Flexible Shogging System And High Speed Response For Warp Knitting Machine Based On Servo Control

With development of servo, automation, networking and the advancement of manufacturing technology of warp knitting machine, warp knitting shogging system began to develop to the direction of electronic control as early as 1979. Electronic shogging system has its own unique advantages in pattern loading, modifying and designing,which is more better than mechanical shogging mechanism. But even in technology advanced countries, the current highest speed of warp knitting machine, which has electronic shogging system, is only 1800r/min. In the other side, production rate of high-speed warp knitting machine which use pattern disk has reached 4000r/min, so there is still significant space for development of electronic shogging. High-speed shogging system has high requirements for accuracy, responsiveness and flexibility. This paper focuses on flexible shogging system and high-speed response to start the study.The paper first introduces the research situation at home and abroad in drive components and movement curve of guide-bar, and has a result that shogging mechanism which include rotary motor and ball screw can be kept under flexible control, which can not only meet requests of high-speed shogging ,but also low costs; Then the paper describes the work requirements of guide-bar shogging and analyses characteristics of electronic shogging which controled by servo. The conclusion is that the current position control mode, because of low response and poor flexibility , does not apply to high-speed shogging system. So the paper develops a new kind of flexible shogging system according to high-speed shogging characteristics ,and explores its control algorithm in depth, then compares it with the position control mode ,the result shows that this flexible shogging system has a higher responsiveness; And the paper introduces some common driven motion rules, chooses part of flexible curves as candidates for a deeper actual testing after analysing dimensionless characteristic value. Then comes to a conclusion from experimental results that the overlap shogging area of GB1 is better not to use complex flexible curves because of its small shogging angle and less shogging distance, but shogging in needle back area ,which has a large shogging angle , that can use flexible curves, which not only can improve machine rate, but also shogging more flexibly and has a low motor load; Finally, the paper analyses the factors of high-speed performance under the flexible shogging system, and gives formulas or methods of parameter settings specifically. The paper still focuses on analysing and modeling the vibration in the process of shogging, gets a relationship between acceleration in centroid of guide-bar , curved arm position and machine rate through acceleration testing, then advances some measures to reduce vibration.The flexible shogging system developed in this paper , analysis and testing of motion rules , and factors of high-speed under the flexible shogging system will further improve the rate of high-speed warp knitting machine ,and has an important significance for further development of warp knitting equipments.