Theoretical control and experimental verification of carded web density - Part I: Dynamic system analysis and controller design

Control of uniform carded fiber webs becomes very important when one wants to push the state of the art with faster and more accurate textile spinning . Four steps are necessary for controlling the carded web and its uniformit y. First, a good design-based model of the plant needs to be considered. Se cond, a good actuator, sensor and, controller that are also realizable must exist. Third, input to the controller must be constructed using knowledge of the system's dynamic response to improve system performance. Finally, al l the effort of the design is meaningful only when tested by experiment. Th is paper presents a complete strategy for a uniform carded fiber web contro l system. Part I illustrates the system dynamics, stability, controllabilit y, and observability by application to feedback control of one worker-strip per group, and uses the root-locus design technique for the controller desi gn. At the same time, a complementary control scheme for precise system con trol is presented. This composite control method gives the corresponding cl osed-loop system not only a time-optimal operation, but also the most effic ient, precise control properties.