STICK-SLIP AND CONTROL IN LOW-SPEED MOTION

Dimensional and perturbation analysis are applied to the problem of st ick slip encountered during the motion of machines. The friction model studied is motivated by current tribological results and is appropria te for lubricated metal contacts. The friction model incorporates Coul omb, viscous and Stribeck friction with frictional memory and rising s tatic friction. Through dimensional analysis an exact model of the non linear system can be formed in five parameters rather than ten, greatl y facilitating study and explicitly revealing the interaction of param eters. By converting the system of differential equations into a set o f integrations, the perturbation technique makes approximate analysis possible where only numerical techniques had been available before. Th e analysis predicts the onset of stick slip as a function of plant and controller parameters; these results are compared with experimental d ata.