Research And Development On Micro-positioning System

Stepping into the 21st century,with the rapid development of science and technology,and with the requirement of aeronautics,integrated electronic manufacturing,biotechnology for other high-tech development of the precision machining and high quality is required.Precision machining technology is a research field mainly sponsored by the country,and micro-positioning system with high performance is the key to realize precision machining.It is very important for china to promote economic and enhance the country's comprehensive national strength,this will have far-reaching significance for national defense building.The project of system have been determined by studying the components of micro-displacement system which is comprise of the advantages and disadvantages.The system makes full use of the inverse piezoelectricity effect of PZT ceramic to gain displacement.At the same time,the precision and the actuating property should be ensured because the PZT ceramic has superior characteristics just like small volume,high motion resolution,big output force and so on.But the maximum displacement of the PZT actuator is only 50μm, for many parts,it is hard to meet the machining requirements,we used the flexible hinge mechanism which can offer several advantages over classical joints,such as compact structure,no friction losses and no assembly.The flexible hinge positioning stage we have made would hardly have an impact on accuracy during the transmission process.And we also designed a lever amplifying frame with flexible hinge that will augment the step size of the positioning system.Step-magnifying mechanism of planar micro-positioner has been presented through using a level enlarging mechanism and a double-nesting structure to design a flexible hinge structure for enlarging the displacement range of piezoelectric ceramics on two directions and feeding step length,and at the same time reducing the response time.To do so,it is necessary to choose the enlarging lever reasonably and optimize the design of the overall structure.A single flexible hinge and the entire of platform have been modeled and used finite element method for static analysis to further the optimize of design in base on theoretical analysis.The closed-loop control system have been developed in order to improve the accuracy of the feed of system,it can solve some problem such as non-linear piezoelectric ceramic retardation factors and improve the ability of anti-interference.