Modeling the manipulator and flipper pose effects on tip over stability of a tracked mobile manipulator

Abstract

Mobile manipulators are used in a number of different applications such as bomb disposal, mining robotics, and search and rescue operations. These mobile manipulators are highly susceptible to tip over due to the motion of the manipulator or the gradient of the slope being traversed by the platform. This paper presents the model of a tracked mobile manipulator for tipover stability analysis in stope mining environments. The Force Angle stability measure is used to compute the stability index of the platform. An environment is simulated using a gradient vector field and a simulated iRobot PackBot platform is modeled moving through the environment. The PackBot manipulator motion is modeled using the forward kinematics of serial structured manipulators. Action of the flippers has the effect of changing the tip over axis and stability index of the platform. The geometry of the platform is used to compute the resultant tip over axis given the angle of the flippers. The overall stability based on the slope of the environment, the manipulator pose and the flipper angle is then computed. The results give new insight into tip over prevention for tracked mobile manipulators.