Applied Research of Hierarchical Multi-objective Optimization Method in High Speed and High Precision Placement Machine

In practical engineering, placement optimization of multi-head in the high speed and high precision Surface Mount Technology (SMT) is a multi-objective optimization problem. It mainly includes the feeder distribution optimization, the component placement sequence optimization and the nozzle configuration optimization. Optimization problems are complicated and mutual coupling between them. In this paper, the hierarchical multi-objective optimization model is developed. In the hierarchical structure, the nozzle optimization is constructed as a 0-1 integer programming optimization model for the first master hierarchy. In the second hierarchical, component mounting sequence, feeder optimization and picking order are parallel optimized based on the first hierarchy optimization. The respective problems related algorithm strategies have been proposed. The engineering experiments show that this hierarchical multi-objective optimization method can significantly improve the overall performance of the multi-head placement machine with high speed and high precision.