Input-Output Selective Linearization (IOSL) and Integral Control: An efficient solution to nonlinear industrial process control's problem

A number of nonlinear control techniques are now available in research literature however Exact Feedback Linearization (EFL) is one of the few techniques which are embraced by the industry. Input-Output Exact Linearization (IOEL) is the method in which nonlinearity (between inputs and outputs of interest) of a plant is exactly linearized (by EFL) and an outer linear control loop is employed to achieve desired performance. However, from application point of view, EFL linearize all the nonlinearities, including those which favor the required performance, which makes the design loop inefficient. In this paper a new and more efficient control technique (Input-Output Selective Linearization, IOSL) is being presented which selectively linearize the nonlinear parameters of a plant. The useful nonlinearities which favor the performance indexes are left unchanged. PID control loops are proposed for the outer control loops in the design to achieve robustness and disturbances rejection properties in the overall design. (author)