Control method of elderly-assistant robot for preventing elderly fall

Abstract

The elderly are prone to fall during walking, which not only leads to injury but also can cause permanent disability or even death. Thus, it is crucial for the walking-assistant robot to prevent the elderly from fall during walking. However, the factors affecting the steadiness of the elderly are not considered comprehensively in the existing studies of elderly fall prevention model and control schemes. In this paper, a novel control method of the elderly-assistant robot for preventing elderly fall is proposed by considering the two main factors affecting steadiness of the elderly, namely, position and velocity of the center of mass. Initially, the dynamics of the robot system for preventing elderly fall are derived respectively from different elderly fall situations. Then, the elderly-assistant robot is controlled to stop at an appropriate position, and to minimize the tilt angle as small as possible to avoid overturned. The control system ensures that the position-velocity coordinates of the center of mass of the elderly reach the dynamic steadiness region which guarantees human balance. Finally, the results of the simulation and the experiments show that the proposed control method of the elderly-assistant robot can be effectively used to prevent the elderly fall during walking.