Dynamic Modeling And Simulation Application Of Pneumatic Damping Knee

Knee is the most important part of trans-femoral prosthesis.Domestic prosthesis knee has been able to complete some of the basic functions.In order to meet the needs of patients,the performance of the knee joint should be improved.In general,physical prototype is used to improve its performance as the experimental object.But in some special cases,the experiment has some risk.Application of virtual prototype can improve the problem.The simulation platform is established based on pneumatic damping knee.The main contents of this paper are:Firstly,the dynamic model of the four bar pneumatic damping knee was established.A simplified virtual prototype was established based on the mechanism analysis.Essential structures were added on the knee to compose a complete prosthesis,such as socket and so on.Then the dynamic model of the whole prosthesis was established.Secondly,a virtual prototype was established with Adams,and its physical parameters were set based on the physical prototype.Controllers were added with Matlab.All the components composed a simulation platform.The platform was verified with the data measured by VICON MX.And the result of the platform was correspond with the facts.Finally,the platform was applied in three situations.One was for the improvement of the control.Simulated with the virtual prototype can reduce the risk of experiment.Applied the result from the virtual platform on the physical prototype,times of motor operations were reduced and the effective time of battery was prolonged.Another one was try to merge the gait pattern with the prosthetic control.Surface EMG signal was added to the platform to predict the next gait.Based on the analysis of the simulation,suggestions were given on the establishment of dynamic knee.The last was for the improvement of the design parameters of prosthetic components,such as the choice of spring coefficient and the increase of the sensor.In a word,a simulation platform was established based on the physical prototype.The results obtained by the simulation platform can provide theoretical guidance for the physical prototype experiment,which can reduce risk and raise efficiency.