126 results about "Magnetic declination" patented technology

Mobile terminals, methods, and program products for generating a magnetic heading. A geographic position of the mobile terminal is determined. A magnetic field at the mobile terminal is sensed. A magnetic inclination and/or a magnetic declination of the magnetic field is determined based on the determined geographic position. A magnetic heading is determined for the mobile terminal based on the sensed magnetic field and based on the determined magnetic inclination and/or magnetic declination.

An apparatus receives a digital image of a sun trace chart having time gradient lines and a sun trace extent line for a site. A selector defines on a display points along the solar trace extent line to define a solar opportunity region. An adjuster adjusts the digital image based on the magnetic declination of the site. The solar exposure potential is determined based on the proportion of solar trace extent lines within solar opportunity region and potential solar exposure. Site adjustments to increase solar energy potential are facilitated. A method of evaluating a site for solar energy potential is disclosed. A solar exposure device for recording and analyzing a solar trace is disclosed.

The invention discloses a correction method of an electronic compass in an underwater vehicle, which comprises the following steps of: inquiring magnetic declination, and carrying out corrected navigation on the water surface of the vehicle; recording navigation data by a navigation sensor; exporting correction navigation data from a communication module; searching a hard magnetic interference parameter, solving the error surface plot between a correction track and a reference track under the condition of (2N+1)<2> disperse hard magnetic interference parameters, wherein the minimum point corresponding to the surface plot is the search result; according to the set correction precision requirement, repeating and reducing the search range and grid, and re-searching to obtain a more precise hard magnetic interference parameter evaluation value; and finally, applying the searched magnetic parameter evaluation value in the navigation of the underwater vehicle. The method disclosed by the invention has the advantages that the operation is simple, the influence of the outer magnetic interference to the electronic compass in the underwater vehicle can be effectively eliminated and thus, the corrected electronic compass can return back to the corrected attitude angle.

The invention discloses a method for determining an initial attitude angle of an aircraft, and the method comprises the following steps of: calculating a pitch attitude angle and a yawing attitude angle psi according to speed information obtained by a GPS (Global Positioning System) receiver; obtaining geomagnetic information My1 and Mz1 by virtue of a double-shaft geomagnetic sensor; and calculating a rolling attitude angle gamma according to the formula shown in the specification, wherein alpha and beta are a magnetic declination angle and a magnetic inclination angle of the current position of the aircraft, respectively. The method, provided by the invention, is low in cost, simple and high in precision, and can be used for realizing the air attitude measurement of a small aircraft.

The invention relates to an online calibration method for north-seeking rotation on the basis of a triaxial MEMS (Micro-Electromechanical System) gyroscope. The online calibration method comprises the following steps of: on a rotary control system, carrying out 'online' rotation control on an attitude instrument integrated with the triaxial MEMS gyroscope, measuring the attitude of the attitude instrument in real time by carrying out installation error calibration, filtering processing and temperature compensation on the triaxial MEMS gyroscope, outputting a course angle when the rolling angle and pitching angle of the attitude instrument are zero, applying a transformation matrix between a carrier coordinate system and a navigation coordinate system to carry out transformation, and after consideration for the local magnetic declination, finally obtaining a north-seeking value. The online calibration method adopts the MEMS gyroscope, is low in cost, high in north-seeking speed, high in accuracy and simple in calculation principle and is applicable to underground north seeking with high requirements.

The invention provides a rotator gesture measuring method based on multisensor data. The method comprises the following steps: calculating an angle of pitch and a roll angle gamma0 of a rotator in a rotary non-launching working condition according to a triaxial acceleration overload component detected by a triaxial accelerometer; calculating a course angle according to an axial geomagnetic component, the angle of pitch, the roll angle gamma0 detected by a triaxial geomagnetic sensor and local geomagnetic components Bx, By and Bz and a magnetic declination angle beta of the position of the rotator; in a launching working condition of the rotator, calculating an angle of pitch and the course angle according to the roll angle gamma0, the pitch of angle and the course angle as well as a triaxial rotary angle velocity detected by a triaxial gyroscope; correcting the geomagnetic component detected by the triaxial geomagnetic sensor in the launched working condition periodically; and calculating a roll angle gamma in the launched working condition according to the corrected geomagnetic component, the pitch of angle, the course angle and the local geomagnetic components Bx, By and Bz. Themethod provided by the invention is small in size, high in gesture measuring accuracy and low in cost.

The invention relates to a single-axis accelerometer and three-axis magnetic field sensor based attitude measurement system and an attitude measurement method thereof. The system includes: an accelerometer, a three-axis magnetic field sensor, a GNSS module and a data processing module. The accelerometer is a Z axial direction single-axis accelerometer in orthogonal arrangement with a forward shaft and used for measuring gravitational acceleration component so as to obtain the triangle relationship between a ground carrier's roll angle and pitch angle. The data processing module is used for acquiring geomagnetic field model, geomagnetic inclination information and magnetic declination information according to a position information look-up table, and combining the triangle relationship between the ground carrier's roll angle and pitch angle and the three component arrays of a geomagnetic field under a carrier coordinate system to finally work out a course angle, the pitch angle and the roll angle. The new attitude measurement method provided by the invention can realize exact calculation of the carrier attitude angle under a carrier stationary or low speed moving state, can reduce a measurement amount, and avoids introduction of more measurement noise.

The invention discloses a communication vehicle-mounted antenna alignment system based on a Beidou dual-mode terminal. The invention relates to the technology of Beidou messages, the Beidou positioning and orientation technology and the technology of scattering link calculation. The system consists of a Beidou second-generation receiving antenna, a Beidou first-generation antenna, a Beidou positioning and orientation device, and an industrial control computer. The system obtains the longitude and latitude of a communication vehicle-mounted station and the azimuth of a vehicle body through Beidou positioning and orientation, calculates a communication azimuth angle through the longitudes and latitudes of communication vehicle-mounted stations at two ends, outputs an antenna control signal to an antenna control unit so as to drive the front and back antennas to face a communication position, and achieves the quick switching-on of a communication system. The alignment angle of the system is not affected by the terrestrial magnetism and magnetic declination, and the system is convenient to operate.

The invention relates to a permanent magnet magnetic declination measuring watch and a measurement method. The permanent magnet magnetic declination measuring watch comprises a watch shell, a scale base and a watch base which are connected with two sides of the watch shell, and a non-magnetic declination magnet, wherein the front face of the scale base is provided with a scale ring, which center is provided with a pointer which rotation shaft penetrates through the scale base, a test magnet at the back of the scale base is fixedly connected with the rotation shaft of the pointer, the center of the magnetic pole dividing line of the test magnet is at the rotation shaft of the pointer, the pointer is vertical to the magnetic pole dividing line of the test magnet, the center of the watch base is provided with a rectangle hole for arranging the non-magnetic declination magnet. The measurement method comprises: arranging a non-magnetic declination magnet into the rectangle hole of the measuring watch, adjusting zero, taking out the magnet, arranging an object magnet, considering the index of the pointer as the read number of the magnetic declination of the object magnet. The invention has simple measurement process, virtual magnetic deviation read number, fast identification and improved production efficiency.

The invention discloses a geomagnetic matching navigation method based on magnetic declination correction. The geomagnetic matching navigation method comprises the steps that geomagnetic triaxial vector magnetic field intensity data is first collected, and a grid type geomagnetic database is established; an electronic compass is utilized to sample magnetic declination, and a grid type magnetic declination error database is established; then through a method of generalized continuation approximation, database files with grids subdivided as much as possible are generated for the collected discrete data; in the online navigation and positioning stage, a series of geomagnetic field intensity information sequences are measured by a geomagnetic sensor, at the same time, accelerated speeds and direction angles obtained by an inertial device are subjected to dead reckoning to calculate a motion trajectory, and the motion trajectory is integrated with the geomagnetic field intensity informationsequences; the direction of the motion trajectory is corrected through error compensation; and a corrected dead reckoning positioning result and a corrected geomagnetic feature matching positioning result are subjected to extended Kalman filter fusion to obtain a final positioning result. The geomagnetic matching navigation method improves the accuracy of dead reckoning and reduces the computational complexity.

The invention relates to the field of anisotropic permanent magnet measurement, and discloses a device for measuring magnetic declination of a permanent magnet. The device consists of a loading platform (2), a displacement platform (3), a multidimensional electric control device (4), an induced voltage generation unit (5), an induced voltage detection and processing unit (6) and a computer control and processing unit (7). The device provided by the invention can be used for measuring the magnetic declinations of various shapes of the permanent magnets with single easy magnetization direction;and by adopting the device, the measuring method is simplified, and the measuring efficiency is improved.

A blind-guiding magnetic electronic compass relates to direction measurement and blind-guiding techniques. The compass measures geomagnetic field horizontal component by using a geomagnetic sensor, transmits to a microprocessor after digital/analog conversion, obtains a geomagnetic azimuth through calculation in the microcomputer, adds the geomagnetic azimuth with the magnetic declination data stored in the memory to obtain the direction data relative to the north, divides the measured 0-360 DEG direction angle information according to 8 extents and converts into forms such as 'north-by-east X DEG', 'east-by-north X DEG', 'positive east', and the like, which are convenient for understand, and outputs in voice prompt. The direction measurement and voice prompt device is capable of implementing accurate determinant function of direction, and also provided with magnetic field abnormality prompt function, can be convenient for user to determine accurately the reliability of the provided information, which is suitable not only for the blind, but also for the ordinary people for outdoor activity.

The invention discloses a compression molding mold for sintered nd-fe-b. The compression molding mold comprises large magnet-conductive side plates, small non-magnet-conductive side plates and a non-magnet-conductive pressing plate, which can define a sealed forming chamber. Non-magnet-conductive contact plates for making contact with nd-fe-b powder are arranged on the inner walls of the large magnet-conductive side plates. According to the compression molding mold for sintered nd-fe-b, the non-magnet-conductive contact plates are used for replacing the large magnet-conductive side plates to make contact with the nd-fe-b powder, and accordingly friction produced between two ends of blank and the large magnet-conductive side plates during compression orientation of the nd-fe-b powder can be reduced; the blank orientation degree is improved, deformation of the blank after sintering is prevented, the magnetic declination of the blank is reduced, and the compression forming performance of small-size hollow square blank is improved.

The invention discloses a magnetic declination calibration method based on GNSS positioning. The method includes the standard azimuth angle obtaining step used for calculating standard azimuth angles between center points in multiple directions and deviation points through GNSS positioning on a GNSS receiving machine, the projection azimuth angle obtaining step used for calculating projection azimuth angles of projections of the X axes of magnetic sensors in multiple directions in a horizontal plane through collected sensor data, and the magnetic declination obtaining step used for calculating the difference between the standard azimuth angle and the projection azimuth angle in each direction and obtaining magnetic declination on the basis of the average value of differences in all the directions for calibration of the magnetic sensors.

The invention discloses a method for simply measuring an orthogonal angle of a component quadrature coil in a vector magnetic meter. The method comprises the steps that by installing a scalar magnetometer probe on a support inside a magnetic dip coil, after two high-stability constant-current sources are connected with the magnetic dip coil and a magnetic declination coil respectively, the high-stability constant-current sources are utilized for applying currents which are equal in size and same or opposite in direction on the magnetic dip coil and the magnetic declination coil, and then the currents which are equal in size and same or opposite in direction are applied on the magnetic dip coil and the magnetic declination coil simultaneously in sequence, resultant magnetic fields under various conditions are determined separately, and then the orthogonal angle of the component quadrature coil is worked out. In the process, precise mechanical axial alignment operation is not needed, the error brought by inconsistency of assembling is eliminated, the orthogonal angle of a two-dimensional or three-dimensional coil can be measured efficiently and accurately, and scientific research or production use is convenient.

The invention discloses a roll angle detection method of a directional firework shell and a detection device thereof. The method comprises the steps of: firstly, determining and inputting related information of emitting the firework shell during detection; computing a local magnetic inclination and a local magnetic declination; computing a relatively top reference angle and an initiation phase; fixing the initiation phase to the firework shell, loading the firework shell and emitting; beginning to work by a shell-borne part after emitting the firework shell; detecting a geomagnetic signal by a magnetic detection circuit; computing the phase of the geomagnetic signal; finally computing the deviation of the initiation azimuth; and continuously outputting deviation signals to an attitude control device. When the deviation of the azimuth is 0, the initiation azimuth is needed. The detection device comprises a ground part and the shell-borne part. The detection method can be used for directly detecting the deviation of the initiation azimuth without integral or accumulated errors. The detection device has small volume, simple circuit, low cost and strong impact resistant performance.

The invention discloses a compression molding die used in compression of neodymium iron boron green bodies. The compression molding die comprises non-magnetic conductive small side plates and magnetic conductive plates arranged on the cavity wall enclosed by the small side plates. By the additional arrangement of the magnetic conductive plates in the compression molding die, the situation of nonuniform magnetic fields at the positions close to the small side plates is avoided, larger magnetic declination generated from magnet particles at the positions close to the small side plates are avoided, and quality of sintered neodymium iron boron products is further improved.

The invention provides a mould for orientation press of a neodymium-iron-boron magnet. The mould comprises two oppositely arranged big side plates and two oppositely arranged small side plates; the two big side plates and the two small side plates together encircle a cylindrical inner cavity of the mould; the small side plates are provided with clamping bulges on a combined interface of the small side plates and the big side plates; the clamping bulges are arranged on a center line of the small side plates; the big side plates and the small side plates are connected by clamping. The invention also provides an orientation press method of the neodymium-iron-boron magnet. The method comprises the steps of firstly mixing neodymium-iron-boron micro powder and a lubricant to obtain a neodymium-iron-boron micro powder mixture; then placing the neodymium-iron-boron micro powder mixture into the mould to be subjected to orientation press to obtain a neodymium-iron-boron magnet pressed green compact. The neodymium-iron-boron magnet prepared by the orientation press method and a preparation method provided by the invention is relatively low in magnetic declination and relatively high in yield, so the product percent of pass is effectively improved, and the production cost is greatly reduced.