JP4089625B2 - Radio wave transmission device and navigation device - Google Patents

Description

 The present invention relates to a radio wave transmitting device that transmits pseudo satellite radio waves called pseudolites.

  As is widely known, GPS (Global Positioning System) is received by measuring the apparent distance from four or more artificial satellites (GPS satellites) to a receiving device that is a moving body. It is a positioning system that calculates the position of the device. However, in places where it is difficult to receive radio waves from GPS satellites, such as in the vicinity of high-rise buildings or in tunnels, the receiver cannot receive radio waves from a sufficient number of GPS satellites. The position could not be calculated. Even if radio waves of a number of GPS satellites whose positions can be calculated can be received, the position accuracy may be affected by the arrangement of the GPS satellites. This is because the arrangement with the highest accuracy is when the GPS satellite is located at each vertex of the regular tetrahedron and the receiver is located at the center, but the arrangement with the lowest accuracy is at a point where the GPS satellite is located. This is because the GPS satellites may be arranged close to the latter. For this reason, in places where the direction in which GPS satellites can be received is limited, such as in the vicinity of high-rise buildings or under an elevated expressway, GPS satellites are received in the number of positions that can be calculated. Even if it was possible, there was a problem in position accuracy.

In order to solve such a problem, for example, a GPS positioning system using a radio wave transmission device called a pseudolite that transmits a pseudo satellite radio wave as shown in Patent Document 1 is known. In the system described in Patent Document 1, a plurality of pseudolite transmission antennas are arranged opposite to each other on a wall surface of a tunnel, and the distance and transmission power of adjacent pseudolite transmission antennas are appropriately set to calculate the position with high accuracy. It is a system that can.
JP 2000-180527 A

  However, in order to install such a radio wave transmitter, it is necessary to select an installation location and obtain installation permission from the landowner at that location. It is also necessary to pay the landowner for the installation of the radio wave transmitter. Due to such problems of labor and cost, the current situation is that the spread of radio wave transmitters as described above does not progress easily.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a radio wave transmission device that transmits a pseudo satellite radio wave and functions correctly even if the radio wave transmission position is not fixed. .

The radio wave transmission device according to claim 1 made to solve the above-mentioned problem is mounted on a vehicle, and includes a transmission means for transmitting radio waves similar to those of artificial satellites used in the global positioning system, Based on the information acquired by the position specifying information acquiring means for acquiring information for specifying the current position of the radio transmitting apparatus, the current position of the radio transmitting apparatus is specified based on the information acquired by the position specifying information acquiring means, and the specified current position is set. Control means for executing a series of transmission processes for causing the transmission means to transmit radio waves including information based thereon, and stop information acquisition means for acquiring information on whether or not the vehicle is stopped . The control means executes the transmission process when it is determined that the vehicle is stopped based on the information acquired by the stop information acquisition means whether or not the vehicle is stopped. When it is determined that the transmission has ended, the transmission process is stopped.

  In the conventional radio wave transmitting apparatus, the radio wave transmission position is fixed, and information based on the transmission position is transmitted. That is, the conventional radio wave transmitting apparatus does not assume that the radio wave transmission position is changed, and cannot change the content of information to be transmitted flexibly with respect to the change of the transmission position. On the other hand, the radio wave transmission device of the present invention is configured to transmit radio waves including information according to the position of the radio wave transmission device, and thus installed at any location and moved from that location. However, it is possible to transmit an appropriate radio wave. As a result, the receiver used in the GPS can use the radio wave transmitted by the radio wave transmission device of the present invention, and can calculate a position with higher accuracy than the case where only the radio wave from the GPS satellite is used.

  In addition, if it is configured to be movable like the radio wave transmission device of the present invention and is further reduced in size, installation permission can be obtained from the landowner of the installation location, such as a conventional radio wave transmission device, or to the landowner In many cases, it is not necessary to pay for the installation. Therefore, in such a case, it is very advantageous in terms of installation cost as compared with the conventional radio wave transmitter, and it is considered that the degree of spread of the radio wave transmitter is also improved. And if such a radio wave transmission device becomes widespread, the number of places where it has been difficult to receive radio waves from GPS satellites, such as the side of a high-rise building or under an elevated highway, will decrease. The usability of the receiver used in is improved. Further, the influence of the positional accuracy due to the arrangement of the GPS satellites as described above can be reduced.

In addition, since the vehicle itself is movable, it is highly likely that the radio wave transmission device is located in a dead zone where it is difficult to receive radio waves from GPS satellites such as the side of a high-rise building or under an elevated highway. In such a case, the presence effect of the radio wave transmission device is easily obtained. However, when the vehicle moves at a high speed (for example, 80 km / h) like a vehicle, the radio wave transmission device changes the information on the radio wave to be transmitted according to the change in the current position due to the problem of processing capability of the radio wave transmission device It may be difficult to do this.
Therefore, like the radio wave transmission device of the present invention , the control means transmits when it is determined that the vehicle is stopped based on the information acquired by the stop information acquisition means whether or not the vehicle is stopped. When the process is executed and the transmission process is stopped when it is determined that the vehicle is moving , the radio wave transmission device can transmit the radio wave including the correct information according to the current position. . Further, since it is not necessary for the manager (driver) of the radio wave transmitting apparatus to instruct execution and stop of the transmission process, it is possible to save the trouble of instructing.

  In addition, when the radio wave transmission device is mounted on a vehicle, it is necessary to be aware of the problem of power consumed by the radio wave transmission device. In other words, when the vehicle is stopped, the engine is not necessarily in a working state. When the engine is stopped, the radio wave transmission device relies on power supply from a battery mounted on the vehicle. Become. In this case, the amount of power that can be supplied by the battery is limited, and if the radio wave transmitter consumes battery power for a long time, the battery power may be used up.

Therefore, in order to avoid such a situation, it is preferable that the configuration is as described in claim 2 . That is, it is configured to further include engine information acquisition means for acquiring information related to whether or not the vehicle engine is operating, and the control means is executing transmission processing based on the information acquired by the stop information acquisition means. The engine information acquisition means determines whether or not the vehicle engine has been stopped based on the information on whether or not the vehicle engine is operating, and when it is determined that the vehicle engine has stopped, or the vehicle engine has stopped. It is preferable that the transmission process is stopped after a predetermined time from the determination. Note that the predetermined time here refers to, for example, the estimated time until the storage capacity of the battery reaches 50% in consideration of the storage capacity of the battery and the power consumption of the radio wave transmitter. Conceivable. Further, the transmission process may be stopped when the voltage of the battery drops to a specific voltage while measuring the voltage of the battery.

  If this is the case, it is possible to avoid a situation in which the power of the battery is exhausted, so that the battery runs out and the engine cannot be started.

By the way, as an information source of the information acquired by the above-described position specifying information acquiring means, for example, for identifying the current position from a beacon using a DSRC system installed on the road as described in claim 3 Information should be acquired. If it becomes like this, an exact position can be acquired. Note that the DSRC method may not be used as long as information can be transmitted to a specific narrow area.

  Alternatively, map matching may be performed using map data based on information obtained from a gyroscope, a vehicle speed signal, etc., and the current position may be specified. Of course, if it is possible to receive a radio wave from a GPS satellite, the current position may be specified based on the radio wave information. Even in this case, the radio wave transmission device is located in a place where the GPS satellite radio waves can be received, and an example in which radio waves are transmitted to a GPS receiver located in a nearby dead zone is considered. The existence effect of can be obtained.

Also, if there is a state where the radio wave transmitter is transmitting radio waves and a state where it is not transmitting radio waves, the manager of the radio wave transmitter (if the radio wave transmitter is mounted on the vehicle, The person) does not know which state the radio wave transmitter is in. Therefore, as described in claim 4 , the radio wave transmission device may be configured to further include notification means for notifying whether or not the transmission processing is performed by the control means. If this is the case, the manager of the radio wave transmitting apparatus can know whether the power transmission apparatus is currently transmitting radio waves or not transmitting radio waves. And, if the administrator can know the state of the radio wave transmission device in this way, for example, a location where sufficient positioning accuracy can be obtained with only the radio wave from the GPS satellite without relying on the radio wave from the radio wave transmission device For example (for example, a flat ground where the horizon can be seen), the radio wave transmission device can be operated so as not to forcibly transmit radio waves.

By the way, as described in claim 5 , the radio wave transmission device is adapted to cooperate with the navigation device, and the navigation device executes the navigation process on the information for specifying the current location obtained by the position information acquisition means. It is good to use it when doing. The navigation processing here refers to, for example, processing for displaying a map and further displaying the current location on the map, route guidance processing for executing route guidance according to a set route, and the like.

  If it becomes like this, since it becomes unnecessary to prepare another means of the same type as the position information acquisition means, there are advantageous effects in terms of size, weight, power consumption, and cost of the navigation device.

  Embodiments to which the present invention is applied will be described below with reference to the drawings. The embodiments of the present invention are not limited to the following examples, and can take various forms as long as they belong to the technical scope of the present invention.

 FIG. 1 is an explanatory diagram illustrating a usage form of the navigation devices 20a to 20c with pseudo satellite function according to the embodiment. FIG. 1 shows a GPS satellite group 10, a reference station group 13, a beacon 15, a conventional navigation device 17, and navigation devices 20a to 20c with pseudo satellite functions.

  The GPS satellite group 10 orbits altitude 20,000 km and transmits radio waves in the L1 band (1575.42 MHz) and the L2 band (1227.6 MHz). The radio wave includes various information called C / A code and P code.

The reference station group 13 is a reference station group that calculates and transmits correction data necessary for positioning using the real-time kinematic positioning method.
The beacon 15 is a radio wave type beacon using a DSRC (Dedicated Short Range Communication) system installed on or in the vicinity of the road, and transmits position information to a receiving device existing in the vicinity. . An optical beacon using light may be used.

  The conventional navigation device 17 is a general navigation device mounted on a vehicle, has a GPS antenna, receives a radio wave transmitted from the GPS satellite group 10, calculates a current position, and calculates the calculated current position. Based on this, route guidance to the set destination can be performed. Since the navigation devices 20a to 20c with pseudo-satellite function, which will be described in detail later, also transmit radio waves similar to those of GPS satellites, the conventional navigation device 17 can also receive radio waves transmitted from them. Can also be used to calculate the current position.

  The navigation devices 20a to 20c with pseudo-satellite functions are mounted on different vehicles, and can transmit radio waves similar to those of GPS satellites in addition to the functions of the conventional navigation device 17. The configuration and operation of the navigation devices 20a to 20c with pseudo satellite function will be described in detail later.

  In the explanatory view shown in FIG. 1, the conventional navigation device 17 can receive radio waves from the GPS satellite group 10 composed of three GPS satellites, and can also receive radio waves from the navigation devices 20a to 20c with pseudo satellite functions. Existing.

  In addition, the navigation device with pseudo satellite function 20a can receive radio waves from the GPS satellite group 10, and is present in a place where radio waves from the navigation device with pseudo satellite function 20b reach and can receive the radio waves. Further, communication with the reference station group 13 is also possible.

  In addition, the navigation device 20b with a pseudo satellite function can receive radio waves from the GPS satellite group 10, and is present in a place where radio waves from the navigation devices 20a and 20c with pseudo satellite functions reach and can receive the radio waves. In addition to being able to communicate with the reference station group 13, it is located at a place where radio waves from the beacon 15 can be received.

  In addition, the navigation device 20c with a pseudo satellite function can receive radio waves from the GPS satellite group 10, and is present in a place where the radio waves from the navigation device 20b with pseudo satellite functions reach, and can receive the radio waves. Further, communication with the reference station group 13 is also possible. The following description will be continued by taking such a radio wave reception environment as an example.

  Next, the configuration of the navigation devices with pseudo satellite function 20a to 20c will be described in detail. Note that the navigation devices 20a to 20c with pseudo satellite function have the same configuration, so the navigation device 20a with pseudo satellite function will be described as an example.

  As shown in the block diagram of FIG. 2, the navigation device 20a with a pseudo-satellite function includes a position detector 21 that detects the current position of the mounted vehicle, and an operation switch group 22 for inputting various instructions from the user. As with the operation switch group 22, various instructions can be input, and a remote control terminal (hereinafter referred to as a remote controller) 23a that is separate from the navigation device 20a with a pseudo satellite function and a signal from the remote controller 23a are input. A remote control sensor 23b, a map data input device 25 for inputting map data and the like from an external storage medium on which map data and various types of information are recorded, a display unit 26 for displaying maps and various types of information, and various guides An audio output unit 27 for outputting audio and the like, and a microphone that can input a user's audio and convert it into an electric signal 28, a GPS transmitter 31 that can transmit radio waves similar to a GPS satellite, a packet communication device 33 that can communicate with the outside by packet communication, and an in-vehicle LAN connected to the in-vehicle LAN In-vehicle LAN communication unit 35 that communicates with various ECUs, and executes various processes according to the input from the above-described position detector 21, operation switch group 22, remote control sensor 23b, map data input device 25, and in-vehicle LAN communication unit 35. And a position detector 21, a display unit 26, an audio output unit 27, a GPS transmitter 31, and a processing unit 29 for controlling the in-vehicle LAN communication unit 35.

  The position detector 21 receives a radio wave transmitted from a GPS satellite via a GPS antenna (not shown), detects a position of the vehicle, etc., a GPS receiver 21a, and a gyroscope that detects the magnitude of rotational motion applied to the vehicle. 21b, a distance sensor 21c for detecting the distance traveled from the longitudinal acceleration of the vehicle, etc., a geomagnetic sensor 21d for detecting the traveling direction from the geomagnetism, and a beacon existing in the vicinity to communicate with the current position A beacon transmission / reception unit 21e for receiving data.

  Among these, the GPS receiver 21 a includes a single positioning GPS receiver 211 and an RTK-GPS receiver 212. The single positioning type GPS receiving unit 211 can calculate the current position based on the radio wave received from the GPS antenna using the single positioning method. Further, the RTK-GPS receiving unit 212 calculates the current position by the real-time kinematic positioning method using the radio wave received from the GPS antenna and the correction data received from the reference station group 13 via the packet communication device 33. Can do.

  The operation switch group 22 includes a touch panel that is integrated with the display unit 26 and is installed on the display screen, and mechanical key switches that are provided around the display unit 26. The touch panel and the display unit 26 are laminated and integrated. There are various types of touch panels such as a pressure-sensitive method, an electromagnetic induction method, a capacitance method, or a combination of these methods. It may be used.

  The map data input device 25 is a device for inputting various data stored in a storage medium (not shown). The storage medium stores map data (road data, terrain data, mark data, data indicating presence / absence of radio wave transmission, etc.), guidance voice data, voice recognition data, and the like. The terrain data here refers to various three-dimensional shapes including structures such as data showing the three-dimensional shape of buildings and data showing the three-dimensional shape of elevated expressways. Means data. The data indicating the presence / absence of radio wave transmission is data associated with a position, and is data indicating whether radio wave transmission should be performed at an arbitrary position. Specifically, for example, in a place where it is difficult to receive a radio wave from a GPS satellite, the data is “transmit”, and in a place where the radio wave can be received from the GPS satellite with sufficient accuracy. The data indicates that radio waves are not transmitted. As a type of recording medium for storing such data, a CD-ROM or DVD is generally used because of the amount of data, but a medium such as a magnetic storage device such as a hard disk or a memory card may be used. .

  The display unit 26 is a color display device such as a liquid crystal display, an organic EL display, or a CRT, and any of them may be used. The display screen of the display unit 26 includes a mark indicating the current location identified from the current position of the vehicle detected by the position detector 21 and the map data input from the map data input device 25, a guide route to the destination, and a name. Additional data such as landmarks and various facility marks can be displayed in an overlapping manner. Also, facility guides can be displayed.

The voice output unit 27 can output facility guides and various guidance voices input from the map data input device 25.
The microphone 28 outputs an electric signal based on the inputted voice when the user inputs (speaks) the voice. The user can operate the navigation device 20a with a pseudo satellite function by inputting various sounds to the microphone 28.

  The GPS transmitter 31 includes an antenna, a power amplifier, a gain variable amplifier, and the like (not shown), and can transmit input data as radio waves by a specified transmission output. The GPS transmitter 31 can transmit radio waves in the L1 band (1575.42 MHz), the same as GPS satellites.

The packet communication device 33 has an antenna (not shown), and can perform packet communication with the reference station group 13 through the antenna.
The in-vehicle LAN communication unit 35 is connected to the in-vehicle LAN and can communicate with various ECUs connected to the in-vehicle LAN. As the in-vehicle LAN, for example, a CAN (Control Aria Network) is assumed, and an engine ECU, an AT-ECU, and a body ECU are assumed as one of various ECUs.

  The processing unit 29 is configured around a well-known microcomputer including a CPU, ROM, RAM, SRAM, I / O, and a bus line connecting these configurations, and is based on a program stored in the ROM and RAM. Various processes. For example, the current position of the vehicle is calculated as a set of coordinates and traveling directions based on each detection signal from the position detector 21, and a map or the like near the current position read via the map data input device 25 is displayed on the display unit 26. Based on the display processing to be performed, the point data stored in the map data input device 25, and the destination set according to the operation of the operation switch group 22, the remote controller 23a, etc., the optimum route from the current position to the destination is determined. The route guidance process etc. which calculate and guide the calculated route are performed.

  The configuration of the navigation device 20a with the pseudo satellite function has been described so far, and correspondence between each part of the navigation device 20a with the pseudo satellite function and the terms described in the claims is shown. The GPS transmitter 31 corresponds to a transmission unit, the position detector 21 corresponds to a position specifying information acquisition unit, and the processing unit 29 corresponds to a control unit. The distance sensor 21c corresponds to a stop information acquisition unit, the in-vehicle LAN communication unit 35 corresponds to an engine information acquisition unit, and the display unit 26 corresponds to a notification unit.

  Next, by describing characteristic processes (current position positioning process, radio wave transmission process, high-accuracy positioning process, transmission output determination process) executed by the processing unit 29, the characteristics of the navigation devices 20a to 20c with pseudo satellite functions are described. A typical operation will be described. Since the navigation devices with pseudo satellite function 20a to 20c have the same configuration and can operate in the same manner, the navigation device with pseudo satellite function 20a will be described as an example.

(1) Current position positioning process The current position positioning process is performed based on a program stored in the ROM of the processing unit 29, triggered by the start of the engine of the vehicle on which the navigation device 20a with the pseudo satellite function is mounted. Execution is started in the unit 29.

  When the processing unit 29 starts executing the current position positioning process, first, it sends a command to the single positioning type GPS receiving unit 211 to calculate the current position, and acquires the calculation result as current position information (S110). Upon receiving this command, the single positioning type GPS receiver 211 starts receiving radio waves, and the received radio waves (the radio waves transmitted from the GPS satellite group 10 and the radio waves transmitted from the navigation device 20b with a pseudo satellite function). ) To calculate the current position based on the single positioning method. Then, the calculated current position is passed to the processing unit 29 as current position information.

  Next, the processing unit 29 branches the process depending on whether or not the current position information has been received from the single positioning type GPS receiving unit 211 (S120). If the current position information can be received from the single positioning GPS receiver 211, the process proceeds to S140. If the current position information cannot be received from the single positioning GPS receiver 211, the process proceeds to S130. . The case where the current position information could not be received from the single positioning type GPS receiving unit 211 is, for example, when the vehicle is located under an elevated highway or in a tunnel It seems that this is true.

  In S130, which is performed when the current position information cannot be received from the single positioning GPS receiving unit 211, the current position information used last time is read from the SRAM of the control unit 29 and used.

  Next, the processing unit 29 corrects the current position information using information from the gyroscope 21b, the distance sensor 21c, the geomagnetic sensor 21d, and the beacon transmission / reception unit 21e (S140). Then, the corrected current position information is stored in the SRAM in the processing unit 29 so that the current position information is retained even when the power of the navigation device with pseudo satellite function 20a is cut off.

  Subsequently, the processing unit 29 branches the process depending on whether or not the current position specified based on the current position information is a radio wave transmission target place (S150). This is realized by determining whether or not the current position is a position where radio wave transmission should be performed based on the map data input via the map data input device 25. If the current position is a radio wave transmission target location, the process proceeds to S160. If the current position is not a radio wave transmission target location, the process returns to S110.

  In step S160, where the current position is determined to be a location where radio waves are to be transmitted, radio wave transmission processing is executed. This radio wave transmission process is a process for causing the GPS transmitter 31 to transmit a radio wave when the processing unit 29 passes data to be transmitted to the GPS transmitter 31. Details will be described later.

When the radio wave transmission process of S160 is finished, this process (current position positioning process) is finished.
(2) Radio wave transmission processing Next, radio wave transmission processing will be described. The radio wave transmission process is started in the processing unit 29 based on the program stored in the ROM of the processing unit 29 by being called in S160 of the current position positioning process described above.

  When starting the execution of the radio wave transmission process, the processing unit 29 first executes a high-accuracy positioning process (S210). In this high-precision positioning process, the processing unit 29 instructs the RTK-GPS receiving unit 212 to cause the RTK-GPS receiving unit 212 to calculate the current position, and information for specifying the calculated current position is processed by the processing unit. 29 is a process received. Details will be described later.

  Next, the processing unit 29 executes a transmission output determination process (S220). This transmission output determination process is a process for determining the radio wave transmission output that the processing unit 29 outputs to the GPS transmitter 31. Details will be described later.

  Next, the processing unit 29 generates appropriate almanac data (Almanac Data), ephemeris data (Ephemeris Data), time data, ionospheric correction related data, and the like based on the information for specifying the current position received in S210. The GPS transmitter 31 is caused to transmit the same radio wave as that of the GPS satellite (S230). Note that the transmission output at the time of transmission is the transmission output determined in the transmission output determination process of S220. Further, the display unit 26 displays that the transmission of the radio wave has been started.

  Subsequently, the processing unit 29 determines whether or not the vehicle has moved based on information from the distance sensor 21c while continuing to transmit a radio wave to the GPS transmitter 31, and branches the process (S240). The information used in this determination may be, for example, shift position information obtained from the AT-ECU via the in-vehicle LAN communication unit 35 or parking brake information obtained from the body ECU. When these pieces of information are used, for example, it may be determined that the vehicle has moved when the shift position of the automatic transmission is in the D range. Further, it may be determined that the vehicle has moved when the parking brake is released. When it is determined that the vehicle has moved, the processing unit 29 proceeds to S260, and when it is determined that the vehicle has not moved, the processing unit 29 proceeds to S250.

  In S250, which proceeds when it is determined that the vehicle is not moving, the process branches depending on whether or not the engine obtained from the engine ECU is operating via the in-vehicle LAN communication unit 35. If the engine is operating, the process returns to S240, and if the engine is stopped, the process proceeds to S270.

  In S270, which proceeds after determining that the engine is stopped, the processing unit 29 branches the process depending on whether or not 10 minutes have elapsed since the engine stopped. If 10 minutes have elapsed since the engine stopped, the process proceeds to S260. If 10 minutes have not elapsed since the engine stopped, the process returns to S240.

  In S260, a command to stop the transmission of radio waves is sent to the GPS transmitter 31, which causes the GPS transmitter 31 to stop transmitting radio waves and display on the display unit 26 that radio wave transmission has been stopped. Then, this process (radio wave transmission process) is terminated, and the process returns to the current position positioning process.

(3) High-precision positioning process Next, the high-precision positioning process will be described. The high-accuracy positioning process is started in the processing unit 29 based on a program stored in the ROM of the processing unit 29 by being called in S210 of the radio wave transmission process described above.

  When starting the execution of the high-precision positioning process, the processing unit 29 first sends a command to the RTK-GPS receiving unit 212 to calculate the current position, and acquires the calculation result as current position information (S310). Upon receiving this command, the RTK-GPS receiving unit 212 starts receiving radio waves, receives correction data from the reference station group 13 via the packet communication device 33, and calculates the current position using a real-time kinematic positioning method. . Then, the calculated current position is passed to the processing unit 29 as current position information.

  Next, the processing unit 29 branches the process depending on whether or not the current position information has been received from the RTK-GPS receiving unit 212 (S320). If the current position information can be received from the RTK-GPS receiving unit 212, the received current position information is stored in the SRAM in the processing unit 29 (S330), and the power of the navigation device 20a with the pseudo satellite function is shut off. The current position information is retained even in the case of Then, this process (high-precision positioning process) is terminated, and the process returns to the current position positioning process. On the other hand, if the current position information cannot be received from the RTK-GPS receiving unit 212, the current position information already stored in the SRAM in the processing unit 29 is used as it is, so nothing is done (S340). . Then, this process (high-precision positioning process) is terminated, and the process returns to the radio wave transmission process.

(4) Transmission Output Determination Process Next, the transmission output determination process will be described. The transmission output determination process is invoked in S220 of the above-described radio wave transmission process, and execution is started in the processing unit 29 based on the program stored in the ROM of the processing unit 29.

When starting the transmission output determination process, the processing unit 29 first reads the terrain data from the storage medium via the map data input device 25 (S410).
Subsequently, based on the terrain data read from the storage medium via the map data input device 25, the reach range of the radio wave transmitted by the navigation device with pseudo satellite function 20a is determined (S420). For example, an area where it is difficult to receive a radio wave from a GPS satellite is estimated from topographic data, and a radio wave reachable range is set so as to cover the area.

  Subsequently, the transmission output of the GPS transmitter 31 to some extent that can be received by a general GPS receiver at the farthest place within the determined radio wave reachable range is determined (S430). When the transmission output is determined, this process (transmission output determination process) is terminated, and the process returns to the radio wave transmission process.

  Up to this point, the configuration and operation of the navigation devices 20a to 20c with pseudo satellite function of the present embodiment have been described. According to the navigation devices 20a to 20c with pseudo satellite function of the present embodiment, the following effects can be obtained. It is done.

  The navigation devices 20a to 20c with pseudo-satellite function according to the present embodiment are configured to transmit radio waves including information corresponding to the respective positions. Even if moved, an appropriate radio wave corresponding to the position can be transmitted. As a result, the conventional navigation device 17 that uses the GPS positioning system can also use the radio waves transmitted by the navigation devices 20a to 20c with pseudo satellite functions of the present embodiment, compared with the case where only the radio waves from the GPS satellite group 10 are used. Thus, a highly accurate position can be calculated.

  In addition, if the navigation device 20a to 20c with pseudo satellite function of the present embodiment is mounted on a vehicle and configured to be movable, an installation permission can be obtained from the landlord of the installation location, such as a conventional radio wave transmission device. Therefore, it is considered unnecessary to pay the landowner for the installation. Therefore, the navigation devices 20a to 20c with the pseudo satellite function according to the present embodiment are very advantageous in terms of installation cost as compared with the conventional radio wave transmission device, and therefore, like the navigation devices 20a to 20c with the pseudo satellite function. If it is configured to be movable, it is considered that the degree of spread of the radio wave transmitter is also improved. And if radio wave transmitters such as navigation devices 20a-20 with pseudo-satellite function become widespread, conventionally, it is difficult to receive radio waves from GPS satellites on the side of high-rise buildings or under elevated highways. The number of places that were zones is reduced and the usability of receivers used in the GPS system is improved. In addition, the influence of positional accuracy due to the arrangement of GPS satellites is reduced.

Other embodiments will be described below.
(B) In the above embodiment, the navigation devices 20a to 20c with the pseudo satellite function transmit radio waves only when the vehicle on which the navigation devices 20a to 20c with the pseudo satellite function are mounted is stopped. If the navigation devices 20a to 20c with a pseudo satellite function have a processing capability sufficient to transmit a radio wave including information with sufficient accuracy even while the vehicle is traveling, the radio wave can be transmitted even when the vehicle is traveling. May be sent. At that time, the navigation devices 20a to 20c with pseudo-satellite function transmit the radio wave including more accurate information from the moving direction and the moving speed of the vehicle from the start of the measurement of the current position. It is preferable to predict a current position after a time required to transmit a radio wave based on the radio wave and transmit the radio wave based on the predicted position. If it becomes like this, the electromagnetic wave containing the more exact information can be transmitted.

  (B) In the above embodiment, the navigation devices 20a to 20c with pseudo satellite function stop the transmission of radio waves after 10 minutes when the vehicle engine stops after the navigation devices 20a to 20c with pseudo satellite function start to transmit radio waves. However, it is not always necessary to stop the transmission of radio waves depending on the elapsed time. For example, it is possible to continue to detect the voltage of a battery mounted on the vehicle and stop the transmission of radio waves when the voltage falls below a predetermined voltage. Even in this case, it is possible to prevent the battery of the vehicle from running out.

  (C) In the above embodiment, the navigation devices 20a to 20c with the pseudo-satellite function are configured to determine the radio wave arrival range based on the terrain data in the transmission output determination process. Then, the transmission output at each point may be determined in advance and the information may be stored in a storage medium. If the information is read during the transmission output determination process, radio waves can be transmitted with an appropriate transmission output.

  (D) In the above embodiment, the navigation devices 20a to 20c with a pseudo satellite function are supplied with electric power from a battery mounted on the vehicle, but function by receiving electric power supply from the outside of the vehicle. May be. Specifically, for example, a power line (cord) having a connection plug at the tip and connected to the navigation devices 20a to 20c with pseudo satellite function at the other end is used, and the navigation devices 20a to 20c with pseudo satellite function are parked. It is good to receive electric power supply from the electric power supply equipment provided in the parking lot etc. In this way, there is no need to worry about the battery running out.

It is explanatory drawing which shows the utilization form of the navigation apparatus with a pseudo-satellite function. It is a block diagram which shows schematic structure of the navigation apparatus with a pseudo-satellite function. It is a flowchart for demonstrating a present position positioning process. It is a flowchart for demonstrating a radio wave transmission process. It is a flowchart for demonstrating a highly accurate positioning process. It is a flowchart for demonstrating a transmission output determination process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... GPS satellite group, 13 ... Reference station group, 15 ... Beacon, 17 ... Conventional navigation device, 20a, 20b, 20c ... Navigation device with pseudo satellite function, 21 ... Position detector, 21a ... GPS receiver, 21b ... Gyro Scope, 21c ... Distance sensor, 21d ... Geomagnetic sensor, 21e ... Beacon transmission / reception unit, 22 ... Operation switch group, 23a ... Remote control, 23b ... Remote control sensor, 25 ... Map data input device, 26 ... Display unit, 27 ... Audio output unit , 28 ... microphone, 29 ... processing unit, 31 ... GPS transmitter, 33 ... packet communication device, 35 ... in-vehicle LAN communication unit, 211 ... single positioning type GPS receiving unit, 212 ... RTK-GPS receiving unit.

Claims (5)

In a radio wave transmission device that is installed in a vehicle and transmits the same radio wave as the transmission wave of an artificial satellite used in the global positioning system,
Transmitting means for transmitting the radio wave;
Position specifying information acquiring means for acquiring information for specifying the current position of the radio wave transmitting device;
A series of steps for identifying the current position of the radio wave transmitting device based on the information acquired by the position specifying information acquiring unit, and causing the transmitting unit to transmit the radio wave including information based on the specified current position. A control means for executing transmission processing;
Stop information acquisition means for acquiring information on whether or not the vehicle is stopped;
Equipped with a,
The control means executes the transmission process when it is determined that the vehicle is stopped based on the information acquired by the stop information acquisition means whether or not the vehicle is stopped. Stopping the transmission process when it is determined that has moved.
A radio wave transmitter characterized by the above. The radio wave transmitter according to claim 1 ,
Furthermore, an engine information acquisition means for acquiring information on whether the engine of the vehicle is operating is provided,
The control means is configured to execute the transmission process based on the information acquired by the stop information acquisition means, based on information on whether the engine of the vehicle is operated or not acquired by the engine information acquisition means. It is determined whether or not the vehicle engine has stopped, and the transmission process is stopped when it is determined that the vehicle engine has stopped, or after a predetermined time since it has been determined that the vehicle engine has stopped. A featured radio wave transmitter. In the radio wave transmitter according to claim 1 or 2 ,
The radio wave transmitting apparatus, wherein the position specifying information acquiring unit acquires information for specifying the current position from a beacon using a DSRC system installed on a road. In the radio wave transmitter according to any one of claims 1 to 3 ,
Furthermore, the radio wave transmission device further comprising a notification unit that notifies whether the transmission process is performed by the control unit. A navigation device that executes navigation processing using position information,
Includes a radio transmission device according to any one of claims 1 to 4, the information for identifying the current position obtained by the position information acquisition unit of the radio transmission apparatus used in performing the navigation processing A navigation device characterized by that.

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