Comprehensive Evaluation of Hydrodynamic Retarders with Fuzzy Analytic Hierarchy Process and Improved Radar Chart

The braking performance of hydrodynamic retarders is critical for the safety and economy of heavy-duty vehicles. In order to effectively improve the braking system to meet the needs of the market, an evaluation method for quantifying the performance of hydrodynamic retarders is imperative. In this paper, ten evaluation criteria are put forward according to relevant national standards and market requirements, then the scores corresponding to these criteria are obtained by performance bench test. A fuzzy modification of the analytic hierarchy process (AHP) method is applied to determine the relative weights of the chosen evaluation criteria, where uncertain and imprecise judgments of decision-makers are translated into fuzzy numbers. Furthermore, the improved radar chart method is used to comprehensively evaluate and rank the braking performance of three types of hydrodynamic retarders as an empirical example. In addition, the weight sensitivity analysis is conducted to examine the robustness of the ranking results. The results show that the proposed method is effective and feasible. It provides a reference for multi-objective optimization control strategies and structure designs of hydrodynamic retarders.