Sliding Mode Control Devoid of State Measurements

An input-output approach is presented for sliding mode control of linear and nonlinear switched systems of the differentially flat type. Two sliding mode control design options are presented: (1) a Delta-Sigma modulation implementation of a robust continuous output feedback controller design, such as the Active Disturbance Rejection Control scheme and (2) An Integral reconstructor-based approach, involving a suitable linear combinations of iterated integrals of the available system input and the measured output of the system. These reconstructors provide the synthesis of a suitably compensated stabilizing sliding surface coordinate function for stabilization or trajectory tracking problems. The relation of the second approach with Delta-Sigma modulation is also established. Two experimental case studies are presented including nonlinear mechanical plants: An under-actuated convey crane and a DC-motor-Single-link manipulator system.