Approach For Calibrating The Position Of Laser Displacement Sensor And Its Application

With the development of robotics and off-line programming technology, the robotic drilling technology becomes widely available in the field of aircraft manufacturing and assembly. Improving the accuracy and quality of the connection hole is important for enhancing the fatigue performance of the aircraft structure and improving the life and safety of the aircraft. The repeatability of robot is well but absolute positioning accuracy is low, so that all kinds of sensors integrated on the end-effector for the compensation of position and attitude error is a key technology to enhance the precision of the robot drilling. Based on robotic automation drilling system, the calibration of the position of the laser displacement sensor mounted on the robot end-effector is studied deeply.In chapter one, introduce the research status of automation drilling and propose the background and significance of this paper. The application and the current situation of the technology of normal adjust in automation drilling is analyzed deeply. Finally, the contents and framework of research is introduced.In chapter two, robot automation drilling system and its components have been described in detail. The method for calibrating the tool coordinate is elaborated. Firstly, introduce the hardware components of robot automation drilling system, including industrial robot, end-effector and laser tracker, then discussing in detail the TCP(tool center point) calibration method based on points, lines and plane.The third chapter presents a method of the calibration of laser displacement sensor mounting position. Conduct theoretical models and simulation comparison experiments for the plane and spherical template methods. Finally, carrying out calibration experiments on platform of robot drilling system based on spherical template method for the verification and validation of the method.The fourth chapter presents a method of optimization for the selection of posture in calibration. Firstly, analyze the factors such as measurement length, measurement error, numbers of calibration parameters. Then introduce the five observability index. Finally, through optimization of the attitude of 2,000 sets of measurements, the best attitudes and best index are obtained; the ability to eliminate noise is improved.The fifth chapter describes the normal measure and normal adjustment method based on the measurement of laser displacement. Firstly, present a method of normal measurement, then analysis the influence of measurement errors to measurement results. Finally, introduce the pose transformation and the method to adjust normal.In the end, summary for the whole work in this dissertation is given, and the future work is discussed.