243results about How to "Enough precision" patented technology

The invention discloses a Beidou / GPS combination based safe train locating method and system. A Beidou satellite navigation system is combined with a GPS satellite navigation system, a ground differential station system, a train-mounted speedometer and a ground responder system are combined in use, and safe location of a train is realized. The system of the invention can coexist and be compatiblewith existing train locating systems, and satellite navigation is safer in the aspect of train locatin.

The invention provides a forced-convention heat transfer experimental device for a strong inner heat source containing porous medium passage. The device mainly comprises a water storage tank, a cooler, a surge tank, a filter, a preheater, a pebble bed experimental section, a vapor-water separator, a condensing cooler, a water return tank, a cooling water tank and a cooling tower which are connected through pipelines, wherein an electromagnetic inductor is arranged outside the pebble bed experimental section; a circulating water pump is arranged between the cooler and the filter; a cooling water pump is arranged among the cooling water tank, the condensing cooler and the cooler; valves or measuring instruments are arranged on related positions of the pipelines; and the measuring instrumentis connected with a data collection system. By adopting proper technology and reasonable design, the device realize simultaneous heating on all metal balls in the porous medium passage to ensure thatthe passage becomes a strong inner heat source containing porous medium passage, so that the heating condition of the pebble bed water-cooled reactor passage can be truly simulated.

An image reading device is provided which is capable of obtaining an image with satisfactory definition without causing an increase in the number of reading pixels and with reduction in costs. Mirror driving sections change a length of an optical path between an original document and a lens to change a scaling factor of an image to be formed on an image sensor. When high-density reading of a small-sized original document rendering a narrow reading range is required, specified mirrors are rotated to prevent light from travelling through a mirror so as to guide the light into a lens with the decreased number of times of reflection by mirrors occurring during a time period before the light reaches a lens and so that a length of an optical path is shortened, which enables an image, to be formed on an image sensor, to be enlarged.

The invention provides a high-precision point cloud registration method for three-dimensional laser scanning. The method comprises steps of providing strategy of two steps from preposed coarse registration to iterative fine registration; carrying out curvature-based feature extraction on scattered point clouds which are obtained through three-dimensional laser scanning and have different visual angles to obtain feature points; and calculating coordinate transformation parameters of the matched feature point pairs to obtain a preposed coarse registration result, eliminating wrong homonymous points by using a distance constraint condition for the condition that the two-point cloud data is not in a subset relationship, and then performing iterative fine registration to obtain a final registration result. Feature point extraction is rapid and accurate, feature point matching accuracy is high, speed is high, coarse registration provides a good initial position for fine registration, after iterative fine registration is iterated to a certain number of times, an accurate result can reach very high precision, registration precision can reach the millimeter level, the method can be used forcomplex point cloud data, and engineering application requirements are met. The point cloud registration speed and precision are greatly improved, and the registration method is wide in application range.

A spline telescoping shaft is provided with an inner shaft including a male spline, and a cylindrical outer shaft including a female spline. The surface of at least one of the splines is provided with a resin coating. Profile shift coefficient e, the number of teeth Z, module m, reference pitch diameter PCD, the tip diameter d1 and root diameter d2 of the male spline, and the tip diameter D1 and root diameter D2 of the female spline have the relationships according to expressions (1) to (8): m(Z + 4) > d1 > m(Z + 2) (1); mZ > d2 > m(Z - 1) (2); m(Z + 4) > D2 > m(Z + 2) (3); mZ > D1 > m(Z - 1) (4); D2 > d1 (5); D1 > d2 (6); PCD = mZ (7); and 0.4 < e < 1.1 (8).

A method of signalling an aquaplaning condition of a tyre, the latter rolling on a rolling surface (5), a footprint area being defined between said tyre and said rolling surface (5), a layer of water (9) being interposed between the tyre and said rolling surface (5), said method comprising: detecting a first signal (S1) representative of a deformation of said tyre due to rolling of said tyre (1) on said rolling surface (5), said first signal comprising at least one portion representative of the interaction between the tyre and said layer of water (9); processing said first signal (S1) so as to determine a parameter (P1, P2, P3, P4) representative of an aquaplaning condition of said tyre (1), as a function of said first signal (S1); generating a notification signal (SN) as a function of said at least one parameter (P1, P2, P3, P4). Also disclosed is a system for signalling an aquaplaning condition of a tyre.

The invention discloses an indoor offline path guide method and system based on the GPS. The method comprises the steps that firstly, GPS information of a preset beacon of the roof of a building is acquired; coordinate information of a spatial distribution plan of the interior of the building and height distribution information of the building are acquired; then, an offline navigation information database of the navigation system is established according to the GPS information, the coordinate information of the plan and the height distribution information of the building; finally, the navigation system is started and navigation information is downloaded from the offline navigation information database to complete indoor path search guide. According to the indoor offline path guide method and system based on the GPS, the offline navigation information database is adopted to determine path guide for a point, to be navigated, inside the building, so that indoor GPS navigation is made possible, and indoor GPS information has high precision when in use; indoor path guide can be achieved through an existing navigation technology; the complexity of path planning is lowered to a great degree.

The invention discloses a jet printing mechanism nozzle adjusting device and an adjusting system. The adjusting system comprises a jet printing mechanism and the adjusting device. The jet printing mechanism comprises a shell and a nozzle. The shell comprises a back plate and a bottom plate adjustably connected with the back plate. The nozzle is installed on the bottom plate. The adjusting device comprises a support, a first connecting part, a second connecting part, a first micro-adjusting mechanism, a second micro-adjusting mechanism and a third micro-adjusting mechanism. The support is fixedly installed on a plane. The second connecting part is installed on the support in a horizontally moving mode. The third micro-adjusting mechanism is used for driving the second connecting part to move in the horizontal direction. The first connecting part and the second connecting part are connected rotationally. The second micro-adjusting mechanism is used for driving the first connecting part to rotate relative to the second connecting part. The back plate and the first connecting part are connected vertically movably. The first micro-adjusting mechanism is used for driving the back plate to do displacement relative to the first connecting part in the vertical direction.

The invention discloses a prediction method comprising the following steps: based on the analysis and the understanding of geological conditions, the growth characteristics and the law of the fracturestructure and the like in a researched area, firstly analyzing and determining influencing factors closely related to the researched area as well as the distribution and the growth of a coal-bed small-scale structure; establishing an ANN forecasting and prediction model based on the looping principle; and finally developing a mine small-scale structure forecasting and prediction information system. The invention provides a set of complete theory system and working methods for the forecasting and the prediction of mine small-scale structures; the method introduces the looping theory and the ANN coupling technique into the forecasting and the prediction of the small-scale structures in front of the tunneled mine coal-shift for the first time; the artificial neural network used for the quantitative evaluation and prediction provides a comprehensive evaluation model which is close to the human thinking model and combines the qualitative evaluation and the quantitative evaluation, and therefore, the method has enough precision; and by utilizing the information of the abundant and cheap coal bed which is exposed in the coal-shift tunneling process and closely related to the distributionand the growth of the small-scale structures, the method needs low cost and well reflects the characteristics and the information of the distribution and the growth of the small-scale structures.

The invention provides a parameter calibration method and device for a single-rotation compensator type spectral ellipsometer. The method comprises: taking a standard sample piece with any thickness as a sample piece to be detected; using a to-be-calibrated single-rotation compensator type spectral ellipsometer for measurement, performing Fourier analysis on a light intensity harmonic signal obtained through measurement, using a global fitting algorithm, and fitting a Fourier coefficient of the measured light intensity signal and a Fourier coefficient of a theoretical light intensity signal toobtain a calibration result of a first wavelength point system parameter; taking the calibration result of the system parameter of the previous wavelength point as the calibration initial value of the system parameter of the next wavelength point, and adopting a wavelength-by-wavelength fitting algorithm to obtain the system parameter calibration value of each wavelength point so as to obtain thesystem parameter of the full spectrum range. According to the method, based on global fitting, hundreds or thousands of wavelengths exist in a full spectrum participating in fitting, so that the calculated single-wavelength system parameter is very close to the true value of the system parameter.

The invention discloses a coaxiality adjusting method for a heel post of a triangular gate and belongs to the technical field of sluice gates. The method includes the steps that the center of a mounting hole of an upper pull rod support is determined through a first disk; the center of a mounting hole of a bottom pivot hinged support is determined through a second disk; a steel wire is pulled through the centers of the two mounting holes; the steel wire is calibrated to be in a horizontal state, and then a basic reference for calibrating a center line is provided, wherein the distance between the steel wire and the edge of each mounting hole which the steel wire penetrates through can be conveniently measured, the height can be adjusted through gaskets, and then the steel wire is fixed after being calibrated. Through the method, operation is convenient, the coaxiality of the heel post can be quickly and accurately calibrated, construction is convenient, and the requirement that the coaxiality error of the mounting holes does not exceed 0.5 millimeter can be met.