Research On Improved Digital Leather Shrinkage Temperature Measuring Instrument

The shrinkage temperature is an important physical parameter that characterizes the moisture-heat stability of leather.Realizing the accurate and efficient detection it by using measuring instrument for leather shrinkage temperature is very significant and practical in the decision of the application and the tanning method of leather.In order to meet the market and science demands,especially to meet the higher requirements of the new high-tech industry which is represented by biological science in accuracy and intelligentization,in this paper,according to the current national industry standards,the working mechanism and existing problems of MSW-YD4 digital measuring instrument for leather shrinkage temperature are systematically studied based on the relevant theory of electrical engineering.Moreover,an improved instrument which is called MSW-YD4 S is designed.Compared with MSW-YD4,the improved instrument is more accurate and more convenient.The main work of this paper is summarized as follows:(1)Overall design of improved instrument.Through the research and analysis of the current test standard and MSW-YD4 measuring instrument,the improvement scheme is put forward in view of the problems of low detection precision and complicated operation in the system.The scheme mainly improves displacement measurement,temperature measurement and related mechanical devices,so as to improve performance of the whole machine.(2)Design of the system hardware.Building the hardware platform is based on the improved instrument scheme.It mainly designs machine vision system hardware to detect deformation and displacement with high accuracy,and solves the problem of low accuracy of displacement detection by traditionalHolzer sensor.The AD590 temperature module is replaced by the PT1000 temperature measurement system,which improves the accuracy of temperature measurement and widens the range of temperature measurement.In addition,the modules of motor drive,constant-speed heating control,DC-DC switching power supply,main control circuit,man-machine interaction and so on are designed.In terms of mechanical hardware,the main design points are cutting leather sampler,motor drive and other mechanical devices.(3)Research on the application of computer vision in the measurement of leather shrinkage deformation.According to the characteristics of the test system,the corresponding algorithms are studied,including the weighted average gray scale algorithm,the median filtering method that can keep the edge information and the adaptive threshold binaryzation.In particular,Harris corner detection combines with Zhang Zhengyou calibration method,by which the transformation relationship between the world coordinates and image pixel coordinates is established.Futhermore,the system is able to measure the displacement in real time.(4)Design of the system software.According to the requirement of the improved measuring instrument and the hardware system,the corresponding host control software and the computer software are developed.The host control software using C programming language in MDK development environment,mainly to develop the main control module,signal acquisition and processing module,constant-speed temperature control module,human-computer interaction module,and serial-USB communication module.The computer software is programmed by C++ language in the Microsoft Visual Studio 2013 development environment combined with OpenCV2.4.10 library.The computer software mainly realizes the development of image processing and software monitoring interface.(5)Machine performance test.After completing the design,debugging of the hardware and software of the improved tester,the main performance parameters of the tester are tested.From the aspects of the measurement accuracy of the displacement and temperature,the uniformity of the temperature distribution of the heating medium and the effect of the constant-speed temperature control,the two types instrument are tested and compared,and thetest data is analyzed and studied.The analysis results of the whole machine test data show that the main performance parameters of the improved instrument meet the design requirements and meet the national standard.Compared with the MSW-YD4 type tester,it has obvious technical advantages,which has been improved in the accuracy of measurement and in the convenience of operation.The accuracy of displacement measurement is increased from 0.2mm to 0.036 mm,and the accuracy of temperature measurement is raised from 0.5? to 0.18?,and the stability is better.The successful development of the prototype of the MSW-YD4 S leather shrinkage temperature tester not only meets the basic measurement needs,but also provides technical support for the rigorous leather related scientific research.