Abstract
The tip-over instability of an autonomous mobile robot is a significant problem as it can diminish its maneuverability and increase the possibility of damaging the robot and its surrounding environment. For these reasons, it is important to define the stability margin and predict the edge of the tip-over instability considering different robot specifications and environmental conditions. Different stability measures have been developed to evaluate and analyze robot stability margins for diverse conditions. In this work, the Zero Moment Point, Energy Stability Margin, Force-Angle Stability Measure, and Mass-Moment Height Stability Measure methods are considered and applied to different mobile robot architectures including three wheeled, four-wheeled (with rectangular and trapezoidal base surface) and articulated systems. The stability margins are discussed considering the four different stability criteria and evaluating the effect of a sloped surface. Then, the sensitivity of the tip-over instability in relation to the variation of the center of mass height as an important robot configuration parameter is evaluated. Finally, after a theoretical extension of the Force Angle Stability and Mass-Moment Height stability measurement methods, the articulated mobile robot’s stability margin is considered and evaluated.