Ying Yangwei

Bio: Ying Yangwei is an academic researcher from Dalian University of Technology. The author has contributed to research in topics: Ultrasonic thickness measurement & Ultrasonic sensor. The author has an hindex of 3, co-authored 8 publications receiving 30 citations.

Probe adaptively adjusted thin-wall part on-machine ultrasonic thickness measuring method

Abstract: The invention belongs to the technical field of ultrasonic detection, and relates to a probe adaptively adjusted thin-wall part on-machine ultrasonic thickness measuring method In the thickness measuring method, a ball-shaft mechanism is adopted to act as an adaptive adjustment mechanism, and a coupling agent injection mechanism is utilized to provide stable coupling liquid level for ultrasonic thickness measurement; in order to reduce thickness measurement impact and improve the contact stability, a spring is adopted to act as an elastic buffer; a limit switch is adopted to detect the device contact state so as to ensure the thickness measurement process to be safe; and a transit time difference based thickness calculation method is adopted, and the thickness of a current measuring point of a measured workpiece is calculated according to the time difference of ultrasonic echoes of the upper surface of the lower surface of the workpiece and the ultrasonic propagation velocity According to the method, the angle and the position of a probe can be automatically adjusted according to the local surface shape of the measured workpiece so as to achieve an ideal normal consistent state The method provided by the invention has the advantages of high adaptive ability, wide angle adjustment range, high measurement accuracy, ability of performing automatic on-machine thickness measurement in real time, high measurement efficiency and good stability

Incident Angle Identification Based on First-Echo Energy Attenuation in Ultrasonic Thickness Measurement

Abstract: Ultrasonic pulse technology has been widely employed for thickness measurement in the industrial field. Generally, the ultrasonic transducer is required to be perpendicular to the test sample surface when using the longitudinal wave. However, the transducer posture deviation (i.e., incident angle) of ultrasonic beam relative to the local surface normal is always inevitable. In addition, the received ultrasonic pressure will be weakened significantly because of the variation of echo propagation path and the attenuation of echo amplitude. As a result, the incident angle induced thickness error is generated. Therefore, it is necessary to investigate and quantify the negative effect of incident angle on ultrasonic thickness measurement. This paper focuses on the incident angle identification based on the first-echo energy attenuation. First, the influence mechanism of incident angle on pulse-echo pressure is analyzed theoretically by adopting an equivalent transducer model. Furthermore, a novel approach for the incident identification based on the first-echo energy attenuation is developed. A compensation model is established to correct the incident angle induced thickness error. To verify the feasibility of the proposed method, a series of incident angle calibrations and experiments were designed using the developed ultrasonic pulse measurement system. It was indicated that the proposed angle identification and error compensation approach had the capacity to improve the measurement accuracy of ultrasonic thickness.

Precise on-machine extraction of the surface normal vector using an eddy current sensor array

Abstract: To satisfy the requirements of on-machine measurement of the surface normal during complex surface manufacturing, a highly robust normal vector extraction method using an Eddy current (EC) displacement sensor array is developed, the output of which is almost unaffected by surface brightness, machining coolant and environmental noise. A precise normal vector extraction model based on a triangular-distributed EC sensor array is first established. Calibration of the effects of object surface inclination and coupling interference on measurement results, and the relative position of EC sensors, is involved. A novel apparatus employing three EC sensors and a force transducer was designed, which can be easily integrated into the computer numerical control (CNC) machine tool spindle and/or robot terminal execution. Finally, to test the validity and practicability of the proposed method, typical experiments were conducted with specified testing pieces using the developed approach and system, such as an inclined plane and cylindrical and spherical surfaces.

Incident drift angle automatic identifying and error compensating method in ultrasonic thickness measurement

Abstract: The invention provides an incident drift angle automatic identifying and error compensating method in ultrasonic thickness measurement, wherein the method belongs to the field of ultrasonic detecting technology. Particularly the invention relates to an incident drift angle automatic identifying and error compensating method in ultrasonic thickness measurement. The method comprises the steps of firstly, performing ultrasonic incident drift angle calibration, extracting first echo energy of an ultrasonic signal at different calibration incident drift angles, and establishing an association relation between the calibration incident drift angle and the first echo energy; then, performing sampling for acquiring an actual ultrasonic thickness measurement signal of a measured member, and automatically identifying the incident drift angle by means of the association relation between the calibration incident drift angle and the first echo energy; and finally, calculating a current measuring point echo time difference, finishing incident drift angle association thickness error compensation by means of the established thickness error compensation model, and obtaining an accurate thickness measuring result. The incident drift angle automatic identifying and error compensating method realizes incident drift angle automatic identification in ultrasonic thickness measurement and association thickness error compensation thereof. Furthermore the incident drift angle automatic identifying and error compensating method has advantages of simple algorithm, high reliability and high real-time performance.

Ultrasonic on-machine scanning for thickness measurement of thin-walled parts: modeling and experiments

Abstract: The thickness measurement of large thin-walled part has become increasingly important to inspect the machining quality and compensate the machining errors. So far, commercial hand-held ultrasonic thickness gauges have been widely used in the wall thickness inspection of large thin-walled parts. However, the manual operation has some disadvantages such as insufficient measurement efficiency, intensive labor, and limited accuracy. To tackle these problems, an automatic thickness measuring method is supposed to be an effective approach. In this article, an ultrasonic on-machine scanning technique for thickness measurement of large thin-walled parts is proposed. First, a multi-function integrated ultrasonic thickness on-machine measuring device is innovatively designed, which enables the posture of an ultrasonic sensor to adapt to the measured surface orientation automatically. Second, the on-machine measurement model of the thickness distribution is established, which includes a measuring point coordinate extraction model and a precise thickness assessing model. Then, a scanning motion control strategy for contact ultrasonic measurement is proposed to maintain a constant pressure between the ultrasonic transducer and the workpiece during the scanning process. Finally, taking the arched part, inclined plate, and S-shaped thin-walled part as typical objects, the experimental study has been conducted using the proposed method. The experimental results show that the ultrasonic thickness on-machine measurement accuracy can be controlled within 0.04 mm, which validates the feasibility of the ultrasonic thickness on-machine scanning technique on thickness measurement of complex surface thin-walled parts.

Autonomous Profile Tracking for Multiaxis Ultrasonic Measurement of Deformed Surface in Mirror Milling

Abstract: High-precision remaining wall thickness is desirable in the mirror milling of large thin-walled parts. However, the workpiece deformation caused by sheet forming, clamping, and self-gravity makes it difficult to control the thickness if the original tool path generated from the designed CAD model is used directly. In order to solve this problem, the deformed workpiece surface is supposed to be reconstructed, and the original tool path should then be adjusted. In this article, based on a self-developed multiprobe ultrasonic measurement system, an autonomous profile tracking approach, mainly including adaptive sampling point prediction, boundary processing, and feature point extraction, is proposed to scan the deformed surface. The sampling point prediction algorithm calculates the position and orientation simultaneously for the next sampling point. In particular, a current-measurement-output-based orientation prediction algorithm is proposed to guarantee the autonomy of the profile tracking, and a reference-measurement-point-based orientation prediction algorithm is proposed to improve the prediction accuracy. The boundary processing algorithm controls the scanning direction and ensures that the sampling process is implemented inside the measurement boundary. The online feature point extraction algorithm reduces the redundant points for the following surface reconstruction. Practical experiments on freeform surfaces with/without complex boundaries verified the feasibility and effectiveness of the proposed method.

Measurement of Three-Dimensional Information by Single Eddy Current Displacement Sensor

Abstract: The eddy-current displacement sensor (ECDS), due to features of small size and high-measurement accuracy, has great potential for high-precision measurement in a compact space. However, most applications of ECDS are one-dimensional (1D) or two-dimensional displacement measurements. In this paper, a measurement method of three-dimensional (3D) coordinates only by virtue of single ECDS is proposed. In order to realize the 3D coordinates measurement by ECDS, the virtual displacement measurement starting point (VDMSP) and the displacement vector of ECDS are used as the prior information of ECDS to obtain the 3D absolute measuring point coordinate of a spatial target by ECDS from the 1D displacement relative quantity of ECDS. Besides, a 3D measurement method by ECDS based on the spatial vector and optimization has been proposed to obtain the 3D absolute coordinates of the VDMSP and the spatial displacement vector (the prior information). Then, the measurement of 3D absolute coordinates of the measuring point on the target by single ECDS can be realized due to the prior information. Moreover, the plane datum transformation method is analyzed to reduce the impact of data drift on the measurement method. Finally, the experiments of six ECDSs are conducted. The results indicate that the proposed measurement method is universally applicable to different ECDSs. The average measurement accuracy is 0.0212 mm and the mean square error is 0.0127 mm, which can meet the measurement requirement of 3D detection in a compact space.

Coiled Tubing Wall Thickness Evaluation System Using Pulsed Alternating Current Field Measurement Technique

Abstract: In recent years, with the exploitation of shale gas, the amount of coiled tubing has increased dramatically. Due to the harsh working environment, the wall thickness of the coiled tubing is easily thinned. In this paper, The coiled tubing wall thickness evaluation system is proposed based on the pulsed alternating current field measurement technique. The coiled tubing wall thickness evaluation model using pulsed alternating current field is developed by the finite element software COMSOL. The Bx signal is selected as the characteristic signal of thickness evaluation, and the relationship between characteristic signal and wall thickness is analyzed. According to the detection characteristics of the coiled tubing, probe and system for the wall thickness evaluation of the coiled tubing are designed and established. And the test experiment is carried out on different thicknesses of coiled tubing. The test results show that the detecting system can quantitatively evaluate the wall thickness of the coiled tubing accurately.