37results about How to "Fitting results are accurate" patented technology

The invention discloses a method based on monocular vision for detecting and roughly positioning the edge of a road, and relates to the field of machine vision and intelligent control. Aiming at a continuous road with different edge characteristics, two road edge detection methods are supplied and suitable for semistructured and nonstructured roads and can be applied to vision navigation and intelligent control over a robot. The invention provides a method for detecting the edge of the road based on colors and a method for detecting the edge of the road based on threshold value partitioning. On the basis of the obtained edge of the road, an image is subjected to inverted perspective projection transformation, so that a front view is transformed into a top view; and according to a linear corresponding relation between a pixel and an actual distance in the image, a perpendicular distance from the current position of the robot to the edge of the road and a course angle of the robot can be calculated. The method is easy to implement, high in anti-interference performance, high in instantaneity and suitable for the semistructured and nonstructured roads.

The invention belongs to the technical field of laser spectroscopy, and mainly relates to a calibration-free wavelength modulation spectroscopy gas detection method based on an S[2f] method. Corresponding scientific analysis shows that A, i[1], i[2], concentration and phase difference psi[1] and psi[2] have little influence on S[2f]/S[2f]<c> signals, and only WMRF has obvious influence on the S[2f]/S[2f]<c> signals. Therefore, under conditions of uncertain concentration and phase shift, WMRF is obtained by inverting the S[2f]/S[2f]<c> signals, and because fitting parameters are greatly reduced, the method can be guaranteed to be simple, rapid and accurate. On the basis, the concentration of to-be-measured gas is fitted, and a measurement value with higher accuracy degree is obtained. The new method is simple, rapid and accurate, and is suitable for wide promotion in the field of gas detection.

The invention belongs to the technical field of laser spectroscopy, in particular relates to a WMRF new model-based calibration-free wavelength modulation spectrum gas detection method, and solves the technical problem of low precision of a calibration-free wavelength modulation spectrum technology currently used for gas concentration detection. An etalon of a 0.02 cm<-1> free spectral range is used to analyze wavelength change WMRF caused by signal modulation, a first harmonic component with the amplitude linearly changed and a second harmonic component with an amplitude as a constant are observed, and a new model for describing WMRF is described. By using the new model, a system can acquire a more accurate fitting result; compared with a conventional system, hardware module addition and manual operation are not needed, only program improvement is needed, and development and application are facilitated. The method is simple in technical scheme and convenient in operation, consumption of lots of manpower and material resources is not needed, and the cost and convenience degree in use are easily accepted by most application departments.

The invention provides a wind power scene generation method and system based on probability distribution, and the method comprises the steps of obtaining the historical data of a prediction value andan actual measurement value of wind power, and extracting the difference between the prediction value and the actual measurement value of the wind power, i.e., a prediction error; selecting a wind speed, a wind direction and a fitting error which directly influence wind power, and respectively fitting distribution of prediction errors under the influence of the wind speed, the wind direction and the fitting error; combining the prediction error distribution under the three influence factors according to corresponding weight parameters, taking the minimum residual sum of squares of a probability density function and a distribution histogram as an objective function, solving an optimal solution of the weight, and obtaining a prediction error probability density function; discretizing the probability density function to obtain a large number of random scenes, and selecting typical scenes; according to the invention, mixed distribution is adopted, weights are set for error distribution under different influence factors, the influence of the influence factors on the error distribution is comprehensively considered, and an obtained fitting result is more accurate than single error distribution.

The invention discloses a three-dimensional crosslinking network-based calculation method of dynamic mechanical parameters of an asphalt mixture. A three-dimensional network linking model is established according to stress-strain characteristics of different components, load test data are combined, corresponding dynamic mechanical functions of the asphalt mixture are obtained through fitting parameters of energy of all single-chain structures in the network linking model under different stress-strain load states, and then the dynamic mechanical parameters thereof are calculated and determined.According to the method, influences of the different components of the asphalt mixture are fully considered, three-dimensional crosslinking networks are respectively and independently established forthe different components in the asphalt mixture, and influences of the different components on the overall stress-strain characteristics of the mixture are evaluated thereby. According to the method,macroscopic performance characterization of the material under dynamic load action can be linked from the molecular chain energy of the microstructures through establishment of the crosslinking networks, expansion from a microlevel to a macrolevel can be realized, and fitting results are more precise. At the same time, dependence on the test data is also accordingly reduced, test costs are lower,and the method is suitable for promotion.

The invention relates to two die bodies withe the same inventive concept and discloses a hardening calibration method for an X-ray CT beam and based on the die bodies. One X-ray CT beam hardening calibration die body comprises an upper part and a lower part, the upper part is a measurement structure, the main body of the upper part is a cylinder, the outer edge of the bottom face of the cylinder is an Archimedean spiral, step-shaped circular holes are formed in the outer edge of the bottom face of the cylinder, the diameter of the adjacent layers of the circular holes is equal to or slightly larger than the difference of the maximum radius and the minimum radius of the spiral, and an outer spiral parameter and an inner layer number are corrected according to the actual measurement demands;the lower part is an auxiliary structure which is divided into a holding area, a centering area and a clamping area from top to bottom, and the surface of the holding area is rough, convenience is provided for operation; the centering area is a smooth cylinder used for conducting centering operation on a detector; in the operation process, the radius of the corresponding inner layer is selected according to the required penetration distance, firstly, the centering area in the auxiliary structure is placed in the center of a view field for centering, then the die bodies are downwards moved, the steps of the inner layer, corresponding to the selected radius, in the measurement structure are placed in the center of the view field for 360-degree scanning.