Design And Research Of A Robotic Mobility Platform With Variable Wheel-tracked Structure For The Elderly And Disabled

With Worsening of aging population and a growing number of disabled population, it has brought a significant impact on our Socio-economic development and social harmony and stability. To give them more care and provide Convenience for their traveling, so studying and developing all kind of robotic mobility platforms for the elderly and disabled to help them climbing stair or step is significant.Through analysis and study of rocker systems of wheel, layout of wheel and Crawler, a new structural concept on robotic mobility platforms for the elderly and disabled was proposed in this paper. Based on this, Wheel-tracked transformable structure and working principle of conversions on mobile platform were studied in this paper. Three-dimensional model of robotic mobility platforms was created in software Pro/Engineer and the main components’ parameters on material and size of robotic mobility platforms was given for prototype development.In allusion to two kinds of travel agencies of robotic mobility platforms, nonholonomic constraints kinematic model of wheel travel agency was established and the ways of linear motion and steering movement was discussed. Two kinds of ways to climb stair and step with wheel-tracked cooperative or track was Proposed, Motion Mechanism on stair climbing with two kinds of ways was analysis from the viewpoint of kinematics,and the Mathematical model of critical conditions was established.Through the numerical simulation, theoretical value of mobile platform to climb stair and step with wheel-tracked cooperative or track was analyzed and compared, and was verified by virtual simulation with Multibody system optimization software RecurDyn. The result show that the wheel-track cooperative have a better capacity on climbing,and the practicability of wheel-tracked cooperative robotic mobility platforms for assisting the elderly and disabled was verified.In allusion to stability of robotic mobility platforms to climb stair with wheel-tracked cooperative ways, dynamic equation of the critical attitude was built, and dynamic stability criterions of the robotic mobility platforms contacting stair steps in one point, two and three points are obtained in the process of climbing stairs. Range of angular velocity and angular acceleration of the driving wheels was given in the results, when robotic mobility platforms contact with stair steps in one, two or three points. The results indicated that action plan of wheel-tracked cooperative ways was reasonable, and theoretical basis was provided for Control realization of the robotic platform on stair climbing with wheel-tracked cooperative ways.