Robotic Non-Destructive Testing Technology

The content of this book includes a variety of nondestructive testing (NDT) methods, with many introductions to testing and application cases. The book proposes new ultrasonic testing technology for complex workpieces. It is hard for traditional NDT technology to realize the automatic detection of complex curved components, especially the automatic high-precision nondestructive detection of curved-surface components with variable curvature, variable thickness and complex contour. Therefore, the robotic NDT technique as a combination of manipulator technique and NDT technique can further improve the efficiency and accuracy of NDT. Robotic NDT Technique combines the physical principle of nondestructive testing with the flexible motion control of spatial attitude of articulated manipulator. With NDT as the constraint, it controls the motion attitude and azimuth angle of a transmitting and receiving transducer. Thus traditional NDT technique has developed from plane to curved surface, from 2D to many dimensions and from artificiality to intelligence, into a unique and systematic interdisciplinary robotic NDT technique. Cover Half Title Title Page Copyright Page Table of Contents Preface, Author, Chapter 1 Introduction 1.1 BACKGROUND 1.1.1 Automatic NDT Methods of Complex Components 1.1.2 Development Trend of Robotic NDT Technique 1.2 BASIS OF MANIPULATOR 1.2.1 Type and Structure of Manipulators 1.2.2 Working Mode of Manipulators 1.3 MATHEMATICAL RELATIONSHIP BETWEEN THE COORDINATE SYSTEM AND EULER ANGLE 1.3.1 Definition of a Manipulator Coordinate System 1.3.2 Relationship between Position & Attitude and Coordinate System 1.3.2.1 Position Description 1.3.2.2 Attitude Description 1.3.2.3 Spatial Homogeneous Coordinate Transformation 1.3.3 Quaternion and Coordinate Transformation REFERENCES Chapter 2 Method of Acoustic Waveguide UT 2.1 WAVE EQUATION AND PLANE WAVE SOLUTION 2.1.1 Acoustic Wave Equation for an Ideal Fluid Medium 2.1.2 Plane Wave and Solutions of Wave Equations 2.2 ULTRASONIC REFLECTION AND TRANSMISSION AT THE INTERFACE 2.3 ANALYSIS OF SOUND FIELD IN AN ACOUSTIC WAVEGUIDE TUBE 2.4 MEASUREMENT OF SOUND FIELD IN AN ACOUSTIC WAVEGUIDE TUBE REFERENCES Chapter 3 Planning Method of Scanning Trajectory on Free-Form Surface 3.1 MAPPING RELATIONS BETWEEN MULTIPLE COORDINATE SYSTEMS 3.1.1 Translation, Rotation and Transformation Operators 3.1.1.1 Translation Operator 3.1.1.2 Rotation Operator 3.1.1.3 Transformation Operator 3.1.2 Equivalent Rotation and Quaternion Equation 3.1.2.1 Representation in an Angular Coordinate System 3.1.2.2 Representation in an Equivalent Axial Angular Coordinate System 3.2 SURFACE SPLIT AND RECONSTRUCTION BASED ON NUBRS 3.2.1 Parametric Spline Curve and Surface Split Method 3.2.2 Scanning of Non-uniform Rational B-Splines (NURBS) 3.2.3 Surface Construction Based on Differential Equation and Interpolation Algorithm 3.3 SURFACE SCANNING TRAJECTORY ALGORITHM BASED ON CAD/CAM 3.3.1 Generation of Discrete Point Data of Free-Form Surface 3.3.2 Coordinate Transformation under the Constraint of Ultrasonic Testing (UT) Principle 3.4 SCANNING TRAJECTORY SMOOTHNESS JUDGMENT AND DATA DISCRETIZATION PROCESSING 3.4.1 Wavelet Processing Method of Surface Data 3.4.2 Handling and Judgment of Surface Smoothness REFERENCES Chapter 4 Single-Manipulator Testing Technique 4.1 COMPOSITION OF A SINGLE-MANIPULATOR TESTING SYSTEM 4.1.1 Workflow of a Testing System 4.1.2 Principle of Equipment Composition 4.2 PLANNING OF SCANNING TRAJECTORY 4.2.1 Ultrasonic/Electromagnetic Testing Parameters 4.2.2 Trajectory Planning Parameters 4.3 CALIBRATION AND ALIGNMENT OF ASSEMBLY ERROR 4.3.1 Method of Coordinate System Alignment 4.3.2 Alignment Method Based on Ultrasonic A-Scan Signal 4.3.3 Error Compensation Strategy and Gauss-Seidel Iteration 4.3.4 Positioning Error Compensation 4.4 MANIPULATOR POSITION/ATTITUDE CONTROL AND COMPENSATION 4.4.1 Kinematics Analysis 4.4.2 End-Effector Position Error and Compensation Strategy 4.4.3 Method of Joint Position/Attitude Feedback 4.5 METHOD OF SYNCHRONIZATION BETWEEN POSITION AND ULTRASONIC SIGNAL REFERENCES Chapter 5 Dual-Manipulator Testing Technique 5.1 BASIC PRINCIPLE OF ULTRASONIC TRANSMISSION DETECTION 5.1.1 Basic Principles of Ultrasonic Reflection and Ultrasonic Transmission 5.1.1.1 Basic Principle of Ultrasonic Reflection Detection 5.1.1.2 Basic Principle of Ultrasonic Transmission Detection 5.1.1.3 Comparison between the Elements of an Ultrasonic Reflection Method and Those of an Ultrasonic Transmission Method 5.1.2 Ultrasonic Transmission Testing of Curved Workpieces 5.1.2.1 Principle of Reflection and Transmission of Ultrasonic Wave Incident on Curved Workpieces 5.1.2.2 Principle of Refraction of Ultrasonic Wave Incident on a Curved Surface 5.2 COMPOSITION OF A DUAL-MANIPULATOR TESTING SYSTEM 5.2.1 Hardware Structures in a Dual-Manipulator Testing System 5.2.1.1 Six-DOF Articulated Manipulator 5.2.1.2 Manipulator Controller 5.2.1.3 Data Acquisition Card 5.2.1.4 Ultrasonic Signal Transceiver System 5.2.1.5 Water-Coupled Circulation System 5.2.2 Upper Computer Software of a Dual-Manipulator Testing System 5.2.2.1 Overall Design of Upper Computer Software 5.2.2.2 Data Acquisition 5.2.2.3 Synchronous Control of Dual Manipulator 5.2.2.4 Automatic Scanning Imaging Module 5.2.3 Lower Computer Software of a Dual-Manipulator Testing System 5.3 MAPPING RELATION BETWEEN DUAL-MANIPULATOR BASE COORDINATE SYSTEMS 5.3.1 Transformation Relationship between Base Coordinate Systems 5.3.1.1 Definition of Parameters of a Manipulator Coordinate System 5.3.1.2 Solution of an Unified Variable Method 5.3.1.3 Solving with a Homogeneous Matrix Method 5.3.2 Orthogonal Normalization of Rotation Matrix 5.3.2.1 Basis of Lie Group and Lie Algebra 5.3.2.2 Orthogonalization of Rotation Matrix Identity 5.3.3 Experiment of Dual-Manipulator Base Coordinate Transformation Relationship 5.3.4 Analysis of Transformation Relation Error 5.4 DUAL-MANIPULATOR MOTION CONSTRAINTS DURING TESTING 5.4.1 Constraints on the Position and Attitude of Dual-Manipulator End-Effectors in the Testing of Equi-Thickness Workpiece 5.4.2 Constraints on the Position and Attitude of Dual-Manipulator End-Effectors in the Testing of Variable-Thickness Workpiece REFERENCES Chapter 6 Error Analysis in Robotic NDT 6.1 KINEMATICS ANALYSIS FOR ROBOTIC TESTING PROCESS 6.1.1 Establishment of the Coordinate System in a Moving Device 6.1.2 Matrix Representation of the Position/Attitude Relationship between Coordinate Systems 6.1.3 Coordinated Motion Relation between Manipulator and Turntable 6.1.4 Matrix Representation of Coordinated Motion Relation 6.2 PLANNING OF MOTION PATH IN THE TESTING PROCESS 6.2.1 Algorithm of Detection Path Generation 6.2.2 Resolving of Manipulator Motion Path 6.3 ERROR SOURCES IN ROBOTIC UT PROCESS 6.3.1 Geometric Error in Path Copying 6.3.2 Localization Error in Manipulator Motion 6.3.3 Clamping Error of Tested Component REFERENCES Chapter 7 Error and Correction in Robotic Ultrasonic Testing 7.1 ULTRASONIC PROPAGATION MODEL 7.1.1 Fluctuation of Sound Pressure in an Ideal Fluid Medium 7.1.2 Expression of Sound Pressure Amplitude 7.1.3 Superposition of Multiple Gaussian Beams 7.1.4 Influence of the Curved Surface on Ultrasonic Propagation 7.2 3D POINT CLOUD MATCHING ALGORITHM BASED ON NORMAL VECTOR ANGLE 7.2.1 Matching Features of 3D Point Clouds 7.2.2 Calculation of the Normal Vector on a Curved Surface 7.2.3 Identification and Elimination of Surface Boundary Points 7.2.4 Calculation of Spatial Position/Attitude Deviation of 3D Point Cloud 7.3 CORRECTION EXPERIMENT FOR 3D POINT CLOUD COLLECTION AND INSTALLATION DEVIATION 7.3.1 Steps of 3D Point Cloud Matching 7.3.2 Simulation Verification of Position/Attitude Deviation Correction Algorithm 7.3.3 Experiment and Detection Verification of Curved-Component Deviation Correction REFERENCES Chapter 8 Kinematic Error and Compensation in Robotic Ultrasonic Testing 8.1 THREE-DIMENSIONAL SPATIAL DISTRIBUTION MODEL OF ROBOTIC UT ERROR 8.1.1 Model of Manipulator Localization Error 8.1.2 Relationship between Distance Error and Kinematic Parameter Error 8.1.3 Three-Dimensional Spatial Distribution of Errors 8.2 FEEDBACK COMPENSATION MODEL OF ROBOTIC UT ERROR 8.2.1 Principle of Error Feedback Compensation 8.2.2 Calculation of Kinematic Parameter Errors 8.2.3 Step of Feedback Compensation of Kinematic Parameter Error 8.3 DESIGN AND APPLICATION OF BI-HEMISPHERIC CALIBRATION BLOCK 8.3.1 Design of Bi-hemispheric Calibration Block 8.3.2 Method of UT System Compensation with Bi-hemispheric Calibration Error 8.3.3 Application of Calibration Block in Kinematic Parameter Error Compensation REFERENCES Chapter 9 Dual-Manipulator Ultrasonic Testing Method for Semi-Closed Components 9.1 PROBLEMS FACED BY THE ULTRASONIC AUTOMATIC TESTING OF SEMI-CLOSED CURVED COMPOSITE COMPONENTS 9.2 METHOD OF PLANNING THE DUAL-MANIPULATOR TRAJECTORY IN THE ULTRASONIC TESTING OF SEMI-CLOSED COMPONENTS 9.2.1 Coordinate Systems in Dual-Manipulator and Their Relations 9.2.2 Method of Planning the X-Axis Constrained Trajectory in the Ultrasonic Testing of Semi-Closed Component 9.2.3 Experimental Verification of the Trajectory Planning Method with X-Axis Constraint 9.3 ANALYSIS AND OPTIMIZATION OF VIBRATION CHARACTERISTICS OF SPECIAL-SHAPED EXTENSION ARM TOOL 9.3.1 Calibration of Static Characteristics of Special-Shaped Extension Arm Tool 9.3.2 Improved S-Curve Acceleration Control Algorithm 9.3.3 Trajectory Interpolation Based on Improved S-Curve Acceleration Control REFERENCES Chapter 10 Calibration Method of Tool Center Frame on Manipulator 10.1 REPRESENTATION METHOD OF TOOL PARAMETERS 10.2 FOUR-ATTITUDE CALIBRATION METHOD IN TCF 10.2.1 Calibration of the Position of Tool-End Center Point 10.2.2 Calibration of the Attitude of End Center Point of Special-Shaped Tool 10.3 CORRECTION OF FOUR-ATTITUDE CALIBRATION ERROR OF TOOL CENTER FRAME 10.4 FOUR-ATTITUDE TCF CALIBRATION EXPERIMENT 10.4.1 TCF Calibration Experiment of Special-Shaped Tip Tool 10.4.2 Verivcation Experiment of TCF Calibration Result of Special-Shaped Tip Tool 10.5 FOUR-ATTITUDE TCF CALIBRATION EXPERIMENT OF SPECIAL-SHAPED EXTENSION ARM REFERENCES Chapter 11 Robotic Radiographic Testing Technique 11.1 BASIC PRINCIPLE OF X-RAY CT TESTING 11.1.1 Theory of X-ray Attenuation 11.1.2 Mathematical Basis of Industrial CT Imaging 11.2 COMPOSITION OF A ROBOTIC X-RAY CT TESTING SYSTEM 11.3 ACQUISITION, DISPLAY AND CORRECTION OF X-RAY PROJECTION DATA 11.3.1 Principle and Working Mode of a Flat Panel Detector 11.3.2 Implementation of X-ray Image Acquisition and Real-Time Display Software 11.3.3 Analysis of the Factors Affecting the Quality of X-ray Projection Images 11.4 COOPERATIVE CONTROL OF X-RAY DETECTION DATA AND MANIPULATOR POSITION AND ATTITUDE 11.4.1 Design of Collaborative Control Concept 11.4.2 Method of Manipulator Motion Control Programming in Lower Computer 11.4.3 Modes of Communication and Control of Upper and Lower Computers 11.4.4 Implementation Method of Cooperative Control Software 11.5 AN EXAMPLE OF HOLLOW COMPLEX COMPONENT UNDER TEST REFERENCES Chapter 12 Robotic Electromagnetic Eddy Current Testing Technique 12.1 BASIC PRINCIPLE OF ELECTROMAGNETIC EDDY CURRENT TESTING 12.1.1 Characteristics of Electromagnetic Eddy Current Testing 12.1.2 Principle of Electromagnetic Eddy Current Testing 12.1.2.1 Electromagnetism Induction Phenomenon 12.1.2.2 Faraday’s Law of Electromagnetic Induction 12.1.2.3 Self-Inductance 12.1.2.4 Mutual Inductance 12.1.3 Eddy Current and Its Skin Effect 12.1.4 Impedance Analysis Method 12.1.4.1 Impedance Normalization 12.1.4.2 Effective Magnetic Conductivity and Characteristic Frequency 12.1.5 Electromagnetic Eddy Current Testing Setup 12.2 COMPOSITION OF A ROBOTIC ELECTROMAGNETIC EDDY CURRENT TESTING SYSTEM 12.2.1 Hardware Composition 12.2.2 Software Composition 12.3 METHOD OF ELECTROMAGNETIC EDDY CURRENT DETECTION IMAGING 12.3.1 Display Method of Eddy Current Signals 12.3.2 Method of Eddy Current C-Scan Imaging REFERENCES Chapter 13 Manipulator Measurement Method for the Liquid Sound Field of an Ultrasonic Transducer 13.1 MODEL OF AN ULTRASONIC TRANSDUCTION SYSTEM 13.1.1 Equivalent Circuit Model of an Ultrasonic Transducer 13.1.2 Ultrasonic Excitation and Propagation Medium 13.2 SOUND FIELD MODEL OF AN ULTRASONIC TRANSDUCER BASED ON SPATIAL PULSE RESPONSE 13.2.1 Theory of Sound Field in an Ultrasonic Transducer 13.2.2 Sound Field of a Planar Transducer 13.2.3 Sound Field of a Focusing Transducer 13.3 MEASUREMENT MODEL AND METHOD OF SOUND FIELD OF AN ULTRASONIC TRANSDUCER 13.3.1 Ball Measurement Method of Sound Field of an Ultrasonic Transducer 13.3.2 Hydrophone Measurement Method of Sound Field of an Ultrasonic Transducer 13.4 SOUND-FIELD MEASUREMENT SYSTEM OF ROBOTIC ULTRASONIC TRANSDUCER 13.4.1 Composition of a Hardware System 13.4.2 Composition of a Software System 13.5 MEASUREMENT VERIFICATION OF SOUND FIELD OF MANIPULATOR TRANSDUCER 13.5.1 Measurement of Sound Field of a Planar Transducer 13.5.2 Measurement of Sound Field of Focusing Transducer REFERENCES Chapter 14 Robotic Laser Measurement Technique for Solid Sound Field Intensity 14.1 SOLID SOUND FIELD AND ITS MEASUREMENT METHOD 14.1.1 Definition, Role and Measurement Significance of Solid Sound Field 14.1.2 Current Domestic and Overseas Measurement Methods and Their Problems 14.2 SOUND SOURCE CHARACTERISTICS OF SOLID SOUND FIELD AND ITS CHARACTERIZATION PARAMETERS 14.2.1 Structure and Characteristics of Exciter Sound Source 14.2.2 Characterization Method of Solid Sound Field 14.2.2.1 Analytical Method 14.2.2.2 Semi-Analytical Method 14.2.2.3 Numerical Method 14.2.2.4 Measurement Method of Ultrasonic Intensity in Solids 14.3 COMPOSITION OF A ROBOTIC MEASUREMENT SYSTEM FOR SOUND FIELD INTENSITY 14.3.1 Hardware Composition 14.3.2 Software Function 14.4 PRINCIPLE OF LASER MEASUREMENT FOR SOUND FIELD INTENSITY DISTRIBUTION 14.4.1 Measurement Principle of Laser Displacement Interferometer 14.4.2 Measurement Principle of Normal Displacement of Sound Wave 14.5 MEASUREMENT METHOD FOR TRANSVERSE WAVE AND LONGITUDINAL WAVE BY A DUAL-LASER VIBROMETER 14.6 APPLICATION OF A SOUND FIELD INTENSITY MEASUREMENT METHOD REFERENCES Chapter 15 Typical Applications of Single-Manipulator NDT Technique 15.1 CONFIGURATION OF A SINGLE-MANIPULATOR NDT SYSTEM 15.2 AN APPLICATION EXAMPLE OF ROBOTIC NDT TO ROTARY COMPONENTS 15.2.1 Structure of Clamping Device 15.2.2 Correction of Perpendicularity and Eccentricity of Principal Axis 15.2.3 Generation and Morphological Analysis of Defects in Rotary Components 15.2.4 Analysis of Error and Uncertainty in the Ultrasonic Detection of Defects inside Rotary Components 15.2.5 Application Examples of Robotic NDT of Rotary Components 15.3 ROBOTIC NDT METHOD FOR BLADE DEFECTS 15.3.1 Robotic Ultrasonic NDT of Blades 15.3.2 Detection by Ultrasonic Vertical Incidence 15.3.3 Ultrasonic Surface-Wave Detection Method 15.4 ROBOTIC NDT METHOD FOR BLADE DEFECTS 15.4.1 Principle of Ultrasonic Thickness Measurement 15.4.2 Calculation Method of Echo Sound Interval Difference 15.4.3 Thickness Measurement Method with Autocorrelation Analysis REFERENCES Chapter 16 Typical Applications of Dual-Manipulator NDT Technique 16.1 CONFIGURATION OF A DUAL-MANIPULATOR NDT SYSTEM 16.1.1 NDT Method for Large Components: Dual-Manipulator Synchronous-Motion Ultrasonic Testing 16.1.2 NDT Method for Small Complex Components: Dual-Manipulator Synergic-Motion Ultrasonic Testing 16.2 AN APPLICATION EXAMPLE OF DUAL-MANIPULATOR ULTRASONIC TRANSMISSION DETECTION 16.2.1 Ultrasonic C-Scan Detection of a Large-Diameter Semi-closed Rotary Component 16.2.2 Ultrasonic C-Scan Detection of a Small-Diameter Semi-closed Rotary Component 16.2.3 Ultrasonic C-Scan Detection of a Rectangular Semi-closed Box Component 16.2.4 Ultrasonic Testing of an Acoustic Waveguide Tube REFERENCES