Automatic control of the roller carding machine part II: a study on the application of a sliding mode controller on the roller carding machine

The current roller carding machine control methods lack in the theoretical basis of using an auto-leveler, and are limited to the control of the cotton web layer thickness or the input amount of fibers. When the input amount changes, the output response is relatively slow, thus resulting in considerable impact on fiber web quality. Therefore, this study first established the theoretical modeling, and validated the dynamic mathematical model of the roller carding machine. This study used the sliding mode control in the design of the controller to control uniformity of the output fiber web of the roller carding machine. The sliding mode control used in this study was to allow the system to move in the dynamic process according to the pre-determined sliding mode trajectory, and then use the preset approximation conditions and switching conditions as the control law to navigate the system, in order to achieve the control objectives. Under the sliding mode control, with robust performance to suppress external disturbances and appropriate design of the sliding surface and boundary layer, dynamic model analysis and control adjustment for the system can be implemented to achieve the control objectives and uniform fiber web output. The experimental results confirmed that sliding mode control can effectively control fiber web uniformity of the roller carding machine.