| With the improvement of science and technology and the improvement of public living standards,the traditional manual wheelchair has been unable to meet the living needs of the elderly and the disabled.Therefore,the traditional wheelchair has been gradually replaced by the intelligent wheelchair,intelligent wheelchair compared with the traditional wheelchair has the characteristics of convenient operation,faster speed and so on.However,when driving on some complex roads,the vibration caused by road bumps will cause damage to the body of the elderly and the disabled.Therefore,electric wheelchairs with good comfort and stability can better meet the travel needs of the elderly and the disabled.Based on the research laboratory development fund background,this paper analyzes and evaluates the stability and comfort of the wheelchair-human body system under complex road surfaces,and explores the dynamic response of the human body under vibration excitation by using the finite element human bone finite element model.Firstly,based on the traditional vehicle stability analysis method,the mathematical theory of roll stability and pitch stability of the wheelchair-human system was established,and the maximum roll Angle and pitch Angle of the wheelchair-human system were calculated.The national standard ISO-2631-1 "Vibration and shock: the evaluation of human body exposure to whole body vibration: general requirements" and the subjective psychological annoyance rate index were used to establish the human comfort evaluation system.Secondly,a multi-rigid body dynamics model with human bone and joint stiffness was established based on the multi-body dynamics method,and the wheelchair-human system was simulated and analyzed on the ditch,step and combined road.The acceleration and Euler Angle changes of the human head,chest and the wheelchair truss position were obtained,and the data results were analyzed to evaluate the stability and comfort of the system.Then,a wheelchair test platform was built,and the road driving test was carried out according to the simulation conditions to obtain the system acceleration and Angle data during the driving process,and the simulation analysis was compared to verify the accuracy of the multi-body dynamics method,and the stability and comfort of the system were evaluated.Finally,using the THUMS human fine structure model,a finite element model of human skeleton was established,and modal analysis and random vibration analysis were performed on the model to explore the dynamic response of human skeleton under vibration excitation. |
