| In the field of modern industry,all kinds of metallic and non-metallic components is widely used in the automotive,wind energy,aerospace,the safety for equipment and personal are closely related to the quality of these artifacts,so it have very strict requirement to its quality.The ultrasonic testing technology,as an important method to inspect the quality of products,play an important role for guarantees the reliability of material,improve the productivity,and reduce cost.In recent years,Due to rapid development in aeronautics and astronautics,the application requirement is not only limited to the single-curved surface testing,more and more complex hyperbolic testing,which put forward higher requirements for automation control system.As an integral part of the whole inspection system,the flexibility of manipulates,the testing accuracy,reliability depends on automation control system.The main objective of this project is that design a control system to inspect the complex hyperbolic surface,can quick extract discrete point?s space information form surface form its 3D model,and control the probe?s gesture to complete the testing using these space coordinate.This article focus on design and implement the control system of ultrasonic testing equipment,the main tasks are as follows:1.First Teach & Learn method is put forward for single-Curved Surface in ultrasonic testing application,and then describe the probe control and its scan trajectory for some irregular shape materials testing.Finally describe the software function for the Teach & Learn method,and analyze the causes that the Teach & Learn method is not apply with the complex hyperbolic testing.2.Study the representation method of rigid body in space,the D-H method in robotics.Analysis the mechanical model of the nondestructive testing equipment,derive the kinematic and inverse kinematics equation based on D-H method,build up a mathematical relationship between each joint and top point on probe.3.Study how to using the rhino software,the basic knowledge for NURBS surface;introduce how to extract discrete points based on Isoparametric curve,study the binary search algorithm in extraction process.Describe the scan trajectory in complex hyperbolic surface testing.Introduced Rodrigo matrix to achieve the coordinate conversion process form the object coordinate system to equipment coordinate system.The secondary development on rhino using VB software to extract discrete points and its normal vector from 3D model,coordinate conversion function.4.Analysis the characteristics for several typical control system,Finally choose UMAC to build up entire test platform based on requirements for complex hyperbolic surface testing.Realize the control circuit design;focus on security control and Axis control circuit.Realize the software function design on host computer(VB)and slave Computer(UMAC),focus on dual-channel read & write function and Spline motion mode in UMAC Controller.5.Complete the debugging work basically,Optimize the PID Parameter in Position loop control,improve the positioning precision using compensation in software.Then Selected an actual object,achieved extract discrete points and its normal vector in rhino;Validate the coordinate transformation based on Rodrigo matrix;finally realize the testing process and get C-SCAN imaging.The experimental results show that extract discrete points and its normal vector form surface in rhino,is completed available for the complex hyperbolic surface testing,which greatly simplifies the whole process and improve its productivity. |
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