6results about How to "Practical method" patented technology

The application discloses a pumped storage full-power frequency converter power unit variable frequency control method and device, N power units are cascaded at an AC end to form a test valve, and M power units are cascaded at the AC end to form a test valve; the method is used for controlling the test valve to output several AC frequency target values, and the method comprises the following steps: pre-charging DC capacitors in the test valve and the test valve to target values; determining corresponding output current / power target values according to the AC frequency target values to be output; controlling the turn-on and turn-off time of the turn-off semiconductor of each power unit in the test valve and the test valve, so that the actual output current / power of the test valve is the output current / power target value, and the actual output frequency of the test valve is the AC frequency target value. The application can simulate the continuous speed regulation operation condition of the pumped storage full-power frequency converter power unit on the pumped storage unit.

The present application relates to a kind of excavating anchor integrated machine fast excavation working face ventilation dust removal system process parameter determination method, comprising the following steps: S1, establish field simulation entity three-dimensional physical model;S2, after grid division, grid independence verification experiment is carried out;S3, the numerical simulation experiment of different ventilation conditions influence air curtain formation is carried out, the influence of different ventilation conditions on dustproof air curtain is compared and analyzed, and the dustproof air curtain formation condition is obtained;S4, the numerical simulation experiment of different ventilation conditions on the dust concentration distribution of fast excavation working face is carried out, combined with step S3, obtain the key process parameter value under the best dust-settling effect of fast excavation working face ventilation dust removal system;S5, field application verification and correction, wherein different ventilation conditions refer to ventilation dust removal system pressure suction ratio, different distance between axial air outlet of self-adaptive air control dust device and head-on, axial radial air outlet ratio;By determining the best process parameter, improve the effect of dust control of fast excavation working face.

This invention discloses a control method and system for indirectly obtaining commutation signals based on BLDC terminal voltage, belonging to the field of brushless DC motor positionless control. The method includes: sampling the voltage of the floating phase at the current commutation point after a set electrical angle; sampling the voltage of the floating phase at the next detected zero-crossing point after the current commutation point; calculating the actual zero-crossing time using the linear relationship between the back electromotive force of the first and second sampling points; obtaining the lag compensation time from the zero-crossing point to the commutation point by combining the difference between the actual and detected zero-crossing times and the commutation reference time delay; sampling the same floating phase at an electrical angle interval of α after the current commutation point and at an electrical angle interval of (60°-α) after the turn-off point, summing the two samples, and determining whether the commutation is leading or lagging based on the result; and using a PI regulator to correct the lag compensation time in a closed loop. This invention is simple, practical, and can accurately obtain the commutation signal.

A kind of deep coal bed gas horizontal well perforation section optimization method based on well logging data, using conventional well logging data (natural gamma, gas side total hydrocarbon content), deep coal rock analysis test data (coal rock industrial component), first, crossplot means is used to determine the horizontal section completion quality parameter (Young's modulus, Poisson's ratio, brittleness index) in steps, then the formation reservoir quality parameter (gas side total hydrocarbon content) is arranged, finally, combined with the brittleness index parameter capable of reflecting the completion quality and the gas side total hydrocarbon content capable of reflecting the reservoir quality two parameters, the purpose is to form deep coal bed gas horizontal well perforation section comprehensive index to optimize and determine the horizontal section perforation favorable area;The application takes into account the mineability of reservoir and the compressibility of stratum, also reflects the formation reservoir quality and completion quality characteristics, emphasizes the influence of horizontal well section rock mechanics heterogeneity on perforation fracturing efficiency, with the characteristics of coal bed gas reservoir type evaluation precision, simple and practical method.

This application provides an electrochemical sensor for detecting luteolin, comprising a working electrode and a sensing material modified on the working electrode; the sensing material is a Co-N / C nanomaterial. The Co-N / C nanomaterial prepared in this application possesses a unique structure and excellent electrocatalytic activity, which can significantly enhance the electrochemical response signal to luteolin, thereby achieving highly sensitive detection of luteolin. Simultaneously, this sensor exhibits good selectivity, effectively avoiding interference from other coexisting substances in the sample.

The invention relates to the technical field of image processing technology, artificial intelligence technology, neural network technology and computer vision, in particular to a lightweight human body posture estimation network and method based on HRNet, comprising an overall structure of the network and a backbone part of the network, the overall structure of the network is provided based on a high-resolution network architecture, and the backbone part of the network is provided based on the HRNet. The main body part comprises four network branches with different resolutions and two network stages. According to the method, a lightweight network for multi-person body posture estimation from bottom to top can be realized, so that the whole method is more practical in use, redundant errors of single-person posture estimation by the network can be eliminated to a certain extent through preprocessing operation, and a detected posture graph has a better visualization effect; the feature map dimension exchange module of the network is inserted before the feature map of the backbone part enters the branch network, and aims to enhance information exchange between different branch feature maps.