الفهرس | Only 14 pages are availabe for public view |
Abstract For both rigid bodies and multibody systems sliding on a rough surface, a range of uncertaintyor non-uniqueness of solution could be found, which is termed: Painlevé paradox. Painlevéparadox is the reason of a wide range of undesired bouncing motion, observed during sliding.As Painlevé paradox is a practical problem in case of multibody systems, this thesis hasinvestigated that paradox. In this thesis, the condition leading to Painlevé paradox has beenreviewed for a general manipulator. To clarify the factors that affect the Painlevé paradox, aparametric study has been performed on two sliding robots; (P-R) and (R-P) robot. Thisparametric study investigated the effect of links’ length and mass ratios. The effect of thevertical distance between the robot base and the sliding surface, and the coefficient of frictionhave been illustrated, as well. To solve the paradox and determine the motion, a tangentialimpact is assumed at the contact point. The impact model has been developed and the paradox,consequently, has been solved, additionally, the robot’s kinematics have been determined.According to the parametric study and the paradox solution, some important recommendationshave been suggested to escape the paradox both in robot design process and in the operation. |