Key Techniques On New Type Laser Target Pose Measurement System

Object pose measurement has been widely used in engineering application, main method including: image visual method, inertial guidance method, prism method and laser target method. To overcome problems in current pose measurement system, such as limited measurement range, low precision and poor portability, the paper demonstrates a new type laser target pose measurement system. Design a laser target based on embedded system, which can achieve pose measurement cooperating with a total station. Embedded within Linux platform, the paper proposes a spot center positioning algorithm based on barycenter method, connected component labeling and edge recognition. Define the coordinate system of laser target measurement system. Propose an attitude resolving algorithm based on camera calibration and determination of relative relations of camera coordinate system and laser target coordinate system. Tested by experimental results, the system has high stability and precision, the overall error is less than 1 mm in confirmatory experiment which used a 2 meters long rigid body to simulate object. Demonstration result indicates that the new type laser target measurement system is well matched demands of pose measurement in industrial engineering, has an extensive applied foreground.The main works and innovations of this paper are summarizd as follow:1. Widely study pose measurement system used in engineering application, summarize the advantage and weakness of current systems, make clear the research direction and aim. Propose a new type laser target measurement system.2. Complete development of the laser target. Achieve miniaturization of laser target and guarantee good portability of the system by optimizing hardware design. Select embedded Linux as platform after comparing variety of embedded system and program the application program of laser target.3. After comparing variety of spot center extraction algorithm and considering laser target's requirements to the algorithm, choose barycenter method as core, achieve an algorithm which has high repeatability precision and good robustness.4. Define the coordinate system of laser target measurement system. Accomplish camera calibration and determine the relative relations of camera coordinate system and laser target coordinate system. Build up the one to one mapping relationship of spot position and angle of incident laser in laser target coordinate system; propose an attitude resolving algorithm based on the relationship.5. Set up experimental platform, validate and analyze measurement precision of laser target measurement system.