JP2553163Y2 - In-vehicle combined navigation system - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention relates to an in-vehicle combined navigation device that hierarchically and combinedly uses three types of navigation.

[Prior Art] Navigation that estimates the current position by relying only on internal information without using external position information is called self-contained navigation or inertial navigation, etc., and the on-board self-contained navigation device shown in FIG. 1 is
The present position of the vehicle is estimated from the travel history determined by the arithmetic unit 4 using the direction sensor 2 and the vehicle speed sensor 3 and displayed on a road map on the display device 5 in the vehicle compartment. However, when the measurement errors of the sensors accumulate, the in-vehicle self-contained navigation device 1 also needs to correct the traveling history. For example, the traveling history is compared with a route pattern on a road map at an intersection or an inflection point of a road. There are also a number of devices that use a so-called map matching method to correct the current location that is considered correct.

However, since the in-vehicle self-contained navigation device 1 using the above-described map matching method cannot completely prevent the estimation error due to the accumulation of the measurement error, it is necessary to introduce a system for more accurately specifying the current position by external position information. Are being considered. As a system for providing external information, the United States Department of Defense is developing a GPS (Global Positioning System)
Or the road-to-vehicle information system under development by the Ministry of Construction as a “public-private solidarity joint research”, or AMTICS (Advanced Mob) under joint development by the National Police Agency, the Ministry of Posts and Telecommunications, and vehicle / electronic device manufacturers.
ile Traffic Information & CommunicationSystems)
Etc. are listed as candidates.

The GPS is a radio navigation system that performs two-dimensional (latitude, longitude) positioning using three satellites for one position measurement. The on-vehicle navigation device 6 shown in FIG. 4 has a synchronized clock. The ranging signals sent from the three satellites 7, 8, and 9 are received by the receiver 10, and each of the satellites 7,
Based on the distance from 8,9, the positioning device 11 specifies the receiving point (current position of the vehicle) as the intersection of three spherical surfaces centering on the satellites 7,8,9 and displays it on the display device 12. Configuration. However, this kind of on-vehicle navigation device 6 has satellites 7, 8,
Depending on the state of the ionosphere through which the radio wave from 9 passes, the arrival time to the receiving point may be slightly disturbed, or in a valley of a building with many shields, the positioning accuracy may be degraded by the effect of ghost, Another problem is that positioning is practically impossible in places where radio waves do not reach, such as in a tunnel.

On the other hand, the absolute position information transmission means installed on the ground, such as the road-vehicle information system using the absolute position information emitted by the position beacon and sign post and AMTICS, not only provide the absolute position information, but also the traffic congestion information, etc. There is also a plan to use it as a traffic information transmission base, and the integration of both systems is considered to be a matter of time. The on-vehicle navigation device 13 shown in FIG. 5 receives a ground wave transmitted from the absolute position information transmitting means 14 by a receiving antenna 15 mounted on a vehicle, and a verification device 16 Matching is performed using a built-in matching map, and the specified current location is displayed on the display device 17.

[Problem to be Solved by the Invention] The above-mentioned conventional on-vehicle navigation device 13 is configured to use absolute position information transmitting means 14 such as a position beacon or a sign post installed on the ground to specify a passing point. There is no problem when traveling in an urban area where such transmitting means 14 are installed at appropriate intersections and inflection points, but in counties and towns and villages where the absolute number of transmitting means 14 installed is small, the absolute Location information may not be available,
At present, there has been a problem that accuracy cannot be guaranteed nationwide.

[Means for Solving the Problems] The present invention solves the above-mentioned problems, and receives the absolute position information generated by the absolute position information transmitting means installed on the ground, and specifies the passing point of the vehicle. An apparatus, a sub-navigation device that receives radio waves from a plurality of satellites and locates the current position of the vehicle, a self-contained navigation device that estimates the current position of the vehicle according to a traveling history calculated from an azimuth and a traveling distance, and the main navigation An error vector connecting the expected road location on the road and the estimated current location by the sub-navigation device each time the vehicle travels a certain distance from the time when the vehicle passed the current location on the road specified by the device, and the expected road point on the road and the self-contained navigation device The error vector connecting the estimated current position is calculated, the arithmetic mean of both error vectors totaled over a certain period is calculated, and the arithmetic average value of the error vector is calculated. Is provided with a control device for selecting a current position estimated by the navigation device having the smaller value.

[Operation] The present invention is based on a main navigation system that specifies a passing point of a vehicle from absolute position information, a sub navigation system that measures the current position of the vehicle from radio waves from a plurality of satellites, and a current position of the vehicle according to the traveling history. The self-contained navigation device to be estimated is selectively used in combination with the one with the smaller error, and the overall navigation accuracy is improved through the hierarchical use of three types of navigation devices.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram showing an embodiment of the in-vehicle combined navigation device of the present invention, and FIG. 2 is a traveling locus diagram for explaining a control operation of the control device shown in FIG.

In FIG. 1, an on-board composite navigation device 21 is based on a main navigation device 22 that specifies a passing point of a vehicle from absolute position information, and a secondary navigation device 23 that measures the current position of the vehicle from radio waves from a plurality of satellites. In addition, the self-contained navigation device 24 for estimating the current position of the vehicle according to the travel history is configured to selectively use the one with the smaller error. Display device 25 consists of three navigation devices
22, 23 and 24 are connected to a control device 26 for controlling in a hierarchical manner.

The selection between the satellite navigation and the self-contained navigation by the control device 26 is made by comparing the magnitudes of the estimation errors by the two navigations. That is, the estimated errors of the satellite navigation and the self-contained navigation are totaled for a certain period of time as error vectors Gm, Sn indicating a deviation between the actual road on the road map and the respective estimated current locations, and the totaled error vectors Gm, Sn Arithmetic mean (の | Gm |) / m or (Σ |
Sn |) / n is a guide for navigation selection. Where m, n
Represents the estimated number of times within a certain period in each navigation.

In the case of the present embodiment, when the current position is specified by the main navigation device 22 and it is clear that the vehicle has passed the point P shown in FIG. The selective use of the navigation is started, and as the vehicle travels a certain distance, the current position estimated by the two navigations is written on the road map. In FIG. 2, the current position estimated by the satellite navigation is written as x, and the current position estimated by the self-contained navigation is written as Δ, and the error vector Gm indicating the deviation between the written position and the expected passage point on the road, respectively. Sn is counted for a certain period. However, in this case, when there are a plurality of roads extending from the latest road current location P that has already been specified as the starting point, the planned on-road passing point is not necessarily on the same road in both navigations, and is obtained by each navigation. The error vectors Gm, Sn are determined based on the road closest to the estimated current position.

Next, the arithmetic mean of the error vector obtained by satellite navigation and the error vector obtained by self-contained navigation (一定 | G
m |) / m and (Σ | Sn |) / n. Then, the arithmetic mean values are compared in magnitude, and the current position estimated by the navigation device having the smaller arithmetic mean value is selected. This process is performed after the vehicle passes through the point P and then passes through a point Q at which the current position of the vehicle is specified by the absolute position information. This allows
The current position is estimated by the navigation with higher reliability at regular intervals.

As described above, the in-vehicle combined navigation device 21 is based on the main navigation device 22 that specifies the passing point of the vehicle from the absolute position information,
A configuration in which a sub-navigation device 23 for positioning the current position of a vehicle from radio waves from a plurality of satellites 7, 8, and 9 and a self-contained navigation device 24 for estimating the current position of a vehicle in accordance with a running history are selectively used in combination with a smaller error. Therefore, comprehensive navigation accuracy can be improved through the hierarchical use of the three types of navigation devices 22, 23, and 24. For example, the absolute position information transmitting means 14 installed on the ground
When traveling in an urban area where absolute position information is continuously obtained, the navigation system 22 can provide the most accurate navigation guidance by itself, and in areas where absolute position information can only be obtained sporadically. , As if filling the hole in the main navigation system 22,
By selectively using either the side navigation device 23 or the self-contained navigation device 24, it is possible to continuously identify or estimate the current position of the vehicle, thereby enabling the vehicle to follow the optimal navigation suited to geographical conditions. You can be guided to your destination.

In addition, even if the current position estimated by satellite navigation and self-contained navigation is on a completely different road, the estimation accuracy is compared using the arithmetic mean of the error vectors Gm and Sn. The inconvenience that the history jumps on two roads is hardly possible.

Furthermore, by adding whether or not the current position estimated by the self-contained navigation device 24 is within a certain range centered on the current position estimated by the sub-navigation device 23 to the selection criterion of the above two navigations, the satellite navigation and the self-contained navigation can be mutually performed. It is also possible to increase the navigation accuracy in a way that complements the above.

[Effects of the Invention] As described above, this invention is based on a main navigation device that specifies absolute position information, a sub navigation device that positions the current position based on satellite radio waves, and a self-sustaining device that estimates the current position of a vehicle according to the traveling history. An error vector connecting a predicted roadway passing point predicted every time a certain distance is traveled and a current position estimated by the sub-navigation device from the time when the navigation device is used hierarchically and passing the current position on the road specified by the main navigation device. And each of the error vector connecting the expected passage point on the road and the current position estimated by the self-contained navigation device, respectively, taking the arithmetic mean of both error vectors aggregated over a certain period,
Since the arithmetic current value of the error vector is configured to select the estimated current position by the navigation device with the smaller one, the overall navigation accuracy can be improved through the hierarchical use of the three navigation devices. When traveling in an urban area where the absolute position information generated by the absolute position information transmission means installed on the ground is continuously obtained, the navigation system with the highest accuracy is possible with the main navigation device alone, and the absolute position information is In areas that can only be obtained sporadically, it is possible to continuously identify or estimate the current location of the vehicle by selectively using either the secondary navigation system or the self-contained navigation system, as if filling the hole in the main navigation system. The vehicle can be guided to the destination according to the optimal navigation according to the geographical conditions.

In addition, the sub navigation device and the self-contained navigation device obtain an error vector connecting the estimated current position on the road and the estimated current position each time the vehicle travels a certain distance from the time when the vehicle passes the current position on the road specified by the main navigation device, and The arithmetic mean of the error vectors collected over the period is calculated, and the navigation device with the smaller arithmetic mean value is selected. Using the latest current road location and the road extending from the current road location, it is possible to reasonably perform the current position estimation with less error while the navigation by the main navigation device is not effective. To play.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the in-vehicle combined navigation device of the present invention, FIG. 2 is a traveling locus diagram for explaining the control operation of the control device shown in FIG. 1, and FIG. Figures to Fifth
FIG. 1 is a schematic configuration diagram illustrating various conventional on-vehicle navigation devices. 2 azimuth sensor 3… vehicle speed sensor 4… arithmetic unit 7,8,9… satellite 11… positioning device 14… absolute position information transmitting means 16… verification device 21… in-vehicle combined navigation device 22 … Main navigation device 23… Sub navigation device 24… Self-contained navigation device 26 …… Control device

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Claims (1)

(57) [Scope of request for utility model registration] 1. A main navigation device for receiving absolute position information from an absolute position information transmitting means installed on the ground, specifying a passing point of a vehicle, and receiving radio waves from a plurality of satellites to determine a current position of the vehicle. A secondary navigation device for positioning, a self-contained navigation device for estimating the current position of the vehicle according to a traveling history calculated from the bearing and the traveling distance, and a fixed distance from the time when the vehicle passes the current location on the road specified by the main navigation device. In each case, an error vector connecting the expected road on the road and the estimated current position by the sub-navigation device and an error vector connecting the estimated road on the road and the estimated current position by the self-contained navigation device are obtained,
A control device for taking an arithmetic mean of both error vectors collected over a certain period of time and selecting an estimated current position by a navigation device having a smaller arithmetic mean value of the error vectors. Navigation equipment.