Comparing two online tip-over avoidance algorithms for mobile manipulators

In this paper, a real-time intelligent algorithm to avoid tipping-over of redundant wheeled mobile manipulators, taking into account the interactions between the arm and the mobile-base, is presented. To this end, the Moment-Height Stability (MHS) criterion is utilized to predict the toppling down occurrence and to trigger the suggested online stability recovery algorithm. To enhance the dynamic stability of robotic system a Stability Margin Metric-Increment Function (SMMIF) is proposed by which the most effective motion parameters are found to improve the robot dynamic stability. Next a fuzzy logic-based planner is utilized to design the stabilizing movement. Considering a planar mobile manipulator system, the response of proposed algorithm is analyzed and compared with a previous algorithm which is based on the Force-Angle (FA) Stability margin measure. The obtained simulation results indicate efficient performance of the proposed algorithm as compared to the previously proposed one.