The Research On Tension Test Module And Its Anti-interference For Automatic Single Yarn Strength Tester

The Single-yarn strength tester is an instrument that can test the stretched performance of textile materials, such as yarn and fiber filament. It is mainly used to test breaking strength, breaking elongation, fracture work of cotton, wool, hemp, chemical fiber pure yarn and blended yarn(strands). The Single-yarn tensile strength and nonuniformity not only affects the quality and style of textile products but also the textile processing technology and production efficiency, so the yarn must be tested more strict in the textile production process. The traditional single yarn strength testers can't meet the current testing requirements because of low test accuracy, limited data storage, poor human-computer interaction and so on. Many small and medium enterprises who need to improve their own quality can't afford expensive imported single-yarn strength tester. This paper studied the key components of the automatic single yarn tensile strength tester, which is tension test module and its anti-interference techniques.In this paper, the overall hardware structure of tension control unit based on STM32 and PC software framework were introduced; the research of tension test module included the section of the force sensor, the design of the mechanical structure which output is independent of load position,the analysis and calculation of static testing precision of the sensor according to the principle of error synthesis; this paper also analyzed the dynamics modeling of sensor and designed the viscous fluid damper, thus achieving desired dynamic characteristics; the amplifier circuit and filtering circuit of the signal was designed; SCM preprocesses the conditioned signal and real-time data was sent to the host computer; due to the electromagnetic interference caused by the electrical equipment,the impact of non-stationary operation of the loading mechanism and mechanical vibration, there exist a large of jamming signal, so a series of hardware anti-jamming measures were taken like isolation, shielding, filtering, ground connection; moreover, the programmable amplification algorithm was used to ensure the test sensitivity of low input of the A/D module; through the analysis of the frequency characteristic of the yarn tension data and the section principle of the sampling frequency, the technique of real-time synchronization and smoothing was taken to process the signal, results show that the noise interference were weaken, and the test precision of the yarn tension were improved.