Chaos suppression control of a coronary artery system with uncertainties by using variable structure control

Nonlinear behavior and the chaos suppression problem are studied in a coronary artery chaotic system. Based on the variable structure control (VSC) theory, the sliding mode control scheme is used to design a chaos suppression controller in this study. A suitable sliding surface is selected to ensure a sliding mode motion of error states when the proposed control law is applied. As expected, the error state drives to zero with matched external uncertainties or into a predictable neighborhood of zero with mismatched external uncertainties. Therefore, suppressing the abnormal chaotic behavior of a coronary artery system to a normal unstable periodic orbit of the nominal coronary artery system can reduce the occurrence of heart disease. A modified continuous sliding mode controller is also proposed to avoid chatter. Illustrative examples are given to demonstrate the superiority of the proposed approach.