Aiming at the problem that the current pavement crack detection methods have less research on the repair trajectory planning for subsequent cracks, a raod crack detection and repair trajectory planning approach based on image processing is proposed. Firstly, the preprocessing method based on augmented nonlinear diffusion denoising is used to remove pretzel noise points; then, the FCM algorithm based on adaptive weighted spatial information is used to segment the crack features; then, the connectivity domain area filtering is used to remove the large noise points; finally, the coordinate point extraction and polynomial least squares are used to carry out the repair trajectory planning, and combined with the pavement crack detection and repair prototype simulation of the actual scene testing, to validate the reliability of the proposed approach.
Based on the measurement principle of laser triangulation, error affecting factors considering the surface characteristics of measured object (including inclination angle, incident rotation angle, incident swing angle, etc.) is analyzed. The influence rules of error sources on the detection accuracy of the system are discussed, and a compensation algorithm for improving the detection accuracy is worked out. Taking the calibration of standard bar geometry center as an example, the measured values in machine reference frame are obtained through the coordinate conversion, and three calibration schemes are formulated: 1) When the measuring plane of the laser sensor is vertical and parallel to the axial direction of the standard rob respectively (that is, the installation rotation angles are 0° and 90° respectively), the laser sensor scans horizontally within the measurement range, the laser sensor measurement is used as the measurement value, and after obtaining the compensation from the above compensation algorithm, the standard rod center coordinates are obtained; 2) The position of the laser sensor is stable at the measurement center distance of the laser (that is, the displacement is 0), the displacement grating value of the coordinate measuring instrument is read as the measured value, and the standard bar center coordinates is obtained through the coordinate transformation theory; The accuracy of the above three measurement schemes is compared, the feasibility and accuracy of the theory are verified, which lays a foundation for the research and development of the measurement system.
On the basis of traditional PID algorithm, the paper analyzes the improvements of control algorithm of PMAC
(Programmable Multiple-Axis Controller) with feedforward control, and presents the computational model of the control
algorithm. The debugging results of motors are analyzed in combination with PMAC as the controller. The problems and
the final graphics data that appear throughout debugging process are analyzed in detail, which proves that there are better
steady characteristics and dynamic performance for the servo-control system based on PMAC with feedforward control.
The control system is rebuilded by parameter-adaptive PID+feedforward control for higher machining accuracy.
A viable green manufacturing method is provided. The theory and application of laser machining interior contour are proposed. The interaction physics theory between laser and transparent material, the knowledge of CAD/CAM and ultrasonic vibration are combined to manufacture the transparent material and remove chips. Adopting the method in manufacturing, the distortion of machine, noise and chemic pollution can be eliminated.
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