Design and Analysis of controllers for paper machine subsystem

The economy of the paper industry largely depends on the quality of the paper manufactured and the quality depends on the precise operation of Headbox, which is the key element of the paper machine and is highly responsible for the quality of the paper manufactured. Being a nonlinear multivariable system, a headbox needs to be controlled efficiently to have the desired response which in turn reflects in the quality of the paper. The headbox is subjected to various disturbances and thus it is required not only to suppress the effect of disturbances but also to ensure the smooth start of the headbox and fast response to the set-point changes. A control technique is proposed in this paper for a paper machine headbox based on the determination of ultimate gain and frequency using the fractional-order integrator (FOI). The PID tuning technique proposed has been applied on paper machine headbox and the responses are compared with the existing techniques.