JPH07134040A - Method for detecting motion of traveling body by satellite navigation - Google Patents

Abstract

PURPOSE:To properly detect the position of a traveling body by satellite navigation. CONSTITUTION:A GPS receiver 3 periodically detects the position of a vehicle by satellite navigation. On the other hand, a primary correction part 10b of a navigation controller 10 calculates a current average velocity using a previous detection vehicle position and a current detection vehicle position every time a vehicle position is detected by satellite navigation and checks to see if the current average velocity is within an allowable range which is considered according to the motion characteristics of vehicle judging from the previously calculated average velocity. If it determines that the velocity is within the allowable range, it makes the current detection vehicle position valid and then outputs it to a secondary correction part 10e for performing map matching. However, it determines that the velocity is outside the allowable range which is considered according to the motion characteristics of vehicle judging from the previously calculated average velocity, the primary correction part 10b makes the current detection vehicle position to be invalid, estimates the current vehicle position from the past vehicle position, vehicle velocity, etc., and then outputs the estimated vehicle position to the secondary correction part 10e.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting motion of a moving body by satellite navigation, and more particularly to a vehicle-mounted navigation device,
The present invention relates to a method for detecting a motion of a mobile body by satellite navigation, which is suitable for periodically detecting motion information such as the position and speed of a mobile body such as a vehicle or a ship in a navigation device for navigation.

[0002]

2. Description of the Related Art There is a vehicle-mounted navigation device that displays a vehicle position on a map image to provide driving guidance.
With the spread of the highway network, it is now possible to easily drive long distances.By using an in-vehicle navigation device, it is possible to drive on the road without mistakes even in strange areas, and to detour congestion appropriately. It has excellent convenience.
In this vehicle-mounted navigation device, the vehicle position is detected, the map data including the vehicle position is read from a map data storage medium such as a CD-ROM, an IC memory card, etc., and a map image including the vehicle position is drawn on the screen. The vehicle position mark is drawn so as to overlap with the position corresponding to the vehicle position on the map image.

By the way, as a method of detecting a vehicle position, self-contained navigation which is cumulatively detected from the outputs of an azimuth sensor and a distance sensor (speed sensor), and satellite radio waves from GPS satellites or the like are received to perform triangulation. There are two satellite navigation methods that can be detected by the principle. Among them, the former self-contained navigation has a drawback that it is difficult to retrofit the vehicle, and the sensor error accumulates to cause a large detection error. On the other hand, in the latter satellite navigation, the detection error at the time of normal reception is less than a certain value, it is easy to retrofit to the vehicle, and the size and cost are being advanced, so it has spread rapidly in recent years. It's starting.

The GPS receiver is a device for detecting the position and speed of the vehicle by satellite navigation using GPS satellites, and there are three devices that can be seen in the sky (two-dimensional positioning; the altitude of the current location is known).
Alternatively, the satellite radio waves of four GPS satellites (three-dimensional positioning) are captured, each satellite position is specified by referring to the navigation message, the vehicle position-satellite distance is measured from the PN code, and a predetermined simultaneous equation is established. The vehicle position (longitude,
Latitude). Also, the speed and direction are obtained from the Doppler shift generated in the satellite radio waves. The GPS receiver detects the vehicle position and speed at regular intervals (for example, every one second) and outputs these data.

[0005]

However, in the above-mentioned satellite navigation, when the vehicle is traveling in the suburbs without buildings or mountains, for example, as shown in FIG. 4, the vehicle is traveling in the building street. During this time, the satellite radio wave from the GPS satellite SAT1 is blocked by the building BD1 and cannot be directly received by the GPS receiver, and the reflected wave at the building BD2 may be received. At this time, GPS satellite SAT1
Until the radio waves emitted from the vehicle reach the vehicle
Since the vehicle travels a distance longer than the distance between the S satellite SAT1 and the vehicle, the vehicle position detected by satellite navigation becomes V1 'which is deviated from the actual vehicle position V1, and the position of the vehicle position mark displayed on the map image on the screen. Sometimes flew significantly from the previous driving route.

Such a vehicle position detection error can be corrected to a certain extent by map matching if there are few surrounding roads or if the error is small, but it can be detected when traveling in an area with high road density such as a building street. When the error is large, it cannot be corrected and the driver cannot be informed of the correct vehicle position. In view of the above, an object of the present invention is to provide a method for detecting a motion of a moving body by satellite navigation, which can correctly detect the position and the like of the moving body.

[0007]

SUMMARY OF THE INVENTION In the present invention, the above-mentioned object is based on means for periodically detecting the motion of a moving body by satellite navigation, motion information detected so far by satellite navigation and motion characteristics of the moving body. , The means for determining whether the motion information detected by this time's satellite navigation is normal or abnormal, and when the motion information detected by this means is normal, the motion information detected by this time satellite navigation is validated, and when it is determined to be abnormal, this time by satellite navigation This is achieved by invalidating the detected motion information and estimating the current motion information by inferring it from the motion information detected in the past.

[0008]

According to the present invention, the motion of the moving body is periodically detected by the satellite navigation, and the motion information detected by the satellite navigation this time is obtained from the motion information detected by the satellite navigation and the motion characteristics of the moving body. When it is determined that it is normal or abnormal, the motion information detected by the satellite navigation this time is valid when it is determined to be normal, and the motion information detected by the satellite navigation this time is invalid when determined to be abnormal,
The current motion information is obtained by inferring from the motion information detected in the past. This makes it possible to obtain almost accurate motion information even if satellite radio waves cannot be normally received and incorrect motion information is detected, and it is possible to provide the user with highly accurate motion information.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device embodying a motion detection method of a mobile body by satellite navigation according to the present invention. Reference numeral 1 denotes a CD-ROM that stores map data (including map drawing data, map matching road data, etc.) divided into predetermined longitude and latitude widths. 2 is an operation panel equipped with a map search key, an enlargement / reduction key, etc. 3 is a GPS receiver that detects the vehicle position by satellite navigation using GPS satellites, and is regularly (here, at 1 second intervals) The vehicle position (longitude, latitude), speed, and direction are detected, and vehicle position data, vehicle speed data, and vehicle direction data are output. A display device 4 displays a map image together with a vehicle position mark on the screen.

Reference numeral 10 denotes a navigation controller having a microcomputer configuration, which draws a map image around the vehicle position together with the vehicle position mark using the map data in the CD-ROM 1 based on the vehicle position data detected by the GPS receiver 3. Display on the display device 4. 10a is CD-
The buffer memory 10b for temporarily storing the map data read from the ROM 1 is a primary correction unit for correcting the vehicle position data detected by the GPS receiver 3 before performing the map matching. Based on the vehicle position and the vehicle's motion characteristics detected in the above, it is determined whether the vehicle position detected by satellite navigation this time is normal or abnormal, and when it is determined that the vehicle position data detected by satellite navigation this time is valid When it is output and determined to be abnormal, the vehicle position data detected by the satellite navigation this time is invalidated, the current vehicle position data is obtained by estimating from the vehicle position data detected in the past, and the estimated vehicle position data is output. . Reference numeral 10c is a determination reference memory that stores determination criteria for determining whether the vehicle position data is normal or abnormal, and 10d is a data memory that stores the latest two vehicle position data and the latest one average speed data.

The reference numeral 10e designates a secondary correction unit for outputting the corrected vehicle position data by correcting the vehicle position data input from the primary correction unit on the road by map matching using a projection method or a pattern matching method using map data. A map drawing unit that draws a map image around the vehicle position using the map data based on the corrected vehicle position data input from the secondary correction unit, a video RAM that stores the map image drawn by the map drawing unit, and 10h A vehicle position mark generation unit 10i that generates a vehicle position mark in a direction corresponding to the vehicle traveling direction based on the vehicle direction data detected by the GPS receiver reads a map image from the video RAM and combines the vehicle position mark in the center. Synthesizer, 10
Reference numeral j is a conversion unit that converts the image in which the vehicle position mark is combined by the combining unit into a video signal of a predetermined system and outputs the video signal to the display device.

FIG. 2 is an explanatory view for explaining a vehicle position correcting method by the primary correcting section 10b. As shown in FIG. 2 (1), when the vehicle is traveling on the road RD, the vehicle position detected by the GPS receiver 3 at 1 second intervals by satellite navigation is A.
~ It's supposed to be like G. Although the vehicle position was correctly detected by satellite navigation except points D, it is assumed that the point D was largely deviated from the actual vehicle position due to erroneous detection due to the reflection of buildings and the like. When the moving amount is expressed in units of m and the speed is expressed in units of m / s, the moving amount P _{A, B} from point A to point _B is the average speed V _{A, B} between points _{A and B.} This is calculated from the coordinates of points A and B. Further, the moving amount P _{B, C} from the B point to the C point is the average speed V _{B, C} between the B point and the C point, which is also calculated from the coordinates of the B point and the C point.
The same applies to the other two points.

Here, when the previous average speed is V _{i-1, i} from the running performance (motion characteristics) of the vehicle, the current average speed V _{i, i + 1} is compared with V _{i-1, i.} It should be within a certain range. Therefore, by accelerating or abruptly decelerating the vehicle from various speeds, it is possible to experimentally take the current average speed V _{i, i + 1} with respect to various values of the previous average speed V _{i-1, i.} You can set the value. FIG. 2 (2) shows V of various values.
Allowable range of V _{i, i + 1} for _{i-1, i} (hatched part)
Is a motion characteristic diagram determined with a slight margin, and data of the upper boundary line P and the lower boundary line Q is stored in the determination reference memory 10c. For example, the time t _n-1 from every second of the time the t _n, as t n _{+ 1,} time t _n-1 and t _n-1 results the vehicle position is detected successfully, the time t _n-1 from t after the previous average speed up to _n becomes v _n, the average velocity v _{n + 1} of the current if the time t _{n + 1,} even the vehicle position detected correctly from the time t _n to t _{n + 1} is the acceptable range If the vehicle position is abnormally detected at time t _{n + 1} , the average speed v _{n + 1} ′ of this time is out of the allowable range (FIG. 2).
(2) See N and N ').

When a vehicle position (i + 1) point is detected by satellite navigation at a certain time, the primary correction unit 10b refers to the judgment reference memory 10c and compares the previous average speed V _{i-1, i with the} current average. By checking whether the speed V _{i, i + 1} is within the allowable range of FIG. 2 (2), it is determined whether the (i + 1) point is normal or abnormal, and if normal, the current vehicle position (i + 1) point is valid. The data is output to the secondary correction unit 10e. For example, when the point C in FIG. 2 (1) is detected, if the current average speed V _BC is within the allowable range with respect to the previous average speed V _AB , the point C is directly output as the current vehicle position data. . However, when the point D is detected, the current average speed V _CD is outside the allowable range with respect to the previous average speed V _BC , so the point D is invalid data. In this case, the point d estimated that the vehicle has traveled in the direction of extension of _BC at the previous average speed V _BC is output as the vehicle position data in place of the point D.

When the next E point is detected, V _BC is used as the previous average speed V _Cd , and if the current average speed V _dE is within the allowable range with respect to the average speed V _Cd , the E point is left as it is. Output as current vehicle position data. Even when the F point is detected, if the current average speed V _EF is within the allowable range with respect to the previous average speed V _dE , the F point is directly output as the current vehicle position data. The same applies to point G. Although the previous average speed and the current average speed are obtained from the vehicle position data here, the vehicle speed data detected by satellite navigation may be used as it is.

FIG. 3 is a flowchart showing the operation of the navigation controller 10, which will be described below with reference to this figure. When the power of the set is turned on, the GPS receiver 3 detects the vehicle position, the vehicle speed, and the vehicle azimuth at intervals of 1 second by satellite navigation, and outputs them to the navigation controller 10. The vehicle position detected by the GPS receiver 3 is assumed to change as A, B, C, D, E, F, G, ... In FIG. The navigation controller 10 inputs the first vehicle position data and the vehicle azimuth data (step 101 in FIG. 3), the primary correction unit 10b stores the vehicle position data in the data memory 10d, and then the secondary correction unit 10b.
It is directly output to e (step 102) and the secondary correction unit 1
0e is also output as the corrected vehicle position data as it is.

The map drawing unit 12f reads the map data around the vehicle position from the CD-ROM 1 with reference to the map leaf management information and stores it in the buffer memory 10a, and then uses the map data to center the vehicle position 1 A map image for the screen is drawn on the video RAM 10g with the north facing upward (step 103). On the other hand, the vehicle position mark generator 10
h generates a vehicle position mark oriented in the vehicle azimuth direction based on the vehicle azimuth data input first (step 10).
4). Then, the synthesizing unit 10i reads the map image from the video RAM 10g, synthesizes the vehicle position mark in the center, and then the transforming unit 10j transforms it into a predetermined video signal and outputs it to the display device 4 for screen display (step 10).
5). As a result, the map image centering on the point A is displayed on the screen together with the vehicle position mark at the point A.

Then, in step 106, the second vehicle position data (point B) detected by the GPS receiver 3 and the vehicle azimuth data are input, and the primary correction section 10b stores the previous data stored in the data memory 10d. Vehicle position data (point A)
Using and, the average speed V _{A, B} moving from A to _B is calculated (step 107). Subsequently, it is checked whether or not the previous average speed data has been stored in the data memory 10d (step 108), and since the initial result is NO, after storing the current vehicle position data (B) and the average speed V _{A, B} in the data memory 10d. (Step 109), the current vehicle position data (point B) is directly output to the secondary correction unit 10e. The secondary correction unit 10e uses the map data stored in the buffer memory 10a to correct the vehicle position data input from the primary correction unit 10b on the road by map matching, and outputs the corrected vehicle position data to the map drawing unit 10f. (Step 110).

The map drawing unit 12f reads new map data from the CD-ROM 1 as necessary, and the buffer memory 1
0a, and a map image for one screen centered on the vehicle position is redrawn in the video RAM 10g using the map data (step 103). Also, the vehicle position mark generation unit 1
0h generates a vehicle position mark oriented in the vehicle azimuth direction based on the second vehicle azimuth data input (step 104). The map image and the vehicle position mark are combined by the combining unit 10i and then displayed on the screen. As a result, the map image is displayed on the screen together with the vehicle position mark on the road RD.

After that, the routine proceeds to step 106, where the third vehicle position data (point C) detected by the GPS receiver 3 and the vehicle azimuth data are input, and the primary correction section 10b stores the previous vehicle data stored in the data memory 10d. Vehicle position data (point B)
Using and, the average speed V _{B, C} of moving from B to _C is calculated (step 107). Then, the data memory 10d
It is checked whether or not the previous average speed data has been stored (step 108), and this time since it is YES, the judgment reference memory 1
With reference to the determination reference data stored in 0c, the previous average speed V _{i-1, i} = V _{A, B} , but the current average speed V _{i, i + 1} =
It is determined whether V _{B, C} is within the permissible range as seen from the motion characteristics of the vehicle (step 111). Here, if it is within the allowable range, the primary correction unit 10b determines that the current vehicle position data (C
The point) and the average speed V _{B, C} are stored in the data memory 10d (step 109), and the current vehicle position data (point C) is directly output to the secondary correction unit 10e. Secondary correction unit 10
e uses the map data stored in the buffer memory 10a to correct the vehicle position data input from the primary correction unit 10b on the road by map matching, and outputs the corrected vehicle position data to the map drawing unit 10f (step 11).
0).

The map drawing unit 12f reads new map data from the CD-ROM 1 as necessary, and the buffer memory 1
0a, and a map image for one screen centered on the vehicle position is redrawn in the video RAM 10g using the map data (step 103). Also, the vehicle position mark generation unit 1
0h generates a vehicle position mark oriented in the vehicle azimuth direction based on the vehicle azimuth data input third (step 104). The map image and the vehicle position mark are combined by the combining unit 10i and then displayed on the screen. As a result, the map image is displayed on the screen together with the vehicle position mark on the road in the image.

Then, the process proceeds to step 103 again, and the GP
The fourth vehicle position data (D
Point) and the vehicle heading data, and the primary correction unit 10b uses the previous vehicle position data (point C) stored in the data memory 10d to move from C to D.
_{C and D} are calculated (step 107). Subsequently, it is checked whether or not the previous average speed data has been stored in the data memory 10d (step 108), and since it is YES, the determination reference data stored in the determination reference memory 10c is referred to and the previous average speed V _{i-1, i} = V _{B, C} for this average speed V
_It is determined whether _{i, i + 1} = V _{C, D} is within the allowable range as seen from the motion characteristics of the vehicle (step 111). Here, at the point D, a large detection error occurs due to an obstacle such as a building, and if it exceeds the allowable range, the current vehicle position data (D) is treated as invalid.

That is, in the direction from the previous vehicle position B stored in the data memory 10d to the previous vehicle position C,
The estimated vehicle position d is obtained by calculating the position advanced from _C at the previous average speed V _{B, C} for 1 second. Further, the estimated average speed V _{C, d} required to move from C to d is calculated (step 112). Then, the estimated vehicle position data (d) calculated this time and the estimated average speed V _{C, d} are stored in the data memory 10d (step 113), and this time is calculated instead of the vehicle position data (D) detected by satellite navigation. The estimated vehicle position data (d) is output to the secondary correction unit 10e. The secondary correction unit 10e uses the map data stored in the buffer memory 10a to correct the estimated vehicle position d input from the primary correction unit 10b on the road by map matching, and outputs the corrected vehicle position data to the map drawing unit 10f. Output (step 114). Since the estimated vehicle position d is almost the actual vehicle position, it can be surely corrected on the road currently running by performing map matching.

The map drawing unit 12f reads new map data from the CD-ROM 1 as necessary, and the buffer memory 1
0a, and a map image for one screen centered on the vehicle position is redrawn in the video RAM 10g using the map data (step 103). Also, the vehicle position mark generation unit 1
0h generates a vehicle position mark oriented in the vehicle azimuth direction based on the vehicle azimuth data input fourth (step 104). The map image and the vehicle position mark are combined by the combining unit 10i and then displayed on the screen. As a result, the vehicle position mark is displayed on the screen at almost the actual vehicle position on the map image.

Next, in step 106, the fifth vehicle position data (point E) detected by the GPS receiver 3 and the vehicle heading data are input, and the primary correction unit 10b stores the previous data stored in the data memory 10d. The average speed V _{d, E} of moving from d to _E is calculated using the vehicle position data (point d) of (step 107). Subsequently, it is checked whether or not the previous average speed data has been stored in the data memory 10d (step 108), and since it is YES, the determination reference data stored in the determination reference memory 10c is referred to and the previous average speed V
_{For i-1, i} = V _{c, d} , the average speed V _{i, i + 1} = V _{d, E this time}
It is determined whether is within the allowable range as seen from the motion characteristics of the vehicle (step 111). Here, if a particularly large detection error does not occur at the point E and it is within the allowable range, the current vehicle position data (E) is valid.

That is, the current vehicle position data (E) and the average speed V _{d, E} are stored in the data memory 10d (step 109), and the current vehicle position data (E) is directly output to the secondary correction section 10e. . The secondary correction unit 10e corrects the road by map matching and outputs it as corrected vehicle position data (step 110). Then, the map drawing unit 12f redraws a one-screen map image centering on the vehicle position in the video RAM 10g (step 103), and the vehicle position mark generating unit 10h determines the vehicle direction data input fourth. A vehicle position mark oriented in the vehicle azimuth direction is generated (step 104). As a result, the map image is displayed on the screen together with the vehicle position mark on the road RD.

In the same manner, the primary correction section 10b similarly determines, with respect to the vehicle positions F, G, ... Detected by satellite navigation, that the current average speed is within the allowable range when viewed from the previous average speed. The vehicle position data detected this time is output as it is to the secondary correction unit 10e, but if the current average speed is outside the allowable range from the previous average speed, the vehicle position data detected this time is invalid. By calculating the vehicle position estimated from the movement of the vehicle up to the previous time and outputting the estimated vehicle position data to the secondary correction unit 10e, the map matching is performed based on the data close to the actual vehicle position, and the occurrence of matching error is minimized. Let

In the above-described embodiment, each time the vehicle position is detected by satellite navigation, the average speed per second of this time is calculated from the motion characteristics of the vehicle with respect to the previous average speed per second. The possible range is set as shown in Fig. 2 (2) and the validity / invalidity of the vehicle position data detected by satellite navigation this time is determined, but the maximum speed of the vehicle is limited,
Since the maximum moving distance L _MAX per second is also limited, the moving distance L from the vehicle position detected by the previous satellite navigation to the vehicle position detected by the current satellite navigation is calculated,
By determining whether the L is less than or equal to L _MAX (or L _MAX + L _C , where L _C is a positive constant value), it is possible to determine whether the vehicle position data detected by satellite navigation this time is valid or invalid. Alternatively, due to the motion characteristics of the vehicle, the maximum acceleration magnitude α
_{Since MAX} is limited, calculate the magnitude α of the average acceleration this time from the average speed per second this time and the average speed per second last time (at this time, vector calculation considering the vehicle direction) Or a simple scalar calculation assuming that the vehicle is traveling on a straight line), where α is α
_MAX (or α _MAX + α _C , where α _C is a positive constant value)
It may be possible to determine whether the vehicle position data detected by the satellite navigation this time is valid or invalid by determining the following.

Further, in the above-mentioned embodiment, the in-vehicle navigation device has been taken as an example, but it may be applied to a moving body other than a vehicle such as a navigation system for navigation, or the speed of the moving body may be changed instead of the position of the moving body. The same can be applied to the case of detecting other types of motions such as.

[0030]

As described above, according to the present invention, the motion of the moving body is periodically detected by the satellite navigation, and is detected by the satellite navigation this time based on the motion information detected so far by the satellite navigation and the motion characteristics of the moving body. If it is determined that the motion information is normal or abnormal, the motion information detected by the satellite navigation this time is valid when it is judged as normal, and the motion information detected by the satellite navigation this time is invalid when judged as abnormal, and it is detected in the past. Since it is configured to obtain the motion information of this time by inferring it from the motion information, it is possible to obtain almost accurate motion information even if incorrect motion information is detected due to the failure to receive satellite radio waves normally. , It is possible to provide the user with highly accurate exercise information.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device embodying a motion detection method of a mobile body by satellite navigation according to the present invention.

FIG. 2 is an explanatory diagram of a method for determining normality / abnormality of a detected vehicle position in satellite navigation.

FIG. 3 is a flowchart showing the operation of the navigation controller.

FIG. 4 is an explanatory diagram illustrating a problem of satellite navigation.

[Explanation of symbols]

 1 CD-ROM 3 GPS receiver 4 Display device 10 Navigation controller 10b Primary correction part 10e Secondary correction part 10f Map drawing part 10g Video RAM 10h Vehicle position mark generating part 10i Compositing part

Claims (1)

[Claims] 1. A motion detection method for periodically detecting the motion of a moving body by satellite navigation, wherein the motion information detected by satellite navigation this time is calculated from the motion information detected so far by satellite navigation and the motion characteristics of the moving body. Whether it is normal or abnormal, if it is normal, the motion information detected by the satellite navigation this time is valid, and if it is abnormal, the motion information detected this time by satellite navigation is invalid, and the motion information detected in the past A method of detecting the motion of a moving body by satellite navigation, which is characterized by guessing the motion information of this time.