JPS63115300A - Current position estimating apparatus - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a current position estimation device that can accurately estimate the current position of a vehicle, which changes from moment to moment as the vehicle travels. Regarding.

(Prior Art) Conventionally, many devices have been proposed that assist the occupant in driving by making the occupant aware of the driving route of the vehicle and driving the vehicle along the desired route without making a mistake.

Particularly on expressways, if you make a mistake at the wrong refueling location or interchange, you will be unable to turn back, resulting in a huge waste of time. Therefore, based on data on the expressway that is the driving route, data on the start of high-speed driving, and data on the distance to the destination, when the vehicle travels close to the destination, the driver is notified that the destination is near, and the driver is notified that the vehicle has traveled too far. Devices that call attention to avoid this are widely known (JP-A-56-42899, JP-A-58-132899, etc.)
.

(Problems to be Solved by the Invention) However, even with the above-mentioned device, it is still not sufficient and has the following problems.

The above device essentially calculates the distance from the point where the vehicle starts high-speed driving (starting point) to the destination (end point) from expressway data (map), and combines this calculated value with the starting point. This system notifies you that the end point is approaching based on the difference between the distance traveled by the vehicle and the distance traveled by the vehicle. In other words, the current position of the vehicle is simply detected from the vehicle's starting point and travel distance, and notification is made based on the difference between that position and the ending point.

However, the odometer installed in a vehicle is not very accurate, and its errors accumulate over long distances and cannot be ignored, resulting in a large error being included in the calculated value of the current position. In addition, if the vehicle travels on a route other than the expected route, such as when entering a supply station or service area, the current position of the vehicle is There was a large error between the detection results.

The present invention has been made to solve the above problems,
It is an object of the present invention to provide a current position estimating device that can always accurately estimate the current position of a vehicle, regardless of the accuracy of the vehicle's odometer or the approach of a supply station, service area, etc.

Five plates! (Means for solving the problem) The means constructed by the present invention to solve the above problem is as shown in the basic configuration diagram of FIG. 1, which displays the current position installed along the road. A guide sign recognition means C1 for recognizing a guide sign; a movement amount detecting means C2 for detecting the amount of travel of the vehicle; a travel route storage means C3 for storing a map of the route on which the vehicle is traveling; and the guide sign recognition means. When C1 recognizes the guide sign, the current position of the vehicle is confirmed on the travel route map stored in the travel route storage means C3, and the travel route is determined based on the detection result of the movement amount detection means C2 after the command. The gist of the present invention is a current position estimating device comprising: current position estimating means C4 for estimating the current position of the vehicle on a map;

(Function) The guide sign recognition means C1 in the present invention is for recognizing guide signs installed along the road that display the current position. There are various types of guide signs that display the current location, such as those that display the boundaries of administrative divisions such as cities and prefectures, and the distance to each interchange near the expressway, and any one of them may be used. Note that various currently available image processing and pattern recognition techniques are used to recognize the signs.

The movement amount detection means C2 detects the amount of travel of the vehicle. Vehicles are usually equipped with an odometer, so the amount of travel can be calculated using the measured value, or the amount of travel can be calculated as an integral value of the speedometer, or even the average of multiple calculated values can be used. Either is fine.

The traveling route storage means C3 is for storing a traveling route map along which the vehicle travels. This is the basis for determining where on the road the vehicle is currently located.

The current position estimating means C4 estimates the current position as follows by utilizing the effects of each of the above-mentioned means. First, when the guide sign recognition means C1 recognizes a sign, the traveling route storage means C3
Check the current location on the route map stored by the driver. In other words, it is checked to see which position on the road the current position indicated by the sign corresponds to. After this confirmation, the current position is estimated by determining how far the vehicle has moved on the road based on the detection result of the movement amount detecting means C2. Therefore, the current position of the vehicle is confirmed with the actual position at the point where a traffic sign is recognized, and the current position is confirmed during the period until the next traffic sign is recognized and the current position is reconfirmed. The current position is estimated based on the amount of movement of the vehicle.

EXAMPLES Hereinafter, in order to explain the present invention more specifically, the present invention will be described in detail by giving examples.

(Embodiment) FIG. 2 is a block diagram showing the overall configuration of an expressway position information providing device incorporating a current position estimating device as an embodiment. When installed in a vehicle, this device estimates the current position of the vehicle using the current position estimating device as an embodiment,
When the current position is near the destination, a notification to that effect is given by synthesized voice or display on the CRT.

As shown in the figure, this device is composed of a logic operation circuit centered on an electronic control circuit 10 centered on a microcomputer, and as is well known, a CPU 1 that executes logic operations.
2. It is equipped with a ROM 14 that stores a control program to be described later, a RAM 16 that temporarily stores information, and an input/output board 18 that is an interface with external equipment. Devices connected to the input/output port 18 include an odometer 20 that detects the distance traveled by a vehicle equipped with this device;
A card reader 24 decodes the code attached to the interchange at the entrance point from the toll sign 22 handed out at the gate of each interchange on the expressway, and a voice or key operation selects the desired interchange or branch point as the destination point. A destination input device 26 is provided for inputting information to the electronic control circuit 10 .

Also, a voice synthesizer 30 that drives the speaker 28 serves as an output means for making the above-mentioned notification. A CRT controller 34 for controlling the CRT 32 is provided. The database 36 is a magnetic disk, magnetic tape, or IC.
The electronic control circuit 10 is a storage device with a large capacity such as a card.
used as an external storage device. The memory contents include the positional relationship and distance between each interchange on the expressway,
This is so-called map information such as locations of branch points, etc., and is connected to the electronic control circuit 10 via an interface 38 to enable exchange of such information. Furthermore,
Connected to the electronic control circuit 10 is an image recognition device 50 that processes color images from a color television camera (hereinafter referred to as color TVC) 40 as described below, identifies and recognizes guide signs, and monitors landscapes that change as the vehicle travels. This makes it possible to import data in real time.

3 and 4 are explanatory diagrams showing the configurations of the color TVC 40 and image recognition device 50 in more detail. As shown in the figure, the color TVC 40 is placed on the front left side of the vehicle, and constantly photographs the scenery in front of the left. The color video captured by this color TVC 40 is a general composite video signal, and is first converted into three primary color signals of the RGB system by the decoder 52 of the image recognition device 50. These three primary color signals are then input to an analog-to-digital converter (hereinafter referred to as an A/D converter) 54 for converting them into digital signals suitable for subsequent digital image processing, and are independently converted into digital signals. The three RGB signals thus digitized are each input to the color processing circuit 56, and only the R signal is input to the image memory 58. The color processing circuit 56 is used for guiding signs GM installed on expressways as illustrated in FIG.
is detected based on its color characteristics. As shown in the figure, the guide sign GM is displayed with a place name and distance to the current point in white letters on a strong green (or blue) background. Therefore, the color processing circuit 56 uses the following formula (
1) Extract the region of the video signal that satisfies (2>), and accurately detect only the guide sign GM from among the miscellaneous video signals.

3G>4R...(1) G>8...(2) The position detection circuit 60 uses the above processing to increase the area where the guide sign GM is present by a certain value or more with respect to the entire video signal) When detected, its position in the video signal is determined and output to the image memory 58. In this way, the image memory 58 is given the RGR video signal and the position information of the guide sign GM occupied therein, and stores the RGB video signal at the location according to this position information. The binarization circuit 62 further converts the signal stored in the image memory 58 into a binarized signal based on brightness and processes it so that the character information depicted on the guide sign GM can be easily determined. It is output to the recognition section 64 at the next stage. A reference memory 66 is connected to the recognition unit 64, in which basic data necessary for analyzing character information such as place names and numbers is prepared in advance. Therefore, by comparing the binarized information transmitted as described above with the information stored in the reference memory, the recognition unit 64 detects the guide sign G.
It becomes possible to recognize the character drawn on M, and the recognition result is sent to the electronic control circuit 10.

The position information providing device configured as described above has a ROM14
The information from each of the external devices described above is processed according to a control program stored in advance in the controller, and when a predetermined condition is satisfied, a notification is issued to the occupant. Figure 6 shows the ROM14 above.
2 is a flowchart of a control program stored in the .

Next, the operation of the location information providing device will be explained along the processing steps of this flowchart.

This program starts processing when the main power source of the vehicle is turned on. First, it is determined whether or not a toll sign is inserted into the card reader 24 (step 100). If it is inserted, the code of the toll sign is Decipher the vehicle's travel reference point (current position) and memorize it (step 110).
, proceed to the next step 130. If it has not been inserted, it is determined whether or not the base point setting and storage processing as described above have already been completed, and if the setting has been completed, the process proceeds to the next step 130 in the same way as above, and if the setting has not been done yet, the process proceeds to the next step 130. The process returns to step 100 again (step 120).

In step 130, it is determined whether the destination, which is the end point, has been input to the destination input device 26. Then, if the destination is not known, repeat step 100.
Return to step 1 and repeat the same process as above, and when the destination has been input, proceed to the next remaining distance calculation process (step 1).
40) is executed. This is done by using the database 3 to store the distance between the base point of the trip and the destination, which has been clarified through the above processing.
The initial remaining distance is calculated by using the map information stored in the odometer 6, and the initial remaining distance is calculated by calculating the distance traveled from the base point of the trip based on the detection result of the odometer 20. The remaining distance during travel is calculated by subtracting the calculated travel distance from the vehicle. In other words, since the driving base point is known and the distance traveled from that base point is known in real time, the remaining distance to the destination can be determined by roughly estimating the current position of the vehicle while referring to the information in the database. be.

Furthermore, in this embodiment, in order to improve the accuracy of the remaining distance calculation process, the next step of guide sign detection process (step 1) is performed.
50) and position correction processing (step 160) are executed. The guide sign detection process (step 150) is to determine whether or not the guide sign GM has been recognized by the image recognition device 50, and only when it is determined that the guide sign GM has been recognized, the next position correction process is performed. (Step 160) is selectively executed. The position correction process (step 160) is a process for calculating the true remaining distance by correcting the remaining distance value calculated by the remaining distance calculation process (step 140). That is, here, the display content of the guide sign GM recognized by the recognition device 50 is decoded and compared with the map information in the database 36 to detect the current position of the vehicle in real time. Then, the distance between the detected current position and the destination is calculated based on the map information in the database 36, and is used as the true remaining distance value.

As mentioned above, after the current position is corrected and the remaining distance is recalculated depending on whether the guide sign GM is recognized or not, it is determined whether the remaining distance is a value that should be notified to the crew. A determination is made (step 170), and if the distance does not require notification, the process returns to step 140 and calculation of the remaining distance, position correction when the guide sign GM is recognized, etc. are performed again.

On the other hand, when the distance requires notification, for example, when it is determined that the remaining distance is 10 km, 5 km, 2 km, or 500 m, a control signal to that effect is output to the voice synthesizer 30 or CRT controller 34, A notification is given to the occupants using synthetic audio or a display on the CRT 32 (step 180). After these series of processes, step 190 is executed to determine whether there is still a remaining distance, that is, whether the destination has not been reached yet. If so, the process returns to the initial state of step 100.

According to the device of this embodiment configured and operated as described above,
Instead of determining the current position based only on the measurement data of the odometer 20 and calculating the remaining distance, the guide sign GM
When the system recognizes the vehicle while driving, it can accurately determine the current location by comparing it with map information and correct the remaining distance based on that data. Therefore, the current position of the vehicle is indicated by the guide sign G.
Each time M is detected, it becomes a true value, and only the section until the next guide sign GM is detected becomes an estimated value based on the measured value of the odometer 20. Normally, the distance until the next guide sign GM is detected is not that long, and if the distance traveled is around this range, the measured value on the odometer 20 will not deviate greatly from the true distance traveled. Therefore, the current position of the vehicle can always be accurately determined during the entire travel distance of the vehicle.

Furthermore, since the remaining distance to the destination is calculated based on the current position determined in this way, the calculated value is also an accurate value, and no inappropriate notification is given to the occupants.

In addition, in the above embodiment, the remaining distance is targeted as the notification information, but the average traveling speed of the vehicle is detected and the time required to reach the destination is notified assuming that the vehicle continues to travel at this traveling speed. It may also be a configuration.

Effects of the Invention As described above in detail with reference to embodiments, the current position estimating device of the present invention accurately determines the current position every time a guide sign is recognized, and also calculates the current position in a short period when adjacent guide signs are recognized. The current position of the vehicle can be estimated based on the amount of travel of the vehicle. Therefore, problems in which the estimated current position differs significantly from the true current position due to measurement errors occurring in calculating the distance traveled by the vehicle or due to driving other than driving toward a destination such as entering a service area or the like are eliminated. Moreover, since the true current position can always be detected in real time based on the guide sign, the current position of the vehicle can be accurately determined at the time of first recognizing the guide sign without having to separately input the travel starting point.

[Brief explanation of the drawing]

FIG. 1 is a configuration block diagram illustrating the basic configuration of the present invention, FIG. 2 is a configuration block diagram of a location information providing device using the current location estimating device of the embodiment, and FIGS. 3 and 4 are the same implementations. FIG. 5 is an explanatory diagram showing a detailed configuration of the image recognition device used in the example, FIG. 5 is an explanatory diagram showing an example of display of a guide sign, and FIG. 6 is a flowchart of the control program of the same embodiment. C1...Guidance sign recognition means C2...Movement amount detection means C3...Traveling route storage means C4...Current position estimation means 10...Electronic control circuit 20...Odometer 36... Database 50...image recognition device

Claims (1)

[Scope of Claims] Guide sign recognition means for recognizing a guide sign installed along a road to display the current position; movement amount detection means for detecting the travel distance of a vehicle; and a travel path on which the vehicle travels. a driving route storage means for storing a map; and when the guide sign recognition means recognizes the guide sign, confirming the current position of the vehicle on the driving route map stored in the driving path storage means, and determining the movement of the vehicle after the confirmation. A current position estimating device comprising: current position estimating means for estimating the current position of the vehicle on the traveling route map based on the detection result of the amount detecting means.