Design Of Standard Testing Platform For Ultra-precision And Dynamic Laser Heterodyne Interferometry Signal Process Unit

Because of the advantages of non-contact,strong anti-interference and high precision,laser heterodyne interferometers have become the classical tools and main ways of static and quasi-static precision measurement.Accordingly,measure institutions,such as NIM,NIST,PTB,etc.have all made exhaustive calibration standards and provided guarantees for the studying and expending of static and quasi-static precision measurement.Whereas,as the microelectronics manufacturing and ultra-precision mechanical processing in ultra-precision equipment industry developing these years,studying focus of laser heterodyne interferometer measuring has changed from static measurement to dynamic measurement.Based on these,laser heterodyne interferometers’ measurement calibration should possess the characteristics of ultra-precision and dynamic measuring calibration.Especially in our country,because of lacking new dynamic measurement calibration standards,the evaluation of interferometers’ dynamic measurement properties are in deficiency of reliable methods,and this also becomes one of the technical obstacles on the way of our countries’ laser heterodyne interferometers dynamic measurement techniques turning towards productivity and influences the sustainable development of ultraprecision,dynamic laser heterodyne interferometers’ research and developing.The subject ‘Design of standard testing platform for ultra-precision and dynamic laser heterodyne interferometry signal process unit’ is based on the foundation of laser heterodyne interferometry signal process technology and having a thorough studying of measurement solutions on fast and ultra-precision laser heterodyne interferometers’ varied characteristics.,designing standard for laser heterodyne interferometry signal processing test,which has electrical signal testing simulation unit,static/dynamic characteristics testing unit and several evaluation platform standard interfaces.The subject supplies reliable technical support and platform guarantee for the establishment of national level evaluation standard on ultraprecision,dynamic laser heterodyne interferometers’ characteristics testing.The main research works are as follows:1.Based on the fundamental model of laser heterodyne interferometer measurement,subject established interferometer dynamic interference signal model on the state of target object moving,analyzed interference signal’s frequency and phase changing when the target is moving in uniform speed,uniform acceleration and uniform deceleration.These works provided theoretical foundation and parameters evaluation base for electrical signal testing simulation;2.Focusing on the sensitivity of extremely low phase stepping and extra high phase stability both proposed in electrical signal testing simulation,subject thoroughly analyzed technical theory and spectrum output of direct digital synthesis,designed dual channel synchronous displacement signals simulation unit with the DDS integrated chip as core component whose phase could be tuned,simulated varied motion track of interferometer’s measuring object,realized simulation test of laser heterodyne interferometry signal processing unit;3.Aiming at features of complicated interfaces,high requirements of signal switching and controlling speed,subject designed digital main controller with DSP center,realized fast,stable and accurate electrical signal output of DDS,the signal could be accord with the technical indexes after passing high speed signal modulation unit.With the implementation of FPGA,subject also achieved matching of ISA,USB standard interfaces and high speed data transmission,improved the universality and normatively of evaluation platform;4.To solve the professional problems of complicated testing model and tedious operation steps,subject designed applicant program and user interface with Windows/CVI,made task established and switching in varied tasks more convenient,fulfilled changing the according parameters of evaluation platform online and realized the simulations of complex motion trace.At last,to verify the feasibility and performance index of evaluation platform on laser heterodyne interferometers ‘characteristics’ test,subject carried on functional experimentations with HP5527 B and UOI500 interferometer.Experimental results show that evaluation platform of the subject could simulate the motion with uniform speed less than 5000mm/s,and uniform acceleration or uniform deceleration,acceleration less than 2g,consequently,realize the evaluation of laser heterodyne interferometers’ signal processing unit.