A comprehensive evaluation method of diesel engine sound quality based on paired comparison, uniform design sampling, and improved analytic hierarchy process

The paired comparison (PC) is an easy and effective way to distinguish the nuances among sound stimuli of diesel engine in sound quality subjective evaluation. However, the PC method is inefficient for the subjective evaluation of large quantities of stimulus or to rank the results of overall perception of sound stimuli. To overcome the shortcoming of the PC method, this paper presents a comprehensive evaluation method of diesel engine sound quality based on the PC method, uniform design sampling (UDS), and the improved analytic hierarchy process (AHP). An hierarchical tree of comprehensive evaluation models of diesel engine sound quality is constructed and simplified through UDS to ensure that the sound sample size is in the application range of the PC method or the grouped paired-wise comparison (GPC) method. An improved AHP is developed by introducing a new method calculating the relative weight based on evaluators' preference order instead of the traditional 1-9 scale method, which reduces subjective liberty and difficulty of the consistency of the judgment matrix meeting the requirement, and the requirements of evaluators' specialized knowledge. With three diesel engines' noise stimuli as example, a realization of sound quality comprehensive evaluation based on UDS-AHP method with the GPC method is introduced. The results show that the proposed subjective comprehensive evaluation method can accurately provide the ranks of the sound stimuli over all subjective perception with a significant decrease of the evaluation workload.