10 results about "Polynomial method" patented technology

The invention discloses a method for optimizing operation time and impact of a Niryo One robot based on a multi-strategy improved dung beetle optimization algorithm, and belongs to the technical field of multi-degree-of-freedom industrial robot control. Four interpolation points are set for the motion trail of the Niryo One robot for optimization; on the basis of three sections of motion tracks of Niryo One, six joint motion tracks of each section are described through cubic polynomial interpolation, quintic polynomial interpolation and cubic polynomial interpolation methods, and a 3-5-3 mixed polynomial method is constrained; after six joint coefficients of different polynomials of Niryo One are solved, the influence of multiple constraints such as optimal time and impact and the maximum speed and acceleration of a motor of each joint is synthesized, and a fitness function which finally needs to be optimized is defined; and optimizing the trajectory of the Nryo One by using a multi-strategy improved dung beetle optimization algorithm, and returning the optimal operation time and fitness value of each section of trajectory after optimization. Compared with an original dung beetle optimization algorithm and other algorithms, the method has the advantages that the iteration speed is higher, a better solution can be found, and the working efficiency of the Niryo One robot in use is improved.

The present invention discloses a fatigue crack growth rate test method based on incremental polynomial supplementary calculation, which belongs to the technical field of fatigue crack growth rate testing. The method comprises the following steps: (1) obtaining an a-N curve through a fatigue crack growth rate test; (2) using an incremental polynomial method to calculate the da / dN values ​​and ΔK values ​​of other data points in the a-N curve except for the front n data points and the end n data points; (3) supplementing n virtual data points at the front or end of the a-N curve; (4) using an incremental polynomial method to calculate the da / dN values ​​and ΔK values ​​of the front n data points or the end of the a-N curve based on the supplemented n virtual data points; (5) using the da / dN values ​​and ΔK values ​​obtained in steps (2) and (4) to draw a da / dN-ΔK curve, thereby obtaining a fatigue crack growth rate curve. The method of the present invention can obtain effective da / dN and ΔK data to the maximum extent.

The invention belongs to the technical field of electronic information and wind tunnel test measurement, and particularly relates to a wind tunnel six-component balance dynamic decoupling method and application based on multi-mode transfer learning and physical constraint, and the method comprises the following steps: feature extraction and data preprocessing; the preprocessed data features are input into a pre-trained convolutional neural network ResNet-18 model, and hierarchical data feature extraction is carried out; the processed image feature data, strain feature data and vibration and temperature feature data are input to a full splicing layer for heterogeneous fusion splicing, the spliced data are input to a pre-trained machine learning regression XGBoost model for feature fusion regression and mapping, and finally six aerodynamic force / torque components acting on the aircraft are output. Through fusion of multi-modal transfer learning and physical constraint, in actual measurement of subsonic and hypersonic wind tunnels, the dynamic decoupling precision is improved by more than 50% and 65% compared with a traditional least square method and a polynomial method.

This invention discloses a method for optimizing the dynamic transmission error distribution characteristics of a harmonic reducer, comprising: establishing a static transmission error probability model to obtain the probability distribution of the overall static transmission error; constructing a dynamic transmission error mathematical model considering static transmission error and dynamic parameters; constructing a high-precision surrogate model of dynamic transmission error including the probability distribution of static transmission error and the range of dynamic parameters; obtaining the probability distribution of dynamic transmission error; and dynamically adjusting the range of dynamic parameters based on a particle swarm optimization strategy to find the parameter range that optimizes the dynamic transmission error distribution. By introducing static transmission error into the dynamic model of the harmonic reducer, considering the influence of the processing and assembly of the harmonic reducer on the transmission error, a probability-range hybrid uncertainty model is used to mathematically describe the probability distribution characteristics of static transmission error and the range of dynamic parameters, and a Chebyshev polynomial method is used to construct an approximate model of dynamic transmission error.

The present invention discloses a modal analysis method and system based on segmented iteration, belonging to the technical field of modal analysis. The measured frequency response is grouped according to different reference points, and a multi-modal peak function is selected as the modal indicator function according to the grouping result; the peak-valley points are identified from the modal indicator function, and the frequency domain is segmented; the frequency points to be calculated are sampled between the peak-valley points to construct a frequency response sequence to be calculated; the orthogonal polynomial method of introducing a weighted matrix is used for modal analysis, parameter identification is carried out for the segmentation, and the coefficients of the polynomial are obtained; the fitting frequency response is calculated according to the polynomial coefficients of the segmentation, the fitting frequency response is subtracted within the frequency band of the frequency response to be calculated, and modal analysis is re-performed on the new frequency response to be calculated to obtain the polynomial coefficients within the segmentation; according to the polynomial coefficients calculated for each segmentation, polynomials of the frequency response within each segmentation are constructed, and finally the structural inherent characteristics are obtained. The present invention solves the calculation error caused by the mutual influence between noise and frequency bands in modal analysis.

The application relates to the technical field of automatic driving and discloses an intelligent networked vehicle trajectory planning method based on a space-time corridor combined with real-time aggressiveness. The intelligent networked vehicle trajectory planning method considers other vehicles in a dynamic traffic environment and their predicted trajectories by constructing a space-time corridor, and real-time driving behavior information of the other vehicles is integrated into trajectory planning of a host vehicle. On this basis, a 7th-degree polynomial method based on sampling is used to generate a path, and a sequence quadratic programming optimization technology with soft constraints is combined to balance safety, efficiency and comfort of the trajectory. In this way, the application can effectively predict and respond to aggressive changes in the traffic environment, adjust the trajectory in real time, ensure safety and comfort during vehicle driving, so as to handle complex urban traffic environments, ensure that the host vehicle can dynamically adjust its driving path under different driving scenarios to respond to changes of surrounding vehicles and obstacles, and provide more efficient and stable driving experience.

This invention relates to the field of geophysical exploration technology, specifically to a high-precision three-dimensional forward modeling method for airborne electromagnetic spectral elements considering induced polarization effects. Based on the Cole-Cole model, a complex conductivity expression considering induced polarization effects is established, and the frequency domain Helmholtz equation is introduced to construct the corresponding governing equations. A regular hexahedral mesh is generated, and reference domain vector basis functions are constructed using the Gauss-Lobatto-Legendre orthogonal polynomial method according to the spectral element method. The mapping relationship between these functions and physical mesh elements is established. The Galerkin weighted residual method is applied to discretize the governing equations into element system matrices, which are then assembled to form the overall system matrix and the corresponding linear equation set. A direct solver is used to obtain the frequency domain three-dimensional electromagnetic response, and the time domain three-dimensional forward modeling result of the computational region is obtained through Hankel transformation. This invention achieves rapid and high-precision three-dimensional forward modeling simulation of complex geological models containing induced polarization effects.

The invention discloses a fatigue crack growth rate testing method based on incremental polynomial supplementary calculation, and belongs to the technical field of fatigue crack growth rate testing. The method comprises the following steps: (1) obtaining an a-N curve through a fatigue crack growth rate test; (2) calculating da / dN values and delta K values of other data points except the n data points at the front end and the n data points at the tail end in the a-N curve by adopting an incremental polynomial method; (3) supplementing n virtual data points at the front end or the tail end in the a-N curve; (4) calculating da / dN values and delta K values of the n data points at the front end or the tail end in the a-N curve by utilizing an incremental polynomial method based on the supplemented n virtual data points; and (5) drawing a da / dN-delta K curve by using the da / dN value and the delta K value obtained in the steps (2) and (4) to obtain a fatigue crack growth rate curve. By means of the method, effective da / dN and delta K data can be obtained to the maximum extent.

The present invention belongs to the technical field of seismic data processing for oil and gas exploration, and specifically discloses a method and system for estimating formation Q value by two-dimensional Legendre polynomial decomposition in the time-frequency domain. The method of the present invention first calculates the time-varying logarithmic amplitude spectrum of seismic data based on the short-time Fourier transform, and then maps the time-varying logarithmic amplitude spectrum of seismic data into a two-dimensional square-integrable function space spanned by Legendre polynomials. In this space, the time-varying logarithmic amplitude spectrum of seismic data is decomposed by two-dimensional Legendre polynomials to estimate the time-varying wavelet amplitude spectrum, and finally the equivalent formation Q value is calculated using the time-varying wavelet amplitude spectrum. The method of the present invention uses Legendre polynomial decomposition to estimate the time-varying wavelet amplitude spectrum. Compared with the methods of decomposing into Fourier series and traditional polynomials, this method has the advantages of fast convergence, strong approximation ability, and reduction of matrix ill-conditioning. It can also eliminate the influence of factors such as local strong reflections and waveform coupling, and improve the stability and accuracy of Q value estimation.

The invention belongs to the technical field of oil-gas exploration seismic data processing, and particularly discloses a stratum Q value estimation method and system based on time-frequency domain two-dimensional Legendre polynomial decomposition. The method comprises the following steps: firstly, calculating a time-varying logarithmic amplitude spectrum of seismic data based on short-time Fourier transform, and then mapping the time-varying logarithmic amplitude spectrum of the seismic data into a two-dimensional square integrable function space spanned by a Legendre polynomial; and performing two-dimensional Legendre polynomial decomposition on the time-varying logarithmic amplitude spectrum of the seismic data to estimate a time-varying wavelet amplitude spectrum, and finally calculating a stratum equivalent Q value by using the time-varying wavelet amplitude spectrum. According to the method, the Legendre polynomial decomposition is used for estimating the time-varying wavelet amplitude spectrum, and compared with a method for decomposing the amplitude spectrum into Fourier series and a traditional polynomial, the method has the advantages of being fast in convergence, high in approximation capability, capable of reducing matrix morbidity and the like, can eliminate influences of factors such as local strong reflection and waveform coupling, and improves stability and precision of Q value estimation.