A new combined robust controller using sliding mode and feedback linearization with NDO observer proposed for minimum phase quadruple tank process

In this paper a new combined method for design of robust controller proposed for minimum phase systems. In order to design of controller, a new method which is combination of feedback linearization method and sliding mode technique was used. The used method is improved system robustness against uncertainties and disturbances. The proposed control scheme is simulated on a quadruple tank process to observe it's performance. There is a robust controller for controlling the height of the fluid level within tanks. There is also a nonlinear disturbance observer, in order to estimate uncertainties exerted to system. This observer was combined with designed controller to decrease the effects of the estimated uncertainties. The simulation results demonstrate that performance of the proposed method is notably promoted in comparison with other controllers presented for quadruple tank process.