Study And Design Of The System Of Accurately Measuring The Length Of Cloth Based On The PSD Technology

This paper according to the textile industry in the length of the measurement of the fabric of instrument of upgrade discusses the based on position sensitive device PSD in a fixed distance measurement in the application of the theoretical basis, this text introduces the principle of the PSD structure topic, optical triangle method, the PSD signal processing, modulation and demodulation, and phase lock loop, etc.In the project cost control are put forward on the basis of SHARP GP2Y0A21 type PSD module with solutions, this paper discussed the eliminate dark current, background light effects of light signals modulation method is introduced, and the working mechanism of SHARP GP2Y0A21 module, Based on SHARP GP2Y0A21 module introduced from pure sure signal output and the circuit design and application.In a circuit design, from the basic requirements of engineering project, combining with the photoelectric theory, supplemented by relevant Keil uVision program design platform and Proteus, multisim hardware simulation platform designed, simulation signal processing circuit in the laboratory, and then repeated forms of validation and perfect.Focuses on the premise of cost control, the system set distance reach 26 mm, resolution to 0.1 mm, system response time less than 10 ms, and basic not affected by background light etc environmental impact; Design system can not only replace traditional the length of the measurement of the fabric of instrument can also widely used in other industries spacer measurement.