JP4640827B2 - Vehicle position prediction method and apparatus - Google Patents

Description

  The present invention measures a vehicle position using GPS, and implements a vehicle position prediction method for preventing a sudden position jump due to poor GPS reception by positioning the vehicle position by autonomous navigation using a gyro and vehicle speed data, and the method It is related with the improvement technique of an apparatus.

  In the vehicle navigation device, when measuring the position of the host vehicle, the movement distance is calculated from a vehicle speed signal, an acceleration sensor, etc., the rotation angle of the vehicle is obtained from an azimuth detection sensor such as an angular velocity sensor, etc. A hybrid method that uses either one of the positioning methods or a combination of both navigation methods, using autonomous navigation that adds GPS and GPS navigation that detects the current position by receiving radio waves from GPS (Global Positioning System) satellites. Is used.

  In the navigation device, in order to display the current location and traveling direction obtained as described above on the map screen, the map data in the vicinity of the current location is read from a map data storage medium such as a DVD-ROM provided in the navigation device, and is monitored. The electronic map is displayed on the screen, and the vehicle position is superimposed on the map. In addition, in order to display the vehicle position on the map, it has a map matching function that compares the road data on the map and displays the corrected vehicle position on the road considered appropriate. In such a map matching function, when there are a plurality of candidate roads when the position of the moving body is determined, for example, the priority of the route in the route guidance is increased, etc. Choose a high road.

  In the navigation apparatus as described above, it is extremely important to accurately measure the current position, and when the data mainly used is GPS satellite reception data, the received GPS data itself must be accurate. In addition, the positioning of GPS satellites required for positioning must be appropriate. In recent receiver technology, the so-called “all-in-view” method, in which all visible satellites are used for positioning calculation, has become the mainstream, and appropriate satellites are selected and used among all visible satellites. In order to perform 3D positioning in which the current position of the vehicle is measured in consideration of the height of the place where the vehicle is present, it is necessary to perform position measurement using at least four satellites.

  When surveying the current position using the GPS satellite as described above, the received signal including the GPS data to be received must be accurate, whereas the signal from the GPS satellite is It deteriorates due to signal attenuation caused by obstacles such as distance and clouds above and multipath noise due to the influence of surrounding buildings. When such multipath noise enters, for example, as shown in FIG. 10, the GPS positioning position changes greatly, and after that, an abnormal display is made on the screen until it gradually returns to the normal position by correction. There was a problem that caused distrust and discomfort.

  In order to solve the above-described problems, the inventors have developed the following technique and filed a patent application. As shown in FIG. 11, the outline of the technology is as follows: GPS position PGPS obtained from GPS data, GPS traveling angle θGPS, GPS speed VGPS, traveling angle θGYRO in autonomous navigation using vehicle speed by gyro and distance pulse, Vc, etc. Using the data, the predicted movement position and the predicted movement range PRG1 are obtained from the predicted movement angle range and the predicted movement distance range where the vehicle may travel from the position P0.

  The operation shown in FIG. 12 is performed by a method for obtaining the movement predicted position and the movement predicted range. That is, as shown in FIG. 12 (a), when the movement predicted position P1 and the movement predicted range PRG1 from the position P0 at time T0 are obtained, the GPS positioning position PGPS moves as shown in FIG. 12 (b). If it is included in the prediction range PRG1, the next movement prediction position P2 and the movement prediction range PRG2 are calculated in the same manner as described above, assuming that the GPS positioning data is correct. For example, as shown in FIG. 5C, when the movement prediction position P1 is obtained from the position P0 and the movement prediction range PRG1 is obtained, the GPS positioning position PGPS is predicted to move due to the influence of multipath or the like. When the GPS position is outside the range PRG1, it is assumed that the GPS position is inappropriate data, and the previously calculated movement predicted position P1 is adopted as a more correct position. From this position, the next movement predicted position P2 and The movement prediction range PRG2 is calculated.

  On the other hand, even when accurate position measurement is performed using four satellites as described above, it may be necessary to perform position measurement using only three satellites in the middle. Since only 2D positioning that cannot be calculated can be performed, the height data when 3D positioning including height positioning was performed using the four satellites immediately before the 2D positioning was performed. Assuming that the height does not change thereafter, 2D positioning calculation of the horizontal plane (XY) at that height is performed.

  In addition, after 3D positioning becomes impossible during driving, 2D positioning data using altitude data at the time of 3D positioning is adopted, and the vehicle position obtained by dead reckoning navigation or map matching navigation is more accurate. In order to enable accurate vehicle position correction even if there is a change in road altitude after switching to 2D positioning, it is necessary to continue until a certain distance is reached after switching to 2D positioning. Patent Document 1 discloses a technique in which position detection data based on two-dimensional positioning data is not used after position detection data based on two-dimensional positioning data is employed and after running a certain distance.

In addition, in order to obtain a GPS receiver capable of obtaining a more practical estimation error, altitude data and altitude error data obtained when the last three-dimensional positioning was performed are stored, and altitude data and altitude data input from the outside are stored. The error data is stored, the first error is calculated based on the first elapsed time of the data by actual measurement, the second error is calculated based on the second elapsed time of the stored value of the external data, and the first error and the second error are calculated. Patent Document 2 discloses a technique for comparing data with errors and converting the data with less errors into altitude data and altitude error data at the time of two-dimensional positioning.
JP-A-4-3537883 JP 2002-341010 A

  As described above, even when 3D positioning is performed using GPS satellite data, the current vehicle speed, etc. is always used to solve the problem of positioning and displaying a position based on data that should not be originally due to the influence of multipath or the like. We have proposed a technology that calculates the range that can be taken at the next measurement from the current location and uses data within that range when it is not within that range, but also in that technology, as described above, from 3D positioning to 2D positioning Even if the height cannot be calculated when switching to, two-dimensional positioning is performed as the same as the previous height.

  At that time, it is good if there is little difference in altitude from the point where 3D positioning is switched to 2D positioning to the point where 3D positioning is possible again, but actually the height is also large during the 2D positioning period. When the 2D positioning period is long, the data by 2D positioning is further away from the current position. In such a case, if the predicted movement range based on the 2D positioning data is correct even though the position data of the 3D positioning at the time of resumption is correct, the subsequent 3D is corrected. Although the positioning data is also gradually corrected to the correct position, an inappropriate position display will be made for a while, causing the user to feel uncomfortable or distrustful.

  Therefore, the present invention obtains a range that can be taken at the time of the next measurement from the current location, and switches from three-dimensional positioning to two-dimensional positioning in a vehicle position prediction method that uses data within the range when it is not within that range, and then again three-dimensional positioning. The main object of the present invention is to provide a vehicle position prediction method and apparatus capable of always predicting an accurate vehicle position even when the gradient between the two becomes larger than a predetermined value.

The vehicle position prediction method according to the present invention performs three-dimensional positioning based on a GPS received signal received from a GPS satellite, calculates a vehicle position, saves a vehicle travel history, and uses the travel history and vehicle speed data to present a current vehicle. Calculate the predicted movement range that may move from the position, when the three-dimensional positioning is not performed by the GPS reception signal , predict the vehicle position by two-dimensional positioning by the GPS reception signal or by the gyro and the vehicle speed signal, the GPS receiver signal the vehicle position calculated by performing three-dimensional positioning by is adopted said vehicle position when present in the prediction range of movement the last calculated, when the absence adopted vehicle position the prediction, the three-dimensional positioning The altitude data corresponding to the vehicle position is saved together with the previous data, and the 3D positioning is not performed again. When 3D positioning is enabled, the difference between the altitude of the last vehicle position at which 3D positioning is no longer performed and the altitude of the first vehicle position when 3D positioning is resumed, and the distance between these vehicle positions When the calculated gradient is greater than or equal to a predetermined distance, the vehicle position by GPS positioning when the three-dimensional positioning becomes possible again exists within the predicted movement range. When not, the vehicle position by GPS positioning is selected.

  In the vehicle position prediction method according to the present invention, in the vehicle position prediction method, when selecting the vehicle position by GPS positioning when the calculated gradient is equal to or greater than a predetermined value, all saved travel histories are deleted and a new The travel history is updated.

Other vehicle position prediction method according to the present invention, in the vehicle position prediction method, when the GPS received signal the vehicle position calculated by performing three-dimensional positioning by is not in the prediction range of movement, the three-dimensional when the distance point positioning is point and three-dimensional positioning is no longer carried out is resumed is equal to or higher than a predetermined, to characterized in that the selection of vehicle position by GPS positioning.

A vehicle position prediction apparatus according to the present invention includes a GPS three-dimensional positioning unit that performs three-dimensional positioning using a GPS reception signal received from a GPS satellite and calculates a vehicle position, a traveling history storage unit that stores a traveling history of the vehicle, Predicted movement range calculation means for calculating a range that may move from the current vehicle position using the travel history and the vehicle speed data, and when 3D positioning is not performed by the GPS reception signal, Predicted position calculation means for predicting the vehicle position by dimensional positioning or by a gyro and a vehicle speed signal, and the vehicle position measured by the GPS three-dimensional positioning means exist in the predicted movement range previously calculated by the predicted movement range calculation means. Sometimes the vehicle position is adopted, and when the vehicle position does not exist, the vehicle position selected by the vehicle position predicted by the predicted position calculation means is adopted. If, when performing a three-dimensional positioning at the GPS three dimensional positioning means, and advanced data storage means for storing altitude data corresponding to the vehicle position together with the previous data, the three-dimensional positioning at the GPS three-dimensional positioning means lines When 3D positioning becomes possible again from the time of failure, the difference between the altitude of the last vehicle position where 3D positioning is no longer performed and the altitude of the first vehicle position when 3D positioning is resumed, and the distance between their vehicle position, a gradient calculating means for calculating a slope between said vehicle position, the vehicle position selection means, when the slope was calculated by the gradient calculating means is equal to or greater than the predetermined, the re-tertiary vehicle position calculated by the GPS reception signal when the original positioning becomes possible, when not in the prediction range of movement calculated in the predicted moving range calculating means, the vehicle position by GPS positioning And wherein the-option to Turkey.

  In another vehicle position prediction apparatus according to the present invention, in the vehicle position prediction apparatus, when the traveling history storage unit selects a vehicle position by GPS positioning when the gradient calculated by the gradient calculation unit is greater than or equal to a predetermined value, All saved travel histories are deleted, and a new travel history is saved.

  Another vehicle position prediction apparatus according to the present invention is the vehicle position prediction apparatus, wherein the vehicle position selection means is configured such that a distance between the point where the three-dimensional positioning is stopped and the point where the three-dimensional positioning is restarted is a predetermined distance or more. At this time, the vehicle position is selected by GPS positioning.

  Since the present invention is configured as described above, a predicted movement range that can be taken at the time of the next measurement is determined from the current location, and when the vehicle position prediction method that is set within the range is not used, When switching to 3D positioning or autonomous navigation positioning becomes possible again, even when the gradient between points where 2D positioning or autonomous navigation positioning was performed is large, accurate vehicle position selection is performed. And the subsequent vehicle position can be obtained accurately.

  In the present invention, when the three-dimensional positioning becomes possible again after switching from the three-dimensional positioning by the GPS to the two-dimensional positioning or the positioning by the autonomous navigation, the gradient between the points where the two-dimensional positioning or the autonomous navigation positioning has been performed is large. However, the purpose of selecting an accurate vehicle position is to perform three-dimensional positioning using a GPS received signal received from a GPS satellite to calculate the vehicle position and to save the vehicle travel history, and to store the travel history and vehicle speed data. To calculate the predicted moving range that may move from the current vehicle position, and when the 3D positioning is not performed by the GPS reception signal, the vehicle position is determined by the 2D positioning by GPS or by the gyro and the vehicle speed signal. When the vehicle position predicted by the GPS is within the predicted movement range calculated last time, the vehicle position is adopted, and when the vehicle position does not exist When the predicted vehicle position is adopted and the 3D positioning is performed, altitude data corresponding to the vehicle position is saved together with the previous data, and the 3D positioning can be performed again when the 3D positioning is not performed. Then, the difference between the altitude of the last vehicle position where 3D positioning is no longer performed and the altitude of the first vehicle position when 3D positioning is resumed, and the distance between those vehicle positions, When a gradient between the vehicle positions is calculated, and the calculated gradient is equal to or greater than a predetermined value, a vehicle position obtained by GPS positioning when the three-dimensional positioning is possible again is not within the predicted movement range. Realized by selecting the vehicle position by positioning.

  Embodiments of the present invention will be described with reference to the drawings. Although the present invention corresponds to the improved technique of the invention previously filed by the present inventors, it is not yet known at the time of the filing of the present application. Therefore, the portions necessary for the description of the present invention will be described in duplicate. The vehicle position prediction apparatus according to the present invention is a software of the system control unit 10 in association with other functional units in the position prediction control unit 30 that predicts the position of the host vehicle in the vehicle navigation apparatus that includes the functional blocks of FIG. Is done by. In addition, the function part which performs each function in FIG. 1 can also be said to be a means which performs each function.

  In the navigation apparatus shown in FIG. 1, as in the prior art, a ROM in which software for comprehensively performing various predetermined functions is recorded in the system control unit 10, a CPU and a RAM for processing the software, etc. Are provided, and the respective functional units connected thereto are associated and controlled comprehensively. In the illustrated navigation apparatus, the system control unit 10 includes a data capturing unit 12 that captures necessary map data, facility information, and the like from a map / information data recording medium 11 such as a CD-ROM, DVD-ROM, or hard disk. I have.

  The instruction signal input unit 15 inputs an instruction signal from the user of the navigation device such as the remote control 13 or the touch panel. Further, a signal of the voice recognition unit 14 that inputs a user instruction signal by processing for recognizing the user's voice as necessary is also input to the instruction signal input unit 15. The guide route calculation unit 16 calculates a guide route between a destination input by the user by various methods and a vehicle position (described later) obtained by GPS or the like, and the guide route storage unit 17 has various conditions. One guidance route selected by the user from among the guidance routes presented in step S1 is stored, and the guidance route guide unit 18 causes the speaker 19 to output the voice 19 so that the vehicle can travel safely along the stored guidance route. From the image output unit 22 and displayed on the monitor 21 from the image output unit 22 for guidance.

  The GPS receiver 23 receives GPS signals sent from GPS satellites, calculates the absolute current position (GPS position) and traveling direction of the vehicle, and uses the Doppler shift to speed the vehicle (GPS speed). 3D positioning as a positioning including the height is possible because the number of satellites that can be used for GPS positioning is 4 or more, or only 2D positioning is possible because only 3 satellites can be used. GPS positioning enabled / disabled signals are output, such as whether or not two or less, or even one cannot be used.

  The autonomous navigation sensor unit 26 includes an angle sensor 27 that detects a traveling direction using a gyro every predetermined time, and a distance sensor 28 that detects a traveling distance and a vehicle speed from a vehicle speed pulse of the vehicle. In the autonomous navigation position prediction calculation unit 29, a traveling direction signal from the angle sensor 27, a vehicle speed signal from the distance sensor 28 using a vehicle speed pulse, and a current position signal measured by a GPS receiver as necessary are input. In particular, the current position positioning data when setting the predicted movement range so that the current position does not jump to another position due to a sudden abnormal signal due to multipath etc. even when the GPS is in 3D positioning, and when the 3D positioning is changed to the 2D positioning. Therefore, it is used for predicted vehicle position data when GPS reception is impossible, such as in a tunnel. Data obtained by the autonomous navigation position prediction calculation unit 29 is mainly used in a position prediction control unit 30 described later.

In the autonomous navigation position prediction calculation, as shown in FIG. 6, when the reference azimuth (θ = 0) is the positive direction of the X axis and the counterclockwise direction from the reference azimuth is the + direction, the previous vehicle position is set to the point P0 ( X0, Y0), the absolute azimuth in the vehicle traveling direction at point P0 is θ0, and the output of the relative azimuth sensor at the time of movement distance L0 (= V × t) after unit time t is Δθ1, The change in position is
ΔX = L0 · cos (θ0 + Δθ1)
ΔY = L0 · sin (θ0 + Δθ1)
Thus, the accumulation direction θ1 and the accumulation vehicle position (X1, Y1) in the vehicle traveling direction at this point P1 are θ1 = θ0 + Δθ1 (1)
X1 = X0 + ΔX = X0 + L0 · cos θ1 (2)
Y1 = Y0 + ΔY = Y0 + L0 · sin θ1 (3)
As a result, the predicted position at the next calculation can be calculated by vector synthesis.

  The position prediction control unit 30 includes a predicted position calculation unit 31, and uses various data of the autonomous navigation sensor unit 26 as described above, data of the GPS receiver 23, and the like according to the method shown in FIG. Or the position which drive | works after predetermined time is estimated by the method explained in full detail behind. In addition, the reliability determination unit 32 determines the reliability of GPS data by a method described later, and performs control such as current position prediction control according to the degree of the reliability. The predicted movement range calculation unit 33 calculates the predicted movement range by a method described later. Further, as will be described in detail later, the position prediction control unit 30 is provided with a travel history storage unit 34, and the difference ΔV between the GPS speed and the vehicle speed detected by the autonomous navigation sensor unit as travel history information together with the vehicle traveling direction. save. While this data is updated by the travel history update unit 35, an appropriate number of histories such as 10 for the latest plurality of travel history information, for example, data as shown in FIG.

  Further, the position prediction control unit 30 performs position prediction control for performing position prediction control corresponding to a difference in altitude during traveling from when 3D positioning by GPS becomes impossible to when 3D positioning becomes possible thereafter. A prediction control unit 36 is provided. The altitude corresponding position prediction control unit 36 includes an altitude data storage unit 37, which stores altitude data currently measured and altitude data measured last time when 3D positioning is possible by GPS. The altitude difference calculation unit 38 performs altitude data when 3D positioning can be resumed after 3D positioning by GPS cannot be performed, and finally 3D positioning stored in the altitude data storage unit 36 at that time. Calculate altitude difference based on altitude data of time. In addition, the travel distance calculation unit 39 when 3D positioning is impossible calculates the cumulative travel distance when 3D positioning is possible after the 3D positioning is disabled as described above.

  In the gradient calculation unit 40 in the altitude corresponding position prediction control unit 36, the altitude difference H calculated from the 3D positioning impossible to the 3D positioning possible calculated by the altitude difference calculating unit 38 and the travel distance calculating unit 39 when 3D positioning is impossible are calculated. The gradient (H / L) during the 3D positioning impossible period is calculated based on the distance L. Further, the gradient determination unit 41 determines whether or not the gradient calculated by the gradient calculation unit 40 is a predetermined gradient or more. Here, when it is determined that the gradient is greater than or equal to a predetermined gradient, the GPS positioning position when the 3D positioning by GPS is enabled by the vehicle position selection unit 43 is the 2D positioning by GPS or the position by the autonomous navigation position prediction calculation unit 29 Even when it exists outside the prediction range by prediction, the output which makes the positioning position by 3D the vehicle position is performed. Thereby, the position prediction by 2D positioning or the like gradually increases due to a large difference in altitude, and avoids the inconvenience of positioning due to using the data when 3D positioning is resumed. At this time, the travel history deletion unit 42 deletes all the history data in the travel history storage unit 34, assuming that the travel history up to the restart of 3D positioning is inappropriate for the travel history update unit 35, and creates a new travel history. Instruct to update

  In this invention which consists of the above functional blocks, it can be operated by the operation flow shown in FIGS. Hereinafter, the operation flow will be described with reference to the functional block diagram of FIG. In the operation flow of the current position detection process shown in FIG. 2, it is first determined whether or not the position calculation timing set every predetermined time has come (step S1). When the position calculation timing is reached, a predicted position calculation is performed. The unit 31 obtains GPS calculation data (GPS position PGPS, GPS speed VGPS, GPS traveling direction θGPS, GPS positioning state signal from the GPS receiver 23, and further obtains a traveling direction change θGYRO and a vehicle speed Vc from the autonomous navigation sensor unit 26. (Step S2).

  In the operation flow of FIG. 2, it is then determined whether or not 3D positioning by GPS is possible (step S3). This determination is performed by the reliability determination unit 32 of the position prediction control unit 30 using a GPS positioning enable / disable signal obtained from the GPS calculation unit 25 in the GPS receiver 23 of FIG. That is, in this process, the reliability determination unit 32 checks whether or not 3D positioning can be performed by using at least four satellites in the GPS receiver. As a result, when it is determined that 3D positioning is not possible, in step S11, as shown in FIG. 4, a current position prediction process when 3D positioning is not possible using GPS, which is a feature of the present invention, is performed.

  When it is determined in step S3 that 3D positioning by GPS is possible, update processing of travel history information is performed (step S4). This process is performed according to the operation flow shown in FIG. 3A, for example, as in the travel history information update process example shown in FIG. In the example of the travel history information update process shown in FIG. 3A, it is monitored whether or not it is the first travel history storage timing, that is, the position measurement timing (step S21). It is checked whether there is reliability (step S22). Whether or not the GPS data is reliable is measured by the reliability determination unit 32 and the measurement result is input to the travel history update unit 35.

At this time, in the reliability determination unit 32,
(1) Is it possible to measure the position using GPS signals?
(2) Whether the vehicle speed obtained from the GPS reception signal is 1 km / h or more,
(3) Whether the difference between the change in the GPS traveling direction obtained from the GPS reception signal and the traveling direction change θGYRO obtained from the angle sensor 27 is equal to or greater than the set value
(4) Whether the change in the traveling direction change θGYRO is equal to or greater than a set value,
Determine and monitor.

Based on the judgment and monitoring results,
(1) The position cannot be measured by the GPS reception signal.
(2) The vehicle speed obtained from the signal received from the GPS satellite is 1 km / h or less.
(3) The difference between the GPS traveling direction change and the traveling direction change θGYRO is greater than or equal to the set value.
(4) The change in the traveling direction change θGYRO is equal to or greater than a set value.
When any of the above is established, it is determined that the GPS position is not reliable. On the contrary, the position can be measured by the GPS received signal, the vehicle speed obtained from the signal received from the GPS satellite is greater than 1 km / h, and the difference between the change in the GPS traveling direction and the traveling direction change θGYRO is greater than the set value. When the change in the traveling direction change θGYRO is smaller than the set value, the GPS position is determined to be reliable. It should be noted that when determining whether or not the position measurement based on the GPS received signal can be performed here, it is also possible to determine that the GPS positioning is possible if the positioning is performed by the 2D positioning in addition to the 3D positioning.

If the GPS data is reliable, the travel history update unit 35 saves the latest GPS traveling direction θGPS obtained from the GPS reception signal in the traveling direction history storage unit as shown in FIG. The difference ΔV between the GPS speed obtained from the signal and the vehicle speed obtained by the distance sensor 28 is stored (step S23). That is, the following formula (θREF) 1 = θGPS
ΔV1 = ΔV
Update processing is performed.

Thereafter, the traveling history update unit 35 updates the traveling direction history information by removing the oldest traveling direction history information and adding the traveling direction change θGYRO obtained from the angle sensor to the remaining traveling direction history information (step S24). ). That is, the following equation (θREF) i + 1 = (θREF) i + θGYRO
ΔVi + 1 = ΔVi
Is updated to obtain the data shown in FIG. As described above, all the 10 sets of traveling directions are updated so as to be the current traveling direction of the vehicle.

On the other hand, when it is determined in step S22 that the GPS data is not reliable, the traveling direction history information is updated by adding the traveling direction change θGYRO to all the traveling direction history information stored in the traveling history storage unit 34. (Step S25). At this time, the vehicle speed difference is not changed. That is, the following equation (θREF) i = (θREF) i + θGYRO
ΔVi = ΔVi
Is updated to obtain the data shown in FIG. As a result, as in the case where the GPS data is reliable, the 10 traveling directions are all updated to be the vehicle traveling direction at the present time.

  In the embodiment shown in FIG. 2, following the travel history information update process in step S4, an update process of the current and previous altitude data is performed (step S5). This processing is performed in the altitude data storage unit 37 in the altitude corresponding position prediction control unit 36 of FIG. In this process, the altitude data storage unit 37 is provided with a memory for storing only the current and previous data, and is updated and stored each time new data is entered. As a result, as described later, 3D positioning cannot be performed after that, and when 3D positioning is enabled after that, altitude data at the time when 3D positioning is enabled and 3D positioning, which is the previous data, cannot be performed. When the process proceeds to step S11 in step S3, when the data stored in step S5 remains and the 3D positioning is resumed, the altitude difference calculation unit 38 in FIG. Become.

  Thereafter, it is determined whether or not the position measured by GPS is within the predicted movement range predicted last time (step S6). This determination is performed by detecting whether or not the GPS positioning position exists within the predicted movement range set in step S8, step S10, and the like described later at the previous position measurement timing. As a result of this determination, when it is determined that the GPS positioning position is within the predicted movement range, the GPS position is output as the current position (step S7), and the predicted position at the next time and the GPS traveling direction θGPS and the GPS speed are output. Calculate the predicted movement range.

  In the calculation process of the predicted movement range in step S8, vehicle-specific travel characteristic data as shown in FIG. 8 is used in this embodiment. That is, as shown in FIG. 8A, a large number of measured values of the relationship between the actual running speed of the vehicle and the angular speed as the direction change state at that speed are measured and plotted as shown in the figure. Taking the standard deviation value that causes the angular velocity at the velocity of 3σ, the range of 3σ that is a value that exists with a probability of 99.7% is the upper line represented by the equation as shown in the figure, plus or minus this It can be seen that this is the range between the lower line.

  Similarly, as shown in FIG. 8B, a large number of actual measured values of the relationship between the actual traveling speed of the vehicle and the degree of acceleration of the vehicle at that speed are measured and plotted as shown in the figure. Taking the standard deviation value at which acceleration at speed occurs, it can be seen that the range of 3σ is within the range of the lower line similar to the upper line represented by the formula shown in FIG. Accordingly, for example, as shown in FIG. 9, when the current position of the vehicle is P0, the movable angle at which the vehicle may travel from the position of P0 using the vehicle speed obtained from the GPS data or the vehicle speed as the vehicle data. The range can be obtained from the relational expression in FIG. 8A, and similarly, the movable distance range in which the vehicle may travel from the position P0 can be obtained from the relational expression in FIG. As a result, the predicted movement range PRG1 of FIG. 9 is obtained. FIG. 9A shows an ideal example in which a 3D positioning position PGPS by GPS exists on the center direction PL in the vicinity of the center within the predicted movement range PRG1, and the predicted movement position P1 also exists.

  FIG. 9B shows a state in which positioning by GPS is performed in the state of FIG. 9A and the position PGPS is different from the predicted movement position P1, but is included in the movable range PRG1. Show. In such a state, in step S6, it is determined that the GPS positioning position is within the predicted movement range, and in step S7, this GPS position PGPS is output as the current position. Note that when setting the predicted movement range, prediction may be made by adding another method such as adjusting the prediction range so as to always include a road, for example, in addition to the above method. You may carry out by another method like the Example of an application.

  When calculating the predicted position in step S8, for example, in the autonomous navigation position prediction calculation unit 29 of FIG. 1, a pulse is output every time the vehicle travels a predetermined distance by the distance sensor 28, and thus occurs per unit time. The vehicle moving speed Vc can be measured by counting the number of pulses, and can also be obtained as VGPS from GPS Doppler shift data.

  In the example shown in FIG. 2, in step S6, the GPS positioning position is calculated the previous time when it does not exist in the predicted movement range PRG1, such as the PGPS in FIG. The position closest to the center bearing line of the predicted movement range at the time is output as the current position. That is, as shown in FIG. 9 (c), the GPS positioning position PGPS existing outside the predicted movement range PRG1 is a position projected on the central bearing line PL of the predicted movement range PRG1, in other words, GPS PGPS1 where the positioning position PGPS is closest to the center bearing line PL is defined as the current position. Instead of such a current position correction method, the predicted position or the autonomous navigation predicted position can be output as the current position as in the previous application. Thereafter, a predicted position and a predicted movement range at the next time are calculated using the traveling direction having the smallest vehicle speed difference ΔV and the GPS speed VGPS (step S10).

  As the vehicle traveling direction θ used here, the vehicle traveling direction with the smallest vehicle speed difference ΔV is selected from the 10 traveling direction history data stored in the travel history storage unit 34. This is because the reliability of the traveling direction data is highest when the difference between the GPS speed VGPS and the speed Vc obtained from the vehicle speed sensor is minimum. Since the GPS speed VGPS is detected based on the Doppler shift, the accuracy is high even if the GPS position is not reliable. Thereafter, the process returns to step S1 together with step S8 to repeat the operation. Note that the calculation of the predicted position and the predicted movement range in step S10 is performed by substantially the same method as in step S8, and thus description thereof is omitted here.

  On the other hand, if it is determined in step S3 in FIG. 2 that 3D positioning by GPS is impossible, the process proceeds to step S11, and the processes shown in FIG. 4 and the subsequent FIG. 5 are performed. That is, in the example of the current position prediction process when GPS 3D positioning is not possible as shown in FIG. 4, it is first determined whether or not GPS 2D positioning is possible (step S31). If it is determined that 2D positioning is possible even if 3D positioning by GPS is not possible, the 2D positioning position by GPS is output as the current position in step S33.

  Further, when 2D positioning by GPS is impossible, for example, when entering a tunnel, the predicted position calculated by the autonomous navigation calculated earlier is calculated and output as the current position (step S32). After the current position is output in steps S32 and S33, the travel history information is updated (step S34). In the travel history information update process in FIG. 3, it is determined that the GPS data in step S22 is not reliable in the travel history information update process in FIG. 3, and θGYRO in step S25. Is used to update the history information, and the update process as in the example of FIG. 3B-3 is performed. Thereafter, the predicted position and the predicted movement range at the next time are acquired (step S35). In this process, the predicted position and the predicted movement range are acquired mainly by data obtained by autonomous navigation. However, when even one GPS can be received, the GPS data can be used.

  Next, in the embodiment of FIG. 3, the running distance after the 3D positioning by GPS is disabled is integrated (step S36). This integration makes it possible to determine whether or not the vehicle has traveled more than a predetermined distance such as 500 m when 3D positioning by GPS as described later is possible. Thereafter, it is determined whether or not the next position calculation timing has been reached (step S37). If the timing has not yet been reached, this operation is repeated to stand by. When it is determined that the timing for the next position calculation has come, it is determined whether or not 3D positioning by GPS is possible. If 3D positioning by GPS is still impossible, the process returns to step S31 and the above operation is repeated. Thereafter, when 3D positioning by GPS becomes possible, the current position detection process at the time of resuming 3D positioning by GPS shown in FIG. 5 is performed (step S39).

  In the current position detection process at the time of resuming 3D positioning by GPS shown in FIG. 5, the current position and the height of the position are first acquired by GPS (step S42). Next, it is determined whether or not the GPS position is within the predicted movement range (step S43). If it is determined that the GPS position does not exist within the predicted movement range, it is determined whether or not the accumulated travel distance from when GPS 3D positioning is not possible is equal to or greater than a predetermined distance such as 500 m (step S44). For this determination, data obtained by integrating the travel distance after the 3D positioning by GPS is disabled in step S36 of FIG. 4 is used. This integration process is performed by the travel distance calculation unit 39 when 3D positioning is impossible in the altitude corresponding position prediction control unit 36 of FIG.

  When it is determined in step S44 that the accumulated travel distance from when GPS 3D positioning is not possible is equal to or greater than a predetermined distance such as 500 m, the current altitude difference from when 3D positioning is impossible is calculated (step S45). Next, the gradient from when 3D positioning is impossible to this time is calculated (step S46). This processing is performed by the gradient calculation unit 40 in the altitude corresponding position prediction control unit 36 of FIG. Thereafter, it is determined whether or not the calculated gradient is greater than or equal to a predetermined value (step S47).

  As a result of the determination, when it is determined that the gradient is greater than or equal to a predetermined value, only the current travel history information is stored, and the others are cleared (step S49). That is, in step S44, when the accumulated travel distance from when GPS 3D positioning is disabled is longer than a predetermined distance such as 500 m, the error is accumulated by continuous 2D positioning or continuous autonomous navigation positioning without GPS positioning. Since the gradient during the running period is greater than or equal to the predetermined value in step S47, the error associated with the altitude difference increases. Therefore, even if the position of 3D positioning by GPS is not within the predicted movement range, It is determined that the 3D positioning position indicates the correct position.

  In relation to the determination, it is determined in step S49 that the driving history information so far has a large error, the driving history information is deleted, and the 3D positioning data by GPS restarted this time is used. It is assumed that the data is correct, and this is stored as the first travel history information. Thereafter, data is sequentially accumulated and further updated by the above-described method. Next, when it is determined in step S43 that the GPS position is within the predicted movement range, the GPS position is output as the current position (step S50).

  Further, when it is determined in step S44 that the accumulated travel distance from when GPS 3D positioning is impossible is not greater than a predetermined distance such as 500 m, and when it is determined that the gradient calculated in step S47 is not greater than a predetermined distance, 3D positioning is performed. 2 is relatively short, or the slope between them is not so large as to cause a positioning error. Similar to step S9 of FIG. Is output as the current position (step S52). Thereafter, similarly to step S10, the predicted position and the predicted movement range are calculated using the traveling direction with the smallest vehicle speed difference ΔV and the GPS speed VGPS (step S10). Thereafter, similar to step S51, the process returns to step S1 in FIG. 2 and the operation is repeated.

  In the present invention, when such a process is performed, the 3D positioning becomes impossible while the 3D positioning by the GPS is being performed, and the 3D positioning by the GPS becomes possible again after that. If the slope of the period is greater than a predetermined value, the current position predicted by 2D positioning or autonomous navigation during that period is incorrect, and the 3D positioning position by GPS is not within the prediction range. Even in this case, the current position can be output assuming that the position of 3D positioning by GPS is correct. Moreover, when 3D positioning is resumed as described above, the travel history information that has been accumulated up to that point is deleted, and new accumulation is started, so that the current position shift due to erroneous use of data continues for a long period of time. Can be prevented.

It is a functional block diagram of the Example of this invention. It is an operation | movement flowchart of the Example. It is an operation | movement flowchart of the driving history information update process part in the operation | movement flow of FIG. It is an operation | movement flowchart of the present position prediction process part at the time of 3D positioning by GPS in the operation | movement flow of FIG. FIG. 5 is an operation flowchart of a current position detection processing portion when 3D positioning is restarted by GPS in the operation flow of FIG. 4. It is a figure which shows a vehicle position prediction process. It is a figure which shows the example of driving history data. It is a figure which shows the example of the driving | running | working characteristic data peculiar to the vehicle used for the calculation process of an estimated moving range. It is a figure which shows the relationship with an estimated moving range and GPS positioning present position. It is a figure which shows the example of a change of a positioning position by the influence of the multipath etc. in the conventional GPS positioning. It is a figure which shows the setting of the movement prediction range by the autonomous navigation previously proposed, and the example of a movement prediction position. It is a figure which shows the relationship between the vehicle position prediction proposed previously, the estimated movement range, and GPS positioning data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 System control part 23 GPS receiver 24 GPS receiving part 25 GPS calculation part 26 Autonomous navigation sensor part 27 Angle sensor 28 Distance sensor 29 Autonomous navigation position prediction calculating part 30 Position prediction control part 31 Predictive position calculating part 32 Reliability determination part 33 Predicted movement range calculation section 34 Travel history storage section 35 Travel history update section 36 Altitude corresponding position prediction control section 37 Altitude data storage section 38 Altitude difference calculation section 39 3D positioning impossible travel distance calculation section 40 Gradient calculation section 41 Gradient determination section 42 Travel history deletion unit 43 Vehicle position selection unit

Claims (6)

Performs three-dimensional positioning based on GPS received signals received from GPS satellites to calculate the vehicle position and save the vehicle travel history,
Using the travel history and vehicle speed data to calculate a predicted movement range that may move from the current vehicle position,
When the three-dimensional positioning is not performed by the GPS reception signal , the vehicle position is predicted by the two-dimensional positioning by the GPS reception signal or by the gyro and the vehicle speed signal,
When the vehicle position calculated by performing three-dimensional positioning by the GPS reception signal is present in the previously calculated predicted movement range, the vehicle position is adopted, and when not present, the predicted vehicle position is adopted,
When performing the three-dimensional positioning, the altitude data corresponding to the vehicle position is saved together with the previous data,
When the 3D positioning becomes possible again from the time when the 3D positioning is not performed, the altitude of the last vehicle position at which the 3D positioning is no longer performed, and the first vehicle position when the 3D positioning is resumed The gradient between the vehicle positions is calculated from the difference between the vehicle height and the distance between the vehicle positions,
When the calculated gradient is not less than a predetermined value, the vehicle position by GPS positioning is selected when the vehicle position by GPS positioning when the three-dimensional positioning becomes possible again does not exist within the predicted movement range. A vehicle position prediction method.   2. The vehicle position prediction according to claim 1, wherein when the calculated gradient is equal to or greater than a predetermined value, when a vehicle position is selected by GPS positioning, all saved travel histories are deleted and a new travel history is updated. Method. The GPS receiver signal the vehicle position calculated by performing three-dimensional positioning by the said when not within the prediction range of movement, the distance of the point where the three-dimensional point and the three-dimensional positioning which positioning is no longer carried out is resumed when more than a predetermined vehicle position prediction method according to claim 1, characterized in that the selection of the vehicle position by GPS positioning. GPS three-dimensional positioning means for performing three-dimensional positioning using a GPS received signal received from a GPS satellite and calculating a vehicle position;
Traveling history storage means for storing the traveling history of the vehicle;
Predicted movement range calculation means for calculating a range that may move from the current vehicle position using the travel history and vehicle speed data;
Predicted position calculation means for predicting the vehicle position by two-dimensional positioning by GPS reception signal or by gyro and vehicle speed signal when three-dimensional positioning is not performed by the GPS reception signal ;
When the vehicle position measured by the GPS three-dimensional positioning means is present in the predicted movement range previously calculated by the predicted movement range calculating means, the vehicle position is adopted, and when it does not exist, the vehicle position predicted by the predicted position calculating means is used. Vehicle position selection means adopting,
Altitude data storage means for storing altitude data corresponding to the vehicle position together with previous data when performing 3D positioning with the GPS 3D positioning means ;
When 3D positioning is possible again when 3D positioning is not performed by the GPS 3D positioning means, the altitude of the last vehicle position at which 3D positioning is no longer performed, and 3D positioning is resumed. the first difference between the altitude of the vehicle position, and the distance between their vehicle position, a gradient calculating means for calculating a slope between said vehicle position when,
When the gradient calculated by the gradient calculation unit is greater than or equal to a predetermined value , the vehicle position selection unit calculates the vehicle position calculated by the GPS received signal when the three-dimensional positioning is possible again by the predicted movement range calculation unit. in the absence on the calculated prediction range of movement, the vehicle position prediction device comprising a benzalkonium select the vehicle position by GPS positioning. When the gradient calculated by the gradient calculation unit is greater than or equal to a predetermined value and the vehicle position by GPS positioning is selected, the travel history storage unit deletes all the stored travel history and stores a new travel history. The vehicle position prediction apparatus according to claim 4.   The vehicle position selection means selects a vehicle position by GPS positioning when a distance between the point where the 3D positioning is no longer performed and the point where the 3D positioning is resumed is a predetermined distance or more. 4. The vehicle position prediction apparatus according to 4.

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