A new dynamic point specification approach to optimise surface mount placement machine in printed circuit board assembly

Abstract

Some factors that significantly contribute to the overall assembly efficiency of the placement machines are robot motion control, sequence of placement points and feeder setup. Many techniques have been developed to improve the sequence of placement points and/or the feeder setup for the PCB assembly process. However, a limited number of works have reported on improving the robot motion control. This paper proposes a revised dynamic pick-and-place point (DPP) specification approach called Chebychev DPP (CDPP). We formulate a problem for a placement machine that is a type of cartesian robot which is able to move in both X and Y directions concurrently. The formulations are constructed based on the triple objectives of minimising robot assembly time, feeder movements and PCB table movements. Experimental results show that our CDPP is superior to Wang's DPP approach in terms of robot assembly time, feeder movements and PCB table movements.