# Research on a Comfort Evaluation Model for High-Speed Trains Based on Variable Weight Theory
###### Abstract  
As a result of the continuous improvement in passengers' requirements for the quality of train operation, the comfort of high-speed train operation has been paid increasing attention. The evaluation of comfort has gradually changed from the narrow sense of a comfort evaluation model containing only vibration to the generalized evaluation of passengers' overall satisfaction with the ride environment of specific lines. The factors affecting comfort evaluation include physical, physiological, and psychological aspects. To address the problems that the existing comfort evaluation model has a single index and that the weight determination of some indicators is greatly affected by subjectivity, we built a high-speed train comfort evaluation model based on variable weight theory. Combined with the actual working conditions of the Baolan passenger dedicated line, dynamic detection data and noise monitoring data captured by a track inspection car were combined with a passenger ride comfort questionnaire survey. In addition, the initial weight value of each factor was optimized by constructing an equilibrium function to realize the balance between the various factors, so as to realize the comprehensive fuzzy evaluation of high-speed train comfort. The results show that the comprehensive evaluation result of the comfort degree of the high-speed train on the Tongwei to Lanzhou section of the Baolan passenger dedicated line has a grade of II. The fuzzy scores of the evaluations using variable weights and constant weights were analyzed from the perspective of membership degree. The variable weight optimization avoids the one-sidedness and extremeness of the constant weight calculation. The comprehensive evaluation results are closer to the real situation. The research results can provide a reference for the comfort evaluation of high-speed trains with extreme differences in state values and constant weights and help in the acquisition of more realistic evaluation results. high-speed train; ride comfort; comprehensive evaluation; variable weight theory; comfort evaluation model +
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feelings, and physical feelings. At this point, the relevant factors affecting the comfort of the train were basically considered comprehensively. After basically exploring the influencing factors of train comfort, the corresponding evaluation methods were included in the research agenda. Some scholars have analyzed and explored some of the many aspects involved in the influencing factors, such as for example, using biomechanical knowledge to study the comfort of a single seat [8; 9; 10], using the model simulation method to study the noise in a train [11], and using finite element simulation to study the auditory physiological comfort of a train running in a tunnel [12; 13]. Although these evaluation methods are meaningful for the analysis and exploration of some influencing factors, they ignore the coupling effect of various influencing factors and lack the overall evaluation of comfort. Some scholars have also used the combination of the analytic hierarchy process and entropy weight methods [14] and the fuzzy analytic hierarchy process [15] to analyze and evaluate the comfort of trains involving many influencing factors. Among these approaches, fuzzy logic based on multi-factor index values has been applied in comfort evaluation. The fuzziness of index evaluation is studied using the method of the fuzzy set. By using the membership function relationship to deal with the fuzzy relationship, the uncertainty problem in the process of fuzzy judgment is solved. Similarly, the incomplete consideration of influencing factors and the quantitative difficulties in the evaluation processes lead to some limitations of the research results. Faced with the current situation of evaluation difficulties, researchers have also proposed various solutions. Among the typical studies, [PERSON] et al.