Study On The Jacquard Control Method Of Tufting Machine And System Design

Jacquard carpet is manufactured by the tufting carpet machine with variable pile heights or different color arrange of the yarns. The needles in the tufting machine stitch the yarns into the base with different feed amount which is controlled by a jacquard control system. Jacquard control technology is the key technology to make high quality jacquard carpet. In this paper, the jacquard control system of tufting carpet machine is studied. The jacquard control method based on Electromagnetism Clutch is analyzed and improved; a new jacquard control method based on Brushless DC Motor (BLDCM) is proposed. By studying on the related theory and experiment, the jacquard control systems are designed and the comparative analysis is processed on the systems. The main research work is as follows:1) As researching the jacquard control system based on Electromagnetism Clutch, two types of control system are designed in terms of different power resources of jacquard roller shafts, the shafts are driven by mechanical transmission or synchronous servo. By toggling the Electromagnetism Clutch, the jacquard rollers have different rotate speed and feed different amount of the yarn to the looper, then the pile height of jacquard is controlled. 2) The main factors affecting jacquard looping are analyzed. To control the yarn feeding accurately, dynamic characteristics of the Electromagnetism Clutch improvement and servo compensation method are proposed. The control system based on PWM is designed to improve the dynamic characteristics of Electromagnetism Clutch. On the other side, in the servo control method, the relationship between the rotate speed of servo motor and the pile height is described by analysis on experiment data.3) To achieve multi pile jacquard, a new jacquard control method based on BLDCM is proposed. Each yarn feeding roller is controlled by one BLDCM to get wide adjustable range of pile height, and the feeding speed of each roller is different from each other. CAN bus is applied on the jacquard control system. Each jacquard servo motor composes one node of the CAN bus. Besides, jacquard motor and principal shafts motor is controlled synchronously through CAN bus.4) The control system of jacquard servo motor based on DSP is designed, as the servo performance of jacquard node is directly affecting the precision of yarning feeding amount control. A math model of the force applying on the yarn is constructed, and the mechanical load characteristic of jacquard node is analyzed, the jacquard node control system is simulated and the control strategy of the system is studied. Normal PID and Fuzzy-PID are applied on rotate speed adjustment respectively, the adjustability of the two methods is compared and analyzed to provide theoretical basis for high performance servo control.Comparing jacquard control method based on Electromagnetism Clutch and BLDCM, it is showed that the jacquard control method based on BLDCM has wider range adjustability of yarn feeding and is more flexible and precise. Moreover, the control system based on CAN bus has strong extensibility and is easy to achieve integrative control, which represents digitalization and informatization trends of the tufting machine.