Research On Macro/Micro Precision Positioning And Motion Platform Based On Piezoelectric Driver

The combination of macro-micro and dual-stage driving precision positioning technology is one of the key supporting technologies in the field of defense and military, aerospace, precision machining, biological science and precision optical etc. With the development of science and technology, the demand of stroke and precision of positioning system for precision positioning technology become larger and larger. In addition, the combination of macro-micro and dual-stage driving precision positioning technology overcomes the disadvantages of traditional single drive positioning technology,for instance, it is difficult to realize the technical problems of long stroke and high precision, and it has greater advantages in volume, stroke, response speed, positioning precision aspects, on the basis of these facts, domestic and foreign researchers carry out a systematic deep study for the combination of macro-micro and dual-stage driving precision positioning technology.This paper designs and develops a kind of 3-DOF and motion platform and the AC servo motor and piezoelectric stack are used as the macro and micro driven power components to achieve a long stroke and high precision and high carrying capacity, combining with piezoelectricity, mechanics of materials, theoretical mechanics related basic theory of the subjects.In the design part of micro positioning system, by the comparing analysis of the mechanical model and performance of three kinds of flexure hinges, straight circular flexure hinge, straight beam flexure hinge and “Z” type flexure hinge, I selected “Z” type flexible hinge as transmission part of the micro positioning platform, and chose the double parallel six connecting rod steering mechanism to reduce the coupling displacement of the platform which increases the bearing capacity. The dynamic model of micro positioning platform was established, and the structure optimization and mechanical simulation analysis were carried out with ANSYS finite element software to verify the rationality of the structure design.In the design part of the macro positioning system, the AC servo motor, ball screw and linear guide structure components for the platform are chosen to be analyzed and studied, the macro positioning platform X axis displacement in the horizontal direction of the harmonic force F(t) under the action of dynamic model is established and its dynamic characteristics are analyzed. Moreover, the six order modal shape and vibration mode analysis of macro positioning platform have been analyzed with the finite element simulation software ANSYS.The combination of macro-micro dual-stage driving precision positioning platform test system was built, testing out positioning accuracy is 1.54μm in the macro positioning system, so the platform has an excellent motion stability property; The voltage displacement motion characteristics of micro positioning system in X and Y direction are tested and studied,strokes respectively are 17.86μm and 15.45μm. The carrying capacity of micro positioning platform is tested and analyzed, and the test and analysis of the input sine wave signal on the micro positioning platform verify the micro positioning platform with good movement characteristics. The test analysis of input step response signal on the micro positioning platform shows that the response speed of the micro positioning along the X and Y direction respectively are 0.00755m/s and 0.00625m/s.