Effect of Novel Postural Stability Strategies on Lower Body Joint Forces during Stair Climbing with ASR-EXO

The exoskeletons and the postural stability strategies implemented on them should guarantee the health and safety of the users. Many of these users are those patients who are suffering from joint disorders and need a reliable orthosis ensuring that this exoskeleton does not harm their already damaged joints. In this regard, the newly posited postural stability strategies of Centroidal Moment Pivot (CMP), Trunk’s Angular Jerk (TAJ) and Trunk’s Translational and Angular Acceleration (TTAA) need to be examined to see whether they are healthy for joint angles or not? To this end, an MSC ADAMS-Matlab co-simulation is presented in this research to examine this matter. Finally, the contact forces of the lower limb joints were extracted for each of the strategies and compared. The model under the control of the CMP, TAJ and TTAA strategies can preserve their postural stability for 9, 17 and 12 stairs respectively. All the strategies are completely healthy for the joints because the exoskeletons bear a large portion of the joint contact forces. With this in mind, the effect of the postural stability torques would be divided between the subject’s joints and the artificial joints of the robot.