Design of a PLC-Based Conveyor Sorting System with Color and Size Detection for Small-Scale Manufacturing

Sorting products by color and size is a frequent task in packaging and quality control, and small manufacturers need low-cost solutions. This paper presents the design of a PLC-based conveyor sorting system that classifies objects by color and size and diverts them into separate outputs. Detection signals are combined with item tracking by timing or encoder pulses, and diverters are actuated at the computed moment. The sorting accuracy and throughput are evaluated. In simulation the system sorted 98.6 % of 2838 test objects correctly by color and size, rejected 100 % of unclassifiable objects and reached up to 267 objects per minute.