JP5096809B2 - GPS positioning system and GPS positioning method - Google Patents

Description

  The present invention relates to a GPS positioning system for positioning a mobile station using information of a GPS satellite, and more particularly to a system for positioning a mobile station more accurately by receiving correction information from a reference station.

  As a positioning system using a GPS satellite, there is a car navigation or the like. However, since many of these are independent positioning by a GPS mobile station (a vehicle carrying a GPS), the accuracy is poor at 50 m to 10 m. This is because, in the process in which the radio wave signal from the GPS satellite reaches the GPS antenna on the ground, an error is caused by a radio wave propagation delay when passing through the atmosphere.

  As an improvement measure, there is a relative positioning method in which a GPS reference station antenna is installed at a predetermined absolute coordinate value, the antenna position is measured, a correction signal is generated based on this positioning, and the correction signal is transmitted to the mobile station. . The principle is that the positioning result (coordinate value) at the GPS reference station should match the predetermined absolute coordinate value, but in reality, the position is different from the absolute coordinate value due to the influence of the radio wave propagation delay described above. Will be positioned. The difference (error) between the absolute coordinate value of the GPS reference station (antenna) and the measured coordinate value is wirelessly transmitted as correction information from the GPS reference station to the GPS mobile station, and a position with improved accuracy can be obtained in the GPS mobile station. Note that it is assumed that the difference (error) at the GPS reference station is equally included in the mobile station.

  Examples of the relative positioning method include high-accuracy positioning such as DGPS (differential GPS) and RTKGPS (real-time kinematic GPS) positioning. Here, in order to maintain accuracy, the number of common satellites that can be captured simultaneously by both the reference station and the mobile station is important. Even if many satellites are captured by either the mobile station or the reference station, If the number of acquisitions is small, the number of common satellites will be reduced, which will affect the positioning accuracy.

  Since the number of captured satellites (the number of visible satellites) depends on the surrounding environment (such as the presence / absence of a GPS radio wave shielding structure), a place where the influence of satellite capture is small is selected and installed in advance.

  Japanese Patent Laid-Open No. 2004-133867 describes a method of moving an antenna so that a mobile station can capture a large number of satellites or selecting an optimum antenna from a plurality of antennas.

JP-A-8-178649

  Japanese Patent Application Laid-Open No. 2004-228561 is designed to capture as many satellites as possible in a mobile station, but does not consider the reference station. In urban areas, there are many cases where a building is built around the base station after the base station is installed, or there are many cases where a base station must be installed between existing buildings. This affects the positioning accuracy.

  An object of the present invention is to provide a GPS positioning system and a GPS positioning method capable of capturing more satellites in a GPS reference station even in an environment where there are shielding structures around.

  The present invention provides a reference station that generates and transmits correction information based on the installation position and GPS information from a GPS satellite, and is mounted on a mobile unit, and is based on the GPS information from the GPS satellite and the correction information of the reference station. In a GPS positioning system comprising a mobile station for positioning a mobile body, the reference station is a GPS antenna that receives GPS information, a gantry that supports the GPS antenna, and a GPS receiver that analyzes the GPS information and calculates satellite orbit information. And a computer that detects an antenna position where the number of captured satellites is larger based on the calculated satellite orbit information and calculates the amount of movement thereof, and an actuator that moves the gantry based on the calculated amount of movement. It is characterized by that.

  The reference station includes a GPS antenna that receives GPS information, a gantry that supports the GPS antenna, a GPS receiver that analyzes GPS information to calculate satellite orbit information, and a captured satellite based on the calculated satellite orbit information. The number of antenna positions that increase in number is detected and the amount of movement is calculated, and the computer that generates and transmits correction information at the moved antenna position, and the platform is moved based on the calculated amount of movement. An actuator is provided.

  The reference station includes a GPS antenna that receives GPS information, a gantry that supports the GPS antenna, a GPS receiver that analyzes the GPS information and calculates satellite orbit information, and the calculated satellite orbit information and shielding around the reference station. A computer that detects an antenna position where the number of captured satellites increases based on shielding information by an object and calculates the amount of movement thereof, and generates and transmits correction information at the moved antenna position, and the calculated movement An actuator for moving the gantry based on the amount is provided.

  Further, the reference station whose installation position is specified generates and transmits correction information based on the GPS information from the GPS satellite, and the mobile station mounted on the moving body receives the GPS information from the GPS satellite and the correction information of the reference station. In the GPS positioning method for positioning the mobile object based on the above, the reference station analyzes the GPS information received by the GPS antenna to calculate satellite orbit information, and the number of captured satellites based on the calculated satellite orbit information , Detecting the position of the antenna where the number of antennas increases, calculating the amount of movement, and moving the GPS antenna based on the calculated amount of movement.

  In addition, the reference station analyzes GPS information received by a GPS antenna to calculate satellite orbit information, detects an antenna position where the number of captured satellites is larger based on the calculated satellite orbit information, and calculates the amount of movement thereof. Then, the GPS antenna is moved based on the calculated movement amount, and correction information is generated based on the received GPS information and the moved GPS antenna position, and transmitted to the mobile station.

  Further, the reference station analyzes GPS information received by a GPS antenna to calculate satellite orbit information, and an antenna position where the number of captured satellites is larger based on the calculated satellite orbit information and shielding information by shielding objects around the reference station. Is detected, the movement amount is calculated, the GPS antenna is moved based on the calculated movement amount, correction information is generated based on the received GPS information and the moved GPS antenna position, and transmitted to the mobile station. It is characterized by doing.

  According to the present invention, the GPS reference station is fixed on a rail that can move the installation location of the GPS reference station, and the reference station on the rail is moved based on the almanac information so that the maximum number of satellites can always be acquired. However, by performing positioning, the operation of the reference station can always be realized with a large number of satellites captured. In addition, by generating and transmitting correction information corresponding to the coordinate value of the GPS antenna of the reference station, the role of the reference station is realized while moving, so that the influence of shielding at the location where the GPS reference station is installed is reduced. The function of the reference station can be realized.

  Examples of the present invention will be described. FIG. 1 shows the concept of a GPS positioning method to which the embodiment is applied. Reference numeral 10 denotes a reference station, which includes a GPS antenna, a GPS receiver, a correction information transmission radio, and a radio transmission antenna. A mobile station 11 has a GPS antenna, a GPS receiver, a correction information receiving radio, and a radio receiving antenna. The GPS correction information is sent from the reference station 10 to the mobile station 11 via the wireless transmission antenna and the wireless reception antenna, and is measured by the relative positioning method.

  In the reference station 10 and the mobile station 11, it is necessary to simultaneously acquire a common GPS satellite in both as described above. FIG. 1 shows a state in which a total of seven GPS satellites exist above the mobile station 11 and the reference station 10. However, there are only four satellites 12 to 15 that can be captured in common due to the influence of surrounding objects (buildings, advertising towers, etc.) around the reference station 10 and the mobile station 11. The remaining three are examples in which the satellites can be captured by only one of the reference station 10 and the mobile station 11. That is, the satellites 16 and 17 can be captured only by the GPS reference station 10, and the satellite 18 can be captured only by the mobile station 11.

  FIG. 2 shows a device configuration of the reference station 10 of the embodiment. The reference station 10 is installed in a place where the absolute coordinates are clear in advance. Reference numeral 105 denotes a device-mounted gantry that travels on a rigid linear guide rail 106, and a servo motor actuator that moves and drives the GPS antenna 101, the GPS receiver 102, the movement amount calculation computer 103, and the device-mounted gantry 105. A servo amplifier 110 that performs drive command control and an actuator (servo motor) 104 that moves the device mounting base 105 in accordance with a command from the servo amplifier are mounted.

  Further, in order to grasp the actual movement amount of the equipment mounting base 105, a movement amount detection encoder 107 for detecting the rotation amount of the base movement wheel 111, and correction information including an absolute coordinate value corresponding to the position of the GPS antenna 101 are transmitted. The correction information transmitting radio device 108 and the antenna 109 of the radio device 108 are also mounted. As described above, the reference station 10 is configured to be movable on the linear guide rail 106.

  FIG. 3 shows a connection block diagram of each device on the device mounting base 105. The GPS antenna 101 is connected to the GPS receiver 102 via a GPS antenna cable 208. The GPS receiver 102 and the movement amount calculation computer 103 are connected by an RS232C serial communication cable 209. The movement amount calculation computer 103 and the servo amplifier 110 are connected by a serial communication cable 210. The servo amplifier 110 and the servo motor 104 that is an actuator are connected by a servo motor power line 211.

  In order to detect the amount of movement of the GPS antenna 101 mounted on the device mounting base 105 (the amount of movement of the base 105), a movement amount detecting encoder 107 coupled to the base moving wheel 111 is provided. The movement amount detection encoder 107 and the movement amount calculation computer 103 are connected by a counter signal cable 212. In addition, a power converter 206 is also mounted in order to convert from AC 100 V into a power supply voltage (DC 24 V) that can be used by the movement amount detection encoder 107.

  In the above configuration, the GPS receiver 102 analyzes the GPS information received from the satellite and calculates satellite orbit information (almanac data). The movement amount calculation computer 103 obtains an antenna position that can supplement the largest satellite on the linear guide rail 106 based on the calculated satellite orbit information and shielding information registered in advance by surrounding shielding objects, and this position and the current position The distance from is calculated as movement information. This movement information is sent to the actuator 104 via the servo amplifier 110.

  FIG. 4 shows the relationship between the antenna position of the reference station 10 and the shielding state by the shielding object. It is assumed that the GPS antenna 101 is installed on the roof of the building A. FIG. 4A shows the shielding portion 302 by the building B when the GPS antenna 101 is at the X position on the linear guide rail 106. FIG. 4B shows a shielding portion 304 by the building C when the GPS antenna 101 is at the Z position on the linear guide rail 106.

  FIG. 5 is an explanatory diagram of a visible satellite (captured satellite) calculated from satellite orbit information (almanac data) when shielding by the building C is considered when the antenna 101 is at the position Z. The part 401 covered with the lattice mesh of the satellite orbit information in FIG. 5B shows the shielding information by the building C, and the other part is the range of the visible satellite from the antenna 101. The numbers in circles and the display positions indicate the satellite numbers and the positions at the time, and the curves indicate the orbits of the satellites. The number of visible satellites can be grasped by counting the satellites in the visible satellite range.

  FIG. 6 is an explanatory diagram of a visible satellite (captured satellite) calculated from satellite orbit information when the shielding by the building B is considered when the antenna 101 is at the position X. In FIG. 6 (2), a portion 501 covered with the lattice mesh of the satellite orbit information indicates shielding information by the building B, and the other portion is the range of the visible satellite from the antenna 101.

  FIG. 7 is an explanatory diagram of the visible satellite (captured satellite) calculated from the satellite orbit information when the shielding by the building B and the building C is considered when the antenna 101 is at the intermediate position Y between the positions X and Z. In FIG. 7B, the portion 601 covered with the lattice mesh of the satellite orbit information shows the shielding information by the building C, the portion 602 covered with the lattice mesh shows the shielding information by the building B, and the other portions are the antennas. 101 is the range of visible satellites.

  FIG. 8 shows a flow for generating and transmitting movement amount calculation processing and correction information in the movement amount calculation computer 103 of the reference station 10. Hereinafter, the operation of the reference station 10 will be described with reference to FIG.

  When the movement amount calculation computer 103 is started up and a predetermined application is started up, the next processing continues. First, a process (step) 701 is a process in which the GPS receiver 102 receives almanac data, which is the approximate orbit information of the satellite. The GPS receiver 102 can acquire almanac data by capturing radio signals from GPS satellites.

  A process 702 is a process of fetching from the memory a definition file indicating a shielding range at a preset position where the GPS antenna 101 can move. In a memory (not shown), a shielding range at a movable position of the GPS antenna 101 caused by a specific shielding object at the installation location of the reference station 10 is set in the definition file as shielding information and stored in advance.

  A process 703 is a process of calculating the number of visible satellites for each movable position (movement target position) of the GPS antenna 101 from the shielding information of the definition file registered in advance and the satellite orbit arrangement information of the almanac data. In the next process 704, the number of satellites calculated in process 703 is compared between large and small. That is, the software program compares and determines which position among the movable positions (movement target positions) of the GPS antenna 101 can be captured by the software program.

  The process 705 is a process of calculating and determining a movement amount and a direction for moving the reference station aiming at the position because the position of the GPS antenna 101 that can be captured by the most satellites is specified in the process 704.

  A process 706 is a process of taking the absolute coordinate value of the position (current position) before the GPS antenna 101 is moved. This capture is for memorizing the absolute position before the movement and clarifying the antenna position during the subsequent movement. The GPS correction information at this stage is transmitted to the mobile station side under the condition that the absolute coordinate value of the GPS antenna 101 before movement is set.

  A process 707 is a process for sending a command value to the servo amplifier 110 in order to drive the actuator 104 based on the movement amount and direction calculated in the process 705. Based on this command value, the servo amplifier 110 drives the motor accurately and moves the GPS antenna 101 to the target position.

  A process 708 counts the amount of movement of the device mounting base 105 to the amount of rotation (rotation pulse) of the encoder 107 connected to the base moving wheel 111 in order to grasp the actual amount of movement of the GPS antenna 101 after the command. Then, it is a process of converting as a moving distance. A process 709 is a process for calculating the absolute coordinate value of the GPS antenna 101 moving (moving) on the rail from the actual movement amount calculated in the process 708 and the absolute coordinate value acquired in the process 706. is there. The encoder 107 acquires the rotation amount in real time, calculates the movement distance from the rotation amount, and calculates and grasps the absolute coordinate position on the rail.

  A process 710 is a process for generating GPS correction information with the content of setting the absolute coordinate value of the GPS antenna 101 calculated in the process 709. The GPS correction information is determined by an international standard, and correction information conforming to the RTCM SC-104 standard is generated.

  Process 711 is a process of transmitting the GPS correction information generated in process 710 to the mobile station. Specifically, processing for transmitting the correction information from the correction information transmitting radio 108 of the reference station 10 to the correction information receiving port of the mobile station is performed. At this stage, correction information during the movement of the GPS antenna 101 is transmitted to the mobile station.

  A process 712 performs a process of determining whether or not the GPS antenna position of the reference station has reached the movement target position commanded in the process 707. Specifically, the determination is made based on whether or not the arrival completion signal from the servo amplifier 110 has been received. If the target position has not been reached, the process returns to process 707 and the movement process on the rail 106 is continued. If it is determined that the movement has been completed, the process returns to the top of the process 701 to continue the process in order to follow the next movement command.

  Even when the movement to the target position is completed and the process is stopped, the processes 701 to 711 are repeated. In process 709, the absolute coordinate value at the stop position is calculated, and in process 710, the current position (absolute coordinate value) that is stopped. GPS correction information corresponding to is generated, and in step 711, the GPS correction information is transmitted to the mobile station.

  Since each satellite is moving along its orbit, the place where the number of captured satellites becomes maximum changes with time. Accordingly, in practice, the position of the GPS antenna 101 of the reference station is often changed while repeating the processes 701 to 711. However, GPS correction information corresponding to the absolute coordinate value is always generated at any position, and is transmitted to the mobile station 11. The mobile station 11 can perform accurate positioning.

  Since the position of the GPS antenna 101 is obtained from the actual movement amount by counting the rotation amount (rotation pulse) of the encoder 107, it is always an actual accurate position, and accurate correction information is generated based on this position. Sent.

The conceptual diagram of the GPS positioning system of an Example of this invention. The equipment block diagram of the GPS reference station of this invention Example. The connection block diagram of the apparatus of the apparatus mounting base of an Example of this invention. The relationship figure of the antenna position and shielding of the GPS reference station of an Example of this invention. Explanatory drawing of the antenna position Z and shielding of the Example of this invention. Explanatory drawing of the antenna position X and shielding of the Example of this invention. Explanatory drawing of the antenna position Y and shielding of the Example of this invention. The operation | movement flowchart of the computer of the reference | standard station of an Example of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Reference station, 11 ... Mobile station, 12-18 ... GPS satellite, 101 ... GPS antenna, 102 ... GPS receiver, 103 ... Movement amount calculation computer, 104 ... Actuator, 105 ... Equipment mounting stand, 106 ... Linear guide rail, 107: Movement amount detection encoder, 108: Correction information transmitting radio, 401, 501, 601, 602: Shielding information.

Claims (3)

A reference station that obtains and transmits correction information based on the installation position where the coordinate value is known and GPS information from the GPS satellite, and is mounted on the mobile body, and is based on the GPS information from the GPS satellite and the correction information of the reference station. In a GPS positioning system comprising a mobile station that performs positioning of the mobile object,
The reference station includes a GPS antenna that receives GPS information, a gantry that supports the GPS antenna, a GPS receiver that analyzes the GPS information to calculate satellite orbit information, and the calculated satellite orbit information and shielding around the reference station. calculates the amount of movement by detecting the antenna position number of acquired satellites is more based on the occlusion information, a computer generates and transmits correction information of the moved antenna position, the movement amount the calculated and an actuator for moving said frame based,
The GPS positioning system, wherein the correction information is generated from the movement amount information and the installation position . Reference station coordinates of the installation position is known is had based on GPS information from GPS satellites and transmits the generated correction information, the correction information of the mobile station mounted on the moving body and the GPS information from GPS satellites the reference station In the GPS positioning method for positioning the mobile object based on
The reference station analyzes GPS information received by a GPS antenna to calculate satellite orbit information, and detects an antenna position where the number of captured satellites is larger based on the calculated satellite orbit information and shielding information by shielding objects around the reference station. The movement amount is calculated, the GPS antenna is moved based on the calculated movement amount, the correction information is generated from the movement amount information and the installation position, and transmitted to the mobile station. GPS positioning method. A reference station in a GPS positioning system that generates correction information based on GPS information from an installation position and a GPS satellite whose coordinate value is known, and transmits the correction information to a mobile station,
The reference station includes a GPS antenna that receives GPS information, a gantry that supports the GPS antenna, a GPS receiver that analyzes the GPS information to calculate satellite orbit information, and the calculated satellite orbit information and shielding around the reference station. A computer that detects an antenna position where the number of captured satellites is increased based on shielding information and calculates the amount of movement thereof, and an actuator that moves the gantry based on the calculated amount of movement,
A reference station in a GPS positioning system, wherein the correction information is generated from the movement amount information and the installation position.

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