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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.

The present article reviews the literature pertaining to the control system analysis of multivariable process. MIMO control system analysis techniques like relative gain array (RGA), Neiderlinski Index , Morari Resiliency Index , Condition Number (CN), Singular Value Decomposition and robustness analysis (RA) using model mismatch are shown with the help of flow chart. In multivariable control system analysis, the important terms include interaction analysis, stability analysis, controllability test, observability test, singular value decomposition, resiliency and conditionality. Also, the capabilities such as tracking of set-point level, rejection of disturbance signals and robustness are explored for the controllers of MIMO processes.

All the chemical industrial processes are influenced by the unmeasured and measured input and output disturbances. An efficient controller is considered to be the one that reduces the effects of disturbance as early as possible to avoid significant degradation caused in the performance of the controller designed. Prediction based control system analysis is an indispensable strategy to control complex interactive industrial delayed processes. This paper provides a rigorous review of the evolution pertaining to linear MPC and its variants. It also highlights MPC strategy and its implementation for design of MPC basedcontroller.

Graphene film drooped on a bottom gate bottom contact (BGBC) is adopted for fabricating gas sensing technology. The sensors are competent of identifying toxic gases like CO2, NO2, CO of ultra-low concentration i.e., ppb in surrounding air by calibrating sensitivity which is the measure of change in maximum drain current in presence of air and in absence of any toxic material on graphene layer whereas, the initial condition of graphene remaining constant except temperature. The main principle of the device is that graphene can act productively to endeavor abounding physio-chemical properties that are beneficial for gas sensing techniques which would keep a check on increasing toxic level at homes, schools, car and would prove to be beneficiary against sick building syndrome (SBS). The sensors provide an advantage of low power, low cost, good sensitivity and stability.