Friction generated limit cycles

This paper treats limit cycles caused by friction. The goal has been to exp lain phenomena that have been observed experimentally in mechatronic system s. Experiments have shown that oscillations of qualitatively different type s can be obtained simply by changing controller specifications, Stiction is important in some cases but not in others. Necessary conditions for limit cycle are given for the case where stiction is important, Conditions for lo cal stability of the limit cycles are also presented. The results give insi ght into phenomena observed experimentally.