The Decoupling Design And Experimental Research On High Efficiency Piezoelectric Stick-slip Stages With High Load Capacity

The piezoelectric stick-slip stages have advantages of high output precision,fast response speed,no electromagnetic interference and so on.It has shown good scientific significance and good application prospect in the fields of micro-nano processing,semiconductor manufacturing and precision optical system.However,the output performance of the current piezoelectric stick-slip drive stages decline sharply or even fail to work when the load is applied,which has become a bottleneck problem restricting the further development of piezoelectric stick-slip stages.To overcome the above problem,the driving unit and the moving unit of the piezoelectric stick-slip driving stage are separated by introducing the load unit in this paper.And the friction between the driving unit and the moving unit is almost constant after the load is added,which realizes the efficient high load driving of the piezoelectric stick-slip stages and improves the output performance of the stages.In this paper,the basic theory of piezoelectric stick-slip drive is introduced,including the piezoelectric effect and the development process of piezoelectric materials.At the same time,the composition of piezoelectric stack and the response rate driven by sawtooth wave are analyzed.By analyzing the design idea and working principle of the current rod-type piezoelectric stick-slip driving stages.The piezoelectric stack is equivalent to a spring damping system,and the driving unit and the moving unit are replaced,equivalently.The dynamic models of the piezoelectric stick-slip driving stages under no load and load are established.The differences of equations under no load and load are summarized,and the main reasons for the sudden drop of the output performance of the piezoelectric stick-slip driving stages under load are obtained.It is proposed to decouple the driving unit and the moving unit of the driving stage,and introduce the design idea of load unit to solve the bottleneck problem that the current piezoelectric stick-slip driving stages have poor output performance and even cannot work.Based on the above design ideas,the structures of a linear and rotary high efficiency piezoelectric stick-slip stages are designed respectively.And the compositions and working principles of the two stages are introduced.The critical conditions for the piezoelectric driving stages to produce stick motion and slip motion are analyzed,and the necessary conditions for the piezoelectric driving stages to move are introduced.At the same time,the design structure is simulated and analyzed,and the feasibility of the scheme design is verified.The corresponding prototype of high efficiency rod type piezoelectric stick-slip stage with linear and rotary structures are developed.In order to verify the feasibility of the design idea,test systems of a linear and rotary high efficiency piezoelectric stick-slip stages with high load capacity are built respectively.And the output characteristics of the whole machine are tested.The test results show that the load capacity of the state is greater than 10 kg.The minimum bidirectional resolution of the prototype under open loop condition is 30 nm and 33 nm.At the same time,the positioning accuracy of the prototype is 70 nm under free load and 10 kg load when under semi-closed loop control.The load capacity of the rotary stage is greater than 1 kg,the rotating speed of the prototype can reach 5232.5 μrad/s when the driving voltage is 100 V and the driving frequency is 30 Hz.The resolution of the prototype can reach 1.7 μrad under the open loop condition.In this paper,the design idea of decoupling the driving unit and the moving unit of the piezoelectric stick-slip driving states by introducing the load unit is proposed.Which provides specific guidance for the design and manufacture of the piezoelectric stick-slip stages.