JP5012549B2 - Position calculation device for moving body - Google Patents

Description

  The present invention relates to a moving body position calculation device that is mounted on a moving body and detects the position of the moving body.

Conventionally, an image processing means that collects surrounding images of a vehicle, identifies a predetermined image from the surrounding images, detects a feature of the current position of the vehicle, calculates the current position of the vehicle, and corresponds to the calculated current position The navigation device capable of displaying both the map information and the current position of the vehicle detected by the image processing means and the current position of the vehicle or the map information calculated by the navigation device, and based on the comparison result There is known a car navigation device including a control unit that corrects the current position of a vehicle calculated and displayed by the navigation device (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-152348

  By the way, in the configuration in which the intersection passage is determined by the image recognition as in the configuration described in Patent Document 1, the intersection passage can be determined with high accuracy, but the camera and the image recognition device are necessary for the intersection passage determination.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a moving body position calculating apparatus that can determine the passing of an intersection and calculate the moving body position with a simple algorithm without using a camera or an image recognition apparatus.

In order to achieve the above object, a first aspect of the present invention provides a moving body position calculating apparatus that is mounted on a moving body and detects the position of the moving body.
Receiving means for receiving radio waves from a plurality of satellites orbiting around the earth;
An intersection determination means for determining whether or not the mobile body has passed through an intersection based on a reception state of radio waves from a satellite in the reception means ;
The intersection determination means is in a state of receiving radio waves from a satellite located in a predetermined range centered on a direction perpendicular to the moving direction of the moving body in plan view and in a predetermined low elevation angle range. Based on this, it is determined whether or not the moving body has passed an intersection .

  Here, as a definition of the term, whether or not the moving body has passed the intersection is determined not only by whether or not the moving body has passed the intersection, but whether or not the moving body is actually passing the intersection. (That is, whether or not the current position of the moving object is located within the intersection).

3rd invention is the position calculation apparatus for moving bodies which concerns on 1st invention,
The intersection determination means is the number of observable satellites that can receive radio waves, and is located in a direction within a predetermined range centered on a direction perpendicular to the moving direction of the moving body and within a predetermined low elevation angle range. The number of satellites located at (hereinafter referred to as the number of target satellites) is monitored, and it is determined whether or not the mobile body has passed an intersection based on a variation mode of the number of target satellites. .

4th invention is the position calculation apparatus for moving bodies based on 3rd invention,
The intersection determination means determines that the moving body has passed the intersection when the number of the target satellites increases by a predetermined number or more.

  Here, as the definition of the term, the determination that the mobile object has passed the intersection includes not only the determination that the mobile object has passed the intersection but also the determination that the mobile object is actually passing the intersection. .

According to a fifth aspect of the present invention, in the mobile object position calculating apparatus according to the third aspect of the present invention,
The intersection determination means is an average value of the number of the target satellites, and the average value of the number of the target satellites within a predetermined distance or a predetermined time is equal to or less than a predetermined reference number. When the situation exceeds the predetermined reference number, it is determined that the moving body has passed an intersection.

In a sixth aspect of the present invention, there is provided a movable body position calculating apparatus that is mounted on a movable body and detects the position of the movable body.
Receiving means for receiving radio waves from a plurality of satellites orbiting around the earth;
An intersection determination means for determining whether or not the mobile body has passed through an intersection based on a reception state of radio waves from a satellite in the reception means;
The intersection determination means is configured to allow the moving body to pass through the intersection based on a multipath generation mode in a radio wave from a satellite located in a direction within a predetermined range centered on a direction perpendicular to the moving direction of the moving body. It is characterized by determining whether or not. The multipath generation mode includes a variation mode of the number of satellites in which the multipath has occurred, in addition to the multipath generation frequency and the like.

7th invention is the position calculation apparatus for moving bodies based on 6th invention,
The intersection determination means monitors the number of satellites (hereinafter referred to as the number of satellites of interest) that are located in a predetermined range centered on a direction perpendicular to the moving direction of the moving body and that have a multipath. Based on the variation mode of the number of the satellites of interest, it is determined whether or not the moving body has passed the intersection.

According to an eighth aspect of the invention, in the mobile object position calculating apparatus according to the seventh aspect of the invention,
The intersection determination means determines that the moving body has passed the intersection when the number of the target satellites has decreased by a predetermined number or more.

A ninth aspect of the invention is the mobile object position calculating apparatus according to the seventh aspect of the invention,
The intersection determination means is an average value of the number of the target satellites, and the average value of the number of the target satellites within a predetermined distance or a predetermined time is equal to or greater than a predetermined reference number. When the situation falls below a predetermined reference number, it is determined that the moving body has passed an intersection.

According to a tenth aspect of the present invention, there is provided a moving body position calculating apparatus that is mounted on a moving body and detects the position of the moving body.
Receiving means for receiving radio waves from a plurality of satellites orbiting around the earth;
An intersection determination means for determining whether or not the mobile body has passed through an intersection based on a reception state of radio waves from a satellite in the reception means;
The intersection determination means determines whether or not the mobile body has passed the intersection based on the reception intensity of the radio wave derived based on the reception state of the radio wave from the satellite.

An eleventh aspect of the present invention is the mobile object position calculating device according to the tenth aspect of the present invention,
The intersection determination means monitors the reception intensity of the satellite radio wave derived based on the reception state of the radio wave from the satellite, and determines whether the mobile body has passed the intersection based on the variation mode of the reception intensity. It is characterized by determining.

A twelfth aspect of the present invention is the mobile object position calculating device according to the eleventh aspect of the present invention,
The intersection determination means determines that the moving body has passed the intersection when the reception intensity of radio waves from the satellite increases by a predetermined value or more.

A thirteenth aspect of the invention is the mobile object position calculating device according to the eleventh aspect of the invention,
The intersection determination means is an average value of the radio wave reception intensity from the satellite, and the radio wave reception intensity from the satellite is the predetermined value from a situation where the average value within a predetermined distance or predetermined time is equal to or less than a predetermined reference value. When the situation exceeds the reference value, it is determined that the moving body has passed the intersection.

14th invention is the position calculation apparatus for moving bodies which concerns on any one of 10th-13th invention,
The intersection determination unit performs the determination based on the reception intensity of radio waves of a satellite located within a predetermined high elevation angle range.

A fifteenth aspect of the present invention is the mobile object position calculating device according to any one of the first to fourteenth aspects of the present invention,
The intersection determination means comprises detection means for detecting that the moving body is located around the intersection within a predetermined distance from the intersection based on given map data including position information of the intersection,
The intersection determination unit performs the determination when the detection unit detects that the moving body is located around an intersection.

In a sixteenth aspect of the present invention, in the mobile object position calculating apparatus according to any one of the first to fifteenth aspects of the present invention,
When the said intersection determination means determines with the said mobile body passing the intersection, the correction means which correct | amends the positional information on a mobile body based on given intersection position information is further provided.

In a seventeenth aspect of the present invention, in the mobile object position calculating apparatus according to the sixteenth aspect of the present invention,
The correction means corrects the position information of the moving body so that the moving body is positioned at the position of the intersection when the intersection determining means determines that the moving body has passed the intersection. To do.

According to an eighteenth aspect of the present invention, in the mobile object position calculating apparatus according to any one of the first to seventeenth aspects of the present invention,
The moving body is a vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, the position calculation apparatus for moving bodies which can determine a crossing of an intersection and calculate a moving body position with a simple algorithm without using a camera or an image recognition apparatus is obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a system configuration diagram showing an overall configuration of a GPS (Global Positioning System) to which a moving body position calculating apparatus according to the present invention is applied. As shown in FIG. 1, the GPS is composed of a GPS satellite 10 that orbits the earth and a vehicle 90 that is located on the earth and can move on the earth. The vehicle 90 is merely an example of a moving body, and other moving bodies include motorcycles, railways, ships, airplanes, hawk lifts, robots, information terminals such as mobile phones that move with the movement of people, and the like. There can be.

  The GPS satellite 10 constantly broadcasts navigation messages (satellite signals) toward the earth. The navigation message includes satellite orbit information (ephemeris and almanac) regarding the corresponding GPS satellite 10, a clock correction value, and an ionosphere correction coefficient. The navigation message is spread by the C / A code, is carried on the L1 wave (frequency: 1575.42 MHz), and is constantly broadcast toward the earth. The L1 wave is a combined wave of a Sin wave modulated with a C / A code and a Cos wave modulated with a P code (Precision Code), and is orthogonally modulated. The C / A code and the P code are pseudo noise codes, and are code strings in which -1 and 1 are irregularly arranged periodically.

  Currently, 24 GPS satellites 10 orbit the earth at an altitude of about 20,000 km, and each of the four GPS satellites 10 is evenly arranged on six orbiting earth surfaces inclined by 55 degrees. ing. Therefore, as long as the sky is open, at least five GPS satellites 10 can be observed at any time on the earth.

  The vehicle 90 is equipped with the GPS receiver 1 and the navigation device 2.

  The GPS receiver 1 converts the radio wave received from the GPS satellite 10 via the GPS antenna into an intermediate frequency, performs C / A code synchronization using the C / A code generated in the GPS receiver, and sends a navigation message. Take out. The GPS receiver 1 generates information (hereinafter referred to as GPS satellite position information) regarding the position (azimuth and elevation angle) of each GPS satellite 10 based on the satellite orbit information included in the navigation message, and supplies the information to the navigation device 2. .

  The GPS receiver 1 measures the position and speed of the vehicle 90 based on the radio wave received from the GPS satellite 10, generates information on the position and speed of the vehicle 90 (hereinafter referred to as vehicle position information), and navigation. Supply to device 2. The positioning method is arbitrary, and single positioning or interference positioning may be used, or inertial navigation using speed information obtained from a carrier Doppler frequency, a vehicle speed sensor, or the like may be used in combination. Inertial navigation is preferably used in combination when vehicle position information cannot be obtained by satellite navigation alone, particularly when the number of observable GPS satellites 10 is insufficient.

  As shown in FIG. 2, the navigation device 2 includes an ECU 20 that performs various types of information processing, a display 22, and a map database 24 that holds map data. The ECU 20 includes a microcomputer, and includes, for example, a CPU, a ROM that stores a control program, a readable / writable RAM that stores calculation results, a timer, a counter, an input interface, an output interface, and the like. The display 22 may be a liquid crystal display installed on an instrument panel of the vehicle 90, for example. The map database 24 stores information related to the position of the intersection (hereinafter referred to as intersection position information) and information (hereinafter referred to as peripheral environment information) representing the surrounding environment (city area, urban environment, presence or absence of street trees, etc.) described later. Is done.

  FIG. 3 is a diagram showing a basic algorithm of main processing realized by the ECU 20 of the navigation device 2. In the ECU 20 of the navigation device 2, as shown in FIG. 3, an intersection determination process is performed to determine whether or not the vehicle 90 has passed the intersection (or has passed, the same applies hereinafter). If it is determined that the vehicle has passed, map matching processing for the intersection is executed.

  FIG. 4 is a flowchart illustrating an example of an intersection determination process realized by the ECU 20 of the navigation device 2. The processing routine shown in FIG. 4 may be repeatedly executed at predetermined intervals synchronized with the positioning cycle of the vehicle position of the GPS receiver 1, for example.

  In step 400, it is determined whether or not the vehicle 90 is traveling in an urban area or an urban environment based on the map data (surrounding environment information) in the map database 24 and the own vehicle position information from the GPS receiver 1. The The urban area and the urban environment are specific examples representing an environment where there are many radio wave shielding objects such as high-rise buildings that prevent reception of radio waves from the GPS satellite 10. If the vehicle 90 is traveling in an urban area or an urban environment, the process proceeds to step 402. If the vehicle 90 is not traveling in an urban area or an urban environment, the process returns to step 400.

  In step 402, based on the GPS satellite position information from the GPS receiver 1 and the own vehicle position information, the reception state of the GPS satellite 10 located in a direction perpendicular to the vehicle traveling direction (movement direction) is grasped. The vehicle traveling direction may be grasped from the own vehicle position information from the GPS receiver 1 or may be grasped from information from other in-vehicle sensors (for example, vehicle speed sensors). The direction perpendicular to the vehicle traveling direction need not be one direction that is completely perpendicular to the vehicle traveling direction in plan view, and is typically a direction that is substantially perpendicular to the vehicle traveling direction in plan view. And may be defined within a predetermined angle range (for example, ± 10) with the direction perpendicular to the vehicle traveling direction as the center.

  In step 404, it is determined whether or not the average value of the number of GPS satellites 10 located within a predetermined low elevation angle range is less than a specified value based on the processing result in step 402. The predetermined low elevation angle range is a low elevation angle range in which radio waves cannot be received by the high-rise building in an environment where a high-rise building such as an urban area or an urban environment is built, and is appropriately determined based on the test result etc. Also good. For example, the predetermined low elevation angle range may be an angle within 30 to 45 degrees from the horizontal plane. The average value of the number of GPS satellites 10 positioned within a predetermined low elevation angle range may be an average value in a traveling process of a predetermined distance in the past (for example, 500 m), or traveling for a predetermined time in the past (for example, 10 seconds). It may be an average value in the process.

  Here, since the average value of the number of GPS satellites 10 located within the predetermined low elevation angle range is calculated based on the processing result of step 404 above, the average value is positioned in a direction perpendicular to the vehicle traveling direction and the predetermined low elevation angle. This is the average value of the number of observable GPS satellites 10 located in the elevation angle range. Here, the observable GPS satellite 10 means a GPS satellite 10 from which a radio wave is received from the GPS satellite 10 with a reception intensity equal to or higher than a predetermined level. Accordingly, in an environment where high-rise buildings such as urban areas and urban environments are built, the average value of the number of the GPS satellites 10 is significantly smaller than in an environment where there are no high-rise buildings and the periphery is open. The specified value in this step 404 is a threshold for isolating such environmental changes, and the vehicle is actually driven in an environment where high-rise buildings such as urban areas and urban environments are built and in an environment where the surroundings are open. It may be determined appropriately based on the reception status (test result) of the GPS satellite 10 obtained.

  In this step 404, when the average value of the number of GPS satellites 10 located within the predetermined low elevation angle range is less than the specified value, the process proceeds to step 406, and otherwise, the process returns to step 402.

  In step 406, since the average value of the number of GPS satellites 10 located within a predetermined low elevation angle range is less than the specified value, it is determined that the vehicle 90 is traveling at a location other than the current intersection, and the routine proceeds to step 408.

  In step 408, it is determined whether or not the vehicle 90 is located around the intersection based on the map data (intersection position information) in the map database 24 and the own vehicle position information from the GPS receiver 1. For example, when the vehicle 90 is located within a predetermined distance (for example, ± 100 m) from the intersection, it may be determined that the vehicle 90 is located around the intersection. If it is determined that the vehicle 90 is located in the vicinity of the intersection, the process proceeds to step 410; otherwise, the process returns to step 402.

  In step 410, the number of observable GPS satellites 10 located in a direction perpendicular to the vehicle traveling direction and within a predetermined low elevation angle range is equal to or greater than a predetermined value based on the processing result of step 402 in the current cycle. It is determined whether or not. The specified value may be the same as the specified value used in step 404 above. If the number of observable GPS satellites 10 located in a direction perpendicular to the vehicle traveling direction and within a predetermined low elevation angle range is equal to or greater than a specified value, the process proceeds to step 412; Return to step 402.

  In step 412, it is determined that the vehicle 90 has passed the intersection (or has passed, the same applies hereinafter), and this processing routine is terminated.

  By the way, if the vehicle 90 passes through an intersection in an environment where a high-rise building such as an urban area or an urban environment is built, the surroundings suddenly open when passing the intersection, so that the vehicle 90 is positioned in a direction perpendicular to the vehicle traveling direction and has a low elevation angle. The GPS satellite 10 located within the range changes to an observable state. According to the processing shown in FIG. 4 described above, paying attention to this point, the number of observable GPS satellites 10 located in a direction perpendicular to the vehicle traveling direction and within a predetermined low elevation angle range is increased. Based on this, since it is determined whether or not the vehicle 90 has passed the intersection, it can be accurately detected that the vehicle 90 has passed the intersection.

  When it is determined that the vehicle 90 has passed the intersection in this manner, the map matching process is executed as described above with reference to FIG. In the map matching process, when it is determined that the vehicle 90 has passed the intersection, the position information (own vehicle position information) of the vehicle 90 is corrected based on the map data (intersection position information) in the map database 24. There are a wide variety of correction modes, and any appropriate method may be adopted. For example, if it is determined that the vehicle 90 has passed an intersection, the position information of the intersection may be used as the vehicle position information. That is, the vehicle position information may be corrected so that the vehicle 90 is positioned at the intersection. In addition, the vehicle position may be corrected to a position deviated from the center position of the intersection in consideration of delay time such as time required for determination and communication time. When the vehicle position information is corrected by the map matching process in this way, the navigation device 2 determines the position of the vehicle position display on the map displayed on the display 22 based on the corrected vehicle position information. It may be corrected.

  According to the moving body position calculating apparatus according to the first embodiment described above, the following excellent effects are achieved.

  As described above, according to the first embodiment, based on the increasing mode (variation mode) of the number of observable GPS satellites 10 positioned in a direction perpendicular to the vehicle traveling direction and within a predetermined low elevation angle range. Since it is determined whether or not the vehicle 90 has passed the intersection, it can be accurately detected by a simple algorithm that the vehicle 90 has passed the intersection.

  Further, as shown in step 408 of FIG. 4, it is assumed that the vehicle 90 has passed the intersection on the condition that the vehicle 90 is detected around the intersection using the map data in the map database 24. Since it is determined, it is possible to accurately detect that the vehicle 90 has passed the intersection. From the same point of view, other conditions may be similarly adopted as necessary conditions in order to accurately detect that the vehicle 90 has passed the intersection. For example, it may be adopted as a necessary condition that a right / left turn state is detected based on information from a steering sensor (steering angle sensor). This condition may be employed only when, for example, it can be predicted from the route information of route guidance that the vehicle will turn left and right at the intersection. In addition, since the first embodiment described above is particularly suitable for determining the passage of an intersection of a certain size or more (for example, an intersection where roads of two or more lanes intersect), the map data in the map database 24 is used. In addition, it may be used as a necessary condition that it is detected that the vehicle 90 is located around an intersection of a certain size or more.

  In the above-described first embodiment, in step 410 shown in FIG. 4, based on the processing result of step 402 in the current cycle (latest processing cycle), the vehicle is positioned in a direction perpendicular to the vehicle traveling direction and has a predetermined low level. It is determined whether or not the number of observable GPS satellites 10 located within the elevation angle range is equal to or greater than a specified value. However, the number of observable GPS satellites 10 positioned in a direction perpendicular to the vehicle traveling direction and within a predetermined low elevation angle range based on the processing result of step 402 in a predetermined number of cycles before the current cycle. An average value may be calculated, and it may be determined whether the average value is equal to or greater than a specified value. At this time, the predetermined number is a number necessary to eliminate the influence of noise or the like (however, the number is an average value in a section shorter than the average value in step 404), but the size of the intersection (from the map data) (Acquisition). Further, from the same viewpoint (from the viewpoint of eliminating the influence of noise or the like), the number (or average value) of observable GPS satellites 10 located in a direction perpendicular to the vehicle traveling direction and within a predetermined low elevation angle range is It may be filtered.

  In the above-described first embodiment, the observable GPS satellite 10 is a GPS satellite 10 in which radio waves are received from the GPS satellite 10 with a reception intensity of a predetermined level or higher. 10 may be a GPS satellite 10 in which radio waves are received from the GPS satellite 10 with a reception intensity equal to or higher than a predetermined level, and multipath is not generated (that is, a direct wave is received).

  Further, as a modification of the above-described first embodiment, from the same viewpoint as the process shown in FIG. 4, an observable GPS satellite 10 located in a direction perpendicular to the vehicle traveling direction and within a predetermined low elevation angle range is used. When the number (the number of single cycles or the average value of the number of multiple cycles) increases by a predetermined number or more, it may be determined that the vehicle 90 has passed the intersection. This is because when the vehicle 90 passes through an intersection in an environment where a high-rise building such as an urban area or an urban environment is built, the periphery suddenly opens when the vehicle passes through the intersection. This is because the number of observable GPS satellites 10 located within the low elevation angle range increases rapidly. At this time, the predetermined number may be appropriately determined based on various test results obtained by actually passing through an intersection in an environment where high-rise buildings such as urban areas and urban environments are built.

  The second embodiment is different from the first embodiment in consideration of the reception state of the observable GPS satellite 10 located in a direction perpendicular to the vehicle traveling direction and within a predetermined low elevation angle range. The main difference is that a multipath generation mode in a radio wave from a GPS satellite 10 positioned in a perpendicular direction is considered. In the following, the configuration unique to the second embodiment will be mainly described, and other necessary configurations may be the same as those of the first embodiment.

  The GPS receiver 1 detects a multipath occurrence state based on the radio wave received from the GPS satellite 10. A wide variety of multipath detection methods have been proposed and known, and any appropriate method may be employed. For example, when a reflected wave due to multipath is superimposed on a direct wave, even if multipath is detected based on the amount of deviation of the correlation peak value, considering that the correlation peak value at the time of phase tracking is shifted. Good. The GPS receiver 1 generates information for specifying the GPS satellite 10 in which the multipath is detected (hereinafter referred to as multipath information) and supplies the information to the navigation device 2.

  The navigation device 2 according to the second embodiment is similar to the above-described first embodiment with respect to the hardware configuration illustrated in FIG. 2 and the basic algorithm illustrated in FIG. 3. As described below, an intersection determination process is performed. The method is different.

  FIG. 5 is a flowchart illustrating an example of an intersection determination process realized by the ECU 20 of the navigation device 2 according to the second embodiment. The processing routine shown in FIG. 5 may be repeatedly executed at predetermined intervals synchronized with the positioning cycle of the vehicle position of the GPS receiver 1, for example.

  In step 500, it is determined whether or not the vehicle 90 is traveling in an urban area or an urban environment based on the map data (surrounding environment information) in the map database 24 and the own vehicle position information from the GPS receiver 1. . The urban area and the urban environment are specific examples representing an environment in which there are many buildings that hinder the reception of direct waves from the GPS satellite 10 (that is, an environment in which multipath is likely to occur). If the vehicle 90 is traveling in an urban area or an urban environment, the process proceeds to step 502. If the vehicle 90 is not traveling in an urban area or an urban environment, the process returns to step 500.

  In step 502, based on the GPS satellite position information from the GPS receiver 1 and the own vehicle position information, the reception state of the GPS satellite 10 located in the direction perpendicular to the vehicle traveling direction (movement direction) is grasped. The vehicle traveling direction may be grasped from the own vehicle position information from the GPS receiver 1 or may be grasped from information from other in-vehicle sensors (for example, vehicle speed sensors). The direction perpendicular to the vehicle traveling direction does not need to be one direction that is completely perpendicular, but is typically a direction substantially perpendicular to the vehicle traveling direction in plan view, for example, a predetermined angular range centered on the perpendicular direction. (For example, ± 10).

  In step 504, based on the multipath information from the GPS receiver 1 and the processing result in step 502, it is determined whether or not the average value of the number of GPS satellites 10 in which the multipath is detected is equal to or greater than a specified value. Is done. The average value of the number of GPS satellites 10 in which the multipath is detected may be an average value in a traveling process of a predetermined distance in the past (for example, 500 m), or an average value in a traveling process in a past predetermined time (for example, 10 seconds). It may be a value.

  Here, since the average value of the number of the GPS satellites 10 in which the multipath is detected is calculated based on the processing result of the above step 504, the multipath is detected in the direction perpendicular to the vehicle traveling direction. This is the average value of the number of GPS satellites 10. Therefore, in an environment where high-rise buildings such as urban areas and urban environments are built, multipath is likely to occur. Therefore, the average value of the number of GPS satellites 10 is higher than that in an environment where there are no high-rise buildings and the surroundings are open. Significantly larger. The specified value in this step 504 is a threshold for isolating such environmental changes, and the vehicle is actually driven in an environment where high-rise buildings such as urban areas and urban environments are built and in an environment where the surroundings are open. It may be determined appropriately based on the obtained reception state of the GPS satellite 10 (test result relating to the multipath occurrence state) or the like.

  In this step 504, when the average value of the number of GPS satellites 10 in which the multipath is detected is equal to or larger than the specified value, the process proceeds to step 506, and in other cases, the process returns to step 502.

  In step 506, since the average value of the number of GPS satellites 10 in which the multipath is detected is equal to or greater than the specified value, it is determined that the vehicle 90 is traveling at a position other than the current intersection and the process proceeds to step 508.

  In step 508, it is determined whether or not the vehicle 90 is located around the intersection based on the map data (intersection position information) in the map database 24 and the own vehicle position information from the GPS receiver 1. For example, when the vehicle 90 is located within a predetermined distance (for example, ± 100 m) from the intersection, it may be determined that the vehicle 90 is located around the intersection. If it is determined that the vehicle 90 is located around the intersection, the process proceeds to step 510; otherwise, the process returns to step 502.

  In step 510, based on the processing result of step 502 in the current cycle, whether or not the number of GPS satellites 10 that are positioned in a direction perpendicular to the vehicle traveling direction and in which a multipath is detected is less than a specified value. Determined. The specified value may be the same as the specified value used in step 504 above. If the number of GPS satellites 10 that are located in the direction perpendicular to the vehicle traveling direction and in which multipath is detected is less than the specified value, the process proceeds to step 512; otherwise, the process returns to step 502.

  In step 512, it is determined that the vehicle 90 has passed the intersection, and this processing routine is ended.

  By the way, if the vehicle 90 passes through an intersection in an environment where a high-rise building such as an urban area or an urban environment is built, the surroundings are suddenly opened when the vehicle passes through the intersection. Therefore, the GPS satellite 10 positioned in a direction perpendicular to the traveling direction of the vehicle. The direct wave can be received from (ie, no multipath occurs). According to the processing shown in FIG. 5 described above, paying attention to this point, the vehicle 90 is based on the variation mode of the number of GPS satellites 10 that are located in a direction perpendicular to the vehicle traveling direction and in which a multipath is detected. Since it is determined whether or not the vehicle has passed the intersection, it can be accurately detected that the vehicle 90 has passed the intersection.

  When it is determined that the vehicle 90 has passed the intersection in this manner, the map matching process is executed as described above with reference to FIG. In the map matching process, when it is determined that the vehicle 90 has passed the intersection, the position information (own vehicle position information) of the vehicle 90 is corrected based on the map data (intersection position information) in the map database 24. There are a wide variety of correction modes, and any appropriate method may be adopted. For example, if it is determined that the vehicle 90 has passed an intersection, the position information of the intersection may be used as the vehicle position information. That is, the vehicle position information may be corrected so that the vehicle 90 is positioned at the intersection. In addition, the vehicle position may be corrected to a position deviated from the center position of the intersection in consideration of delay time such as time required for determination and communication time. When the vehicle position information is corrected by the map matching process in this way, the navigation device 2 determines the position of the vehicle position display on the map displayed on the display 22 based on the corrected vehicle position information. It may be corrected.

  According to the moving body position calculating apparatus according to the second embodiment described above, the following excellent effects are achieved.

  As described above, according to the second embodiment, on the basis of the variation mode (decrease mode) of the number of GPS satellites 10 that are positioned in a direction perpendicular to the vehicle traveling direction and in which a multipath is detected, the vehicle 90 detects the intersection. Since it is determined whether or not the vehicle has passed, it can be accurately detected by a simple algorithm that the vehicle 90 has passed the intersection.

  Further, as shown in step 508 of FIG. 5, it is assumed that the vehicle 90 has passed the intersection on the condition that the vehicle 90 is detected around the intersection using the map data in the map database 24. Since it is determined, it is possible to accurately detect that the vehicle 90 has passed the intersection. From the same point of view, other conditions may be similarly adopted as necessary conditions in order to accurately detect that the vehicle 90 has passed the intersection. For example, it may be adopted as a necessary condition that a right / left turn state is detected based on information from a steering sensor (steering angle sensor). This condition may be employed only when, for example, it can be predicted from the route information of route guidance that the vehicle will turn left and right at the intersection. In addition, the second embodiment described above is particularly suitable for an intersection having a certain size or more (for example, an intersection where roads of two or more lanes intersect), so that the vehicle 90 is located around the intersection having a certain size or more. It may be used as a necessary condition that it has been detected.

  In the second embodiment described above, in step 510 shown in FIG. 5, the multipath is located in a direction perpendicular to the vehicle traveling direction and based on the processing result of step 502 in the current cycle (latest processing cycle). It is determined whether or not the number of detected GPS satellites 10 is less than a specified value. However, based on the processing result of step 502 in the predetermined number of cycles before the current cycle, the average value of the number of GPS satellites 10 that are positioned in a direction perpendicular to the vehicle traveling direction and in which a multipath is detected is calculated. You may determine whether the said average value is less than a regulation value. At this time, the predetermined number is a number necessary to eliminate the influence of noise or the like (however, the number is an average value in a section shorter than the average value in step 504), but the size of the intersection (from the map data) (Acquisition). From the same viewpoint (from the viewpoint of eliminating the influence of noise or the like), the number (or average value) of GPS satellites 10 that are positioned in a direction perpendicular to the vehicle traveling direction and in which a multipath is detected may be filtered. .

  Further, as a modification of the above-described second embodiment, from the same viewpoint as the process shown in FIG. 5, the number of GPS satellites 10 (single cycle) that are positioned in a direction perpendicular to the vehicle traveling direction and in which a multipath is detected. It is also possible to determine that the vehicle 90 has passed through the intersection when the number or the average value of the number of multiple cycles decreases by a predetermined number or more. This is because when the vehicle 90 passes through an intersection in an environment where a high-rise building such as an urban area or an urban environment is built, the periphery suddenly opens when the vehicle passes through the intersection. This is because the number of GPS satellites 10 in which a path is detected decreases rapidly. At this time, the predetermined number may be appropriately determined based on various test results obtained by actually passing through an intersection in an environment where high-rise buildings such as urban areas and urban environments are built.

  As an equivalent modification to the above-described second embodiment, the multipath occurrence frequency (corresponding to an average value) is monitored for each GPS satellite 10 positioned in a direction perpendicular to the vehicle traveling direction, and each GPS satellite is monitored. In the situation where the multipath occurrence frequency is high with respect to 10, when the multipath occurrence frequency rapidly decreases, it may be determined that the vehicle 90 has passed the intersection. Further, as an equivalent modification to the above-described second embodiment, when the number of GPS satellites 10 that are located in a direction perpendicular to the vehicle traveling direction and in which no multipath is detected increases by a predetermined number or more, the vehicle 90 is crossed. It is good also as determining with having passed.

  The third embodiment is different from the first embodiment described above in that a GPS is used instead of a variation mode of the number of observable GPS satellites 10 positioned in a direction perpendicular to the vehicle traveling direction and within a predetermined low elevation angle range. The main difference is that a variation aspect of the received radio wave intensity from the satellite 10 is considered. In the following, the configuration unique to the third embodiment will be mainly described, and other necessary configurations may be the same as those of the first embodiment.

  The GPS receiver 1 detects the radio wave intensity received from each GPS satellite 10. A variety of methods for detecting the radio field intensity are proposed and known, and any appropriate method may be employed. The GPS receiver 1 generates information indicating the radio wave intensity received from each GPS satellite 10 (hereinafter referred to as radio wave intensity information) and supplies it to the navigation device 2.

  The navigation device 2 according to the third embodiment is similar to the above-described first embodiment in the hardware configuration illustrated in FIG. 2 and the basic algorithm illustrated in FIG. 3. As described below, the intersection determination processing method Is different.

  FIG. 6 is a flowchart illustrating an example of an intersection determination process realized by the ECU 20 of the navigation device 2 according to the third embodiment. The processing routine shown in FIG. 6 may be repeatedly executed at predetermined intervals synchronized with the positioning cycle of the vehicle position of the GPS receiver 1, for example.

  In step 600, based on the map data (peripheral environment information) in the map database 24 and the own vehicle position information from the GPS receiver 1, it is determined whether or not the vehicle 90 is traveling in an urban area or an urban environment. . The urban area and the urban environment represent an environment in which many roadside trees that interfere with reception of radio waves (direct waves) from the GPS satellite 10 are present on the sidewalk (that is, an environment in which radio waves from the GPS satellite 10 are easily attenuated and received). It is a specific example. If the vehicle 90 is traveling in an urban area or an urban environment, the process proceeds to step 602. If the vehicle 90 is not traveling in an urban area or an urban environment, the process returns to step 600.

  In step 602, the radio field intensity from each GPS satellite 10 is monitored based on the radio field intensity information from the GPS receiver 1.

  In step 604, based on the monitoring result in step 602, it is determined whether or not the average value of the radio field intensity is less than a specified value. Here, in an environment with many roadside trees such as an urban area and an urban environment, the radio wave from the GPS satellite 10 is easily attenuated by the roadside roadside trees. Significantly smaller than in an open environment. The specified value in this step 604 is a threshold value for distinguishing such environmental changes, and the vehicle is actually driven in an environment where there are many road trees such as an urban area or an urban environment, and in an environment where no road trees exist. It may be determined appropriately based on the reception state (test result regarding the radio wave intensity) of the GPS satellite 10 obtained in this way. The average value of the radio wave intensity may be an average value in a traveling process of a predetermined distance in the past (for example, 500 m), or may be an average value in a traveling process of a predetermined time in the past (for example, 10 seconds). Further, the average value of the radio field intensity may be an average value of the radio field intensity regarding all the observable GPS satellites 10, or the average of the radio field intensity regarding a specific GPS satellite 10 among all the observable GPS satellites 10. It may be a value. The specific GPS satellite 10 is preferably a GPS satellite 10 located near the zenith. This is because such a radio wave from the GPS satellite 10 located near the zenith is particularly easily attenuated by roadside trees.

  In this step 604, if the average value of the radio field intensity is less than the specified value, the process proceeds to step 606, and otherwise, the process returns to step 602.

  In step 606, since the average value of the radio wave intensity is less than the specified value, it is determined that the vehicle 90 is currently traveling under a radio wave shield such as a roadside tree, and the process proceeds to step 608.

  In step 608, it is determined whether or not the vehicle 90 is located around the intersection based on the map data (intersection position information) in the map database 24 and the own vehicle position information from the GPS receiver 1. For example, when the vehicle 90 is located within a predetermined distance (for example, ± 100 m) from the intersection, it may be determined that the vehicle 90 is located around the intersection. If it is determined that the vehicle 90 is located around the intersection, the process proceeds to step 610; otherwise, the process returns to step 602.

  In step 610, based on the processing result in step 602 in the current cycle, it is determined whether the radio wave intensity is equal to or greater than a specified value. The specified value may be the same as the specified value used in step 604 above. Here, the radio field intensity to be compared with the specified value is the radio field intensity related to the GPS satellite 10 used to calculate the average value in step 604. When there are a plurality of GPS satellites 10 used to calculate the average value in the above step 604, the average value of the radio wave intensities of those GPS satellites 10 may be used and compared with the specified value.

  In step 610, if the radio wave intensity is equal to or higher than the specified value, the process proceeds to step 612, and otherwise, the process returns to step 602.

  In step 612, it is determined that the vehicle 90 has passed the intersection, and this processing routine is ended.

  By the way, if the vehicle 90 passes through an intersection in an environment with many roadside trees such as an urban area or an urban environment, the surrounding roadside trees disappear when the intersection passes, so that the radio wave from the GPS satellite 10 is received with high reception intensity. become able to. According to the processing shown in FIG. 6 described above, focusing on this point, it is determined whether or not the vehicle 90 has passed the intersection based on the fluctuation mode of the radio wave intensity from the GPS satellite 10. It is possible to accurately detect that the vehicle has passed the intersection.

  When it is determined that the vehicle 90 has passed the intersection in this manner, the map matching process is executed as described above with reference to FIG. In the map matching process, when it is determined that the vehicle 90 has passed the intersection, the position information (own vehicle position information) of the vehicle 90 is corrected based on the map data (intersection position information) in the map database 24. There are a wide variety of correction modes, and any appropriate method may be adopted. For example, if it is determined that the vehicle 90 has passed an intersection, the position information of the intersection may be used as the vehicle position information. That is, the vehicle position information may be corrected so that the vehicle 90 is positioned at the intersection. In addition, the vehicle position may be corrected to a position deviated from the center position of the intersection in consideration of delay time such as time required for determination and communication time. When the vehicle position information is corrected by the map matching process in this way, the navigation device 2 determines the position of the vehicle position display on the map displayed on the display 22 based on the corrected vehicle position information. It may be corrected.

  According to the moving body position calculating apparatus according to the third embodiment described above, the following excellent effects are achieved.

  As described above, according to the third embodiment, since it is determined whether or not the vehicle 90 has passed the intersection based on the fluctuation mode (increase mode) of the radio wave intensity from the GPS satellite 10, the vehicle 90 determines the intersection. Passing can be accurately detected with a simple algorithm.

  Further, as shown in step 608 of FIG. 6, it is assumed that the vehicle 90 has passed the intersection on the condition that the vehicle 90 is detected around the intersection using the map data in the map database 24. Since it is determined, it is possible to accurately detect that the vehicle 90 has passed the intersection. From the same point of view, other conditions may be similarly adopted as necessary conditions in order to accurately detect that the vehicle 90 has passed the intersection. For example, it may be adopted as a necessary condition that a right / left turn state is detected based on information from a steering sensor (steering angle sensor). This condition may be employed only when, for example, it can be predicted from the route information of route guidance that the vehicle will turn left and right at the intersection. In addition, since the third embodiment described above is particularly suitable for an intersection having a certain size or more (for example, an intersection where two or more lanes intersect), the vehicle 90 is located around the intersection having a certain size or more. It may be used as a necessary condition that it has been detected.

  In the above-described third embodiment, in step 610 shown in FIG. 6, based on the processing result of step 602 in the current cycle (latest processing cycle), whether the radio wave intensity from the GPS satellite 10 is equal to or higher than the specified value. It is determined whether or not. However, based on the processing result of step 602 in the predetermined number of cycles before the current cycle, the average value of the radio wave intensity from the GPS satellite 10 is calculated, and it is determined whether or not the average value is equal to or greater than the specified value. May be. At this time, the predetermined number is a number necessary to eliminate the influence of noise or the like (however, the number is an average value in a section shorter than the average value in step 604), but the size of the intersection (from the map data) (Acquisition). Further, from the same viewpoint (from the viewpoint of eliminating the influence of noise or the like), the radio wave intensity (or average value) from the GPS satellite 10 may be filtered.

  Further, as an equivalent modification to the above-described third embodiment, from the same viewpoint as the process shown in FIG. 6, the number of GPS satellites 10 having a received radio wave intensity of a predetermined level or more (the number of single periods or multiple periods) When the average value of the number increases by a predetermined number or more, it may be determined that the vehicle 90 has passed the intersection. This is because when the vehicle 90 passes through an intersection in an environment with many road trees such as an urban area or an urban environment, the road tree disappears when the vehicle passes through the intersection. Is considered to increase rapidly. At this time, the predetermined number may be appropriately determined based on various test results obtained by actually passing through an intersection under an environment with many roadside trees such as an urban area or an urban environment.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the intersection determination process is realized by the ECU 20 of the navigation device 2, but may be realized by a microcomputer inside the GPS receiver 1, or may be realized by the ECU 20 of the navigation device 2 and the GPS receiver 1 inside. It may be realized in cooperation with the microcomputer, or may be realized by another ECU.

  In the above-described embodiment, an example in which the present invention is applied to the GPS has been shown. However, the present invention can also be applied to satellite systems other than GPS, for example, other GNSS (Global Navigation Satellite System) such as Galileo. is there.

  Also, it is in the form of an inequality sign of less than or greater than and may be replaced with an inequality sign of less than or greater than.

1 is a system configuration diagram showing an overall configuration of a GPS to which a moving body position calculating apparatus according to the present invention is applied. It is a figure which shows the basic algorithm of the principal part process implement | achieved by ECU of the navigation apparatus. It is a figure which shows the basic algorithm of the principal part process implement | achieved by ECU20 of the navigation apparatus. It is a flowchart which shows an example of the intersection determination process implement | achieved by ECU20 of the navigation apparatus 2 of Example 1. FIG. It is a flowchart which shows an example of the intersection determination process implement | achieved by ECU20 of the navigation apparatus 2 of Example 2. FIG. 12 is a flowchart illustrating an example of an intersection determination process realized by the ECU 20 of the navigation device 2 according to the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 GPS receiver 2 Navigation apparatus 10 GPS satellite 10
20 ECU
22 Display 24 Map database 90 Vehicle

Claims (17)

In a moving body position calculation device that is mounted on a moving body and detects the position of the moving body,
Receiving means for receiving radio waves from a plurality of satellites orbiting around the earth;
An intersection determination means for determining whether or not the mobile body has passed through an intersection based on a reception state of radio waves from a satellite in the reception means ;
The intersection determination means is in a state of receiving radio waves from a satellite located in a predetermined range centered on a direction perpendicular to the moving direction of the moving body in plan view and in a predetermined low elevation angle range. Based on this, it is determined whether or not the moving body has passed an intersection . The intersection determination means is the number of observable satellites that can receive radio waves, and is located in a direction within a predetermined range centered on a direction perpendicular to the moving direction of the moving body and within a predetermined low elevation angle range. the number of satellites located in (hereinafter, referred to as the number of interest satellites) to monitor, based on the variation mode of the number of remarked satellite, the mobile determines whether passed the intersection, in claim 1 The position calculation apparatus for moving bodies described. The position calculation device for a moving body according to claim 2 , wherein the intersection determination unit determines that the moving body has passed the intersection when the number of the target satellites increases by a predetermined number or more. The intersection determination means is an average value of the number of the target satellites, and the average value of the number of the target satellites within a predetermined distance or a predetermined time is equal to or less than a predetermined reference number. The position calculation apparatus for moving bodies according to claim 2 , wherein when the situation exceeds the predetermined reference number, it is determined that the moving body has passed an intersection. In a moving body position calculation device that is mounted on a moving body and detects the position of the moving body,
Receiving means for receiving radio waves from a plurality of satellites orbiting around the earth;
An intersection determination means for determining whether or not the mobile body has passed through an intersection based on a reception state of radio waves from a satellite in the reception means;
The intersection determination means is configured to allow the moving body to pass through the intersection based on a multipath generation mode in a radio wave from a satellite located in a direction within a predetermined range centered on a direction perpendicular to the moving direction of the moving body. A position calculation apparatus for a moving object, characterized by determining whether or not The intersection determination means monitors the number of satellites (hereinafter referred to as the number of satellites of interest) that are located in a predetermined range centered on a direction perpendicular to the moving direction of the moving body and that have a multipath. The position calculation apparatus for moving body according to claim 5 , wherein it is determined whether or not the moving body has passed an intersection based on a variation mode of the number of the target satellites. The position calculation device for a moving body according to claim 6 , wherein the intersection determination unit determines that the moving body has passed the intersection when the number of the target satellites has decreased by a predetermined number or more. The intersection determination means is an average value of the number of the target satellites, and the average value of the number of the target satellites within a predetermined distance or a predetermined time is equal to or greater than a predetermined reference number. The position calculation apparatus for moving bodies according to claim 6 , wherein when the situation falls below a predetermined reference number, it is determined that the moving body has passed an intersection. In a moving body position calculation device that is mounted on a moving body and detects the position of the moving body,
Receiving means for receiving radio waves from a plurality of satellites orbiting around the earth;
An intersection determination means for determining whether or not the mobile body has passed through an intersection based on a reception state of radio waves from a satellite in the reception means;
The intersection determining means, based on the reception intensity of the radio wave which is derived based on a reception state of a radio wave from a satellite, the moving body and wherein the determining whether passing through the intersection, the moving object Position calculation device. The intersection determination means monitors the reception intensity of the satellite radio wave derived based on the reception state of the radio wave from the satellite, and determines whether the mobile body has passed the intersection based on the variation mode of the reception intensity. The position calculation apparatus for moving bodies according to claim 9 , wherein the determination is performed. The position calculation device for a moving body according to claim 10 , wherein the intersection determination means determines that the moving body has passed the intersection when the reception intensity of the radio wave from the satellite increases by a predetermined value or more. The intersection determination means is an average value of the radio wave reception intensity from the satellite, and the radio wave reception intensity from the satellite is the predetermined value from a situation where the average value within a predetermined distance or predetermined time is equal to or less than a predetermined reference value. The position calculation apparatus for moving bodies according to claim 10 , wherein when the situation exceeds a reference value, it is determined that the moving body has passed an intersection. The mobile object position calculation according to any one of claims 9 to 12 , wherein the intersection determination means performs the determination based on a reception intensity of radio waves of a satellite located within a predetermined high elevation angle range. apparatus. The intersection determination means comprises detection means for detecting that the moving body is located around the intersection within a predetermined distance from the intersection based on given map data including position information of the intersection,
The intersection determining means, when the movable body by said detecting means is detected to be located around the intersection, and performs the determination, the moving object according to any one of claims 1 to 13 Position calculation device. When the movable body in the intersection determining means is determined to have passed the intersection, based on a given intersection position information, further comprising correcting means for correcting the positional information of the movable body, according to claim 1-14 The position calculation apparatus for moving bodies according to any one of the above. The correction means, when the moving member at the first intersection determining means is determined to have passed the intersection, as the moving body to the position of the intersection is located, to correct the position information of the movable body, according to claim 15 The position calculation apparatus for moving bodies described in 1. The position calculation apparatus for moving bodies according to any one of claims 1 to 16 , wherein the moving body is a vehicle.

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