and fast response speed,and correct the posture deviation between the arm and base to achieve the capture and connection procedures.