Research On Visual Vibration Measurement Method Based On Motion Amplification Method

With the development of measurement technology,higher and higher requirements are put forward for the accuracy of measurement.The performance and life of mechanical structure are affected by vibration,so it is necessary to carry out in-depth research on the measurement method of mechanical structure vibration.However,at present,the main vibration measurement method is still the contact measurement based on sensors,but in some complicated working conditions,the contact method is limited,so it is more convenient to use visual vibration measurement method to measure vibration.This paper mainly studies the visual vibration measurement methods,and proposes corresponding vibration measurement methods for two different application scenarios.At present,higher precision is required for vibration measurement,and the application scenarios of vibration measurement method are more abundant.In some complicated working conditions,traditional measurement methods may be difficult to complete the measurement task.Aiming at the demand of high precision and high efficiency,this paper introduces the motion amplification method,firstly introduces the common video motion amplification method,and then proposes the improvement of the visual vibration measurement method to meet the demand of visual vibration measurement in different application situations.The main contents are as follows:First,a local phase correlation matching algorithm based on motion amplification cross-correlation is proposed in the case of obvious texture features on the surface of the structure.The method improves the rough estimation accuracy of the algorithm through the motion amplification cross-correlation function,and reduces the analysis and calculation area of the fine estimation step without sacrificing the measurement accuracy,thereby greatly improving the computational efficiency of the algorithm.The results show that the improved algorithm and the original algorithm can achieve the same accuracy results when measuring the same structural object,and the calculation time is greatly reduced.Secondly,for the structural vibration measurement with insignificant characteristic texture,a structural vibration measurement method based on the variation of acceleration phase amplification deviation is proposed.The method first uses the acceleration phase amplification algorithm to preprocess the structural vibration video to enhance the high-frequency and low-amplitude motion components in the video image;then,the deviation extraction process in the deviation amplification algorithm is used for reference to extract the amplified structural edge deviation.The information constitutes the original analysis matrix.Finally,the SVD-based signal extraction method is used to extract valuable information in the deviation change.The results show that the dynamic response parameters of the structure are effectively obtained by this method.Through the verification and explanation of the common cantilever beam structure in agricultural machinery equipment,in order to facilitate the explanation,this paper selects the ideal light cantilever beam to verify the two visual vibration measurement methods,and compares it with the Euler Bernoulli beam theory.The calculated values are compared to verify the effectiveness of the two methods;the accuracy comparison experiment is carried out on the grating scale motion platform to verify the efficiency of the improved local phase correlation matching algorithm;finally,the efficiency of the improved local phase correlation matching algorithm is verified;Vibration test was carried out to verify the effectiveness of the improved local phase correlation matching algorithm in the vibration measurement of agricultural machinery,and the feasibility of the two visual vibration measurement algorithms in the vibration measurement of agricultural machinery was also preliminarily verified.In this paper,two visual vibration test methods are proposed,and effective vibration tests are carried out on common cantilever beam structures,grating motion platforms and tractors,which not only verifies the effectiveness of the visual vibration measurement method,but also verifies the practical application of the method.Feasibility in vibration testing of agricultural machinery.