The Design Of Automatic Single-Yarn Strength Tester Based On ARM

The Single-yarn strength tester is a technical index instrument that can test tensile performance. It is mainly used for testing separation strength, separation elongation, separation energy and separation time of cotton, wool, hemp, chemical fiber pure yarn and blended yarn (strands). The Single-yarn strength uneven not only affects the quality and style of textile products but also affects the textile processing technology and production efficiency, so the yarn must be tested more higher in the textile production process. The traditional single-yarn strength testers can’t meet the current testing requirements because they have many defects such as low test accuracy, litter data storage and low efficiency for man machine interactive. Many small and medium enterprises who need to improve their own quality can’t afford to buy single-yarn strength tester import at a high price. To meet the market demand, the topic develops a new type automatic single-yarn strength tester based on STM32control.The tester can measure separation strength and separation elongation. In this paper, the hardware structure of the controller, the software flow and debugging are descripted in detail. The hardware system consists of control circuit, force value acquisition circuit, force value output circuit and feedback input circuit. In control circuit it controls the peripheral device based on STM32and communicates with the host computer using efficient CAN to exchange data. In force value acquisition circuit it uses high precision tension sensor to realize the strength value acquisition and AD conversion. In Motion output circuit it uses the drive plate, electromagnetic valve, AC motor, and stepper motor drive to complete the change action, tube feeding movement and strength testing. In feedback input circuit it uses the adapter plate, Holzer sensor and encoder to send signals when the device moves to the specified position. The software structure of the system realizes the change action, tube feeding movement and strength testing based on the μC/OS operating system. Each module requires the corresponding test and debugging until it meets the design requirements. We finally get the breaking strength and elongation according to testing standard yarn sample and then compare it with the standard measuring yarn prototype results. It’s proved the controller has the characteristic of high accuracy and low cost. It can be used for textile production field.