Abstract: Disclosed is a GNSS receiver, including a state monitoring sensor and a processor. The state monitoring sensor is configured to monitor a state of the GNSS receiver, and generate a first triggering signal according to the state of the GNSS receiver. The processor is configured to switch from a resting operating state to a wake-up operating state according to the first triggering signal, and transmit position information about the GNSS receiver to a remote server at a preset rate. Further disclosed is a GNSS device.

Abstract: A method for converting state space representation (SSR) information to observation space representation (OSR) information includes: obtaining the SSR information, obtaining the OSR information, obtaining information of a virtual observation distance, and obtaining delay information of a troposphere and delay information of an ionosphere. A device for converting SSR information to OSR information includes: a satellite antenna, a global navigation satellite system (GNSS) board, a radio antenna, a mobile network module and antenna, a Bluetooth module and antenna, a Wi-Fi module and antenna, a status indicator light, a plurality of output interfaces, and a power supply unit. A conversion algorithm is realized for converting SSR information to OSR information, and the converted OSR information follows the international standard protocols and can be received by most GNSS receivers. A conversion device is developed based on the aforementioned method.

Abstract: A modified-material-based high-precision combined antenna for satellite navigation and communications includes a high-frequency satellite navigation antenna metal radiating surface, a low-frequency satellite navigation antenna metal radiating surface, a WIFI/Bluetooth antenna metal radiating surface, a PCB, a shielding metal cavity and an injection molded modified-material-based substrate. The low-frequency satellite navigation antenna metal radiating surface is located between the high-frequency satellite navigation antenna metal radiating surface and the PCB. The WIFI/Bluetooth antenna metal radiating surface is located on a side of the low-frequency satellite navigation antenna metal radiating surface. The injection molded modified-material-based substrate is made of polyphenyl ether doped with a modified material, and the modified material has a relative permittivity of 2.65 and a density of 1.06 g/cm3.

Abstract: Provided is a navigation board, a multi-source data fusion method for a navigation board and a transporter. The navigation board includes a printed circuit board, a global navigation satellite system module, an inertial sensor, a processor, and a data interface; the processor is configured to execute a large misalignment angle initialization algorithm, an inertial strapdown solution algorithm, and a multi-source data fusion solution; and a size of the navigation board is smaller than or equal to a size of a standard GNSS board, and the navigation board at least includes the same data interface as a data interface of the standard GNSS board.

Abstract: A method for converting state space representation (SSR) information to observation space representation (OSR) information includes: obtaining the SSR information, obtaining the OSR information, obtaining information of a virtual observation distance, and obtaining delay information of a troposphere and delay information of an ionosphere. A device for converting SSR information to OSR information includes: a satellite antenna, a global navigation satellite system (GNSS) board, a radio antenna, a mobile network module and antenna, a Bluetooth module and antenna, a Wi-Fi module and antenna, a status indicator light, a plurality of output interfaces, and a power supply unit. A conversion algorithm is realized for converting SSR information to OSR information, and the converted OSR information follows the international standard protocols and can be received by most GNSS receivers. A conversion device is developed based on the aforementioned method.

Abstract: A method of automatically switching a mode of receiving differential data for driving test and driver training using a mobile station includes the following steps of: after a mobile station installed on a training vehicle is powered on, using a mode of receiving the differential data by a radio station; if the differential data cannot be received within a preset time period under the mode, switching the radio station to a GPRS mode; if the radio station of the mobile station receives failure information, feeding the information back to a back-end server by the mobile station; informing a technician, by the back-end server, to perform troubleshooting, after the radio station failure is eliminated, feeding information back to the mobile station through the back-end server, and switching the mobile station back to the mode of receiving the differential data by the radio station.

Abstract: A method for initial alignment of an inertial navigation apparatus, comprising the following steps: providing an apparatus loaded with a sensor, and preprocessing the sensor; carrying out relative alignment to calculate an installation error angle of the sensor; carrying out absolute alignment to calculate an installation attitude angle error of the sensor to increase an accuracy of an error attitude angle calculated during the relative alignment. The relative alignment process calculates a relative error attitude angle, the relative error attitude angle being used as the initial value for attitude error in a stat vector in the absolute alignment process, thereby accelerating convergence of the Kalman filter. Alignment precision is further enhanced by the absolute alignment process.

Abstract: A precision calibration method of attitude measuring systems is provided. The precision calibration method of attitude measuring systems includes the following steps: calibrating a zero-deviation, a scale coefficient, and a non-orthogonal angle between axes of an accelerometer to the attitude measuring system via an ellipsoid fitting model (S1); compensating original data of the accelerometer using a calculated ellipsoid parameter (S2); calibrating an electronic compass via the ellipsoid fitting model according to compensated accelerometer data (S3); compensating original electronic compass data by the calculated ellipsoid parameter (S4); calculating an attitude according to the compensated data of the accelerometer and compensated data of the electronic compass (S5). The above steps of the method have a reliable calibration result and a high precision with a less time consumption of calibration.

Abstract: The present invention discloses a GNSS-INS vehicle attitude determination method based on a single antenna, including the steps as below: mounting a GNSS antenna at a centroid and in the center of the vehicle, and mounting the IMU measuring unit of the MEMS sensor on the steering shaft of the vehicle; obtaining the position and velocity information of the vehicle by means of the GNSS antenna, obtaining the heading angular speed information of the vehicle by means of the IMU measuring unit; calculating the attitude angle of the vehicle by means of the combination with accelerometer and gyroscope; calculating the heading angle of the vehicle based on the position, velocity, and heading angular speed of the vehicle. The method combines the advantages of the short-term high precision of the IMU gyroscope and the long-term high stability of the GNSS single antenna, so as to avoid the divergence phenomenon.

Abstract: A tilt measurement method for an RTK measuring receiver includes the following steps: step S1: fixing the bottom of a centering rod and performing a measurement after an inclination and shake; step S2: obtaining a measurement point sequence, a measurement point tilt sequence, a length of the centering rod, and a height of an antenna phase center based on the measurement; step S3: obtaining a positioning quality threshold and a geodetic coordinate of the to-be-measured point based on values obtained from the measurement; and step S4: determining whether the positioning quality threshold meets a requirement or not to decide whether to finish the measurement or not. In the method, the position of a to-be-measured point is calculated according to the position and the tilt angle of the antenna phase center of the receiver, and the length of the centering rod etc. during multiple tilt measurements.

Abstract: A tilt measurement method for an RTK measuring receiver includes the following steps: step Si: fixing the bottom of a centering rod and performing a measurement after an inclination and shake; step S2: obtaining a measurement point sequence, a measurement point tilt sequence, a length of the centering rod, and a height of an antenna phase center based on the measurement; step S3: obtaining a positioning quality threshold and a geodetic coordinate of the to-be-measured point based on values obtained from the measurement; and step S4: determining whether the positioning quality threshold meets a requirement or not to decide whether to finish the measurement or not. In the method, the position of a to-be-measured point is calculated according to the position and the tilt angle of the antenna phase center of the receiver, and the length of the centering rod etc. during multiple tilt measurements.

Abstract: A flight control system of an unmanned aerial vehicle with differential positioning based on a CORS network includes a MEMS sensing unit for collecting data of angular velocity, linear velocity, air pressure, and magnetic field; a GNSS positioning unit for acquiring GNSS positioning data; a network communication unit for acquiring CORS differential data; an attitude/navigation control unit for controlling the attitude and navigation of the unmanned aerial vehicle, a main control unit for performing data processing, data fusion and system control operations among functional units. The 3G mobile network is used to obtain the differential data from CORS base station and realize an RTK differential positioning of the flight control system, which can satisfy the requirements of centimeter-level positioning accuracy of unmanned aerial vehicles for high-end consumer market and professional surveying and mapping.

Abstract: An automatic calibration method of an angle sensor for an automatic drive control system of a farm machine includes the following steps. S1: fixing a steering wheel of the farm machine to make front wheels of a vehicle kept at a fixed angle. S2: collecting a plurality of pieces of current position information of the farm machine, and processing the plurality of pieces of current position information to obtain an average value. S3: establishing a two-wheel farm machine kinematics model based on a center of a rear axle. S4: performing a radius calculation to obtain a set of angle correspondences. S5: rotating the farm machine by a preset angle at a constant speed with the rear axle of the farm machine as a center, and performing S1 through S4. S6: after performing S5 for several times, performing an angle value fitting calculation to obtain a calibration coefficient.

Abstract: Disclosed is a hydraulic control valve assembly of automatic steering system for agricultural machine including a proportional directional valve (3). A balancing valve (1) is arranged between the proportional directional valve (3) and the steering cylinder. A first shuttle valve (2) is arranged between the proportional directional valve (3) and the balancing valve (1). The first shuttle valve (2) is positioned on one side of the proportional directional valve (3). An overflow valve (4) is positioned on another side of the proportional directional valve (3). The overflow valve (4) is connected to a second shuttle valve (6) and a logic valve (5) respectively. The hydraulic control valve assembly has a large control power, a rapid response, and is more suitable for the autonomous navigation operation of agricultural machine. Moreover, the system saves more energy, such that the autonomous navigation operation of agricultural machine is more stable.

Abstract: A method far verifying accuracy of RTK tilt compensation measurement is provided by the present invention. By firstly collecting the central coordinates and subsequently collecting the compensation measurement points, the offset and the height difference of the measurement points are calculated in real time, recorded and displayed. The maximum and minimum errors of the compensation measurement points near a point location are automatically counted, and whether an accuracy of the tilt compensation measurement of the RTK equipment meets the designed requirement of accuracy is verified. Therefore, the requirements for the operators are minimized. The method of the present invention can be used to detect the accuracy of the tilt compensation measurement of the RTK equipment.

Abstract: An automatic calibration method of an angle sensor for an automatic drive control system of a farm machine includes the following steps. S1: fixing a steering wheel of the farm machine to make front wheels of a vehicle kept at a fixed angle. S2: collecting a plurality of pieces of current position information of the farm machine, and processing the plurality of pieces of current position information to obtain an average value. S3: establishing a two-wheel farm machine kinematics model based on a center of a rear axle. S4: performing a radius calculation to obtain a set of angle correspondences. S5: rotating the farm machine by a preset angle at a constant speed with the rear axle of the farm machine as a center, and performing S1 through S4. S6: after performing S5 for several times, performing an angle value fitting calculation to obtain a calibration coefficient.

Abstract: A method of automatically switching a mode of receiving differential data for driving test and driver training using a mobile station includes the following steps of: after a mobile station installed on a training vehicle is powered on, using a mode of receiving the differential data by a radio station; if the differential data cannot be received within a preset time period under the mode, switching the radio station to a GPRS mode; if the radio station of the mobile station receives failure information, feeding the information back to a back-end server by the mobile station; informing a technician, by the back-end server, to perform troubleshooting, after the radio station failure is eliminated, feeding information back to the mobile station through the back-end server, and switching the mobile station back to the mode of receiving the differential data by the radio station.

Abstract: A method for initial alignment of an inertial navigation apparatus, comprising the following steps: providing an apparatus loaded with a sensor, and preprocessing the sensor; carrying out relative alignment to calculate an installation error angle of the sensor; carrying out absolute alignment to calculate an installation attitude angle error of the sensor to increase an accuracy of an error attitude angle calculated during the relative alignment. The relative alignment process calculates a relative error attitude angle, the relative error attitude angle being used as the initial value for attitude error in a stat vector in the absolute alignment process, thereby accelerating convergence of the Kalman filter. Alignment precision is further enhanced by the absolute alignment process.

Abstract: The present invention discloses a GNSS-INS vehicle attitude determination method based on a single antenna, including the steps as below: mounting a GNSS antenna at a centroid and in the center of the vehicle, and mounting the IMU measuring unit of the MEMS sensor on the steering shaft of the vehicle; obtaining the position and velocity information of the vehicle by means of the GNSS antenna, obtaining the heading angular speed information of the vehicle by means of the IMU measuring unit; calculating the attitude angle of the vehicle by means of the combination with accelerometer and gyroscope; calculating the heading angle of the vehicle based on the position, velocity, and heading angular speed of the vehicle. The method combines the advantages of the short-term high precision of the IMU gyroscope and the long-term high stability of the GNSS single antenna, so as to avoid the divergence phenomenon.

Abstract: A precision calibration method of attitude measuring systems is provided. The precision calibration method of attitude measuring systems includes the following steps: calibrating a zero-deviation, a scale coefficient, and a non-orthogonal angle between axes of an accelerometer to the attitude measuring system via an ellipsoid fitting model (S1); compensating original data of the accelerometer using a calculated ellipsoid parameter (S2); calibrating an electronic compass via the ellipsoid fitting model according to compensated accelerometer data (S3); compensating original electronic compass data by the calculated ellipsoid parameter (S4); calculating an attitude according to the compensated data of the accelerometer and compensated data of the electronic compass (S5). The above steps of the method have a reliable calibration result and a high precision with a less time consumption of calibration.