The System Design Of 6-DOF Manipulators And The Research On Its Key Technology

The kinematics and dynamics modelings of the six-degree-of-freedom manipulator are established in this paper.In view of the complexity of the traditional kinematics modeling method and the existence of singular solution,the kinematic equation and the corresponding error model of the manipulator are obtained by the POE modeling method based on the spin theory,The dynamic modeling method is proposed by combining the POE formula,the Lagrange method and the U-K equation,and the complete expression of the constrained manipulator dynamic is established.The equation has certain versatility.The system of the 6-DOF series manipulator is studied and designed in this article.The two deceleration mechanisms of first three joints adopt motor combination and worm gear and other three joints employ direct drive structure.The form of the electronic control parts includes PMAC motion control card,servo drive and DC motor combination.The single-axis motion and 6-axis linkage of the manipulator are completed.Designing the GUI interface in MATLAB,the positive and negative kinematics,positive and negative dynamics and trajectory planning of the manipulator are obtained.Realizing the data interface between MATLAB and Pro/E,the working space of the manipulator in the experimental environment is analyzed.The strain and stress of the key parts of the manipulator under the stress are analyzed by ANSYS,and the results meet the strength requirement.The end-effecter will be subject to the ideal and non-ideal constraint forces effect in the case of constraints.Considering the uncertainty of non-ideal constraint force,the sliding mode control method is proposed to track and control the non-ideal constraint force.In order to verify the effectiveness of the control algorithm,the simulation experiment of the two-jointed manipulator with vertical constraint is put forward.Considering the redundant variables of the constrained manipulator,the dynamic model order reduction method based on the U-K equation is put forward.To track and control the end-effecter trajectory and the non-ideal constraint force,the corresponding sliding mode controller is designed.In order to weaken the chattering phenomenon in the sliding mode control,a reduced-order adaptive fuzzy sliding mode control and a reduced-order adaptive neural network sliding mode control method are proposed which can realize the high precision control and the approximation and compensation of the unknown non-ideal constraint force.The experimental results show that the reduced-order adaptive fuzzy sliding mode control is about 10000 times compared with that of sliding mode control alone and the reduced-order adaptive neural network sliding mode control is about 100000 times higher than that of sliding mode control alone.The kinematic model and the kinematic error model of the 6-DOF manipulator are obtained by using the POE modeling method based on the spin theory.A direct measurement method based on the Leica total station TC2003 and BMR prisms is proposed to perform the kinematic calibration of the manipulator.The coordinate system transformation and repeat positioning accuracy are measured.The repeat positioning accuracy is ? 0.3 mm,which is satisfied the desired index requirements of ? 0.5 mm.The actual coordinate values of the manipulator in different positions are measured and the errors of the kinematic parameters are identified by the least squares method.The absolute positioning accuracy of the manipulator is increased from the initial 6.11 mm to 0.82 mm.