Design Of Grating Displacement Measurement System Based On USB

With the development of society and the progress of science and technology, the accuracy of displacement measurements in the modern society are becoming more demanding. In the promotion of the rapidly developing technology of integrated circuits and computer technology, equipments of displacement detection are also undergoing tremendous changes. Against this background, grating displacement sensors and detection systems have emerged.Grating displacement sensor is a photo-electricity converter in high-precision displacement measurements. It transforms the displacement of work platform into the movement of MOIRE fringes through transmission of grating, and then electrical signal was sent out through photo-electricity converter. We make full use of the electronic technology to adjust the electrical signal into the signal that can easily be handled by MCU. And then we use the powerful functions of PIC18F4550, which has a USB interface, to transmit the electrical signal to a PC. Finally with the help of powerful computational functions of computer and technology of VC++, the displacement of grating displacement sensor was showed on the PC. Throughout the whole designing process of this system, I, under the guidance of my instructor, adopt a relatively ideal signal conditioning circuits of grating displacement sensor, the latest MCU (PIC18F4550) with USB interface, and more outstanding software algorithms. Finally, we make the design not only with highly anti-interference capability, but also with high precision to 0.1 micrometers.On the basis of many collection and analysis of reports and articles related to grating displacement sensor detection equipment and USB-related, the USB and detection system of grating displacement sensor based on USB are deeply discussed. The following aspects in my thesis are innovative or improved:· It is taking the lead of using the MUC (PIC18F4550) with USB interface for detection equipment in industry in the Asia-Pacific region.· it improved the signal conditioning circuits of grating displacement sensor, as a result, not only the circuits works more steadily, and has strong anti-interference capability, but also it can adjust the sine wave that a grating displacement sensor has output into Lissajious'figuers,this figures is a similar ideals round.· An algorithm is proposed that can not only calculate the large number of the displacement of a grating displacement sensor but also the tiny number (Digital Subdivision) independently and coordinate.· It is one of the earlier designers who combine the protocol of USB2.0 with grating displacement sensors...