含认知不确定性的汽车制动器系统稳定性研究

Stochastic uncertainties and epistemic uncertainties associated with friction properties, contact properties, wear conditions and material aging widely exist in automotive brake systems. The brake system stability is very sensitive to these uncertain factors. Small variations of uncertain system parameters can lead to great changes in system stability by their coupling effects. A deterioration of brake stability may result in brake noise. In this project, the generation of the epistemic uncertainties existing in a brake is explored firstly, and the stochastic and epistemic uncertainties existing in the brake are represented by combining stochastic model with epistemic uncertain models (including interval model, fuzzy model and evidence model). Based on these uncertain models, the stability analysis models of brake system considering epistemic uncertainties are developed, in which the effects of different uncertain parameters on system stability are investigated. Then, based upon these stability analysis models, the corresponding stability optimization models of the brake system considering epistemic uncertainties are established, and the optimization algorithms and optimization procedures are accordingly put forward. By these optimization models, the optimization designs for improving the brake system stability are explored. Finally, comprehensive comparisons among the proposed approaches and the traditional approaches on the studies of brake system stability are carried out to reveal their research features, application scopes and transformation relationships, so as to provide useful references for their engineering applications. This project will be a good complement to the researches on brake noise control, and has important theoretical significances and practical applications.

汽车制动器系统广泛存在着与摩擦、接触、磨损和材料老化等密切相关的随机和认知不确定性。制动器系统稳定性对不确定性因素非常敏感，不确定参数的较小变化，可通过耦合作用使系统稳定性产生较大变化，进而可能引发制动噪声。项目拟探讨汽车制动器中认知不确定性的产生机制，并将随机模型分别与区间、模糊和证据理论模型相结合，有效处理同时存在于制动器的随机和认知不确定性；在此基础上建立相应的含认知不确定性的制动器系统稳定性分析模型，并分析各类不确定参数对系统稳定性的影响规律；进一步建立相应的含认知不确定性的制动器系统稳定性优化模型，提出相应的优化算法及流程，并对系统进行优化设计；最后将提出的研究方法与传统方法进行全面的对比研究，揭示其分析特点、适用范围和转化关系，为各类研究方法的工程应用及选择提供参考依据。研究工作将对面向制动噪声控制的汽车制动器系统稳定性研究理论体系进行补充和完善，具有重要的理论意义与应用价值。

汽车制动器系统广泛存在着各类认知不确定性，建立有效的含认知不确定性的制动器系统稳定性分析与优化方法体系，是目前制动噪声控制领域的重要研究内容。项目针对制动器系统参数未知但有界的不确定情形，基于区间理论提出了含区间不确定性的制动器系统稳定性分析与优化方法，有效规避了工程设计中对系统部分参数的统计特性进行近似和假设所引起的设计风险；针对制动器系统存在模糊特性的不确定情形，基于模糊理论提出了含模糊不确定性的制动器系统稳定性分析与优化方法，有效处理了工程设计中系统可能存在的模糊特性或模糊评判准则；针对制动器系统参数存在不精确信息的不确定情形，基于证据理论提出了含证据不确定性的制动器系统稳定性分析与优化方法，有效处理了工程设计中系统可能存在信息不完整性、差异性、多源性，甚至冲突性的复杂情形；基于统一分析与优化模型的思想内涵，提出了几种制动器系统稳定性分析与优化研究的统一方法，在统一框架内对比研究了不同不确定情形下的系统稳定性分析方法，为各类研究方法的工程应用及选择提供了参考依据。项目的研究工作对面向制动噪声控制的汽车制动器系统稳定性研究理论体系进行了有效补充和完善，有助于提高我国汽车工业的自主研发水平，具有重要的理论意义与应用价值。