Based On Speckle Photographic Method Of Space Of The Motor Rotor Displacement Measurement

Magnetic suspension bearing technology is mature,and its application field is becoming more and more widely,such as high speed machine tools,automobile engine,air compressor,vacuum pump,shock absorber,energy storage flywheel,rate gyro and multidimensional platform positioning,satellite antenna,etc.The characteristics of magnetic suspension bearing,to make it in many application fields and the traditional ball bearing,sliding bearing,and has obvious superiority than the oil film bearing.General use of passive magnetic bearing permanent magnet suspension to maintain the position of the object is stable in all degrees of freedom,and the damping is relatively low;the passive magnetic bearing of the superconducting current is still in the experimental stage,more difficult to achieve,but the cost is very high.Therefore,AMB is widely used in industry.In this paper,in addition to special instructions,the electromagnetic bearings are active magnetic bearings.The electromagnetic bearing uses the sensor to measure the deviation between the actual position and the set position of the rotor,and the controller outputs the control signal to the power amplifier according to a certain control law.The excitation current of the electromagnet is adjusted by the power amplifier,so as to adjust the suction force of the rotor,so that the rotor reaches a certain position in the vicinity of the desired position.Controllability is the biggest characteristic of electromagnetic bearing.According to the basic principle of the electromagnetic bearing.In this paper,the principle of speckle photography is used to carry out the Fu Liye transform of the rotating image of a rotating camera in a constant white light.Both the original image and the deformed image are extracted by Fu Liye transform to extract the phase of the two images.The displacement of the shaft is calculated by the number of interference fringes,and the numerical value of the displacement and the displacement of the bearing in the axial and radial direction is determined.The accuracy of this method is much higher than that of the current sensor.The non-contact measurement does not damage the shaft.With only one camera structure is simple and very practical.The frequency domain analysis method of digital speckle photography is a very effective method to measure micro displacement.The basic algorithm depends only on the surface of gray distribution and characteristic markings at random,so the large structure is successfully applied to the engineering field test,analysis has also been successfully used to obtain microscopic images of scanning electron microscope.In this paper,after overcoming the difficulties of using digital speckle photography in high speed rotating objects,the interference fringes of the radial and axial micro displacement of the shaft are successfully obtained in the laboratory.The dark stripes in the interference fringes of the speckle pattern interferometry are formed by the aggregation of dark dots.Therefore,in the frequency domain,the frequency of dark stripes is higher and the frequency of light stripes is low.However,because of the frequency domain characteristics of speckle pattern interferometry,it is impossible to obtain a clear and non noisy fringe image with high pass filter and low-pass filter.The shear wave coefficients of each frequency band are analyzed comprehensively and the texture features are extracted,and the black stripes are separated by using SVM classifier and PCNN neural network.The number of interference fringes is extracted by thinning and houph transform,and the axial and radial micro displacement of the magnetic bearing is measured.