| At present,the micro-manipulation platform is a research hotspot in the fields of aerospace engineering,nanoscience and technology,precision engineering and manufacturing,integrated circuit manufacturing,and biomedicine.Flexible hinges are widely used in micro-manipulation devices because of their advantages of high displacement resolution,no mechanical friction,and high precision.Scholars at home and abroad have developed many types of flexible micro-operation platforms according to different operating objects.With the continuous development of bioengineering and medicine,the research works of flexible micromanipulation platform are facing with more severe challenges.In order to meet the higher demands of bioengineering and medical fields,this thesis mainly designs a large-stroke flexible micro-operation platform.The platform adopts a 3-RCU parallel mechanism to make the structure more compact.In order to reduce assembly errors,the platform is mainly made of straight round flexible hinges.A lever amplification mechanism is designed to cooperate with the piezoelectric ceramic driver to increase the workspace of the platform.In order to obtain better transmission performance,a composite flexible cylinder pair is designed.First,combined with ANSYS simulation software,the magnification mechanism and the overall platform are designed and optimized.Then,the statics of the micromanipulation platform is analyzed,including the flexibility matrix and the magnification ratio of the magnifying mechanism,and ANSYS software is used to verify them;the reliability of the output of the amplifying mechanism is analyzed,the stress and strain of the platform,and the manifestation of the mechanism under different working conditions are solved;the decoupling performance,bearing capacity,and reliability of the cylinder pair are analyzed,and simulation verification is conducted.The kinematics model of the platform is established,the forward and inverse solutions of the kinematic posture are derived,and the theoretical verification has been carried out.The Jacobian matrix of the platform is derived,and the workspace of the platform is drawn by MATLAB.Finally,the dynamic model of the platform is established,and the energy equations of the rotating joints,the Hooke’s hinges,the cylinder pair and the moving platform are analyzed.According to the Lagrangian function,the dynamic equation of the mechanism is derived.The theoretical natural frequency is compared with the natural frequency obtained by ANSYS modal analysis to verify the accuracy of the theoretical analysis.The mode shapes and natural frequencies of the platform are analyzed,and the motions of the platform are investigated.Through the modal analysis under two different working conditions,the natural frequencies of the platform with and without prestress are compared to verify the reliability of the mechanism.To sum up,the results show that the 3-RCU large-stroke flexible parallel micro-manipulation platform has safe and reliable structural design,and the theoretical derivation is correct.The platform can realize the rotations of the x-axis,the y-axis and the movement of the z-axis in space,and the mechanism has high precision,larger magnification ratio and workspace. |
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