The principle analysis and system design for centring of a skip car and a railroad car with rotatable platform are discussed,which are used in a practical project.This project uses multi-vehicles to transport material.Comparing with the imaging method and the measuring method with light-screen,the measuring method of double-distance-sensor is chosen.PLC and the fuzzy control arithmetic are used to control the railroad car to move some distance for centring the skip car and the railroad car.At last,the error...