Composite Control Based on Robust Disturbance Interval Estimation for Nonlinear Systems With Multiple Disturbances and Its Applications

In this paper, a composite antidisturbance control scheme based on (Formula presented.) robust disturbance interval observer (RDIO) is proposed for a class of nonlinear systems with multiple disturbances. Considering the disturbance with uncertainties in asymmetry bounds, different from the existing composite antidisturbance scheme, here a (Formula presented.) RDIO is designed utilizing the uncertainty information to obtain the possible interval of real disturbance, and the disturbance effect is suppressed by compressing the interval for robust performance. The comparison of estimation accuracy of (Formula presented.) RDIO with traditional disturbance observer (DO) is given in theoretical analysis. Furthermore, algorithms for solving the (Formula presented.) RDIO parameters are provided for generalized and specific situations. Based on (Formula presented.) RDIO and integral sliding mode control (ISMC), a composite integral sliding mode controller with disturbance compensation and attenuation ability is proposed to realize the high-precision stabilization. Finally, the effectiveness and superiority of the proposed control scheme are verified by numerical simulation and the application to the motor rotation tracking with hardware-in-loop (HIL) experiment.