Electronic System Design And Implement On The Machine Of The Paper Smoothness Measurement

Paper is essential in people life,and the quality requirements of paper are not same in different situation.Paper smoothness is a vital parameter for evaluating the paper quality. With the sustainable development of technology, the traditional paper smoothness machine doesn't well meet the needs of customers,because it has a low precision and speed. for testing paper smoothness more convenient and accurate, This thesis will design a paper smoothness machine with automatic detection, display and other functions which bases on Bekk method.Paper smoothness machine bases on a DSP chip as a system microcontroller, and with some additional external devices to achieve paper smoothness testing. The general process is to adjusts drive voltage of vacuum pump by using PWM technology to adjust duty cycle,so that controls speed rate of vacuum extraction by controling vacuum pump rotational speed,and then makes vacuum container pressure stabilize at 50.66KPa by the fuzzy PID algorithm. Real-time detection of air pressure by using pressure sensor,and converts the output of pressure sensor signals to digital signals by AD converter,and inputs signals into the DSP chip to process, records the time of change air pressure in specified range.The whole program uses a 16-bit TMS320F240DSP chip as core control, and achieves control the whole work process of machine. The system is mainly composed of pressure detection, A/D converter, DC speed, man-machine interface module and so on,Through input/output interfaces connect data collection unit and the external device to come true exact test of paper smoothness under the software control.Machine designed in this thesis has the main functions as follow:First of all,achieve automatic rapid determination for the paper sample smoothness according to Bekk method.Secondly, has a high reliabilityandgood accuracy result on testing paper sample smoothness.Third,depending on degree of paper smoothness, realize switch of container chamber, you can use a large vacuum vessel or small vacuum chamber to test.Fourth,the friendly interface, easily understood operation, automatic detection, automatic show measurement results and the print data.