Research On Precise Intersection Of Laser Theodolites

Laser Theodolite measuring system achieve aiming at the target point by laser beam which is concentric with “collimation axis”.It can realize fast,non-contact measurement in large space and large size range,so it has wide application prospects.However,because of the space angle resolution limit of the servo drive system,it is very difficult to ensure that the theodolite "collimation axis" aim at the target point accurately with the increase of the measurement space and size.Then it restricts the application and promotion of laser theodolite system.Under the background of requirement of large size coordinate measuring technology in large equipment precision assembly manufacturing and on the basis of double theodolite measuring system,this paper proposes a method of precise intersection of laser theodolites based on the visualization of laser theodolite "collimation axis".Firstly,control "collimation axis" to scan the target point by minimum stepping angle.Then,obtain the position relationship of the scanning point coordinates and the target point coordinates through image acquisition and image processing.Finally,achieve theodolite aiming at the target point accurately by related algorithm and realize precise intersection of laser theodolites.By laser beam aiming instead of human eye aiming,this method reduces the impacts of manual error and improves the efficiency of measurement.The work details of this paper are as follow:1.With the analysis of the important status and developing prospect of large size coordinate measuring technology in the field of industry and by introducing principles of several large size coordinate measuring systems,we proposes a method of precise intersection of laser theodolites based on the requirement of “intersection” in some large size coordinate measuring systems.2.With the analysis of the theodolite measuring system principle,we introduce the intersection control methods of theodolite system.With the error analysis of imprecise intersection,we propose the basic concept of precise intersection of laser theodolites.3.Based on laser spot feature extraction,target coordinate positioning and the zoom control algorithm of the camera lens,we construct three models to explain how to realize precise intersection of laser theodolites.4.In order to verify the feasibility of the three methods,we carry out simulation and analysis of precision and uncertainty of the system.5.Based on laboratory environment and equipment,we set up a laser theodolite measuring platform and verify the feasibility of the three precise intersection methods by experiments.Finally three methods are analyzed and compared from different angles.