Study On Landing Attenuation Characteristics And Optimum Design Of Combined Airbags

The attenuation airbag is suitable for complex environment,which has excellent attenuation characteristics,easy to fold and carry.It is used in soft landing of spacecraft and other fields.With the increase of the weight of the device,the requirement for the attenuation performance and reliability of the attenuation airbag system is gradually raised.The phenomena of touching the bottom and bouncing off the ground should be avoided in the landing process of the device.Therefore,the analysis of the attenuation characteristics of the airbag system and the effective design of the combination of the parameters of the airbag are important prerequisites for ensuring the smooth landing of the device.Aiming at the landing attenuation problem of heavy load device,the attenuation characteristics of combined airbag system are studied by numerical calculation method,and the combination of airbag exhaust parameters is optimized by multi-objective optimization design method.Firstly,an airbag model is established based on the control volume method.By comparing the simulation results with the literature data,the validity of the numerical calculation method of attenuation dynamics in this paper is verified;A pea-type combined airbag attenuation system model is established for heavy load device.Through the analysis of attenuation characteristics of the combined airbag during the attenuation process,the conclusion that the combined airbag is suitable for landing attenuation of heavy load device is drawn.Secondly,the fators affecting the attenuation performance of the airbag are determined.The attenuation characteristics of the system under the influence of single variable are studied by numerical calculation method.The effects of the opening time of the vent-hole,the type of the vent-hole,the area of the vent-hole and the initial internal pressure of the external air bag on the motion characteristics,the characteristics of the air bag and the energy characteristics are obtained.Thirdly,based on the previous method of controlling exhaust,the attenuation characteristics of the combined airbag in complex environment are studied by dynamic simulation analysis method,and landing situation of the device is analyzed when the landing surface has a slope,and the second method is proposed for the case of a larger slope of the landing surface;The results show that the combined airbag is suitable for landing attenuation of heavy loading device in complex environment.Finally,the optimal Latin hypercube design method is used to sample the sample space efficiently,aiming at the previous research on the parameters affecting the airbag attenuation performance;The index of rebounding off the ground and touching the bottom of the evaluation device is put forward.Taking the maximum overload value of the device and the specific energy absorption of the airbag system as the objective function,the surrogate models of objective functions are constructed by using the elliptic basis function neural network model,and the accuracy of each surrogate model is verified;Based on the surrogate model,the multi-objective optimization design of the model is carried out by using elitist non-dominated sorting genetic algorithm.The Pareto optimal solution set of the maximum overload value and specific energy absorption of the objective function is obtained;Aiming at the results of multi-objective optimization design,the correctness of multi-objective optimization results is verified by using dynamic simulation method;By comparing the optimized scheme with the original one,it is concluded that the optimized airbag attenuation performance is obviously better than that before optimization.The research results can provide a basis for the design of the airbag system of heavy loading landing attenuation device.