JP2014163899A - Positioning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit more highly accurate altitude information of a current location via an interface for performing communication with a satellite positioning communication format designating the altitude of the current location with an absolute value.SOLUTION: The positioning device measures a moving direction and moving amount, and calculates a relative altitude at each fixed time interval on the basis of the moving direction and the moving amount, and, when the relative altitude becomes a predetermined reference value or more, specifies the altitude of the current position to be transmitted via a satellite positioning communication interface on the basis of the output value of the preliminarily specified altitude of the current position and the relative altitude, and to transmit the altitude of the current position via the satellite positioning communication interface.

Description

  The present invention relates to a positioning device that transmits an altitude of a current position via a satellite positioning communication interface that performs communication according to a satellite positioning communication format.

  A GPS receiver used in a satellite positioning system such as GPS measures a current position (latitude, longitude, altitude) as an absolute value. The current position measured by such a GPS receiver changes depending on the positioning satellites and the like, and a large measurement error of 5 to 10 meters occurs even in an open sky environment where there are no buildings or the like.

  On the other hand, the acceleration sensor measures the amount of vertical movement of the current position as a relative value. Such an acceleration sensor can accurately measure the vertical movement amount of the current position.

  Therefore, various positioning devices that use a positioning function using a GPS receiver and an autonomous navigation function using an acceleration sensor have been proposed (see, for example, Patent Document 1).

JP 2012-52898 A

  By the way, in the navigation system, it seems that the general road under the elevated expressway is running side by side, and the general road under the elevated road is running even though the highway is on the elevated road. On the other hand, there is a problem that erroneous guidance is performed as if traveling on a highway on an elevated road while traveling on a general road under an elevated road.

  Therefore, as described above, it is possible to perform route guidance with high accuracy by using a GPS receiver and an acceleration sensor together. For example, in normal times, the current position (latitude, longitude, altitude) is specified based on the altitude information of the current position measured by the GPS receiver, and measured using an acceleration sensor when approaching the expressway entrance By determining whether or not the vehicle has entered the highway using the relative altitude of the current position, the above-described erroneous guidance can be prevented.

  However, the output signal of the GPS receiver is the NMEA-0183 format (satellite positioning communication format) defined by the National Marine Electronics Association (American Marine Electronics Association), and in this NMEA-0183 format, The current position is specified to be specified as an absolute value.

  On the other hand, the output signal of the acceleration sensor is output according to the original format of each manufacturer. That is, it is impossible to specify the relative altitude using an acceleration sensor and send the relative altitude to an external device such as a navigation calculation unit via an interface communicating in the NMEA-0183 format.

  For this reason, it is necessary to provide an interface for inputting a signal from the acceleration sensor, in addition to an interface for communication in a satellite positioning communication format such as the NMEA-0183 format, in an external device such as a navigation calculation unit. As described above, when the external device such as the navigation calculation unit is provided with a plurality of interfaces, there is a problem that the software of the control unit of the external device becomes complicated and the cost increases.

  The present invention has been made in view of the above problems, and is intended to enable more accurate altitude information of the current position to be transmitted via an interface that communicates in a satellite positioning communication format that specifies the altitude of the current position as an absolute value. Objective.

  In order to achieve the above object, the invention according to claim 1 is directed to an absolute position measuring means for measuring the altitude of the current position as an absolute value, and communication according to a satellite positioning communication format for designating the altitude of the current position as an absolute value. Output value specifying means for repeatedly specifying the output value of the current position altitude output via the satellite positioning communication interface, and sending out the altitude of the current position specified by the output value specifying means via the satellite positioning communication interface A positioning device comprising: a movement measuring means for measuring a moving direction and a moving amount; and calculating a relative altitude at regular time intervals based on the moving direction and the moving amount measured by the moving measuring means. A relative altitude calculating means, and the output value specifying means has a relative altitude calculated by the relative altitude calculating means equal to or greater than a predetermined reference value. If it is characterized by specifying the altitude of the current position for sending via the satellite positioning communication interface based at altitude relative calculated by high output value and relative altitude calculating means which last identified current position.

  According to such a configuration, when the relative altitude is greater than or equal to a predetermined reference value, satellite positioning communication is performed based on the altitude of the current position specified last time and the relative altitude calculated by the relative altitude calculating means. Since the altitude output value of the current position transmitted via the interface is specified, the altitude information of the current position with higher accuracy can be obtained via the interface that communicates in the satellite positioning communication format that specifies the altitude of the current position as an absolute value. Can be sent out.

It is a figure which shows the block configuration of the positioning apparatus which concerns on 1st Embodiment of this invention. It is a flowchart of the positioning process by CPU. It is a figure for demonstrating calculation of the height (MNEA output value) of the present position of the present position specific process in 1st Embodiment. It is a flowchart of the map display process by a navigation calculating part. It is a figure for demonstrating calculation of the height (MNEA output value) of the present position of the present position specific process in 2nd Embodiment.

(First embodiment)
FIG. 1 shows a block configuration of the positioning device according to the first embodiment of the present invention. The positioning device 1 measures the altitude of the current position and sends it to the navigation computation unit 2 via a satellite positioning communication interface that performs communication according to a satellite positioning communication format that designates the altitude of the current position as an absolute value.

  The positioning device 1 includes a CPU 10 that performs arithmetic processing, a RAM 11 that provides a working memory space to the CPU 10, a ROM 12 that stores execution programs and setting data, a nonvolatile memory 13, a GPS receiving antenna 14a, and a GPS receiving device. Processing unit 14, gyro sensor 15, vehicle speed input interface (referred to as vehicle speed input IF) 16, acceleration sensor 17, external output interface (referred to as external output IF) 18, external input interface (referred to as external input IF) 19 It has.

  The RAM 11 stores the various data in response to various data write instructions from the CPU 10 and outputs the various data in response to various data read instructions from the CPU 10.

  The ROM 12 stores an execution program for causing the positioning device 1 in the present embodiment to perform positioning processing. The CPU 10 reads and executes the execution program when the power is turned on.

  The nonvolatile memory 13 is configured by, for example, an EEPROM or a flash memory. The nonvolatile memory 13 stores movement position data determined by the control process of the CPU 10 and ephemeris data which is GPS satellite orbit data.

  The GPS reception processing unit 14 demodulates radio wave signals transmitted from a plurality of GPS satellites (positioning satellites) received by the GPS reception antenna 14 based on a control signal input from the CPU 10. The GPS reception processing unit 14 performs arithmetic processing based on these demodulated signals, and outputs the calculated positioning data to the CPU 10 in a set format. The format that can be output from the GPS reception processing unit 14 includes a signal conforming to the NMEA-0183 standard.

  The GPS positioning position calculated in the GPS reception processing unit 14 includes an error. The error range of the GPS positioning position varies depending on the number of GPS satellites used for the arithmetic processing and the arrangement of the GPS satellites. The data according to the NMEA-0183 format output from the GPS reception processing unit 14 includes a GST message output as an index indicating such an error range of the GPS positioning position. Specifically, the GST message output includes the standard deviation of the major axis radius and minor axis radius of the ellipse indicating the error range of the GPS positioning position, the inclination angle of the ellipse, the latitude error, the longitude error, and the altitude. Statistical error items such as standard deviation values of errors are included.

  The gyro sensor 15 detects an angle and an angular velocity. The gyro sensor 15 in the present embodiment detects a rotation angle (angle) and a rotation speed (angular velocity) around the three axes of pitch, roll, and yaw, and outputs them to the CPU 10 as three-axis gyro data.

  The vehicle speed input interface 16 is for inputting a vehicle speed signal corresponding to the vehicle speed from a vehicle speed sensor. Further, the acceleration sensor 17 measures the acceleration in the triaxial direction and outputs it to the CPU 10.

  The external output interface 18 is a satellite positioning communication interface that performs communication according to a satellite positioning communication format (in this embodiment, the NMEA-0183 format) that specifies the altitude of the current position as an absolute value. The positioning device 1 sends the positioning information of the current position to the navigation calculation unit 2 via the external output interface 18 at regular time intervals.

  The external input interface 19 is an interface for inputting various information from the navigation calculation unit 2.

  The navigation calculation unit 2 is configured as a computer including a CPU, a memory, an I / O, and the like, and the CPU performs various processes according to a program stored in the memory. The navigation computing unit 2 is connected to an operation unit that outputs a signal corresponding to a user operation, a map data input device that inputs map data, and a display unit (not shown) having a display such as a liquid crystal display. Yes.

  The navigation calculation unit 2 includes a destination search process for searching for a destination according to a user operation, a host vehicle position specifying process for specifying the host vehicle position based on positioning information input from the positioning device 1, and a host vehicle. Map display processing for displaying the vehicle position mark on the map around the position and displaying it on the display unit, route search processing for searching for the optimal guide route from the current position to the destination, and travel guidance processing for performing travel guidance according to the guide route Etc.

  Next, the operation content of the positioning process will be described according to a flowchart. FIG. 2 shows a flowchart of the positioning control process executed by the CPU 10. The positioning control process of the present embodiment is started when the positioning device 1 enters an operating state in response to a user operation.

  First, the CPU 10 sends a signal to the GPS reception processing unit 14 to start reception processing, and determines whether or not a radio wave from a GPS satellite has been received based on a signal input from the GPS reception processing unit 14 ( S100).

  If it is determined that the radio wave from the GPS satellite is received, the determination in S100 is YES, and then it is determined whether or not the latest ephemeris data is stored in the nonvolatile memory 13 (S102). ). If the latest ephemeris data is not stored in the non-volatile memory 13, the determination in S102 is NO, and the received ephemeris data is acquired from the GPS reception processing unit 14 and stored in the non-volatile memory 13 (S104). move on.

  If the latest ephemeris data is already stored in the nonvolatile memory 13, the determination in S102 is YES and the process proceeds to S106.

  In S106, a GPS positioning process is performed. Specifically, the input data from the GPS reception processing unit 14 is decoded to perform GPS positioning processing for acquiring current position information obtained by GPS positioning, and the process proceeds to S108. The GPS absolute altitude is specified by this GPS positioning process.

  If it is determined in S100 that the radio wave from the GPS satellite is not received, the determination in S100 is NO, and the process proceeds to S108 without performing the processes in S102 to S106.

  In S108, acceleration measurement processing is performed. Specifically, a necessary period (for example, a period from the time when the previous GPS positioning process was performed to the time when the current GPS positioning process was performed) from the data of the triaxial acceleration measured by the acceleration sensor 17. Get the data.

  Next, orientation measurement processing is performed (S110). Specifically, data for a necessary period is acquired from the three-axis gyro data measured by the gyro sensor 15.

  Next, a vehicle speed measurement process is performed (S112). Specifically, data for a necessary period is acquired from vehicle speed information measured based on a vehicle speed signal input from a vehicle speed sensor via the vehicle speed input interface 16.

  Next, it is determined whether or not the reference position data is set (S114). Since there is no reference position data immediately after the start of the positioning control process, the determination in S114 is NO, and the current position and time data acquired in the first GPS positioning process (S106) are used as the initial values of the reference position and time in the RAM 11. (S116), and the process proceeds to S118. This initial value is set regardless of the magnitude of the error.

  As described above, after the initial value of the reference position data is once set and registered, in the determination process of S114, it is determined that there is reference position data, and the process proceeds to S118.

  In S118, an autonomous positioning process is performed. Specifically, the moving direction is specified based on the triaxial acceleration data acquired in S108 and the triaxial gyro data acquired in S110. Further, the movement amount of the movement section is specified based on the vehicle speed data acquired in S112. In the present embodiment, the road gradient of the road section is calculated from the difference between the vehicle acceleration component measured by the acceleration sensor 17 and the vehicle acceleration obtained by differentiating the vehicle speed measured by the vehicle speed sensor. The relative altitude of the road section is calculated from the road gradient of the road section.

  Next, GPS error calculation processing is performed (S120). Specifically, the GST message acquired from the GPS reception processing unit 14 is decoded, a GST error value is set based on the decoded GST message, and the magnitude of the GST error is evaluated (step S13). In this embodiment, when it is determined that the standard deviation of the altitude error included in the GST message is less than a preset threshold, the CPU 10 determines that the reliability of the obtained current position data is high. Let A be the accuracy rank (index). On the other hand, if it is determined that the standard deviation of the altitude error included in the GST message is greater than or equal to another preset threshold value, it is determined that the reliability of the obtained current position data is low, and the accuracy rank Let (index) be B.

  Next, a current position specifying process is performed (S122). In this current position specifying process, the current position (MNEA output value) to be transmitted is specified. The current position specifying process will be described later in detail.

  Next, data transmission processing is performed (S124). Specifically, the current position (MNEA output value) specified in S122 is sent to the navigation calculation unit 2 via the external output interface 18.

  The above processing is repeated at regular time intervals, and the current position (MNEA output value) specified at regular time intervals is sent to the navigation computation unit 2 via the external output interface 18.

  Next, with reference to FIG. 3, the current position specifying process in S122 in the present embodiment will be described. (A) is a figure which shows a mode that the height of the present position of a vehicle changes with driving | running | working of a vehicle. The vertical axis is the absolute value of altitude and the horizontal axis is time. Further, (b) is a diagram showing the relationship between the GPS absolute altitude and the relative altitude specified at each time shown in (a). The GPS absolute altitude is a value specified based on the current position information acquired by the GPS positioning process, and the relative altitude is a value specified by the autonomous positioning process. Further, (c) is a diagram showing the MNEA output value specified in each movement section shown in (a). In the present embodiment, the MNEA output value is specified under the following conditions (1) to (3).

  (1) The rank of the accuracy of the GPS absolute height when the magnitude of the relative height is less than a predetermined reference value (2 meters in this embodiment) as at times t1, t2, t4, and t7. When A is A, the GPS absolute altitude is specified as the output value of the current position altitude (NMEA output value). For example, at time t1, GPS absolute altitude = 5 meters is specified as the output value of the current position altitude (NMEA output value).

  Thus, when the accuracy of the GPS absolute altitude is high, the GPS absolute altitude is specified as the output value (NMEA output value) of the current position altitude.

  (2) When the accuracy of the GPS absolute altitude becomes rank B with low reliability as at times t3 and t8, it is relative to the altitude output value (previous NMEA output value) of the previous current position specified last time. The altitude is added to specify the altitude output value (NMEA output value) at the current position. For example, at time t3, the current position altitude output value (NMEA output value) specified at time t2 last time is added to 4 meters to the current position of the current position by adding the relative altitude ± 0 meter specified at time t3. The altitude output value (NMEA output value) is specified as 4 meters.

  As described above, when the accuracy of the GPS absolute altitude is low, the GPS absolute altitude is not specified as the output value of the current position altitude (NMEA output value), but the output value of the altitude at the previous current position specified last time ( The relative altitude is added to the previous NMEA output value) to specify the altitude output value (NMEA output value) at the current position.

  (3) The output value of the altitude at the current position specified last time also when the magnitude of the relative altitude is equal to or greater than a predetermined reference value (2 meters in the present embodiment) at times t5 and t6. The relative altitude is added to (previous NMEA output value) to specify the altitude output value (NMEA output value) at the current position. For example, at time t5, the altitude output value (NMEA output value) at the current position specified at time t4 last time = 6 meters is added to the altitude at the current position by adding +5 meters, which is the relative altitude specified at time t5. Output value (NMEA output value) is specified as 11 meters.

  Thus, even when the magnitude of the relative altitude is equal to or greater than a predetermined reference value (2 meters in this embodiment), the GPS absolute altitude is set as the output value (NMEA output value) of the current position altitude. Rather than specifying, the altitude output value (NMEA output value) of the current position is specified by adding the relative altitude to the altitude output value (previous NMEA output value) of the current position specified last time.

  For example, when the climbing slope is in front of the entrance to the expressway and the relative altitude is greater than or equal to a predetermined reference value (2 meters in this embodiment), the GPS absolute altitude The output value (NMEA output value) of the altitude at the current position is specified using the relative altitude with higher accuracy.

  The navigation calculation unit 2 can determine whether or not the vehicle has entered the expressway by using the altitude output value (NMEA output value) at the current position thus identified. In a situation where ordinary roads run parallel to the underway of the expressway, a false indication that the user is driving on a general road under the overpass even though the expressway is running over the overpass In addition, it is possible to prevent erroneous display such as traveling on a highway on an elevated road while traveling on a general road under an elevated road.

  In FIG. 4, the flowchart of the map display process of the navigation calculating part 2 is shown. When an operation for instructing the start of the map display process is performed by the user, the navigation calculation unit 2 performs the process shown in FIG.

  First, map data is acquired (S200). Specifically, the current position (latitude, longitude, altitude) is specified based on the positioning information (NMEA output value) of the current position input from the positioning device 1, and the movement locus of the current position is stored in the memory. The map data around the current position is acquired from the map data input device.

  Next, an uphill determination is performed (S202). Specifically, the altitude trajectory of the current position is acquired from the memory, and when the altitude of the current position has increased more than a predetermined reference value, it is determined as an uphill. Further, when the altitude at the current position is greatly reduced from a predetermined reference value, it is determined that the vehicle is downhill.

  Next, map matching processing is performed (S204). This map matching process is a process of correcting the current position to a position on the road. In the present embodiment, the road on which the road is on is specified according to the determination result of the climbing determination in S202. For example, when there is an entrance of an expressway that enters with an ascending slope at a location determined as an uphill in S202, the current position is specified as an uphill on the expressway. In addition, when there is an expressway exit that exits with a downward slope at a location determined to be a downhill in S202, the current position is specified as a downhill highway.

  Next, the vehicle position is displayed (S206). The own vehicle position mark is displayed on the map around the current position specified by the map matching process in S206, and the process returns to S200. The above process is repeated, and the vehicle position mark is displayed at the position of the vehicle on the map around the current position.

  According to the above configuration, when the relative altitude is greater than or equal to a predetermined reference value, satellite positioning is performed based on the output value of the altitude at the current position specified last time and the relative altitude calculated by the autonomous positioning process. Since the output value of the altitude of the current position transmitted via the communication interface is specified, the altitude of the current position with higher accuracy can be obtained via the interface that communicates in the satellite positioning communication format that specifies the altitude of the current position as an absolute value. Information can be sent out.

  In order for the navigation calculation unit 2 to accurately determine the uphill, the positioning device 1 determines that the relative altitude is large at a location where the road gradient is large, that is, where the relative altitude is large. What is necessary is just to be able to determine based on information.

  In the above configuration, when the relative altitude is equal to or greater than a predetermined reference value, the satellite positioning communication interface is based on the output value of the altitude at the current position specified last time and the relative altitude calculated by the autonomous positioning process. Thus, the output value of the altitude at the current position to be transmitted via the navigation device 2 is specified. That is, the navigation calculation unit 2 can accurately perform the climbing judgment based on the positioning information from the positioning device 1.

  In addition, as described above, when the relative altitude is equal to or greater than a predetermined reference value, the relative altitude calculated by the autonomous positioning process is added to the output value of the altitude at the current position specified last time, The altitude output value of the current position transmitted via the satellite positioning communication interface can be specified.

  In addition, when the GPS absolute altitude accuracy index is low, if the GPS absolute altitude is transmitted as positioning information from the positioning device 1, the accuracy of the positioning information is reduced.

  However, in the configuration described above, when the accuracy index of the GPS absolute altitude measured by the GPS positioning process 106 is low, the relative altitude calculated by the autonomous positioning process is added to the altitude output value of the current position specified last time. Then, since the output value of the altitude at the current position is specified, the accuracy of the positioning information can be improved.

(Second Embodiment)
In the first embodiment, in the current position specifying process of S122 in the flowchart shown in FIG. 3, the GPS absolute altitude measured by the GPS positioning process 106 or the value obtained by adding the relative altitude to the previous NMEA output value is Although it was specified as the altitude (NMEA output value) of the position, in this embodiment, the value obtained by multiplying the absolute altitude of the current position measured by the GPS positioning process by the first weighting coefficient K1 is obtained by the autonomous positioning process. An altitude output value (NMEA output value) at the current position is calculated by adding a value obtained by adding the altitude at the current position specified last time to the calculated relative altitude and multiplying by the second weighting coefficient K2.

  Next, with reference to FIG. 5, the current position specifying process in S122 in the present embodiment will be described. (A) to (c) in FIG. 5 correspond to (a) to (c) in FIG.

  Also in the present embodiment, the MNEA output value is specified under the following conditions (1) to (3).

  (1) The rank of the accuracy of the GPS absolute height when the magnitude of the relative height is less than a predetermined reference value (2 meters in this embodiment) as at times t1, t2, t4, and t7. Is A, the value obtained by multiplying the absolute altitude of the current position measured by the GPS positioning process by the first weighting coefficient K1 is used to obtain the altitude of the current position previously identified by the relative altitude calculated by the autonomous positioning process. The value obtained by adding and multiplying by the second weighting coefficient K2 is added to specify the altitude of the current position transmitted via the satellite positioning communication interface. Here, K1 = 0.5 and K2 = 0.5. That is, the NMEA output value is calculated by setting the current position altitude output value (NMEA output value) = GPS absolute altitude × 0.5 + ((previous NMEA output value) + relative altitude) × 0.5. For example, at time t2, since GPS absolute altitude = 4 and relative altitude = ± 0, the altitude output value (NMEA output value) at the current position is calculated as 4.5 meters.

  (2) When the accuracy of the GPS absolute altitude becomes rank B with low reliability as at times t3 and t8, the first weighting coefficient K1 is made smaller and the second weighting coefficient K2 is set to be smaller. The altitude of the current position transmitted through the satellite positioning communication interface is specified to be larger. Here, K1 = 0.25 and K2 = 0.75. That is, the NMEA output value is calculated as the current position altitude output value (NMEA output value) = GPS absolute altitude × 0.25 + ((previous NMEA output value) + relative altitude) × 0.75. For example, at time t3, since GPS absolute altitude = 7 meters and relative altitude = ± 0 meters, the current position altitude output value (NMEA output value) is calculated as 5.1 meters.

  (3) Similarly to (2), when the magnitude of the relative altitude is equal to or greater than a predetermined reference value (2 meters in the present embodiment) as at times t5 and t6, The altitude of the current position transmitted via the satellite positioning communication interface is specified by decreasing the weighting coefficient K1 and increasing the second weighting coefficient K2. Here, the output value of the current position altitude (NMEA output value) = GPS absolute altitude × 0.25 + ((previous NMEA output value) + relative altitude) × 0.75 is calculated as the NMEA output value. For example, at time t5, since GPS absolute altitude = 8 meters and relative altitude = + 5 meters, the altitude output value (NMEA output value) at the current position is calculated as 10.0 meters.

  Thus, in this embodiment, when the magnitude of the relative altitude is equal to or greater than a predetermined reference value, or when the accuracy of the GPS absolute altitude is rank B, the first weighting coefficient K1 is further increased. While decreasing, the second weighting coefficient K2 is further increased, and the output value of the altitude of the current position transmitted via the satellite positioning communication interface is specified.

  As described above, a value obtained by multiplying the altitude of the current position measured by the GPS positioning process by the first weighting coefficient (K1) is added to the relative altitude calculated by the relative altitude calculating means of the altitude of the current position previously identified. A value obtained by adding the output value and multiplying by the second weighting coefficient (K2) can be added to specify the output value of the altitude at the current position.

  When the relative altitude is greater than or equal to a predetermined reference value, the first weighting coefficient (K1) is decreased and the second weighting coefficient (K2) is increased to increase the current position. An advanced output value can be specified.

  When the accuracy index for the altitude of the current position measured by the GPS positioning process is low, the first weighting coefficient (K1) is made smaller and the second weighting coefficient (K2) is made larger. Thus, the output value of the altitude at the current position can be specified.

(Other embodiments)
In the first and second embodiments, the altitude of the current position is transmitted via the satellite positioning communication interface. However, not only the altitude of the current position but also the latitude and longitude of the current position may be transmitted. it can.

  In the second embodiment, when the relative altitude is equal to or greater than a predetermined reference value, or when the accuracy of the GPS absolute altitude is rank B, the first weighting coefficient K1 is made smaller. At the same time, the second weighting coefficient K2 is further increased to specify the altitude output value of the current position transmitted via the satellite positioning communication interface. However, the second weighting coefficient K2 is specified without changing the first weighting coefficient K1. The weighting coefficient K2 may be made larger, or the first weighting coefficient K1 may be made smaller without changing the second weighting coefficient K2.

  The correspondence relationship between the configuration of the above embodiment and the configuration of the claims will be described. S106 corresponds to an absolute position measurement unit, the external output interface 18 corresponds to a satellite positioning communication interface, and S124 serves as a transmission unit. S108, S110, and S112 correspond to the movement measuring means, S118 corresponds to the relative altitude calculating means, S122 corresponds to the output value specifying means, and S120 corresponds to the accuracy specifying means.

1 Positioning Device 2 Navigation Calculation Unit 10 CPU
11 RAM
12 ROM
13 Nonvolatile Memory 14 GPS Reception Processing Unit 15 Gyro Sensor 16 Vehicle Speed Input Interface 17 Acceleration Sensor 18 External Output Interface 19 External Input Interface

Claims (9)

An absolute position measuring means for measuring the altitude of the current position as an absolute value;
Based on the altitude of the current position, an output that repeatedly specifies an output value of the altitude of the current position that is output via a satellite positioning communication interface that performs communication according to a satellite positioning communication format that designates the altitude of the current position as an absolute value Value identification means;
Sending means for sending the altitude of the current position specified by the output value specifying means via the satellite positioning communication interface, and a positioning device comprising:
A movement measuring means for measuring a moving direction and a moving amount;
Relative altitude calculating means for calculating a relative altitude at regular time intervals based on the moving direction and the moving amount measured by the moving measuring means,
The output value specifying means, when the magnitude of the relative height calculated by the relative height calculating means is greater than or equal to a predetermined reference value, the output value of the current position specified last time and the relative height A positioning device characterized in that an output value of an altitude at the current position is specified based on the relative altitude calculated by a calculating means.   When the relative height calculated by the relative height calculation means is equal to or greater than a predetermined reference value, the output value specifying means adds the relative height to the output value of the current position specified previously. The positioning device according to claim 1, wherein the relative altitude calculated by the calculating means is added to specify an output value of the altitude at the current position.   The output value specifying means specifies the value obtained by multiplying the height of the current position measured by the absolute position measuring means by a first weighting factor (K1) to the relative height calculated by the relative height calculating means last time. The output value of the altitude at the current position is specified by adding the value obtained by adding the output value of the altitude at the current position and multiplying by the second weighting coefficient (K2). The described positioning device. An accuracy specifying means for specifying an accuracy index for the altitude of the current position measured by the absolute position measuring means;
The output value specifying means is calculated by the relative altitude calculating means to the output value of the altitude at the current position specified last time when the accuracy index specified by the accuracy specifying means is lower than a predetermined condition. The positioning device according to claim 2, wherein the relative altitude is added to specify an output value of the altitude at the current position.   The output value specifying means makes the first weighting coefficient (K1) smaller when the magnitude of the relative height calculated by the relative height calculation means is equal to or greater than a predetermined reference value, The positioning device according to claim 3, wherein the second weighting factor (K2) is further increased to specify an output value of the altitude of the current position. An accuracy specifying means for specifying an accuracy index for the altitude of the current position measured by the absolute position measuring means;
When the accuracy index specified by the accuracy specifying unit is lower than a predetermined condition, the output value specifying unit makes the first weighting factor (K1) smaller and the second weighting factor The positioning device according to claim 3 or 4, wherein (K2) is made larger to specify an output value of the altitude of the current position.   7. The absolute position measuring means measures the altitude of the current position based on a signal input from a GPS reception processing unit that receives radio waves transmitted from a positioning satellite. The positioning device according to one.   The positioning according to any one of claims 1 to 7, wherein the movement measuring means measures the movement direction and the movement amount based on signals output from an acceleration sensor, a vehicle speed sensor, and a gyro sensor. apparatus.   The positioning device according to any one of claims 1 to 8, wherein the satellite positioning communication format is an NMEA-0183 format.

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