Ultrasonic Testing Technology For Blades Scanning Based On Robot

As the development of modern industry, especially airplane and spaceflight industry, the requirements of inspection for curved-surface including aerial engine blade is improved. Research and development of the system of automation detection with high efficiency, high precision and wide application range has become one of the frontier topics. Regarding the blades as the main research object, we carry out the research on the system of automation detection for curved-surface.Combined the technologies of the ultrasonic testing, robot’s motion control and nc machining simulation, some key techniques and algorithms in relation to trajectory planning, obtain the data points of robot’s movement, synchronous trigger and verifiy correctness of trajectory are systematically studied in this paper.In chapter1, the background of the research work and important significance of the dissertation were discussed. The status of research on the technology of automation ultrasonic detection for curved-surface was introduced. Then, the main existing problem at present was analyzed. Finally, detailed research contents and chapters arrangement were given.In chapter2, the structure and principle of this system was introduced.The propagation characteristics when ultrasonic vertical incident in the interface of curved-surface was simply described.The basic principles of the ultrasonic inspection and measurement was introduced, and the detection principles of pulse reflection method and pulse transmission method used in ultrasonic testing were discussed. Finally, a scheme of automatic detection for blades scanning was presented.In chapter3, the structure of this automated ultrasonic testion system was established. Then, system hadware functions and system softeware functions were introduced.In chapter4, the technique of robot’s motion control was studied. According to the features of ultrasonic nondestructive testing, main research contents were divided into two parts. One was trajectory planning of curved-surface. The other was coordinate transformation of ultrasonic testing robot.In chapter5, this paper expounds the synchronous rollecting technique between ultrasonic echo signal and robot’s position information, which includes the program of lower computer in robot’s controller, the program of upper computer in acquisition system, the communication method between lower computer and upper computer, and the synchronization problem between robot’s position information and ultrasonic collection signal.In chapter6, the test and the result analysis of the system were researched.The verifiying technique for correctness of trajectory in ultrasonic testing was studied, the stability of the system was tested, the inverse transformation between position and pose of robot and model of curved-surface was realized.Then,the practicability of the system was proved by testing some surface workpieces.Finally, main results and conclusions of this dissertation were systematically summarized, the prospects and study emphases of the future research work were discussed and forecast.