EVENT-DRIVEN CNC MODULARIZED SEWING PLATFORM

摘要

With ever increased demand for quality and productivity, modern industrial sewing machine is becoming very complex and requiring sophisticated control. This paper presents a control platform that can be used for all kinds of lockstitch sewing machines. This event-driven control platform can support various kinds of sewing operations, from simple lockstitches, to X-Y lockstitches, as well as thread cutting. The key to the control platform is the precision cooperative control. First, for each motion axis, both the position and the velocity must be precisely controlled. In addition, the multi-axis motions must be synchronized to achieve high accuracy stitches. In order to increase the machine flexibility and decrease variety, a generalized and modularized sewing platform is proposed in this paper. It can be assembled with common lockstitch sewing machine and achieve several kinds of sewing functions. This platform module has independent driving capability to fulfill special movement and the communication ability to collaborate with other modules. Besides the modularized mechanism, the reusable and reconfigurable control system is the key point. For industry sewing machine, the important functions are the single-axis precise control and multi-axis cooperative control. In the X-Y moving platform, the closed-loop stepper motor system is adopted for each axis to obtain precise speed and position control. On the other hand, the cooperative control between modules is realized by event-based control method which uses a time-independent parameter to avoid the uncertain time-delay. To verify the system, the corresponding experiments are taken. And the results satisfy the requirements very well.