Research On Error Calibration And Sensitivity Analysis Of Forging

Because of the strong bearing capacity and the high degree of freedom,forging manipulator has great advantages in the manufacturing of large forgings and special-shaped forgings.And the lifting mechanism is the main motion mechanism of the forging manipulator,which works with the press synchronously to complete forging process like buffering and forging.Which means,the working accuracy of lifting mechanism is directly related to the efficiency and quality of forging.However,the structure of the lifting mechanism is complex and its volume is huge,and there are always some structural errors in the processing and assembly of its components,which leads to the reduction of the motion precision of the end of the mechanism.Therefore,the research on the structural error of lifting mechanism is urgent.The following studies have been carried out in this paper.(1)To solve the positive and inverse kinematics constraint equations of the lifting mechanism without error terms,based on which,the error transfer equation is derived for the structural errors in the joints and elements,and the kinematic model of the lifting mechanism with structural error is established.And all these lays a theoretical foundation for the error analysis,error identification and trajectory correction of the lifting mechanism.(2)In view of the uncertain influences of structural error on the position of the lifting mechanism,the error sensitivity analysis is carried out.The contribution degree of the structural error to the end position deviation of the mechanism is evaluated quantitatively,the reference for the processing and calibration of the key components is provided,and the redundant error terms are eliminated.(3)An error identification method based on the combination of the damping least square method and the identification fit degree is proposed,and the evaluating indicator is established.Meanwhile,the identification effect of the method is evaluated in the simulation environment.(4)In view of the phenomenon that the structural error will cause the deviation of themotion trajectory,the trajectory correction model of the lifting mechanism is build up,and the relevant indicator are set up.And the trajectory correction ability of the model is evaluated.(5)The error identification and trajectory correction experiment are carried out basing on the similarity test bed of the forging manipulator lifting mechanism,and the feasibility of the error identification and trajectory correction method in this paper is verified.