Design Of Vehile Body Dimension And Geometry Error Detection System

Nowadays, our country rail transit is developing with a fast pace. The traditional railway vehiclebody detection means are inefficient, and have a low degree of automation and low precision. It is notgood enough to meet the vehicle manufacturing needs. Geometry precision of the vehicle body is thekey to improve the vehicle manufacturing level and ensure the security and stability of our vehicle.Therefore, to improve the detection precision and the degree of automation is the only way for thedevelopment of rail transit.In this paper a gantry three coordinate measuring system based on laser ranging was raisedaccording to the characteristics of domestic rail vehicle body which can realize the automaticdetection of vehicle body accurately and efficiently. Precisive linear guide rail is laid on the directionof the body length direction. Portal frame is assembled on the linear guide rail across the detectionstation. Laser ranging sensors are assembled on the gantry beam and gantry columns, and on thebottom of detection station. PC controls servo motor to drive gantry do synchronous movementthrough the Motion Card. Data detected by the laser ranging sensors transported to PC through dataacquisition card, then PC calculate the data to coordinates of the vehicle body which can realize thesize and geometry detection of the whole vehicle body automaticly.This paper analyses the detection principle and related hardware of the measuring system.According to the measurement requirements the design and analysis of the whole mechanical part isdetailed discussed. Model selections of the system observe and control part and simulation of thecontrol strategy are analyzed in detail. Multibody system error theory is used to do multi-bodydynamics simulation of the whole control system, and through simulation the source of detection errorand the reliability of the whole system are analysised.