JP2012032277A - Slope detection device, slope detection method and current position display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slope detection device and a slope detection method that speedily and accurately detect whether a traveling path of a moving body is a slope.SOLUTION: The slope detection device which detects whether the traveling path of the moving body is a slope includes atmospheric pressure detection means 12 for detecting atmospheric pressure, angular velocity/acceleration detection means 13, 14 for detecting an angular velocity or acceleration, and slope determination means 19 for determining whether the traveling path of the moving body is a slope based upon the atmospheric pressure detected by the atmospheric pressure detection means 12 and the angular velocity or acceleration detected by the angular velocity/acceleration detection means 13, 14.

Description

  The present invention relates to a slope detection device, a slope detection method, and a current position display device, and in particular, a slope detection device that detects whether or not a traveling path of a moving body is a slope using a combination of atmospheric pressure detection and autonomous navigation, The present invention relates to a slope detection method and a current position display device.

  A navigation device that detects the current position of a moving object and displays a current position mark indicating the current position on a map image displayed on the display, and uses radio waves from GPS satellites as a method for detecting the current position. There are a GPS system (satellite navigation system) and an autonomous navigation system in which a current position is estimated using an inertial sensor such as a moving distance calculation means and a gyroscope mounted on a moving body or a navigation device. A general navigation apparatus uses these two navigation methods in combination.

  However, since the current position of the moving object obtained by these methods includes an error, the road and the current position of the displayed map image do not exactly match, and the detected or estimated current position remains as it is. When displayed on the display, even if the vehicle is actually on the road, the current position mark may be displayed at a position off the road.

  In order to eliminate such problems, the detected current position is compared with the road of the map information stored in the map database, the current position is matched on the correct road using various matching methods, and display means A map matching technique is used in which the current position mark is corrected and displayed on the road of the map image displayed in FIG.

  By the way, for example, like a highway, a main road and a branch road or an approach road (ramp) that is a connection road between the main road and a general road are approaching, or a branch road or an access road is close to a main road or a general road. On the other hand, if it is provided at a slight branch angle, it is possible to reliably determine whether the vehicle is traveling on the main road of an expressway, or traveling on a branch road or approach road using only conventional map matching technology. The current position mark may be displayed at an inappropriate position on the map (actually, the current position is matched with a branch road (general road) while traveling on the main highway).

  Therefore, for example, focusing on the fact that the branch road and the approach road are slopes that are inclined in the vertical direction, it is detected whether the travel path of the mobile body (the road on which the mobile body is traveling) is a slope. The detection result may be used for map matching.

  For example, the following Patent Document 1 (Japanese Patent Laid-Open No. 2010-39954) discloses an invention relating to a “slope detection method and a slope detection device”. In this method and apparatus, the altitude is calculated based on the output of the atmospheric pressure sensor, and the gradient of the travel road is obtained from the altitude difference with respect to the unit travel distance. If the gradient obtained every time is within a predetermined range continuously for a predetermined number of times or more, the traveling road is determined to be a slope.

  By the way, when using an atmospheric pressure sensor, there is a risk of erroneous detection of a slope due to atmospheric pressure fluctuations that occur when the window is opened and closed or when passing with an oncoming vehicle. However, in Patent Document 1, the obtained gradient is more than a predetermined number of times. Since it is determined that the road is a slope when continuously within a predetermined range, erroneous detection can be avoided. In other words, since the atmospheric pressure fluctuation that occurs when the window is opened or closed or when passing the oncoming vehicle is a temporary fluctuation, it is erroneously determined to be a slope only when it is within a predetermined range continuously for a predetermined number of times. Detection can be avoided.

  Further, a gyroscope or an acceleration sensor used in autonomous navigation can be used as means for detecting whether or not the traveling road is a slope. Since the gyroscope can detect a change in the moving direction (up, down, left, right, etc.) of the moving body as an angular velocity, it can detect whether the traveling road is a slope based on the angular velocity. In the case of an acceleration sensor, the detection of gravitational acceleration changes in accordance with the inclination angle of the traveling road, so that it is possible to detect whether or not the traveling road is a slope based on this acceleration. Specifically, when stopping on a flat road, acceleration (gravity acceleration) is output only in the vertical direction (up and down direction) with respect to the road, but it stops on a slope (uphill, downhill). In this case, acceleration is output not only in the direction perpendicular to the road (up and down direction) but also in the traveling direction of the moving body (front and back direction). That is, when the vehicle is stopped on a slope, gravity acceleration is distributed and output in the vertical direction (up and down direction) and the traveling direction (front and back direction). Then, based on the output vertical acceleration and traveling acceleration, it is possible to detect whether the traveling road is a slope.

JP 2010-39954 A (paragraphs [0016] to [0022])

  However, in the case of the above Patent Document 1, in order to avoid erroneous detection, the altitude difference based on the output of the atmospheric pressure sensor is calculated a plurality of times to determine whether or not it is a hill, and detection takes time. The matching process cannot be performed quickly. In this case, it is possible that notification according to the current position is delayed due to a delay in the matching process. That is, in the case of a navigation device, the notification content for route guidance varies depending on the current position after the matching process (such as right / left turn guidance), so the notification is delayed due to the delay in the matching process, and should be left by itself. A situation such as going straight through an intersection may occur.

  In addition, for example, in a state where a route is being searched, when the current position after the matching process deviates from the searched route, the route is searched again, and the current position after the matching process is changed to the current position after the matching process. Since the processes differ depending on the situation, it is desired that the matching process be performed quickly and accurately.

  In addition, unlike the pressure sensor, the gyroscope is not affected by atmospheric pressure fluctuations that occur when the window is opened or closed or when it is passing the oncoming vehicle, so it can quickly detect whether the road is on a slope. It is possible. However, when the moving speed of the moving body is slow due to traffic jams or when the moving body is stopped, the angular speed is small or the angular speed cannot be detected, so it may not be possible to accurately detect whether the traveling road is a slope.

  On the other hand, if the moving body is stopped, the acceleration sensor can detect the direction of gravity and calculate the inclination of the vehicle (the inclination of the road). can do. However, when the moving body is traveling at high speed, the acceleration error in the direction perpendicular to the road surface increases due to the influence of the acceleration in the moving direction. Therefore, it is correctly detected whether the traveling road is a slope. It becomes difficult.

  An object of the present invention is to solve the above-described problems, and to provide a slope detection device and a slope detection method capable of quickly and accurately detecting whether or not a traveling path of a moving body is a slope. It is intended to provide.

  It is another object of the present invention to provide a current position display device that can quickly and accurately map match the actual current position of a moving body and display a mark indicating the current position on a display. .

  In order to solve the above-described problem, the invention according to claim 1 of the present application is a slope detection device that detects whether or not a traveling path of a moving body is a slope, an atmospheric pressure detection means that detects atmospheric pressure, an angular velocity and / or Alternatively, based on the autonomous navigation means for detecting acceleration, the atmospheric pressure detected by the atmospheric pressure detection means, and the angular velocity and / or acceleration detected by the autonomous navigation means, the traveling path of the moving body is a slope. And a slope judging means for judging whether or not.

  The invention according to claim 2 of the present application is the slope detection device according to claim 1, wherein the slope determination unit has a change amount of the atmospheric pressure detected by the atmospheric pressure detection unit being a first threshold value or more, and When the angular velocity and / or the acceleration detected by the autonomous navigation means is equal to or greater than a second threshold value, the traveling path of the moving body is determined as a slope.

  The invention according to claim 3 of the present application is the slope detection device according to claim 1 or 2, wherein the slope determination unit has a change amount of the atmospheric pressure detected by the atmospheric pressure detection unit being a first threshold value or more, and When the angular velocity and / or acceleration detected by the autonomous navigation means is smaller than a second threshold, the traveling path of the moving body is determined as a flat road.

  The invention according to claim 4 of the present application is characterized in that, in the slope detection device according to claim 2 or 3, the slope judgment means changes the second threshold value in accordance with a change amount of the atmospheric pressure.

  The invention according to claim 5 of the present application is a slope detection method for detecting whether or not a traveling path of a moving body is a slope, a step of detecting atmospheric pressure, a step of detecting angular velocity and / or acceleration, and the atmospheric pressure And a step of determining the traveling path of the moving body as a slope when the amount of change is equal to or greater than a first threshold and the angular velocity and / or the acceleration is equal to or greater than a second threshold. .

  The invention according to claim 6 of the present application is the slope detection method according to claim 5, wherein the change amount of the atmospheric pressure is equal to or greater than a first threshold value, and the angular velocity and / or the acceleration is greater than the second threshold value. When it is small, the method includes a step of determining the traveling path of the moving body as a flat road.

  The invention according to claim 7 of the present application is characterized in that, in the slope detection method according to claim 5 or 6, the step of changing the second threshold value according to the amount of change in the atmospheric pressure is included.

  The invention according to claim 8 of the present application is based on the current position detecting means for detecting the current position of the mobile body, the map database for holding map information, the current position and the map information detected by the current position detecting means. A current position display device comprising: map matching means for performing matching processing based on; and display means for displaying a mark indicating the current position based on the matching processing, wherein the current position display device further includes atmospheric pressure detection means for detecting atmospheric pressure; Autonomous navigation means that detects angular velocity and / or acceleration, the atmospheric pressure detected by the atmospheric pressure detection means, and the angular velocity and / or acceleration detected by the autonomous navigation means, the travel path of the moving body Slope determining means for determining whether or not the road is a slope, and the map matching means includes the slope determination means. Characterized by matching processing based on the determination result by.

  The invention according to claim 9 of the present application is the current position display device according to claim 8, wherein the slope determination unit has a change amount of the atmospheric pressure detected by the atmospheric pressure detection unit equal to or greater than a first threshold value, and When the angular velocity and / or the acceleration detected by the autonomous navigation means is equal to or greater than a second threshold, the traveling path of the moving body is determined as a slope.

  According to a tenth aspect of the present invention, in the current position display device according to the eighth or ninth aspect, the slope determination unit is configured such that the amount of change in the atmospheric pressure detected by the atmospheric pressure detection unit is equal to or greater than a first threshold value. And when the said angular velocity and / or the said acceleration detected by the said autonomous navigation means are smaller than a 2nd threshold value, it determines with the traveling path of the said mobile body being a flat road.

  According to an eleventh aspect of the present invention, in the current position display device according to the ninth or tenth aspect, the slope determining unit changes the second threshold value in accordance with a change amount of the atmospheric pressure. .

  In the invention according to claim 1, in the slope detection device that detects whether or not the traveling path of the moving body is a slope, an atmospheric pressure detection means that detects atmospheric pressure, and an autonomous navigation means that detects angular velocity and / or acceleration ( (E.g., gyroscope, acceleration sensor), the atmospheric pressure detected by the atmospheric pressure detection means, and the angular velocity and / or acceleration detected by the autonomous navigation means, Slope judging means for judging whether or not.

  By configuring in this way, it is possible to detect a slope quickly and accurately without erroneously determining that a pressure fluctuation caused when the window is opened or closed or when passing with an oncoming vehicle is a slope.

  In the invention according to claim 2, in the invention according to claim 1, the slope determination means has a change amount of the atmospheric pressure detected by the atmospheric pressure detection means that is equal to or greater than a first threshold value, and the autonomous navigation means When the detected angular velocity and / or acceleration is equal to or greater than a second threshold, the traveling path of the moving body can be determined as a slope.

  In the invention according to claim 3, in the invention according to claim 1 or 2, the slope determination unit is configured such that the change amount of the atmospheric pressure detected by the atmospheric pressure detection unit is not less than a first threshold value, and the autonomous navigation is performed. When the angular velocity and / or the acceleration detected by the means is smaller than the second threshold value, the traveling path of the moving body can be determined as a flat road.

  In the invention according to claim 4, in the invention according to claim 2 or 3, the slope determination means changes the second threshold value in accordance with the amount of change in the atmospheric pressure. For example, when the amount of change in atmospheric pressure is large, there is a possibility of a slope, and the angular velocity or acceleration may also be large. Therefore, the second threshold is set to a large value, and the slope is not affected by noise. It can be determined whether or not there is. In addition, when the amount of change in atmospheric pressure is small, there is a possibility of a gentle slope, and the angular velocity or acceleration may also be small. Therefore, by setting the second threshold value to a small value, the angular velocity or acceleration with a small detection value is set. It is possible to determine whether or not the road is a slope.

  In the invention according to claim 5, in the slope detection method for detecting whether or not the traveling path of the moving body is a slope, a step of detecting atmospheric pressure, a step of detecting angular velocity and / or acceleration, Determining a travel path of the moving body as a slope when the amount of change is equal to or greater than a first threshold and the angular velocity and / or the acceleration is equal to or greater than a second threshold.

  By performing such a determination process, it is possible to quickly and accurately detect a slope without erroneously determining that a change in atmospheric pressure caused by opening / closing of a window or passing of an oncoming vehicle is a slope.

  In the invention according to claim 6, in the invention according to claim 5, when the change amount of the atmospheric pressure is not less than the first threshold value and the angular velocity and / or the acceleration is smaller than the second threshold value, A step of determining that the traveling path of the mobile body is a flat road. By processing in this way, it is possible to distinguish between a slope and a flat road.

  In the invention concerning Claim 7, in the invention of Claim 5 or 6, the step which changes the said 2nd threshold value according to the variation | change_quantity of the said atmospheric | air pressure is included. By processing in this way, it is possible to accurately detect whether the road is a slope without being affected by noise.

  In the invention according to claim 8, based on the current position detecting means for detecting the current position of the mobile body, the map database holding map information, the current position detected by the current position detecting means and the map information. A current position display device comprising map matching means for performing matching processing and display means for displaying a mark indicating the current position based on the matching processing, wherein the current position display device further includes an atmospheric pressure detection means for detecting atmospheric pressure, an angular velocity And / or on the basis of the autonomous navigation means for detecting acceleration, the atmospheric pressure detected by the atmospheric pressure detection means, and the angular velocity and / or the acceleration detected by the autonomous navigation means. Slope judgment means for judging whether or not the road is a slope, and the map matching means comprises the slope judgment. Matching processing based on the determination result by the stage.

  By configuring in this way, it is possible to quickly and accurately determine whether or not the road is a slope without erroneously determining that the pressure fluctuation caused by opening and closing of the window or passing with the oncoming vehicle is a slope. Based on the determination result, correct matching processing can be performed and a mark indicating the current position can be displayed on the display means.

  According to a ninth aspect of the present invention, in the invention according to the eighth aspect of the invention, the slope determination means has a change amount of the atmospheric pressure detected by the atmospheric pressure detection means that is not less than a first threshold value, and the autonomous navigation. When the angular velocity and / or the acceleration detected by the means is equal to or greater than a second threshold, the traveling path of the moving body can be determined as a slope.

  According to a tenth aspect of the present invention, in the invention according to the eighth or ninth aspect, the slope judging means has a change amount of the atmospheric pressure detected by the atmospheric pressure detecting means being a first threshold value or more, and When the angular velocity and / or the acceleration detected by the autonomous navigation means is smaller than the second threshold value, it is possible to determine that the traveling path of the moving body is a flat road.

  According to an eleventh aspect of the present invention, in the invention according to the ninth or tenth aspect, the slope determining means changes the second threshold value according to the amount of change in the atmospheric pressure. By processing in this way, it is possible to accurately detect whether the road is a slope without being affected by noise.

1 is a block diagram of a navigation device to which a slope detection device, a slope detection method, and a current position display device of the present invention are applied. It is a process flowchart of Example 1 in the navigation apparatus shown in FIG. In the process flowchart of FIG. 2, it is explanatory drawing of the atmospheric | air pressure and angular velocity detected when the moving body is drive | working the steep slope. In the process flowchart of FIG. 2, it is explanatory drawing of the atmospheric | air pressure and angular velocity detected when the moving body is drive | working the gentle slope. In the process flowchart of FIG. 2, it is explanatory drawing of the atmospheric | air pressure and angular velocity detected when the moving body is drive | working the flat road. It is a process flowchart of Example 2 in the navigation apparatus shown in FIG. In the process flowchart of FIG. 6, it is explanatory drawing of the atmospheric | air pressure and angular velocity detected when the moving body is drive | working the gentle slope.

  Hereinafter, specific examples of the present invention will be described in detail with reference to examples and drawings, and FIGS. However, the embodiments shown below illustrate and explain a navigation device to which a slope detection device, a slope detection method, and a current position display device for embodying the technical idea of the present invention are applied, The present invention is not intended to specify the navigation device, and is equally applicable to other slope detection devices, slope detection methods, and current position display devices without departing from the technical idea shown in the claims. To get.

  FIG. 1 is a block diagram of a navigation device 1 to which a slope detection device, a slope detection method, and a current position display device according to a first embodiment of the present invention are applied.

  The navigation device 1 is mounted on a moving body such as an automobile, displays the current position of the moving body together with a map image on a display (output means 17), and allows a user who is on the moving body to move to a destination. Provide support. The navigation device 1 includes a control means 10, a current position detection means 11, an atmospheric pressure sensor 12, a gyroscope 13, an acceleration sensor 14, a map database 15, an input means 16, an output means 17, a route search means 18, a slope determination means 19 and a map. A matching unit 20 is provided. Each unit is connected by a bus or the like. For example, the control unit 10 can acquire the atmospheric pressure detected and output by the atmospheric pressure sensor 12.

  The control unit 10 includes a CPU 101, a RAM 103, and a ROM 102. The CPU 101 executes a control program stored in the RAM 103 and / or the ROM 102, thereby controlling and supervising operations of each unit described below.

  The current position detecting means 11 receives signals from a plurality of GPS satellites orbiting over the earth at predetermined time intervals, and based on the time information and satellite position information included in the signals, the current position of the mobile object is received. Calculate the position.

  The atmospheric pressure sensor 12 (atmospheric pressure detecting means) is an atmospheric pressure detecting means for detecting the atmospheric pressure at the current position of the moving body. The detected atmospheric pressure is temporarily stored in the RAM 103 of the control means 10 for slope determination described later.

  The gyroscope 13 (angular velocity detecting means) is an angular velocity detecting means for detecting a change in direction with respect to the vertical direction (pitch angle) at least during traveling of the moving body as an angular velocity. The detected angular velocity is temporarily stored in the RAM 103 of the control means 10 for slope determination described later.

  The acceleration sensor 14 (acceleration detection means) is acceleration detection means for detecting acceleration in at least a vertical direction (up and down direction) and a traveling direction (front and rear direction). The detected acceleration is temporarily stored in the RAM 103 of the control means 10 for slope determination described later. The acceleration sensor 14 is generally composed of a triaxial acceleration sensor that detects accelerations in the three axial directions of the navigation device 1 in the vertical, horizontal, and longitudinal directions. If the acceleration sensor 14 is stopped on a flat road, it outputs only the acceleration (gravity acceleration) in the vertical direction (up and down direction), so if the output of the acceleration sensor is only in the vertical direction (up and down direction). It can be seen that the vehicle is stopped on a flat road, and when the acceleration in the front-rear direction is detected in addition to the vertical direction (up and down direction) during the stop, it is understood that the vehicle is stopped on a slope.

  The gyroscope 13 and the acceleration sensor 14 also constitute an autonomous navigation sensor for detecting the current position of the moving body by the moving body itself, and based on the signal received from the GPS satellite by the current position detecting means 11. It can also be used to complement the calculated current position. In addition, locations that are affected by multipath due to reflection of GPS satellite signals, such as tunnels, underground malls, underground parking lots, parking lots in buildings, or high-rise buildings that cannot receive GPS satellite signals by providing autonomous navigation sensors However, the current position of the navigation device 1 can be calculated based on outputs from the gyroscope 13 and the acceleration sensor 14. That is, an autonomous navigation sensor including the gyroscope 13 and the acceleration sensor 14 may be included in the current position detection unit 11.

  The map database 15 holds map information composed of road data, building data, background data, and text data.

  The road data is composed of node data in which roads are nodes such as inflection points and branch points, and link data in which routes connecting the respective nodes are links.

  The node data includes a node number, node position coordinates (latitude / longitude), node attributes such as intersection information and information indicating the name of the intersection, a slope attribute indicating a slope (may include gentle / slow), the number of connection links, and connection links. Consists of number data.

  The link data includes the node numbers that are the starting and ending points of the link, the road type for distinguishing expressways, ordinary roads, streets, etc., and the road type for distinguishing the main line, connecting road, and branch road of each road. Further, the road is composed of road inclination direction, inclination angle, slope attribute indicating a slope (may include gentle / slow), distance and / or required time, road name such as National Route ○, and traveling direction data. In addition to the above, link data includes data such as bridges, tunnels, railroad crossings, and tollgates as link attributes.

  The building data includes data on building position coordinates (latitude / longitude), types of buildings such as stations, buildings, and private houses, and display colors. Further, the background data is configured to include position coordinates (latitude / longitude) composed of at least three points serving as background image data such as a coastline, a lake, a river shape, and a forest, and display color data. The text data includes characters (names) such as place names and river names, and data of their coordinates (latitude / longitude).

  The navigation device 1 is a stand-alone type in which the map database 15 is built in the navigation device 1, but the present invention is not limited to this. For example, the navigation device 1 is provided with communication means (not shown), connected to an information providing server (not shown) outside the navigation device 1 for communication, and a guide route from a map database provided in the information providing server You may make it acquire the map information linked | related to.

  In that case, the navigation device 1 designates the departure point or the current position and the destination, transmits this to the information providing server as a route search condition, and requests the route search. The information providing server includes route search means, performs route search using the departure point or current position received from the navigation device 1 and the destination as route search conditions, and transmits map information including the search result to the navigation device 1.

  The input unit 16 includes a key and a touch panel for a user to input route search conditions such as a departure point and a destination to the navigation device 1 in order to perform a route search.

  The output unit 17 includes a liquid crystal display panel (display) that displays a current position mark, a map image, a guide route, and the like, and a speaker that provides necessary information to the user by voice.

  The route search means 18 searches for an optimum route (guide route) by referring to the map information stored in the map database 15 according to the route search conditions input by the user using the input means 16. The route search means 18 searches for a link from a road node corresponding to the starting point or the current position to a node corresponding to the destination by a method such as the Dijkstra method, and accumulates the link length (link cost) and the required time. Then, a route having the shortest total link length (travel distance) or total required time is searched for as a guide route.

  Note that the route search means 18 may acquire map information from an external information providing server via communication means and perform route search. In addition, the route searching means may be installed in an external information providing server together with the map database, and the navigation device 1 may be configured to acquire the guide route from the outside.

  The slope determination means 19 determines whether or not the traveling path of the moving body is a slope based on the change amount of the atmospheric pressure detected by the atmospheric pressure sensor 12 and the angular velocity detected by the gyroscope 13. The slope judging means 19 can also judge whether the slope is a steep slope or a gentle slope when the traveling road is a slope. Furthermore, the slope determination means 19 may determine whether or not the traveling path of the mobile object is a slope based on the amount of change in atmospheric pressure and the acceleration detected by the acceleration sensor 14. Furthermore, it may be determined whether the road is a slope based on the change amount of atmospheric pressure, the angular velocity, and the acceleration.

  The map matching means 20 uses the current position calculated by the current position detection means 11 as a temporary current position, and in the vicinity of the temporary current position according to the determination result of whether or not the road is a slope determined by the slope determination means 19. The link corresponding to the map matching candidate, for example, the link corresponding to the main line of the expressway, the link corresponding to the branch road or the approach road branched at a slight inclination angle from the main line is specified.

  Next, route guidance processing using the navigation device 1 configured as described above will be described.

  When the user inputs route search conditions such as a departure point, destination, and waypoint using the input unit 16, the route search unit 18 refers to the map information stored in the map database 15, and starts from the departure point. Alternatively, a guide route from the current position to the destination is searched. The guide route searches for link nodes from the road node corresponding to the starting point or the current position to the road node corresponding to the destination by a method such as the Dijkstra method, and link costs such as time, distance, and cost. Among them, a route that minimizes the cumulative link cost desired by the user can be searched for as a guide route. The searched guidance route is displayed on the output means 17 such as a liquid crystal display panel of the navigation device 1 together with a map image based on the map information read from the map database 15.

  On the other hand, the current position detection means 11 of the navigation device 1 receives a signal including time information and satellite position information from a GPS satellite, and calculates the current position of the mobile body based on these information. Then, a current position mark based on the calculated current position is displayed on the output unit 17 together with the map image and the guide route. The user can move to a desired destination according to the map image, current position mark, and guide route displayed on the output means 17.

  By the way, since the current position calculated by the current position detecting means 11 includes an error, if the current position mark is displayed as it is at the calculated current position, it may not be displayed at an appropriate position on the map image. . Therefore, it is necessary to specify an appropriate current position by matching processing and correct the position (current position) where the current position mark is displayed.

  Therefore, a method for determining whether or not the traveling path of the mobile object is a slope and performing an appropriate matching process using the determination result will be described according to the processing flowchart shown in FIG.

  First, the atmospheric pressure sensor 12 of the navigation device 1 detects the atmospheric pressure P every predetermined time (step S101). The detected atmospheric pressure P is temporarily stored in the RAM 103 of the control means 10.

  Further, the gyroscope 13 of the navigation device 1 detects the angular velocity ω indicating the direction change with respect to the vertical direction at every predetermined time (step S102). Like the atmospheric pressure P, the detected angular velocity ω is temporarily stored in the RAM 103 of the control means 10.

  Next, the slope determination means 19 calculates a pressure difference ΔP which is a difference between the previously detected pressure P (stored in the RAM 103) and the currently detected pressure P (step S103). The atmospheric pressure difference ΔP is not limited to the difference between the previously detected atmospheric pressure P and the currently detected atmospheric pressure P. The atmospheric pressure P detected multiple times before and the currently detected atmospheric pressure P, or a plurality of It may be obtained as a difference between an average value of a plurality of continuous atmospheric pressures P detected before and an average value of a plurality of continuous atmospheric pressures P including the currently detected atmospheric pressure P.

  Next, the slope determination means 19 compares the change amount | ΔP |, which is the absolute value of the atmospheric pressure difference ΔP, with a predetermined threshold th1 (> 0). When | ΔP | ≧ th1 (YES in step S104), the amount of change | ΔP | is compared with a threshold th2 (> th1) (first threshold) larger than the threshold th1. When | ΔP | ≧ th2 is satisfied (step S105, YES), it is assumed that the altitude of the traveling road has changed greatly. For example, as shown in FIG. 3, when the atmospheric pressure P is greatly reduced between times t1 and t2, it is assumed that the travel path is a steep uphill. Similarly, in the case of a steep downhill, the atmospheric pressure P greatly increases and the change amount | ΔP | increases.

  In step S105, when the slope determination means 19 determines that | ΔP | ≧ th2, the slope determination means 19 uses the angular velocity ω detected in the vicinity of times t1 and t2 before and after the period in which the amount of change | ΔP | occurs. (Step S106). That is, since the gyroscope 13 detects the angular velocity ω indicating the direction change in the vertical direction, the angular velocity ω (angular velocity ω due to the slope) is detected at the beginning of the slope and at the end of the slope. Further, the angular velocity ω is detected when there is a change in the vertical direction, but the change amount | ΔP | of the threshold value th2 or more may not be detected unless the vehicle travels a predetermined distance after the change in direction. Therefore, the angular velocity ω detected in the vicinity of times t1 and t2 before and after the period in which the amount of change | ΔP | occurs is read from the RAM 103.

  Next, the slope determination means 19 compares the angular velocity ω with predetermined thresholds th3 (> 0) (second threshold) and th4 (<0) (second threshold). When ω ≧ th3 or ω ≦ th4 (step S107, YES), it is assumed that the slope of the traveling road has changed greatly in the vicinity of times t1 and t2. Therefore, based on the determination result (YES) in step S105 and the determination result (YES) in step S107, it is determined that the travel path is a “steep slope” (step S108).

  Since the numerical value of the angular velocity ω is reversed (plus or minus) depending on the vertical direction, a threshold value th3 and a threshold value th4 are provided. In the present embodiment, the threshold th3 is an upward threshold, and the threshold th4 is a downward threshold. Alternatively, | th3 | = | th4 |. Further, if the angular velocity ω is positive, it may be compared with the threshold th3, and if the angular velocity ω is negative, | ω | may be compared with | th4 |. And then. If the angular velocity | ω | is equal to or greater than th3 or | th4 | (second threshold), it may be determined as “steep slope”. This comparison method is the same in other comparisons.

  That is, the amount of change | ΔP | that is the absolute value of the atmospheric pressure difference ΔP is equal to or greater than a predetermined threshold th2 (th2> th1), and the angular velocity ω is equal to or greater than the predetermined threshold th3 (> 0), or the predetermined threshold th4. In the case of (<0) or less, since the atmospheric pressure P does not fluctuate due to a cause other than a change in altitude of the travel path, it is possible to reliably determine that the travel path is a “steep slope”.

  Although exemplified at times t1 and t2, by performing this flowchart when the change amount | ΔP | is detected at time t1, it is possible to determine immediately whether or not the traveling road is a slope.

  When it is determined that the travel route is “steep slope”, the map matching means 20 is a road (link node) near the current position detected by the current position detection means 11 from the link data of the map information read from the map database 15. The map matching process is performed to identify the link node assigned with the attribute “steep slope” (slope) as the road on which the moving body is traveling (step S109).

  On the other hand, when | ΔP | <th2 (step S105, NO), as shown in FIG. 4, although a predetermined atmospheric pressure difference ΔP is detected, it is more than the fluctuation in atmospheric pressure due to opening / closing of the window or passing with the oncoming vehicle. Since the fluctuation is small, it is determined that the travel path is “slow slope” (step S110). In this case, since it is “slow slope”, it is assumed that the value of the angular velocity ω by the gyroscope 13 is also small. Therefore, when | ΔP | <th2 (step S105, NO), it is determined as “slow slope” without referring to the angular velocity ω by the gyroscope 13. In this embodiment, it is determined that “slow slope” is made without referring to the angular velocity ω, but it is determined whether or not it is “slow slope” (slope) with reference to the angular velocity ω as in Embodiment 2 described later. You may judge.

  When it is determined that the travel route is “slow slope”, the map matching unit 20 uses a road (link node) near the current position detected by the current position detection unit 11 from the link data of the map information read from the map database 15. ), A map matching process is performed to identify a link node to which the attribute of “slow slope” (slope) is assigned as a road on which the moving body is traveling as an up / down attribute representing a road slope attribute (step) S109).

  Further, when | ΔP | ≧ th2 (step S105, YES) and th4 <ω <th3 (step S107, NO), a large fluctuation in the atmospheric pressure P occurs, but the angular velocity ω is small, Alternatively, as shown in FIG. 5, since the angular velocity ω is not detected, it is determined that the pressure fluctuation is not “slope” but due to opening / closing of a window or passing with an oncoming vehicle (step S111). Is determined (step S112).

  That is, since the atmospheric pressure difference ΔP is larger than the threshold value th2, it can be seen that there is a sudden change in atmospheric pressure. In such a case, the vehicle travels on a steep slope at a certain speed or higher (when there is no traffic jam, etc.). And a sudden change in atmospheric pressure due to the opening and closing of the window and the passing of the oncoming vehicle.

  When traveling on a steep slope at a certain speed or higher, the angular velocity ω by the gyroscope 13 is detected to be large as described above. However, the angular velocity ω by the gyroscope 13 is small or not detected in the case of a sudden change in atmospheric pressure due to the opening / closing of a window or the passing of an oncoming vehicle instead of a slope.

  Therefore, when | ΔP | ≧ th2 and th4 <ω <th3, the traveling road can be determined as a “flat road”.

  Further, when | ΔP | <th1 (NO in step S104), since the fluctuation of the atmospheric pressure P is small, the travel path is determined as “flat road” (step S112).

  When it is determined that the travel route is “flat road”, the map matching means 20 uses the link data of the map information read from the map database 15 so that the mobile body travels on a link node to which no road slope attribute is assigned. Map matching processing is performed to identify the existing road (step S109).

  Then, the map matching unit 20 calculates the current position after matching based on the road on which the moving body that has performed the map matching process in step S109 is traveling and the current position detected by the current position detection unit 11. Then, a current position mark indicating the current position after matching is displayed on the output means 17 together with the map image.

  As described above, by correctly determining whether the road is steep, gentle, or flat, and performing map matching, the mobile object is displayed at the correct position on the map image, and an appropriate Route guidance can be performed.

  FIG. 6 is a process flowchart in the navigation device 1 to which the slope detection device, the slope detection method, and the current position display device according to the second embodiment of the present invention are applied.

  In the second embodiment, in the flowchart shown in FIG. 6, when | ΔP | <th2 in step S105, the thresholds th3 and th4 for determining the value of the angular velocity ω are set as new thresholds th5 (th3> th5> 0) and th6. After changing to (0> th6> th4) (step S110a), the processing after step S106 is different from the processing of the first embodiment. Since other processes are the same as those in the first embodiment, description thereof is omitted.

  That is, in the second embodiment, when the amount of change | ΔP | that is the absolute value of the pressure difference ΔP is | ΔP | ≧ th2 (YES in step S105) and the angular velocity ω is ω ≧ th3 or ω ≦ th4. (Step S107, YES) (see FIG. 3), or the amount of change | ΔP | is within the range of th2> | ΔP | ≧ th1 (NO in Step S105), and the angular velocity ω is ω ≧ th5 or ω ≦ When it is th6 (steps S110a and S107), it is determined that the travel path is “slope” (step S108, see FIG. 7). In this case, it is possible to make a slope judgment based on angular velocity without being affected by noise, and there is a risk of misrecognizing a `` slope '' and atmospheric pressure fluctuation due to opening / closing of a window or passing with an oncoming vehicle. Can be reduced.

  Here, th5 <th3 and th6 <th4. That is, as described above, when the amount of change | ΔP | is within the range of th2> | ΔP | ≧ th1, it is considered that the vehicle travels on a gentle slope (slow slope), and therefore the angular velocity ω by the gyroscope 13 Is assumed to be small. Therefore, by replacing the thresholds th3 and th4 with th5 and th6, respectively, there is a risk of erroneously recognizing “slope” and fluctuations in atmospheric pressure due to the opening and closing of windows and the passing of oncoming vehicles even when the angular velocity ω is small. Can be reduced.

  In the present embodiment, the first threshold is th1, and the second threshold is any of th3, th4, th5, and th6.

  In addition, this invention is not limited to the Example mentioned above, It can change in the range which does not deviate from the meaning of this invention.

  For example, the slope determination means 19 determines whether or not the road is a slope based on the atmospheric pressure detected by the atmospheric pressure sensor 12 and the angular velocity detected by the gyroscope 13. Based on the acceleration detected by the acceleration sensor 14, it may be determined whether the road is a slope. That is, the slope determination means 19 extracts only the gravitational acceleration by removing the acceleration accompanying the movement from the output of the acceleration sensor, and determines whether or not the road is a slope based on the gravitational acceleration. Specifically, the acceleration associated with the movement is the case where a movement distance between the current positions detected by the current position detection unit 11, a movement speed calculated based on the detection interval of the current position, or a speed sensor is provided. If there is, it is calculated based on the moving speed detected by the speed sensor, and using the acceleration accompanying the calculated movement, the acceleration accompanying the movement is removed from the output of the acceleration sensor, and only the gravitational acceleration is extracted. If the gravitational acceleration is only in the vertical direction (vertical direction), it can be determined as “flat road”. If the gravitational acceleration is also applied in the front-rear direction (traveling direction), it is determined as “slope”. can do.

  However, when the acceleration sensor 14 is used, when the moving speed is high, the acceleration component (acceleration in the front-rear direction) increases due to the movement. Therefore, the rate at which the gravitational acceleration closes in the output of the acceleration sensor decreases, and the gravitational acceleration is reduced. It is difficult to extract accurately.

  Therefore, the accuracy of slope detection is improved by determining whether or not the road is a slope based not only on the acceleration sensor 14 but also on the atmospheric pressure detected by the atmospheric pressure sensor 12 and the acceleration detected by the acceleration sensor 14. In this case, the above threshold values (th3, th4, th5, th6) are set to, for example, a threshold value indicating whether gravitational acceleration is applied in the front-rear direction (traveling direction) (or whether all gravitational accelerations are applied in the vertical direction). It may be determined whether the road is a slope.

  It should be noted that not only the case where only the acceleration of gravity is extracted by removing the acceleration accompanying the movement from the output of the acceleration sensor 14 described above, but also the amount of change in the output of the acceleration sensor (up and down) when moving at a constant speed. Directional acceleration or longitudinal acceleration change amount) is compared with a threshold value (th3, th4, th5, th6), and the change amount of pressure difference | ΔP | is equal to or greater than the threshold value (th1, th2). When the output change amount is equal to or greater than the threshold (th3, th4, th5, th6), it may be determined as “slope”.

  Further, the atmospheric pressure sensor 12, the gyroscope 13 and the acceleration sensor 14 may be combined. That is, in the flowchart of FIG. 6, when the angular velocity ω is ω ≧ th3 (th5) or ω ≦ th4 (th6) in step S107. In addition to this, when the gravitational acceleration applied in the front-rear direction (traveling direction) is greater than or equal to th3 (th5) or th4 (th6), or the change in the output of the acceleration sensor is th3 (th5) Alternatively, it may be determined that the road is a slope only when it is equal to or greater than th4 (th6), and it may be determined that the road is a flat road in other cases.

  Further, in the above-described embodiment, it is determined whether or not the road is a slope using the detection value by the atmospheric pressure sensor 12, the gyroscope 13 and / or the acceleration sensor 14, but if the road is a slope, the determination is made. In addition to the result, for example, it is possible to determine whether the slope is an uphill or a downhill from the sign of the change amount ΔP of the atmospheric pressure P. Furthermore, the inclination angle of the travel path can be obtained from the change amount ΔP of the atmospheric pressure P. Using these results, map matching with higher accuracy can be performed.

  In the above embodiment, the change amount ΔP of the atmospheric pressure P is calculated and compared with the threshold values (th1, th2). However, the present invention is not limited to this, and as in Patent Document 1, the altitude value is based on the detected atmospheric pressure. And the difference in altitude may be compared with a threshold (th1, th2), or a gradient may be calculated based on the difference in altitude and the gradient may be compared with the threshold (th1, th2).

  Further, based on the current position detected by the current position detection means 11 and the map information, the current position is near a place where an approach road or branch road to the highway and a general road (or highway) are close to each other. The processing of the present invention may be performed only in some cases.

DESCRIPTION OF SYMBOLS 1 ... Navigation apparatus 10 ... Control means 11 ... Current position detection means 12 ... Barometric pressure sensor 13 ... Gyroscope 14 ... Acceleration sensor 15 ... Map database 16 ... Input means 17 ... Output means 18 ... Route search means 19 ... Slope determination means 20 ... Map matching means 101 ... CPU
102 ... ROM
103 ... RAM

Claims (11)

In the slope detection device that detects whether the traveling path of the moving body is a slope,
Atmospheric pressure detection means for detecting atmospheric pressure;
Autonomous navigation means for detecting angular velocity and / or acceleration;
Slope determination that determines whether or not the traveling path of the moving body is a slope based on the atmospheric pressure detected by the atmospheric pressure detection means and the angular velocity and / or the acceleration detected by the autonomous navigation means. Means,
A slope detection device comprising:   The slope determination means has a change amount of the atmospheric pressure detected by the atmospheric pressure detection means that is not less than a first threshold value, and the angular velocity and / or acceleration detected by the autonomous navigation means is not less than a second threshold value. The slope detection device according to claim 1, wherein the traveling path of the moving body is determined as a slope.   The slope determination means has a change amount of the atmospheric pressure detected by the atmospheric pressure detection means that is equal to or greater than a first threshold value, and the angular velocity and / or acceleration detected by the autonomous navigation means is less than a second threshold value. 3. The slope detection apparatus according to claim 1, wherein when it is small, the traveling path of the moving body is determined to be a flat road.   4. The slope detection apparatus according to claim 2, wherein the slope determination unit changes the second threshold according to a change amount of the atmospheric pressure. 5. In the slope detection method for detecting whether or not the traveling path of the moving body is a slope,
Detecting atmospheric pressure;
Detecting angular velocity and / or acceleration;
Determining the travel path of the moving body as a slope when the amount of change in the atmospheric pressure is greater than or equal to a first threshold and the angular velocity and / or acceleration is greater than or equal to a second threshold;
A slope detection method characterized by comprising:   A step of determining that the traveling path of the moving body is a flat road when the amount of change in the atmospheric pressure is equal to or greater than a first threshold and the angular velocity and / or the acceleration is smaller than the second threshold. The slope detection method according to claim 5.   The slope detection method according to claim 5 or 6, further comprising a step of changing the second threshold according to the amount of change in the atmospheric pressure. Current position detecting means for detecting the current position of the moving body, map database for holding map information, map matching means for performing matching processing based on the current position and the map information detected by the current position detecting means, and matching In a current position display device comprising display means for displaying a mark indicating a current position based on processing,
The current position display device further includes atmospheric pressure detection means for detecting atmospheric pressure,
Autonomous navigation means for detecting angular velocity and / or acceleration;
Slope determination means for determining whether or not the traveling path of the moving body is a slope based on the atmospheric pressure detected by the atmospheric pressure detection means and the angular velocity and / or the acceleration detected by the autonomous navigation means. When,
And the map matching means performs a matching process based on a determination result by the slope determination means.   The slope determination means has a change amount of the atmospheric pressure detected by the atmospheric pressure detection means that is not less than a first threshold value, and the angular velocity and / or acceleration detected by the autonomous navigation means is not less than a second threshold value. The current position display device according to claim 8, wherein the traveling path of the moving body is determined to be a slope when there is a certain time.   The slope determination means has a change amount of the atmospheric pressure detected by the atmospheric pressure detection means that is equal to or greater than a first threshold value, and the angular velocity and / or acceleration detected by the autonomous navigation means is less than a second threshold value. The current position display device according to claim 8 or 9, wherein when it is small, the traveling path of the moving body is determined to be a flat road.   11. The current position display device according to claim 9, wherein the slope determination unit changes the second threshold value according to a change amount of the atmospheric pressure.

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