JP2006010657A - Navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a "navigation device" which precisely calculates the slope angle of a road and which can execute the operation for correcting the current position of a vehicle. <P>SOLUTION: The navigation device includes a vehicle speed sensor 103 for detecting the traveling speed and the mileage of the vehicle; an acceleration sensor 101 for measuring the acceleration with respect to the traveling direction of the vehicle; and a navigation controller 115, wherein the navigation controller 115 calculates the vehicle speed acceleration Gp, on the basis of the traveling speed detected from the vehicle speed sensor 103, calculates the slope angle θ of the vehicle, on the basis of the vehicle speed acceleration Gp and the sensor acceleration Gc measured by the acceleration sensor 101, and then corrects the current position of the vehicle on the basis of the vehicle speed acceleration Gp, the sensor acceleration Gc, and the slope angle θ. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a navigation device mounted on an automobile, and more particularly to a navigation device that performs a guidance operation while always correcting a vehicle position.

  The in-vehicle navigation device always detects the current position of the vehicle and executes a guidance operation. In this case, as a means of accurately grasping the current position of the vehicle, a self-contained navigation method that uses a distance sensor and an angle sensor to calculate a moving distance and identifies the vehicle position, and a radio signal from an artificial satellite is received and displayed on the map. GPS (Global Positioning System) navigation that knows the current position of the vehicle is known. Since the self-contained navigation requires an arithmetic process for differentiating or integrating the sensor output, it is susceptible to errors due to factors inside and outside the vehicle, and has a drawback that accuracy is lowered. In addition, GPS navigation has a drawback that an accurate current position cannot be grasped when a vehicle is present in an environment where GPS radio signals are difficult to reach such as in a tunnel or in a forest. Therefore, in recent years, a so-called hybrid type navigation device that complements the drawbacks of the above-mentioned self-contained navigation and GPS navigation has been used.

  Further, in recent years, with the development of the road network, the number of roads with height differences such as three-dimensional intersections and underground roads is increasing. On the other hand, in a conventional navigation device, an image such as a map displayed on a display device provided in the navigation device is basically drawn and displayed in a plane, and thus travels uphill or downhill. When the vehicle is moving, the distance that the vehicle actually moves becomes longer than the planar movement distance on the map. As a result, if the guidance operation is performed using the self-contained navigation, the display position of the vehicle on the map There is a problem that an accurate guidance cannot be performed due to an error between the vehicle and the current position of the vehicle.

  In order to solve such a problem, as shown in Patent Document 1, it is possible to accurately determine the acceleration, speed, moving distance, etc. of the moving body by removing the influence of the inclination of the moving body, for example, the influence of gravity. A movable body position speed calculation device that can be used is disclosed.

Japanese Patent Laid-Open No. 9-96533

  As shown in FIG. 1, the moving body position speed calculation device 1 disclosed in Patent Document 1 includes an inclination angle detection unit 2 that detects an inclination angle with respect to the traveling direction of the moving body, and an angular speed that detects an angle change of the inclination angle. It has a detection means 3, an acceleration detection means 4 for detecting the acceleration in the traveling direction of the moving body, and an absolute position and absolute speed detection means 5 using, for example, a GPS system. Based on the inputs from the means 2 and the angular velocity detection means 3, the absolute inclination angle is calculated. In the inclination correction means 7, the input of the acceleration detection means 4 and the absolute position / absolute velocity detection means 5 and the absolute inclination angle calculation means 6 are calculated. The inclination angle is corrected on the basis of the calculation result, and the acceleration correction means 8 measures the absolute position and the absolute velocity detection means 5 and the inclination angle corrected by the inclination correction means 7. A device for removing the influence of the gravity component that is included in the rate. According to such an apparatus, even if absolute position and absolute speed detection means 6, that is, information on absolute speed and absolute position cannot be obtained from the GPS system, the tilt angle detection means 2 and the angular speed detection means 3 are combined. By using it, it becomes possible to calculate the absolute inclination angle with high accuracy and to remove the influence of the acceleration inclination.

  However, in the moving body position / velocity calculation device 1 disclosed in Patent Document 1, the absolute inclination angle calculated by the absolute inclination angle calculation means 6 and the absolute position / absolute speed detection means 5 are obtained in the correction by the inclination correction means 7. Of the estimated inclination angles derived from the velocity vector obtained, the one with higher accuracy is adopted. Further, in the correction of the acceleration correction means 8, a correction amount is calculated from the difference between the acceleration obtained from the current speed measured by the absolute position and absolute speed detection means 5 and the acceleration obtained at the previous calculation time. The acceleration corrected by the inclination correcting means 7 is corrected. In such correction, if the current data of the absolute position and absolute velocity detection means 5 cannot be obtained, the data at the previous calculation time can only be used, and the error becomes larger than the latest correction. There was a case. In addition, since the current position is calculated by repeating the integral calculation twice for the acceleration corrected in this way, there is a problem that the error further increases.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a navigation device capable of executing an operation of accurately calculating the inclination angle of a road and correcting the current position of the vehicle. To do.

  In order to solve the above-described problems, the present invention provides a first sensor for detecting a traveling speed and a traveling distance of a vehicle, and a second sensor for measuring an acceleration in the traveling direction of the vehicle. A navigation controller, wherein the navigation controller calculates a first acceleration based on a traveling speed detected from the first sensor, and is measured by the first acceleration and the second sensor. A tilt angle of the vehicle is calculated based on a second acceleration, and the navigation controller corrects the current position of the vehicle based on the first acceleration, the second acceleration, and the tilt angle. It is comprised as a navigation apparatus characterized by this. According to such a configuration, when the vehicle is traveling on a slope, the navigation controller calculates the vehicle speed acceleration based on the output from the vehicle speed sensor, measures the sensor acceleration with the acceleration sensor, and calculates these accelerations. Based on this, the vehicle inclination angle is calculated, and then whether the slope is uphill or downhill, and the current position of the vehicle is corrected according to the determination result. An operation of calculating and correcting the current position of the vehicle can be executed.

  The navigation device according to claim 1, for example, according to claim 2, wherein the navigation controller has the tilt angle when a difference between the first acceleration and the second acceleration exceeds a predetermined threshold. Can also be configured to calculate.

  In the navigation device according to claim 1 or 2, for example, as in claim 3, the navigation controller is configured such that the vehicle currently travels according to a magnitude relationship between the first acceleration and the second acceleration. It can also be configured to determine whether it is uphill or downhill.

  The navigation device according to any one of claims 1 to 3 may be configured so that the navigation controller has a function capable of arbitrarily setting the threshold value, for example, as described in claim 4.

  The navigation device according to claim 1, for example, according to claim 5, wherein the first sensor converts rotation into a pulse signal and outputs the pulse signal, and the navigation controller receives the input from the first sensor. It is also possible to calculate the number of pulses sampled in the pulse signal and calculate the first acceleration when the number of samplings reaches a predetermined number.

  ADVANTAGE OF THE INVENTION According to this invention, the navigation apparatus which can perform the operation | movement which calculates the inclination angle of a road correctly and correct | amends the present position of a vehicle is realizable.

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

  First, Example 1 of the present invention will be described. FIG. 2 is a block diagram illustrating a configuration of the navigation device 100 according to the first embodiment. The navigation device 100 includes an input interface 111 that converts outputs from external sensors such as the acceleration sensor 101, the angular velocity sensor 102, and the vehicle speed sensor 103, a GPS signal receiving unit 112, a radio wave receiving unit 113, an operation input unit 114, The navigation controller 115 includes a memory 116, a database 117, an image information display unit 118, and an audio information output unit 119. The acceleration sensor 101 is a uniaxial sensor that detects the actual acceleration in the traveling direction applied to the vehicle during transmission or stop of the vehicle and during acceleration or deceleration, and is parallel to the traveling direction and parallel to the vehicle. Provided in the vehicle. The angular velocity sensor 102 detects an angular velocity and a relative direction when the direction of the vehicle is changed. The vehicle speed sensor 103 is a sensor that outputs a rotation signal in a pulse waveform corresponding to the rotation of the drive shaft or the tire, and can also obtain travel distance data together with the vehicle speed data. Outputs from the acceleration sensor 101, the angular velocity sensor 102, and the vehicle speed sensor 103 are, for example, AD converted by the input interface 111 and input to the navigation controller 115.

  The GPS signal receiving means 112 is a receiver that receives vehicle position information from GPS satellites. The radio wave receiving means 113 is a receiver that receives signal radio wave information (hereinafter referred to as VICS information) from a VICS (road traffic information communication system) center or radio waves such as FM multiplex broadcasting and digital broadcasting. The operation input means 114 is an operation unit provided with various operation keys and the like that can operate the navigation device 100, and may be provided on the surface of the navigation device 100. The GPS signal receiving unit 112 and the radio wave receiving unit 113 are electrically connected to the navigation controller 115. In addition to the case where the operation input unit 114 is provided on the surface of the apparatus, the operation input unit 114 may be connected as an independent operation unit so as to be communicable with the navigation controller 111 by wire or wirelessly.

  The navigation controller 115 is connected to the memory 116, the database 117, the image information display unit 118, and the audio information output unit 119, and controls the operation of the entire navigation device 100. The memory 116 temporarily stores information necessary for control of the navigation device 100 in addition to the output data of various sensors sent from the input interface and the information received by the GPS signal receiving unit 112 and the radio wave receiving unit 113. To do. The memory 116 also stores various programs for operating the navigation controller 111. The database 117 is composed of, for example, a hard disk, a DVD-RW (DVD Rewritable), etc., and is necessary for route guidance, for example, a map data file storing map information, an intersection data file storing information about intersections, road types, Road data files that store information on roads such as the start and end points of roads and information such as the direction of travel of each road, node data files that store east longitude and north latitude coordinates at one point on the road, such as gas stations and convenience stores A guide point data file or the like that stores the position coordinates of a feature such as a facility corresponding to the purpose of use classified into a genre, guidance information about the feature, and the like are stored.

  Further, the navigation controller 115, based on the data stored in the database 117, the vehicle position information by the GPS signal, and the VICS information, the map image around the own vehicle, the vehicle position mark, the departure place mark, the destination mark, the guidance Image information such as a route and a destination setting screen and character information are generated, and at the same time, audio information corresponding to the image information and character information is generated. In addition, the navigation controller 115 sends image information and character information to the image information display unit 118 and issues a command to output the information. On the other hand, the navigation controller 115 sends audio information to the audio information output unit 119 and transmits the audio information. Issue a command to output. The image information display unit 118 is composed of, for example, a liquid crystal monitor or the like, and displays image information and character information based on a command from the navigation controller 115. The audio information output unit 119 is a speaker, for example, and outputs various audio information based on commands from the navigation controller 115.

  Next, the principle of calculating the angle of the slope, that is, the inclination angle of the vehicle in the first embodiment will be described. FIG. 3 is a schematic diagram for explaining the principle of calculating the inclination angle of the vehicle. FIG. 3A shows a case where the vehicle is traveling on a flat road, and FIG. Show. As described above, the vehicle 120 includes the acceleration sensor 101 provided parallel to the traveling direction and parallel to the vehicle, and the rotation signal provided to the drive shaft or the tire and corresponding to the rotation of the drive shaft or the tire. Has a vehicle speed sensor 103 (not shown) for outputting in a pulse waveform. The current speed of the vehicle is obtained from the vehicle speed sensor 103. Hereinafter, the acceleration obtained by subjecting the current speed to differential calculation processing is defined as a vehicle speed acceleration Gp, and the acceleration in the vehicle traveling direction obtained from the acceleration sensor 101 is defined as a sensor acceleration Gc. Further, Gg is the gravitational acceleration that is constantly applied to the vehicle 120. As shown in FIG. 3A, when the vehicle 120 is traveling on a flat road, the traveling direction of the vehicle 120, that is, the direction of the acceleration vector is orthogonal to the direction of the gravitational acceleration Gg. The vehicle speed acceleration Gp has the same direction and size.

On the other hand, as shown in FIG. 3 (b), when the vehicle 120 is traveling on a slope road, it is affected by the gravitational acceleration Gg, so that the sensor acceleration Gc is a progression of the vehicle speed acceleration Gp and the gravitational acceleration Gg. It is obtained as a vector sum with the direction component Gd. That is, the vector Gd is in the opposite direction to the vectors Gp and Gc, and the magnitude is equal to the absolute value difference between Gp and Gc. At this time, if the angle of the slope, that is, the inclination angle of the vehicle is θ, the inclination angle θ can be calculated by the following equation.
θ = sin ⁻¹ (| Gd | / | Gg |)
The above formula is similar to the above because, for example, even when the vehicle 120 is traveling down a slope road, the sensor acceleration Gc is expressed as a vector sum of the vehicle speed acceleration Gp and the traveling direction component Gd of the gravitational acceleration Gg. It is possible to apply.

  Next, FIG. 4 shows a flowchart of an inclination correction guidance operation routine according to the first embodiment, which is executed by the navigation controller 115. Here, this inclination correction guidance operation routine is an operation executed when the vehicle detects the inclination of the vehicle while traveling using the navigation device 100, and is parallel even during the normal route guidance operation. It is possible to correct the current route guidance operation that is in operation. In the inclination correction guidance operation routine, the navigation controller 115 first inputs a vehicle speed pulse signal from the vehicle speed sensor 103 for a predetermined time (step S101). Subsequently, the navigation controller 115 extracts data for one cycle of the rise of the pulse from the input vehicle speed pulse signal (step S102), and calculates the vehicle speed acceleration Gp (step S103). Here, since the signal data for one cycle extracted in step S102 includes the moving distance for one cycle corresponding to the rotation of the drive shaft or the tire together with the time information, the differential calculation process is executed only once. It can be acceleration data. Next, the navigation controller 115 measures the sensor acceleration Gc with the acceleration sensor 101 (step S104), and calculates the difference Gd between the absolute values of the vehicle speed acceleration Gp and the sensor acceleration Gc, as shown in FIG. Step S105).

  Next, the navigation controller 115 determines whether or not Gd calculated in step S105 is larger than a predetermined threshold (step S106). The threshold value determined here is an upper limit value of the difference Gd between the absolute values of accelerations arbitrarily set from parameters such as the vehicle type, tire type, or inclination of the vehicle. Therefore, when it is determined that Gd does not exceed the threshold value, for example, it is determined that there is almost no inclination, and the routine is ended as it is. On the other hand, when it is determined that Gd is larger than the threshold value, the inclination angle θ is calculated using the above-described equation (step S107). Subsequently, the navigation controller 115 determines whether or not the absolute value of the sensor acceleration Gc is larger than the absolute value of the vehicle speed acceleration Gp (step S108). This determination is performed in order to determine whether the currently traveling slope is uphill or downhill. That is, as shown in FIG. 3B, when the vehicle 120 is traveling uphill, the sensor acceleration Gc is a vector opposite to the traveling direction component Gd of the gravitational acceleration Gg. The value is smaller than the absolute value of the vehicle speed acceleration Gp. On the other hand, when the vehicle 120 is traveling downhill, the sensor acceleration Gc is a vector having the same direction as the traveling direction component Gd of the gravitational acceleration Gg, and therefore the absolute value of the sensor acceleration Gc is larger than the absolute value of the vehicle speed acceleration Gp. Become. Therefore, when it is determined in step S108 that the absolute value of Gc is larger than the absolute value of Gp, the navigation controller 115 determines that the vehicle is currently traveling on the downhill (step S109), and is for downhill. Next, the current position of the vehicle is corrected (step S110). Thereafter, a command to output an image including the corrected vehicle position is issued to the image information display unit (step S111), and the routine is terminated.

  On the other hand, if it is determined in step S108 that the absolute value of Gc is not greater than the absolute value of Gp, the navigation controller 115 determines that the vehicle is currently traveling on an uphill (step S112). Then, the current position of the vehicle is corrected for uphill (step S113). Then, it progresses to step S111 and issues the command which outputs the image containing the vehicle position after correction | amendment to an image information display part, and complete | finishes a routine.

  As described above, the inclination correction guidance operation routine calculates the vehicle speed acceleration Gp from the output data from the vehicle speed sensor 103, calculates the absolute value difference Gd from the sensor acceleration Gc measured by the acceleration sensor 101, When it is determined that Gd exceeds a predetermined threshold value, the vehicle inclination angle is calculated, and the current position of the vehicle on the uphill or downhill is corrected to perform the guidance operation.

  In addition, in the tilt correction guidance operation routine according to the first embodiment, after extracting data for one cycle of the vehicle speed pulse signal in step S102, it is determined whether or not the length of time required for one cycle is a predetermined time or more. Steps may be added. By such a step, for example, when the vehicle is traveling on an uphill at a very low speed, the number of pulses included in the vehicle speed pulse signal output from the vehicle speed sensor 103 within a predetermined time becomes very small, and the acceleration Since there is a high possibility that a large error will be included in the differential calculation processing for calculating, the routine can be terminated if the length of time required for one cycle is equal to or longer than the predetermined time.

  Next, an example in which correction is performed by applying the tilt correction guidance operation routine shown in FIG. 4 will be described. FIG. 5 is a diagram for explaining the state of the correction operation by the inclination correction guidance routine. FIG. 5A shows a case where the vehicle is traveling on a downhill, and FIG. 5B is a case where the vehicle is traveling on an uphill. Shows the case. As shown in FIG. 5A, when the vehicle is traveling downhill, the sensor acceleration Gc measured by the acceleration sensor 101 is calculated from the output data of the vehicle speed sensor 103 as described above. It becomes larger than Gp. At this time, the navigation device 100 recognizes that the current position of the vehicle is P1 based on the output of the vehicle speed sensor 103, but the actual current position of the vehicle is P2. Therefore, using the inclination correction guidance operation routine according to the first embodiment, the navigation controller 115 calculates the vehicle inclination angle θ by executing the operation of step S107, and then determines that it is a downhill by the determination of step S108. The current position of the vehicle is corrected from P1 to P2 by a distance L1, and the guidance operation is continued.

  On the other hand, as shown in FIG. 5B, when the vehicle is traveling uphill, the sensor acceleration Gc measured by the acceleration sensor 101 is calculated from the output data of the vehicle speed sensor 103 as described above. It becomes smaller than the calculated vehicle speed acceleration Gp. Therefore, the navigation device 100 recognizes that the current position of the vehicle has advanced to P1 based on the output of the vehicle speed sensor 103, but the actual current position of the vehicle is P2. Therefore, using the inclination correction guidance operation routine according to the first embodiment, the navigation controller 115 calculates the vehicle inclination angle θ by executing the operation of step S107, and then determines that it is an uphill by the determination of step S108. The current position of the vehicle is corrected to return from P1 to P2 by a distance L2, and the guidance operation is continued.

  With the above configuration and operation, the navigation device 100 according to the first embodiment calculates the vehicle speed acceleration Gp from the output of the vehicle speed sensor 103 when the vehicle is traveling on a slope, and the acceleration sensor 101 The sensor acceleration Gc is measured, and the slope of the slope, that is, the inclination angle of the vehicle is calculated based on these accelerations. Subsequently, it is determined whether the slope is an uphill or a downhill, and the determination result is as follows. Accordingly, it is possible to execute a correction operation for the current position of the vehicle.

  Further, the navigation device 100 according to the first embodiment inputs factors for calculating a traveling speed and a traveling distance such as a vehicle type and a tire diameter of the vehicle in advance, and is predetermined while the vehicle is traveling on a flat road. The vehicle speed pulse signal of time is input, the number of samplings in one cycle is calculated from the waveform of the vehicle speed pulse signal, the average vehicle speed acceleration per cycle is calculated, and the vehicle speed acceleration and the measured sensor acceleration measured by the acceleration sensor are calculated. You may have a function which determines the above-mentioned threshold based on a value.

  From the above embodiments, according to the present invention, when the vehicle is traveling on a slope, the navigation controller calculates the vehicle speed acceleration Gp, measures the sensor acceleration Gc, and tilts the vehicle based on these accelerations. After calculating the angle, it is determined whether the slope is uphill or downhill, and the vehicle's current position is corrected according to the determination result. It is possible to provide a navigation device capable of executing an operation for correcting the current position.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims.・ Change is possible.

It is a block diagram which shows the structure of the mobile body position speed calculation apparatus 1 in a prior art. 1 is a block diagram illustrating a configuration of a navigation device 100 according to a first embodiment. FIG. 3A is a schematic diagram for explaining the principle of calculating the tilt angle of a vehicle. FIG. 3A shows a case where the vehicle is traveling on a flat road, and FIG. 3 is a flowchart of a tilt correction guidance operation routine according to the first embodiment. FIGS. 5A and 5B are diagrams for explaining a state of a correction operation by an inclination correction guidance routine. FIG. 5A shows a case where the vehicle is traveling on a downhill, and FIG. 5B is a case where the vehicle is traveling on an uphill. Show.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Navigation apparatus 101 Acceleration sensor 103 Vehicle speed sensor 111 Input interface 112 GPS signal receiving means 114 Operation input means 115 Navigation controller 117 Database 118 Image information display part 119 Audio | voice information output part 120 Vehicle Gp Vehicle speed acceleration Gc Sensor acceleration (theta) Tilt angle of vehicle

Claims (5)

A first sensor for detecting a traveling speed and a traveling distance of the vehicle;
A second sensor for measuring acceleration in the traveling direction of the vehicle;
A navigation controller,
The navigation controller calculates a first acceleration based on a running speed detected from the first sensor, and based on the first acceleration and a second acceleration measured by the second sensor. Calculating the tilt angle of the vehicle,
The navigation device, wherein the navigation controller corrects a current position of the vehicle based on the first acceleration, the second acceleration, and the tilt angle. The navigation device according to claim 1, wherein the navigation controller calculates the tilt angle when a difference between the first acceleration and the second acceleration exceeds a predetermined threshold. The navigation controller determines whether the vehicle is currently traveling uphill or downhill according to a magnitude relationship between the first acceleration and the second acceleration. 3. The navigation device according to 1 or 2. The navigation device according to any one of claims 1 to 3, wherein the navigation controller has a function of arbitrarily setting the threshold value. The first sensor converts rotation into a pulse signal and outputs the pulse signal, and the navigation controller calculates a sampling number of pulses in the pulse signal input from the first sensor, and the sampling number becomes a predetermined number. The navigation device according to claim 1, wherein the first acceleration is calculated when the first acceleration is reached.

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