考虑偏度特征的动态多响应稳健参数设计与优化

研究了具有动态特性的多响应稳健参数设计问题,分析了响应变量往往具有偏度特征的情况,提出了基于多元偏正态分布与响应曲面法相结合的动态多响应稳健优化模型,该模型不仅考虑了动态多响应之间的相关性,而且也考虑了尺度与偏度对动态多响应系统最优性与稳健性的影响。首先,利用非参数检验方法判断在信号因子不同水平下的各响应变量所服从的分布类型;其次,通过构建各响应变量在信号因子不同水平下的联合位置,尺度与偏度的响应曲面模型,进而建立基于多元偏正态分布的期望损失函数;然后,利用混合遗传算法对所构建的综合期望损失函数进行全局优化求解;最后,通过对具体的工业实例进行分析研究,结果表明本文所提出的方法能够有效地解决具有偏度特征的动态多响应稳健参数设计问题。

基于产品质量改进的动态多响应稳健性集成建模策略

文章针对产品质量改进阶段的动态多响应系统稳健性建模问题,阐述了传统田口动态信噪比方法的不足,分析了采用双响应曲面方法进行分别建模策略的优劣,提出了将动态响应的均值与标准差放在统一框架中的集成建模策略,构建了基于集成建模策略的动态多响应稳健参数设计方法。该方法首先依据试验设计表的样本数据得到动态多响应的样本均值与样本标准差,以此构造样本集成响应并作为新响应变量来综合考虑动态多响应的最优性与稳健性;其次,采用似然不相关回归方法进行联合参数估计以考虑动态多响应之间的相关性;最后结合实例进行分析研究。结果表明,所采用的集成建模策略不仅能够考虑动态多响应之间的相关性,而且能够使得动态多响应系统有更为稳健的全局最优解。

动态多响应系统的稳健参数设计

针对动态多响应之间的相关性及试验设计的信息不确定性,提出了一种动态多响应系统的稳健参数设计方法.首先,利用满意度函数对动态系统的敏感度和波动分别进行了度量,在此基础上进行了主成分分析;其次,采用灰色关联分析得到主成分序列与其理想序列的灰色关联度,然后通过TOPSIS方法转换得到综合灰色关联度,并根据综合灰色关联度确定可控因子的最优水平组合;最后,通过两个实例说明了该方法的有效性与优越性.

面向产品质量改进的动态多响应系统相关关系特征分析与建模研究

研究了产品质量改进阶段动态多响应系统中响应变量与信号因子之间的相关关系特征分析与建模问题,考虑了动态多响应系统的最优性、稳健性以及响应之间相关性,提出了基于响应曲面法的动态多响应稳健优化模型。首先,采用散点图对响应变量与信号因子之间的相关关系特征进行分析判断;其次,从试验设计表的横向维度构建能够反映响应变量与信号因子之间相关关系特征的响应曲面模型;同时,从试验设计表的纵向维度构建响应变量与可控因子之间的响应曲面模型;然后,整合纵横两个维度进而构建综合响应曲面模型并采用智能算法对其进行优化求解;最后,结合两个实例进行分析研究。结果表明本文方法不仅能够真实地反映实际系统中响应变量与信号因子之间的线性相关或者非线性相关关系特征,同时也能够保持较高的灵敏度以有效地达到便于系统调节或校正的目的。

Nonlinear multi body dynamic modeling and vibration analysis of a double drum coal shearer

The double drum coal shearer is widely applied for the underground coal exploration in the mining industry.The vibration and noise control are significant factors for the stability design of the double drum coal shearer.In this paper,the vibration properties of a double drum coal shearer are firstly investigated.The horizontal,transverse and torsional vibrations of the motor body and the angle displacements of the rockers are taken into account.The walking units and the hydraulic units are modeled by the stiffness-damping systems.The nonlinear equation of motion of the double drum coal shearer is established by applying the Lagrange’s equation.The nonlinear vibration response of the system is calculated by using the Runge Kutta numerical method.The effects of the shearing loads,the equivalent damping and stiffness of the walking units,the inclination angels of the rockers and the equivalent damping and stiffness of the hydraulic units on the vibration properties of the system are discussed.

Dynamic responses of a multilayer piezoelectric hollow cylinder under electric potential excitation

The dynamic responses of a multilayer piezoelectric infinite hollow cylinder under electric potential excitation were obtained. The method of superposition was used to divide the solution into two parts, the part satisfying the mechanical boundary conditions and continuity conditions was first obtained by solving a system of linear equations; the other part was obtained by the separation of variables method. The present method is suitable for a multilayer piezoelectric infinite hollow cylinder consisting of arbitrary layers and subjected to arbitrary axisymmetric electric excitation. Dynamic responses of stress and electric potential are finally presented and analyzed.

Numerical Simulation of the Spreading Dynamic Responses of the Multibody System with a Floating Base

To simulate the dynamic responses of the multibody system with a floating base when the upper parts spread with a certain sequence and relative speed, the homogeneous matrix method is employed to model and simulate a four-body system with a floating base and the motions are analyzed when the upper parts are spread sequentially or synchronously. The rolling, swaying and heaving temporal variations are obtained when the multibody system is under the conditions of the static water along with the wave loads and the mean wind loads or the single pulse wind loads, respectively. The moment variations of each joint under the single pulse wind load are also gained. The numerical results showed that the swaying of the floating base is almost not influenced by the spreading time or form when the upper parts spread sequentially or synchronously, while the rolling and the heaving mainly depend on the spreading time and forms. The swaying and heaving motions are influenced significantly by the mean wind loads. The single pulse wind load also has influences on the dynamic responses. The torque of joint 3 and joint 4 in the single pulse wind environment may be twice that in the windless environment when the system spreads with 60 s duration.