Stabilizing slider-crank mechanism with clearance joints

In general, in dynamic analysis of mechanical systems, joints are assumed to be ideal without clearance. When joint clearance is introduced, dynamic response is considerably changed. Degradation of dynamic performance, reduction in components fatigue life and generation of undesirable vibrations result from impacts of mating parts in clearance joint. More generally, system responses tend to be chaotic and unpredictable instead of being periodic and regular. In this study, a slider-crank mechanism with a revolute clearance joint between the slider and the connecting rod is addressed. It is shown that the system may exhibit chaotic behavior under specific conditions. A control mechanism based on the Pyragas method is presented for stabilizing an unstable periodic orbit embedded in the chaotic attractor. Under a successful control, contact loss is eliminated and the system exhibits periodic motion by applying only small perturbations.