一种计算步行式底盘局部结构载荷的优化方法

为确定步行式底盘局部结构在作业时的最大受力状态，对底盘结构进行强度设计，建立底盘和局部受力结构在作业状态下包含所有位置自由度参数的力学分析模型，提出一种基于响应面法求解底盘局部结构载荷的优化分析模型。用两级优化模型对局部结构的最大受力状态进行优化：第1级优化模型用逐步二次规划法找到局部结构在给定位置参数下的最大受力状态，然后通过正交试验设计构造出局部结构界面最大受力状态与位置参数之间的响应面函数；第2级优化模型用遗传算法求解响应面函数的最大值，并通过二分法不断缩小位置参数的搜索空间，提高响应面函数的逼近水平。研究表明，该优化方法是解决复杂结构系统中多变量优化问题的有效手段，并为步行式机构设计提供理论依据。

OPTIMUM COMPUTATION FOR SOLVING LOCAL STRUCTURE FORCE OF THE WALKING MOBILE CHAISSIS

In order to confirm the maximum forces acting on local structural interface of the walking mobile chassis for the structural strength design,a mechanical model including all position freedom parameters of the chassis under the operating conditions is established.Furthermore,an optimization model for computing the load acting on the local structure using the bi-level optimization model based on response surface model is proposed.In the first level,the maximum forces acting on local structure of the chassis is optimized by using the sequential quadratic programming method at the given a sets of position parameters.The response surface function between maximum forces state in the local structure and position parameters is constructed by using orthogonal design.In the second level,the genetic algorithm is used to optimize the response surface func- tion.A high precision response surface function is obtained by using an iteration procedure,in which the searching volume is reduced by using the bisection method.The results show that the response surface method is an effective technique for multi-variable optimization of the complex structural system.It is also concluded that the proposed method can provide theo- retical basis for designing the walking mobile mechanism.