Moment-Height Stability Measure for Wheeled Mobile Manipulators

Tipping-over is one of the most important problems in mobile manipulators especially when manipulating heavy objects, also during maneuvers in unknown environment or in rugged terrains. Therefore, estimation and evaluation of dynamic stability with appropriate easy-computed measure throughout the motion of such systems is a challenging task. In this study a new effective tip-over stability measure named as Moment-Height Stability (MHS) measure is presented for wheeled mobile manipulators. The suggested MHS measure can be effectively used for both legged robots and mobile manipulators. Finally, two case studies are presented to demonstrate the new MHS measure performance compared to the ZMP measure results. The obtained simulation results show the merits of the new proposed MHS measure, in terms of prediction the exact time of instability occurrence, without additional precautions which may confine the maneuverability of the system and its operation.