A Vision-Based Self-Calibration Method for Robotic Visual Inspection Systems

A vision-based robot self-calibration method is proposed in this paper to evaluate the kinematic parameter errors of a robot using a visual sensor mounted on its end-effector. This approach could be performed in the industrial field without external, expensive apparatus or an elaborate setup. A robot Tool Center Point (TCP) is defined in the structural model of a line-structured laser sensor, and aligned to a reference point fixed in the robot workspace. A mathematical model is established to formulate the misalignment errors with kinematic parameter errors and TCP position errors. Based on the fixed point constraints, the kinematic parameter errors and TCP position errors are identified with an iterative algorithm. Compared to the conventional methods, this proposed method eliminates the need for a robot-based-frame and hand-to-eye calibrations, shortens the error propagation chain, and makes the calibration process more accurate and convenient. A validation experiment is performed on an ABB IRB2400 robot. An optimal configuration on the number and distribution of fixed points in the robot workspace is obtained based on the experimental results. Comparative experiments reveal that there is a significant improvement of the measuring accuracy of the robotic visual inspection system.

[1]  Kevin L. Conrad,et al.  On the Accuracy, Repeatability, and Degree of Influence of Kinematics Parameters for Industrial Robots , 2002 .

[2]  Hanqi Zhuang,et al.  Calibration of stewart platforms and other parallel manipulators by minimizing inverse kinematic residuals , 1998, J. Field Robotics.

[3]  Ilian A. Bonev,et al.  A new method for measuring a large set of poses with a single telescoping ballbar , 2013 .

[4]  Wisama Khalil,et al.  Modeling, performance analysis and control of robot manipulators , 2007 .

[5]  Dinesh K. Pai,et al.  Programming and control of robots by means of differential algebraic inequalities , 2000, IEEE Trans. Robotics Autom..

[6]  Tom Duckett,et al.  3D modeling of indoor environments by a mobile robot with a laser scanner and panoramic camera , 2004, 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566).

[7]  Louis J. Everett,et al.  A study of kinematic models for forward calibration of manipulators , 1988, Proceedings. 1988 IEEE International Conference on Robotics and Automation.

[8]  Tadeusz Szkodny.  The sensitivities of industrial robot manipulators to errors of motion models' parameters , 2001 .

[9]  Wisama Khalil,et al.  Self calibration of Stewart-Gough parallel robots without extra sensors , 1999, IEEE Trans. Robotics Autom..

[10]  Mumin Song,et al.  Overview of three-dimensional shape measurement using optical methods , 2000 .

[11]  Bahram Ravani,et al.  An overview of robot calibration , 1987, IEEE Journal on Robotics and Automation.

[12]  Santiago Garrido,et al.  Accuracy and Calibration Issues of Industrial Manipulators , 2006 .

[13]  Consolatina Liguori,et al.  Subpixel location of discrete target images in close-range camera calibration: a novel approach , 2007, Electronic Imaging.

[14]  Wei Yang,et al.  Robust and Accurate Surface Measurement Using Structured Light , 2008, IEEE Transactions on Instrumentation and Measurement.

[15]  Jun Ni,et al.  Self-calibration method for robotic measurement system , 1999 .

[16]  Samad Hayati,et al.  Improving the absolute positioning accuracy of robot manipulators , 1985, J. Field Robotics.

[17]  Johan A. P. Kjellander,et al.  An Integrated Platform for 3D Measurement with Geometric Reverse Engineering , 2009 .

[18]  Jorge Santolaria,et al.  Kinematic parameter estimation technique for calibration and repeatability improvement of articulated arm coordinate measuring machines , 2008 .

[19]  Ilian A. Bonev,et al.  Absolute calibration of an ABB IRB 1600 robot using a laser tracker , 2013 .

[20]  John M. Hollerbach,et al.  Autonomous calibration of single-loop closed kinematic chains formed by manipulators with passive endpoint constraints , 1991, IEEE Trans. Robotics Autom..

[21]  Giovanni Legnani,et al.  Three methodologies for the calibration of industrial manipulators: Experimental results on a SCARA robot , 2000, J. Field Robotics.

[22]  Robert P. Judd,et al.  A technique to calibrate industrial robots with experimental verification , 1987, IEEE Trans. Robotics Autom..

[23]  Jigui Zhu,et al.  Calibration technology in application of robot-laser scanning system , 2012 .

[24]  Johan A. P. Kjellander,et al.  An industrial robot and a laser scanner as a flexible solution towards an automatic system for reverse engineering of unknown objects , 2004 .