In this article, a novel intelligent online tip-over avoidance algorithm is presented considering the interactions between the mobile base and manipulator arm. To this end, the newly suggested dynamic stability margin measure named Moment-Height-Stability (MHS) is adopted. Additionally, a function representing the increment of postural stability margin metric is defined based on MHS. The system dynamic equilibrium is then enhanced using a fuzzy logic approach. The response of the suggested method of this paper is compared with that of a previously Force-Angle based proposed one considering a planar mobile manipulator. First the dynamics of the robot is derived using Newton-Euler method via MAPLE 16 and it is verified through the model provided in SimMechanics toolbox of Simulink. The efficiency of the suggested method is illustrated in comparison to the previous one on a destabilizing robot path. Besides, the performance of proposed method of the present study is investigated in the presence of external disturbances. The obtained simulation results reveal the effectiveness of the performance of the suggested technique for stability improvement of wheeled mobile manipulators once encountering unexpected disturbing situations.