采用遗传算法的PDC钻头侧向力平衡优化设计

PDC钻头侧向力平衡优化设计时，散布式钻头与刀翼式钻头相比优化对象数目大幅度增加，最优解搜索空间成指数增长。为了突破PDC钻头结构对侧向力平衡优化设计的限制，采用比率选择、单点交叉、均匀变异和代沟操作等多项技术，利用遗传算法建立了PDC钻头侧向力平衡优化设计方法。利用该方法对刀翼式和散布式PDC钻头进行了侧向力平衡优化设计，优化后侧向力与钻压比值小于1／1000，算法收敛速度快，且算法复杂度受刀翼数量和切削齿数量影响较小。

Optimization design of lateral force balance of PDC bits by genetic algorithm

While optimizing PDC bits structures in terms of the lateral-force balance, the number of objectives to be optimized for a scatter-arranged bit is much more than that of a blade one, thus the searched scope for the optimum solution grows at exponential scale. In order to break the limit to optimization design of lateral force balance from bit structures, a new optimization design method by genetic algorithm was developed, which employed algorithms of proportional selection, single point crossover, uniform mutation and generation communication. A blade bit and a scatter one were optimized by this method. The ratio of lateral force to weight on bit is less than 1/1 000. The convergence rate of the method is rapid, and its computational complexity is not affected by the number of blades or cutters too much.