以降低直臂式高空作业平台变幅系统的油缸最大推力和提高变幅动作的平顺性为优化目标,首先进行变幅机构的工作原理分析和油缸推力数学建模,并通过试验测试验证了数学模型的准确性,然后在此基础上确定优化问题的设计变量、约束条件和目标函数的表达式,采用NSGA-Ⅱ(快速非支配排序遗传算法)对此多目标优化问题进行求解,得到Pareto前沿优化解集,利用基于信噪比的综合满意度函数对解集进行评价,选出满意度最高的解,最后由优化前后的结果对比可知：以较高精度的数学模型为基础的优化设计使变幅油缸最大推力降低了10.8%,每变幅1°的最大油缸位移变化率降低了28.4%,油缸行程减小了2.1%。

Aiming at reducing the maximum thrust of the cylinder and improving the smoothness of the luffing action of the straight-arm aerial working platform, firstly, the working principle of the amplitude changing mechanism and the mathematical modeling of the cylinder thrust were analyzed, and the accuracy of the mathematical model was verified through tests, then, the design variables, constraints and objective function expressions of the optimization problem are determined on the basis. NSGA-Ⅱ( fast non-dominated sorting genetic algorithm) was used to solve the multi-objective optimization problem, and Pareto front optimal solution set was obtained. The comprehensive satisfaction function based on signal-to-noise ratio was used to evaluate the solution set, and the solution with the highest satisfaction was selected. Finally, by comparing the results before and after optimization, it can be seen that the optimal design based on the high-precision mathematical model reduces the maximum thrust of the luffing cylinder by 10.8%, the maximum displacement change rate of the cylinder for each 1° of luffing decreases by 28.4%, and the cylinder stroke goes down by 2.1%.

国家自然科学(51875048)；长沙市科技重大专项项目(kh2301017)。