1st Edition

Camera-Aided Robot Calibration

By Hangi Zhuang, Zvi S. Roth Copyright 1996
    368 Pages
    by CRC Press

    368 Pages
    by CRC Press

    Robot calibration is the process of enhancing the accuracy of a robot by modifying its control software. This book provides a comprehensive treatment of the theory and implementation of robot calibration using computer vision technology. It is the only book to cover the entire process of vision-based robot calibration, including kinematic modeling, camera calibration, pose measurement, error parameter identification, and compensation.

    The book starts with an overview of available techniques for robot calibration, with an emphasis on vision-based techniques. It then describes various robot-camera systems. Since cameras are used as major measuring devices, camera calibration techniques are reviewed.

    Camera-Aided Robot Calibration studies the properties of kinematic modeling techniques that are suitable for robot calibration. It summarizes the well-known Denavit-Hartenberg (D-H) modeling convention and indicates the drawbacks of the D-H model for robot calibration. The book develops the Complete and Parametrically Continuous (CPC) model and the modified CPC model, that overcome the D-H model singularities. The error models based on these robot kinematic modeling conventions are presented.

    No other book available addresses the important, practical issue of hand/eye calibration. This book summarizes current research developments and demonstrates the pros and cons of various approaches in this area. The book discusses in detail the final stage of robot calibration - accuracy compensation - using the identified kinematic error parameters. It offers accuracy compensation algorithms, including the intuitive task-point redefinition and inverse-Jacobian algorithms and more advanced algorithms based on optimal control theory, which are particularly attractive for highly redundant manipulators.

    Camera-Aided Robot Calibration defines performance indices that are designed for off-line, optimal selection of measurement configurations. It then describes three approaches: closed-form, gradient-based, and statistical optimization. The included case study presents experimental results that were obtained by calibrating common industrial robots. Different stages of operation are detailed, illustrating the applicability of the suggested techniques for robot calibration. Appendices provide readers with preliminary materials for easier comprehension of the subject matter. Camera-Aided Robot Calibration is a must-have reference for researchers and practicing engineers-the only one with all the information!

    Introduction
    Motivation
    Historical Perspective
    Camera Calibration
    Introduction
    Camera Models
    Tsai's RAC-Based Camera Calibration Algorithm
    A Fast RAC-Based Algorithm
    Optical Axis Perpendicular to the Calibration Board
    Nonlinear Least-Squares Approach
    Estimation of the Ratio of Scale Factors
    Estimation of the Image Center
    Perspective Projection Distortion of Circular Calibration Points
    Simulation and Experimental Results
    Summary and References
    Kinematic Modeling for Robot Calibration
    Introduction
    Basic Concepts in Kinematics
    The Denavit-Hartenberg Model and Its Modification
    The CPC Model and the MCPC Model
    Relationship Between the CPC Model and Other Kinematic Models
    Parametric Continuity - General Treatment
    Singularities of the MCPC Model
    Discussions and References
    Pose Measurement with Cameras
    Introduction
    System Configurations
    Pose Measurement with Moving Cameras
    Identification of the Relationship between Robot End-Effector and Camera
    Summary and References
    Error-Model-Based Kinematic Identification
    Introduction
    Differential Transformations
    Finite Difference Approximation to Kinematic Error Models
    Generic Linearized Kinematic Error Models
    The D-H Error Model
    The CPC Error Model
    The MCPC Error Model
    Summary and References
    Kinematic Identification: Linear Solution Approaches
    Introduction
    Problem Formulation and a Solution Strategy
    A Hybrid Linear Solution for an All-Revolute Robot
    An All-Recursive Linear Solution Approach for General Serial Manipulators
    Extension of the Hybrid Linear Solution Method to General Serial Robots
    Numerical Studies
    Summary and References
    Simultaneous Calibration of a Robot and a Hand-Mounted Camera
    Introduction
    Kinematic Model, Cost Function, and Solution Strategy
    The Identification Jacobian
    Implementation Issues
    Extension to Stereo-Camera Case
    Summary and References
    Robotic Hand/Eye Calibration
    Introduction
    Review of Quaternion Algebra
    A Linear Solution
    A Nonlinear Iterative Solution
    Simulation Results
    Discussion and References
    Robotic Base Calibration
    Introduction
    Problem Statement
    Estimation of the Base Orientation
    Estimation of the Base Position
    Experimental Results
    Summary and References
    Simultaneous Calibration of Robotic Base and Tool
    Introduction
    Problem Statement
    A Linear Solution
    Simulation Studies
    Summary and References
    Robot Accuracy Compensation
    Introduction
    Workspace-Mapping Method
    Model-Based Pose-Redefinition Algorithm
    Gradient-Based Algorithms
    Summary and References
    Selection of Robot Measurement Configurations
    Introduction
    Problem Statement
    Two Simple Search Algorithms
    Configuration Selection by Simulated Annealing Algorithms
    Summary and References
    Practical Considerations and Case Studies
    Introduction
    Practical Considerations
    Calibration of the PUMA Arm
    Calibration of a SCARA Arm
    Summary and References
    References
    Appendices
    Summary of Basic Concepts in Matrix Theory
    Least Squares Techniques
    Sensitivity Analysis
    Index

    Biography

    Zhuang, Hangi | Roth, Zvi S.

    "…addresses both the concepts and implementation of robot calibration using computer vision technology…well written and clearly presented…figures associated with the text not only help in understanding the mathematics, but the photographs assist in visualising actual calibration systems."
    --Industrial Robot: An International Journal, Vol. 27, No. 6