Research On Quality Control And Assembly Sequence Planning Of Wind Turbine Hub Assembly Process

As a mechanical device to convert wind energy into electric energy,the stable operation of wind turbines plays a pivotal role in reforming energy structure and reducing environmental pollution.The hub acts as the connecting part between the wind turbine blade and the main shaft,which performance directly affects the efficiency and life of the wind turbine.The process quality control in assembly manufacturing and assembly sequence planning of hub directly affect the assembly quality and reliability,therefore,the above two study is particularly urgent.With the support of the National Natural Science Foundation of China,this paper took 2.5MW wind turbine hub as the research object,the hub assembly key process identification mathematical model and process quality control chart were established according to the characteristics of multivariety small batch manufacturing mode and positioning layout mode.The Boolean matrix method is used to establish the hub assembly relationship model.Based on the model,the multi-objective evaluation function expression of the assembly sequence is constructed.The hub assembly sequence is optimized by NSGA-II and MODA algorithm respectively,and the two optimization results are compared finally.This study has significant reference value for the quality control of hub assembly process and assembly sequence planning.The main research contents are as follows:(1)The key process identification of the hub assembly under the positioning arrangement mode was studied.Aiming at the hub assembly manufacturing process for the fixed production target and shifting work of the production group for the positioning arrangement mode,the Taguchi quality loss principle was used to determine the mass loss standard for 12 quantitative mass characteristics of the hub assembly.Combined with the 80/20 principle,the mathematical model of the key process identification of the hub assembly was constructed with the improved mass loss function.The results showed that the model can effectively identify the critical processes of hub assembly as “installation of pitch bearings” and “adjustment of eccentricity of pitch reducer”.(2)The similarity evaluation model for hub assembly process based on intuitionistic fuzzy sets was established.In order to solve the problem of insufficient quantity of relevant quality characteristic data in the manufacturing process of the hub assembly,the method for evaluating the similarity of processes based on intuitionistic fuzzy sets was proposed and 13 specific indicators for the 5M1 E factor in the similarity assessment of the hub assembly process was constructed.Based on the membership degree and non-affiliation degree of the intuitionistic fuzzy set,a multi-model wheel assembly process similarity evaluation model was constructed,and the similar processes of the hub assembly were divided into groups;Meanwhile,the conversion and inspection of the 30 sets of quality characteristic data of the hub assembly process wer completed.The research showed that the method can efficiently complete the quality control of the key process of the hub assembly.(3)The hub assembly relationship model and assembly sequence evaluation index and its evaluation function were formed.According to the problem that the traditional hub assembly sequence planning has experience-based,computational workload,low efficiency,etc.Combined with the actual situation of hub assembly manufacturing,comprehensive consideration of factors such as component connection and support,and introduction of the importance of components determined by assembly key processes,the Boolean matrix method was used to establish the hub assembly relationship model;Five parts level,three product level evaluation indicators and the importance of the components determined by the key processes were comprehensively considered,finally three evaluation functions of the hub assembly sequence were constructed.(4)The hub assembly sequence optimization based on NSGA-II and MODA algorithm was researched.The assembly relationship model was taken as the constraint condition,the evaluation function as the optimization goal.The key parameters such as the population number were simulated and analyzed to affect the performance of the two algorithms by adopted the NSGA-II and MODA algorithm to optimize the hub assembly sequence respectively,and then the optimization results of the two algorithms were compared and analyzed.The research showed that NSGA-II is more suitable for hub assembly sequence optimization than MODA,and from which we can obtain the optimal hub assembly sequence and station allocation scheme.