为提高设计稳健性,将6σ稳健优化设计引入车身噪声传递函数优化过程。将6σ质量管理、可靠性设计稳健设计相结合,考虑设计变量、约束条件目标函数在内所有不确定性信息,不仅满足优化目标函数、提高系统可靠性要求,使系统响应均方差最小化,即提高稳健性。以某型汽车为例,在汽车声固耦合有限元模型基础上采用基于试验设计的二阶多项式响应面模型,以车身总质量一阶模态频率为约束条件驾驶员耳旁声压级响应均方根值为目标函数,在基本随机变量概率特性已知情况下对车身噪声传递函数进行6σ稳健优化设计,与传统确定性优化设计相比表明该方法的有效性。

In order to improve the design robustness of the vehicle’s NVH performance,a six sigma robust optimization method was introduced in the optimization design of noise transfer functions.In the method,the influences of various uncertain factors which result from objective functions,design variables and constraint conditions were considered by integrating the six sigma quality management approach,reliability design approach and robust design approach in the optimization design process.Not only the proper optimal solution and reliability of the system were achieved but also the robustness of production design process was improved.Based on the acoustic-structure coupled finite element model and the quadratic response surface approximate model,the proposed method was implemented to optimize the noise transfer function of a car body.In this numerical example,the probabilistic characteristics of the design variables were assumed to be known,the total mass and the first natural frequency of the

针对不确定参数发动机悬置系统的优化问题,基于区间分析理论,将稳健设计与多目标优化相结合,提出一种提高发动机悬置系统隔振性能的稳健优化设计方法。该方法在区间数学模型的基础上建立悬置系统稳健优化模型,以动反力及其变化范围最小为目标函数,固有频率的合理配置为约束条件,悬置刚度为优化变量,并将悬置刚度和悬置位置的波动范围作为区间参数变量,对某型轿车发动机悬置系统进行稳健优化设计。结果表明,该方法改善了悬置系统的隔振性能,提高了系统参数的稳健性。

Aiming at the optimization issue of engine mount system with uncertain parameters, based on the theory of interval analysis, a robust optimization design method for enhancing the vibration isolation performance of engine mount system is proposed by combining robust design with multi-objective optimization. With the method, a robust optimization model for engine mount system is established based on interval mathematical model. Then with minimizing dynamic reaction forces and their variation range as objectives, the rational allocation of natural frequen-cies as constraints, the stiffness of engine mount as variables and the variation range of mounting location and stiff-ness as interval parameter variables, a robust optimization design for the engine mount system of a car is conducted. The results show that with the method proposed, the vibration isolation performance of engine mount system is im-proved and the robustness of system parameters is enhanced.

采用传统的确定性优化方法对半挂汽车列车行驶平顺性进行设计时,由于忽略了不确定因素导致设计变量波动情况,从而获得的优化结果可靠性低。建立了9自由度的半挂汽车列车平顺性模型,在考虑设计变量波动的基础上,建立了基于容差模型的稳健优化数学模型。将优化结果与确定性优化结果对比可知,两种方法均提高了平顺性能,但是稳健性优化可靠度更高。

When traditional deterministic optimization is applied in the design of semitrailer train ride comfort, low reliability is produced due to neglect of uncertainty which causes design variable fluctuation. 9-DOF of semitrailer train ride comfort model is established, and based on the consideration of design variable fluctuation, a robust optimized mathematics model based on tolerance model is established. The optimization results are compared with deterministic optimization results, which show that both of the two methods improve ride comfort, whereas the robust optimization has better reliability than the traditional deterministic optimization design.

为改善动力总成悬置系统的隔振性能,以某车辆的悬置系统为研究对象,在扭矩轴坐标系下建立6自由度振动分析数学模型,阐述能量解耦的计算方法。以悬置系统振动解耦率和固有频率分布为设计目标,以悬置刚度为设计变量,采用遗传算法对该悬置系统进行优化设计,并且用蒙特卡罗模拟方法对优化结果进行稳健性分析。结果表明,优化后悬置系统的振动解耦率和频率满足设计要求,且系统设计稳健性较好。

To improve the vibration insulation performance of the powertrain mounting system, we use a mounting system as research object and construct a DOF vibration analysis mathematical model in the torque axis coordinate system, and analyze energy decoupling method. The mounting system is optimized with genetic algorithm with vibration decoupling ratios and natural frequencies as design objectives, and dynamic stiffness of individual mount as design variables. Finally, the design robustness is analyzed by using Monte Carlo simulation method. The results illustrate that the decoupling ratios and frequencies meet the design requirements after optimization, and the design robustness is also satisfactory.

载人登月转移轨道具有飞行时间长，动力学模型复杂，非线性强且变系数的特点，而载人登月工程对转移轨道可靠性要求极高，研究地月转移轨道偏差传播机理和轨道稳健性设计不仅具有工程意义，更具有探索地月空间复杂引力场对轨道偏差作用的科学意义。本文首先分析了日地月中心引力和地球J2项摄动等主要作用力对转移轨道偏差的作用范围与影响大小，其次提出了一种基于标称轨道数据的变系数非线性动力学系统偏差传播机理解析分析方法，最后构建了基于偏差传播矩阵的转移轨道稳健性评价指标，并基于NSGA-II (Nondominated Sorting Genetic Algorithms)算法求解了载人登月转移轨道稳健性优化设计问题。仿真结果表明，本文提出的偏差传播机理分析方法能快速准确地求解出载人登月转移轨道偏差传播矩阵，利用偏差传播矩阵进行协方差分析和中途修正脉冲计算是简单准确的，考虑稳健性的转移轨道优化设计可以提高标称轨道品质。

Earth-moon transfer orbit for manned lunar landing needs a long flight time, complex, nonlinear and variable coefficient dynamics model, and asks for a high reliability. Analysis of deviation propagation mechanism and robust design of transfer orbit are investigated in this paper. It is not only practical for projecting, but also significant for exploring the role of earth-moon space gravitational field upon transfer orbit deviation. This paper analyses firstly the boundary and the amplitude of the sun, earth, and moon central gravitation, the earth J2 perturbation that affect the transfer orbit deviation transmission. And then a method to analyse the deviation propagation mechanism based on nominal orbital data is obtained analytically. A robust indicator of transfer orbit based on deviation transition matrix is proposed,and a robust optimization design method that employs NSGA-II(nondominated sorting genetic algorithms) for earth-moon transfer orbit with robust indicator is proposed.