Research On Reliability Evaluation Method Of Rice Transplanter

Rice is the largest food crop in China,and mechanical transplanting is crucial to meet the actual needs of rice planting and production.However,due to the late start of China in the field of agricultural machine reliability research,there is currently less research on the reliability of rice transplanter,and the existing research mainly focus on the key components of the equipment,resulting in the lack of matching and innovation of existing methods applied for the reliability evaluation of rice transplanter system,which make a large error in the results.Therefore,this paper conducts in-depth research on the reliability evaluation method of rice transplanter.The main contents are as follows:(1)The reliability evaluation method for rice transplanter based on improved FMEA is proposed,which is used to achieve qualitative reliability evaluation of rice transplanter.Firstly,the assessment information of FMEA team members is intuitively fuzzy transformed,the subjective weight of risk factors and team members are determined by the trapezoidal fuzzy AHP method,and the objective weight of risk factors is determined by the normal distribution.Secondly,the IFWA operator is used to summarize the assessment information.Then,the intuitive fuzzy TOPSIS method combined with the principle of maximum risk are adopted to the ranking of risk priority.Finally,the proposed method is applied to the original failure data of Z-type rice transplanter,and the risk priority ranking of failure mode of rice transplanter is obtained,which provides a reference for the subsequent reliability evaluation of the rice transplanter.(2)The reliability evaluation methods for rice transplanter based on single model are proposed which are used to achieve quantitative reliability evaluation of rice transplanter.Firstly,according to the qualitative evaluation results,a reliability model based on the triple hybrid Weibull distribution is constructed,and the unknown parameters of the model are solved by using the maximum likelihood method and the BA algorithm.Secondly,a reliability model based on SVR is constructed,and the optimal parameters are obtained.Finally,the proposed single reliability models are used to predict the reliability of Z-type rice transplanters respectively.Experimental results show that the reliability evaluation accuracy of the reliability model based on SVR model is higher.(3)The reliability evaluation methods for rice transplanter based on fusion model are proposed,which are used to improve the prediction accuracy of reliability model.These single models are linearly weighted fusion,and the fixed weight fusion model and variable weight fusion model are constructed.The fixed weight is calculated by the average method,inverse-sum of squared error method,inverse-root sum of squared error method,respectively,and the variable weight is solved by BA algorithm.Finally,the reliability of the Z-type rice transplanter is predicted by using the above fusion models,and the model performance is evaluated.Experimental results show that the prediction performance of the variable weight fusion model is the best,and the inverse-sum of squared error method is the best in the fixed weight fusion models,followed by the inverse-root sum of squared error method,and the average method is the worst.(4)The proposed quantitative reliability evaluation methods are compared and analyzed.Combined with the RMSE and MAPE of the reliability prediction results of each model,the reliability change curve and the prediction error change curve,the performance of proposed methods are compared and analyzed.The model accuracy is derived from high to low: variable weight fusion model,fixed weight fusion model(inverse-sum of squared error method),SVR model,fixed weight fusion model(inverse-root sum of squared error method,average method),and hybrid Weibull distribution model.The results of this paper can not only provide a certain reference basis for farmers or maintenance personnel to make maintenance decisions of rice transplanter,but also point out the direction for the design and improvement of rice transplanter products.