6results about How to "Eliminate nonlinear distortion" patented technology

The application relates to the technical field of integrated circuit design, and particularly discloses a full-dynamic Delta-Sigma modulator circuit which comprises a dynamic integrator, a noise shaping analog-digital converter and a dynamic element matching calibration circuit, the input end of the dynamic integrator is connected with an analog input signal and a feedback signal respectively, the input end of the noise shaping analog-digital converter is connected with the analog input signal and the output end of the dynamic integrator respectively, and the output end of the noise shaping analog-digital converter is connected with the input end of the dynamic element matching calibration circuit; the dynamic integrator is used for integrating a signal obtained by subtracting the feedback signal from the analog input signal and outputting an integrated signal; the noise shaping analog-digital converter is used for quantizing a signal obtained by adding the integrated signal and the analog input signal and outputting a quantized digital signal; and the dynamic element matching calibration circuit is used for calibrating the quantized digital signal and outputting the feedback signal. The application can eliminate the static current of the modulator and realize a very high energy efficiency ratio.

This invention relates to the field of electric motor control technology and discloses an electric motor control method for compressor drive, comprising: acquiring stator current signal and DC bus voltage signal; extracting voltage ripple characteristics based on DC bus voltage signal and determining initial value of quadrature axis current compensation; calculating the amplitude of stator current signal; when the amplitude crosses the linear magnetization current threshold, retrieving the inductor magnetization characteristic table to determine the inductor drop ratio; correcting the initial value of quadrature axis current compensation using the inductor drop ratio; and injecting the corrected compensation command into the current regulating loop. This invention, by integrating voltage ripple sensing and magnetic saturation correction mechanisms, synergistically cancels the pulse load interference of the compressor's single-cycle, fills the torque output gap under magnetic circuit saturation, suppresses stator current oscillation under low-frequency operation, and maintains torque response stiffness under all operating conditions.

This invention relates to the field of wireless communication systems for industrial IoT nodes, and discloses a wireless communication system for industrial IoT nodes, comprising: an interference feature extraction unit for locking the physical falling edge time of periodic high-energy interference pulses based on background noise floor fluctuation characteristics; a transient recovery parameter determination unit for extracting the transient recovery constant required to characterize the automatic gain control circuit of the RF front-end to return to the linear region from saturation; and a transmission blocking control unit for constructing a logical transmission-blocking window, setting its termination time to lag behind the physical falling edge time, and the lag duration equal to the transient recovery constant. This invention avoids communication blind spots caused by hardware gain oscillations by quantitatively compensating for the inherent hysteresis characteristics of RF devices, and achieves high determinism and low power consumption in data transmission under strong interference environments.

The application relates to the field of water quality monitoring and discloses an intelligent water quality monitoring method based on multi-dimensional spectral technology, which comprises the following steps: synchronously collecting the absorption spectrum and the three-dimensional fluorescence spectrum of a water sample to be measured; correcting the three-dimensional fluorescence spectrum by using the absorption spectrum to obtain the corrected three-dimensional fluorescence spectrum; constructing a double-path deep neural network to extract absorption spectrum features and three-dimensional fluorescence spectrum features; inputting the two kinds of spectrum features into a self-attention module for internal correlation weighting; generating a fusion coefficient through a gate fusion unit, and dynamically fusing the two kinds of weighted spectrum features according to the fusion coefficient to obtain a fusion spectrum feature vector; and performing water quality parameter analysis based on the fusion spectrum feature vector. The application eliminates the fluorescence distortion of high-concentration samples through internal filter effect correction, deeply extracts heterogeneous spectrum features through a double-path convolutional neural network, and realizes adaptive weighting of the two kinds of spectrum information through dynamic gate fusion.

This invention discloses an image acquisition method and system suitable for cylindrical well walls, belonging to the field of image processing technology. It includes: acquiring images of the cylindrical well wall at different depth positions to obtain multiple original images and recording the depth position information at the time of acquisition; for each original image, obtaining multiple cylindrical unfolded images through cylindrical back projection transformation; establishing a mapping relationship between image pixels and actual height based on the geometric parameters of the camera array and the cylindrical well wall; for multiple cylindrical unfolded images at the same depth position, calculating the overlapping area of ​​the cylindrical unfolded images of adjacent cameras and performing image fusion to obtain panoramic unfolded images at different depth positions; determining the overlapping area of ​​adjacent cylindrical unfolded images along the well depth direction based on the mapping relationship and depth position information, and performing image fusion to obtain continuous unfolded images of the cylindrical well wall. This invention can generate distortion-free and seamlessly stitched panoramic unfolded images.

This invention discloses a micro-displacement measurement device and method based on a Michelson interferometer and a wedge. The device includes a wedge assembly, a loading test platform, and a vertical Michelson interferometer. The vertical interferometer guides the measurement beam vertically downward through a beam splitter. The wedge assembly is located in this optical path and can move laterally with the deformation of the sample under test, thereby changing the thickness of the medium through which the beam passes, causing changes in the interference fringes. The method automatically identifies the number of fringe changes through image acquisition and processing, calculates the micro-displacement by combining it with the wedge parameters, and then solves for material parameters such as Young's modulus and coefficient of linear expansion. This invention solves the problem of spatial integration with large loading equipment by using a vertical optical path, avoids frictional interference from the traditional moving mirror method by using a laterally moving wedge, and improves measurement accuracy and efficiency through automated image processing.