105 results about "Horizontal coordinate system" patented technology

The invention relates to a photographic measuring method of a position and a swing angle of a lifting hook of a crane. The method comprises the steps of: mounting a set of gesture measuring system and a set of lifting hook photographic measuring system at the top end of an arm rest of a crane, which is close to a lifting rope rolling wheel; mounting a cooperation mark on the lifting hook; measuring inclination gesture of the lifting hook photographic measuring system in real time through a gesture measuring system; measuring the position of the cooperation mark on the lifting hook, with respect to the lifting hook photographic measuring system in real time and in an intersecting manner through double cameras of the lifting hook photographic measuring system; representing the position of the lifting hook by using a horizontal coordinate system based on the inclination gesture; and calculating a swing angle of the lifting hook in real time by utilizing the position of the lifting hook represented by the horizontal coordinate system. As the photographic measuring method is utilized to solve the measurement problem of the position and swing angle of the lifting hook of the crane, the photographic measuring method of the position and the swing angle of the lifting hook of the crane, disclosed by the invention, has the advantages of easy implementation of relevant treatment and calculation and high real-time capability, and can be applied to measurement of positions and swing angles of lifting hooks of multiple cranes.

The invention aims at providing a GPS multi-antenna attitude determination method. The method comprises the following steps: firstly GPS multi-antenna observation data, a GPS satellite ephemeris and the coordinates of antennas on a carrier coordinate system are collected; a smoothing procedure is carried out to C / A code observation data with a carrier wave phase observed value; a carrier platform rough attitude angle, the coordinate of the main antenna in a local horizontal coordinate system, the shared vision satellite elevation angles and direction angles of the antennas and the baseline vector from the main antenna to subordinated antennas in the local horizontal coordinate system are calculated; based on the geometry relations of the baseline vectors among the antennas and the baseline vectors from the satellite to a receiver in the horizontal coordinate system, the single difference integer cycle fuzziness value of different antennas of the same satellite is solved; a reference satellite is selected and a difference operation is carried out to the single difference integer cycle fuzziness value to obtain an integer cycle fuzziness double difference value; the integer cycle fuzziness double difference value obtained is substituted into a carrier wave phase double difference model to obtain accurate coordinate components of the antennas and based on the coordinate components of the antennas, accurate attitude parameters are solved so as to realize GPS multi-antenna attitude determination.

The invention belongs to the technical field of radio signal positioning, in particular to an azimuth information-based beyond-visual-range target geographic coordinate direct estimation method; the method comprises the following steps of establishing a two-dimensional angle array signal model of each observation station, wherein the two-dimensional angles comprise an azimuth angle and a pitch angle, and calculating respective covariance matrixes; based on a ground plane coordinate system of each observation station, establishing a mathematical model of each station arrival azimuth angle relative to the target geographic coordinate parameters; utilizing the covariance matrix of each station, and establishing a mathematical optimization model for jointly estimating the target geographic coordinate parameters and the pitching angle parameters according to the maximum likelihood estimation criterion; and solving the mathematical optimization model through iteration, and obtaining a targetaddress coordinate. By adoption of the method, the target positioning precision under a low signal-to-noise ratio can be remarkably improved, the estimation precision of the target pitch angle is improved, and the convergence speed is relatively high, high-dimensional searching is not needed, and the calculation amount of real-time positioning can be effectively reduced; and the method is relatively high in practical application value, stable and reliable in performance, and efficient.

A magnetic compass includes: a three-axis magnetic sensor for detecting geomagnetic vector as geomagnetic components in directions of three orthogonal axes x, y, and z; a data-plane calculating unit for calculating a data plane on which output data of the three-axis magnetic sensor are present in a sensor coordinate system of the three axes x, y, and z; a unit vector calculating unit for calculating unit vectors of a horizontal coordinate system of three orthogonal axes X, Y, and Z whose Z-axis runs vertically and X-Y plane defines a horizontal plane relative to the earth; a horizontal coordinate system conversion unit for converting geomagnetic components in the sensor coordinate system detected by the three-axis magnetic sensor into geomagnetic components in the horizontal coordinate system; an azimuth calculating unit for calculating azimuth based on the converted geomagnetic components in the horizontal coordinate system; and a display unit for displaying the calculated azimuth.

An apparatus and method of compensating for the change of an earth magnetic sensor output according to an attitude (roll and pitch) using an inclinometer in the case of calculating azimuth information using a two-axis earth magnetic sensor is disclosed. The attitude of the earth magnetic sensor module is measured using the inclinometer, and a coordinate conversion matrix for converting a body coordinate system to a horizontal coordinate system is calculated. Z-axis direction virtual earth magnetic data at the present attitude of the earth magnetic sensor module is generated using the output of the two-axis earth magnetic sensor and the calculated attitude information. After the generated Z-axis earth magnetic data and the measured X-axis and Y-axis earth magnetic data are converted into the horizontal coordinate system, the calculated azimuth angle is considered as the azimuth angle of the earth magnetic sensor module.

The invention relates to an initial alignment method of a strap-down inertial navigation system and particularly relates to the initial alignment method of the strap-down inertial navigation system based on a low-precision micro electro mechanical system (MEMS) under the condition of only utilizing GPS (Global Position System) auxiliary equipment. The initial alignment method comprises the following steps of: obtaining a direction cosine matrix from a carrier coordinate system to a horizontal coordinate system; establishing a coarse alignment Kalman filtering state equation of the strap-down inertial navigation system of the low-precision micro electro mechanical system; establishing a Kalman filtering measurement equation of coarse alignment of the strap-down inertial navigation system of the low-precision micro electro mechanical system; carrying out first-time correction on a carrier posture; establishing a Kalman filtering state equation and a measurement equation of fine alignment of the strap-down inertial navigation system; carrying out second-time Kalman filtering; and carrying out second-time correction on the carrier posture to obtain an accurate strap-down matrix of the strap-down inertial navigation system of the micro electro mechanical system. According to the initial alignment method disclosed by the invention, a method of estimating an error of the strap-down inertial navigation system of the low-precision MEMS by two times of Kalman filtering is utilized to finish the initial alignment of the system, so that the application is convenient.

Method for the computation of horizontal and vertical protection levels, HPL VPL, that bound up to a given confidence level 1-α the horizontal and vertical components, respectively, of the position estimation error δ of a least squares-based GNSS navigation solution, wherein the HPL and VPL are computed as follows:HPL=k·∥r∥·aH, VPL=k·∥r∥aV,where:∥r∥ is the Euclidean norm of the least squares estimation residuals vector r;aH is defined as:aH=hEE+hNN2+(hEE-hNN2)2+(hEN+hNE2)2,andaV is defined as: aV=√{square root over (hUU)}, wherehEE, hNN, hEN, hNE, hEU, hUE, hUU, hNU, hUN are the spatial components of the dilution of precision matrix DoP (HT·H)−1 of the least squares estimation expressed in the local horizontal coordinate system of the estimated position:(HT·H)Space-1=[hEEhENhEUhNEhNNhNUhUEhUNhUU],H being the n×m observation matrix of the least squares-based navigation solution;and wherek is an isotropic confidence ratio computed by numerically solving the following expression Eq. 3 which links k with n, m and a, n and m being the number of observations and of estimated parameters, respectively, of the least squares estimation:Γ(n2)·∫z∈ℜm,z2≤k21+k2(1-z2)n-m-22·z=Γ(n-m2)·πm2·(1-α)[Eq.3]where Γ is Euler's Gamma function; and m denotes a standard m-dimensional real vector space.

The invention relates to a method and a device for judging satellite visibility under carrier rotating condition. The method mainly includes: building a carrier coordinate system, calculating carrier rotating angles, and calculating satellite positions in the carrier coordinate system according to the carrier rotating angles; and calculating satellite elevation angles according to the satellite positions in the carrier coordinate system, comparing the satellite elevation angles and satellite screening angles, and judging satellite visibility according to comparison results. In an embodiment of the method and the device, the carrier coordinate system is built, positions of satellites in a horizontal coordinate system are shifted into the carrier coordinate system and the satellite elevation angles are calculated, and accordingly the satellite visibility can be effectively judged according to the satellite elevation angles under carrier rotating condition.

The invention relates to the technical field of measuring equipment, in particular to an equipment reference rapid leveling method. The method comprises the steps: calibrating equipment, and setting aplurality of calibration points on the equipment; selecting a plurality of feature points on the equipment, and acquiring coordinates of a plurality of feature points through a laser tracker; fittingan equipment reference according to the coordinates of the feature points and establishing an equipment coordinate system according to the equipment reference; after the theoretical coordinates of the calibration point under the equipment coordinate system and the actually measured coordinates of the calibration point under the horizontal coordinate system are obtained, acquiring the adjustment deviation of the calibration point after coordinate conversion, and guiding the adjustment equipment to be leveled according to the adjustment deviation, so the leveling method is intuitive and effective, and the equipment can be leveled quickly.

The invention relates to an inertial measurement unit field calibration method based on a single-axis turntable, wherein the method is technically characterized by comprising the steps: establishing a single-axis turntable model, and establishing the following coordinate systems according to the frame structure of the single-axis turntable: a ground horizontal coordinate system, a turntable rotating shaft coordinate system, a turntable plane coordinate system, a gyro three-axis coordinate system and an accelerometer three-axis coordinate system; establishing a gyro accelerometer inertial component model; and establishing a square box coordinate system, wherein three coordinate axes of the square box coordinate system are perpendicular to one another, and the directions of the three axes are parallel to the pointing directions of a gyro and an accelerometer; the square box provided with an inertial measurement unit is mounted on the single-axis turntable, and then inertial measurement unit field calibration is carried out. The calibration method is reasonable in design, the calibration function of the inertial measurement unit can be achieved only through the single-axis position turntable and the hexahedron square box which are small in size, meanwhile, no leveling requirement exists for installation of the turntable, limitation to the calibration site is small, field installation and application are facilitated, and thus a large amount of time is saved.