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7 results about "Minimum phase" patented technology

In control theory and signal processing, a linear, time-invariant system is said to be minimum-phase if the system and its inverse are causal and stable. The most general causal LTI transfer function can be uniquely factored into a series of an all-pass and a minimum phase system. The system function is then the product of the two parts, and in the time domain the response of the system is the convolution of the two part responses. The difference between a minimum phase and a general transfer function is that a minimum phase system has all of the poles and zeroes of its transfer function in the left half of the s-plane representation (in discrete time, respectively, inside the unit circle of the z-plane). Since inverting a system function leads to poles turning to zeroes and vice versa, and poles on the right side (s-plane imaginary line) or outside (z-plane unit circle) of the complex plane lead to unstable systems, only the class of minimum phase systems is closed under inversion. Intuitively, the minimum phase part of a general causal system implements its amplitude response with minimum group delay, while its all pass part corrects its phase response alone to correspond with the original system function.

Model control method and device based on fuzzy weighted fusion, equipment and medium

The invention relates to the technical field of non-minimum phase systems, and relates to a model control method and device based on fuzzy weighted fusion, equipment and a medium, the method comprises the following steps: obtaining an output signal, and obtaining a first error value and a dynamic error change rate; obtaining a weight coefficient output by the fuzzy system in the current iteration round; obtaining a target reference model of the current iteration round according to the weight coefficient; obtaining a feedforward controller of the current iteration round according to the weight coefficient; and dynamically adjusting the control parameters of the PID controller according to the design parameters of the target reference model and the feed-forward output signal of the feed-forward controller. According to the double-degree-of-freedom model adopted by the invention, feedforward control and feedback control can be independently designed and optimized, the adjustability and flexibility of the double-degree-of-freedom model are improved, and different control requirements can be met; and meanwhile, through cooperation of the feedforward controller and the target reference model, an output signal of the non-minimum phase system can accurately track a reference target signal.
Owner:GUANGDONG POLYTECHNIC COLLEGE

Spatial response compensation method and apparatus, electronic device, and storage medium

The application provides a spatial response compensation method and device, electronic equipment and a storage medium. The spatial response compensation method comprises the following steps: constructing a spatial transfer function according to spatial input information and corresponding spatial response information of a system; splitting the spatial transfer function into a minimum phase system and an all-pass system; determining a first inverse system corresponding to the minimum phase system and a second inverse system corresponding to the all-pass system; constructing a compensation system according to a preset target frequency response, the first inverse system and the second inverse system; compensating the spatial transfer function through the compensation system to obtain a compensated spatial transfer function; and converting the spatial input information of the system into target spatial response information through the compensated spatial transfer function. The application decomposes an arbitrary stable and causal linear time-invariant system into a minimum phase system and an all-pass system with different properties, and solves the inverse systems of the two systems, thereby reducing the complexity of the solution.
Owner:SHANGHAI AWINIC TECH CO LTD

Minimum phase channel skew correction method, apparatus, electronic device, and storage medium

The application provides a minimum phase channel skew correction method and device, electronic equipment and storage medium, and relates to the technical field of communication.The application first acquires training result data corresponding to each line pair of a plurality of line pairs of a target communication system in a training mode, wherein the training result data includes a tap coefficient sequence of a DFE and a received symbol sequence; the plurality of line pairs include a reference line pair and a plurality of to-be-corrected line pairs; then, based on the tap coefficient sequence corresponding to each line pair and a preset cross-correlation operation algorithm, timing offset data is determined; further, based on the timing offset data and the received symbol sequence corresponding to each line pair, the receiving order of each line pair is determined, so as to correct the skew of the target communication system in a data transmission mode based on the timing offset data and the receiving order of each line pair. In this way, skew correction with low complexity and high reliability is realized, the skew correction can be quickly completed in the starting stage, and the accuracy of data transmission is ensured.
Owner:SHANGHAI WU QI MICROELECTRONICS CO LTD +1

Optimal phase matching wave source estimation method based on head wave statistics and norm constraint

The invention discloses an optimal phase matching wave source estimation method based on head wave statistics and norm constraint, and belongs to the field of signal processing. On the basis of statistical method wave source estimation, a Hilbert orthogonal component and a constant phase rotation mechanism are introduced to realize RMS energy retention type all-phase scanning wave source extraction, and the method specifically comprises the following steps: carrying out dynamic correction, first arrival alignment and interception on a fluctuation signal observation data set to obtain an initial time domain wave source under a minimum phase assumption; generating an adjoint component through Hilbert transformation, carrying out phase rotation at a step length of 1 degree, carrying out L2 norm energy maintenance after each rotation, and constructing a candidate wave source library with consistent energy; and keeping the amplitude of each candidate wave source consistent with the original wave source, then carrying out convolution with the measured reflection coefficient to generate a synthetic record, and carrying out cross-correlation analysis on the synthetic record and the actually measured signal record to determine the optimal phase and wave source. The method has the obvious advantages of keeping lower inversion residual error, better fitting of profile waveform and measurement data, higher inversion resolution and the like.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Active noise reduction method and system based on improved variable step size FxLMS algorithm

The invention discloses an active noise reduction method and system based on an improved variable step size FxLMS algorithm, and belongs to the field of active noise control. The method comprises the following steps: acquiring a reference signal and an error signal; decomposing the secondary path transfer function based on an inverse filtering principle to obtain a minimum phase system and an all-pass system, and designing an inverse filter for the minimum phase system to perform cascade compensation to obtain a secondary path after frequency equalization; constructing a cost function containing an L1 regularization item and an error self-correlation item, and deducing a corresponding weight updating rule; dynamically adjusting the step size of the adaptive filter by adopting a variable step size strategy; and generating an anti-noise signal according to the updated weight and the filtered reference signal, playing the anti-noise signal through a secondary path after frequency equalization, and carrying out superposition and cancellation on the anti-noise signal and the original noise to realize noise reduction. According to the method, the problem of frequency distortion caused by non-correlation noise interference and loudspeaker nonlinearity is effectively solved, and the convergence speed, the steady-state performance and the robustness of the algorithm are improved.
Owner:ZHEJIANG UNIV

A method for improving the static correction imaging accuracy of seismic data based on a vibroseis

The present invention discloses a method for improving the imaging accuracy of seismic data static correction based on a vibrator, which includes the following steps: 1. First, perform minimum-phase processing on the vibrator data; 2. Manually and finely pick the first arrival jump point of single-shot data to obtain near-surface geological information; 3. Perform first-arrival wave refraction static correction calculation on the data; 4. Apply the datum static correction in step 3 to the original single-shot data; 5. Modify the first-arrival trace headers of the data picked in step 2 to ensure consistency with the data in step 4; 6. Perform first-arrival wave residual static correction calculation on the data, and jointly use the first-arrival wave refraction static correction to improve the focusing of the imaging quality; 7. Separate the high and low frequencies of the datum static correction, and ensure the authenticity of the underground structure morphology with the low-frequency component of the static correction; the high-frequency component of the datum static correction is combined with the first-arrival wave residual static correction as the high-frequency component of the static correction. The present invention can eliminate the problem of in-phase axis imaging jitter caused by the thickness and velocity variation of the low-velocity layer.
Owner:北京市地质调查研究所

Iterative learning error compensation control method for numerical control machine tool based on stable inverse model

The present application relates to a stable inverse model-based iterative learning error compensation control method for numerical control machine tools, which realizes the stable inversion of the system by regarding the unstable part as a non-causal operation and generating control input based on infinite preview. This method not only ensures the stability of the system, but also realizes fast convergence while maintaining high-precision control effect. Through the innovative technical solution, the present application effectively solves the stability, precision and efficiency problems of the prior art when dealing with non-minimum phase systems, providing a comprehensive and efficient solution for numerical control machine tool error compensation control. The modular design of the stable inverse model-based iterative learning error compensation control system for numerical control machine tools proposed by the present application makes the system have good flexibility and scalability. Different modules can be adjusted or replaced according to specific application requirements. And because it applies the related methods proposed in the present application, it also has the beneficial effects of the related methods.
Owner:SICHUAN CHENTIAN MASCH TOOL MFG CO LTD