JPH06131594A - Position detector - Google Patents

Abstract

PURPOSE:To easily execute the evaluation and investigation of design for a position detector by judging the normality/abnormality of the detector based upon the positional deviation rate of a moving body and then judging which constitional parts in the detector are abnormal. CONSTITUTION:At the time of detecting that the estimated position of a vehicle is different from its actual position, a user or the like operates a keyboard 8 and resets a current position and a position detecting part calculates a positional deviation rate I based upon corrected vehicle positional coordinates Ki, uncorrected positional coordinates Ki-1 and a traveling distance D from the preceding correction to judge the normality/abnormality of the position detector. At the time of judging the abnormality of the detector, the abnormality rates and matching rates of an earth magnetism sensor 1 and a gyro 3 are calculated in order to judge which constitional parts of the detector are abnormal. These relations are displayed on a display part 5 e.g. to judge which constitional parts are abnormal by the position detector itself. Consequently an abnormal position can be forecasted without individually inspecting each of constitional parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device mounted on a moving body such as a vehicle and used to detect the current position of the moving body. The present invention relates to a position detection device with a diagnostic function.

[0002]

2. Description of the Related Art Conventionally, in order to support the driving of a vehicle on an unfamiliar land, a navigation device for displaying the current position of the vehicle on a display device such as a CRT together with a road map around the vehicle is installed in the vehicle. It is installed and used. A so-called map matching method has been conventionally used to detect the current position of the vehicle in such a navigation device. In this map matching method,
The distance sensor and heading sensor detect the distance traveled and the heading of the vehicle, and the current position of the vehicle is estimated based on this. From the estimated position of the vehicle and a road map memory composed of a CD-ROM, etc. The current position of the vehicle is detected based on the result of comparison with the obtained road network data (JP-A-63-148115, JP-A-63-115004, JP-A-64-53112). (See the official gazette).

By the way, in this system, a slight deviation occurs between the estimated position of the vehicle and the actual position of the vehicle due to the existence of an unavoidable error in the performance of the road network data, the distance sensor or the direction sensor. Sometimes. Such positional deviation is based on an error within the allowable range of the position detecting device, and can be corrected by, for example, a user operating a keyboard or the like according to a manual.

[0004]

However, if some abnormality occurs inside the position detecting device, a position shift based on the abnormality occurs. At this time, too, the positional deviation will be corrected, but this is due to the position detecting device itself.
Even if it is once corrected, the position shift occurs again, and the function as the position detection device deteriorates. Therefore, when an abnormality occurs in the position detecting device, it is necessary to redesign the position detecting device.

However, even if the design of the position detecting device is reexamined, it is necessary to judge which component has an abnormality. If the part with the abnormality is unknown,
Since the distance sensor, the direction sensor, the road network data, etc. must be inspected one by one, much labor and cost are required. Therefore, the purpose of the present invention is to
It is an object of the present invention to provide a position detecting device which can predict an abnormal portion by self-diagnosing a tendency of the position detecting device when an abnormality occurs in the position detecting device and facilitate the review of the design of the position detecting device.

[0006]

A position detecting device of the present invention for achieving the above object is used by being mounted on a moving body, and detects a moving distance and a moving direction of the moving body by a distance sensor and a direction sensor, respectively. Then, the current position of the moving body is estimated, the estimated current position of the moving body is compared with the similarity of the road network data obtained from the road map memory, and the current position of the moving body is calculated based on the comparison result. In the map matching type position detecting device for detecting, a position reset means for resetting the current position of the moving body from the outside when a position shift occurs, and a reset position by the estimated current position of the moving body and the position resetting means. First, it is determined whether the position deviation rate from the current position is outside the allowable range.
If the position deviation rate is outside the predetermined range by the determining means and the first determining means, whether the abnormality occurrence rate of the azimuth sensor is outside the predetermined range. If the positional deviation rate is determined to be outside the predetermined range by the second determining means for determining whether the current position of the vehicle and the road network data match, A third judging means for judging whether or not is outside a predetermined range, and a recording means for recording the results judged by the second and third judging means. To do.

As the above-mentioned direction sensor, a geomagnetic sensor, a gyro, etc. can be considered.

[0008]

According to the above construction, when the position shift occurs, the current position of the moving body is reset by the position resetting means. Next, the first determination means determines whether or not the positional deviation rate between the reset current position and the current position estimated by the distance sensor and the azimuth sensor is outside the allowable range. As a result of this determination, if it is determined that the position deviation rate is outside the allowable range, it can be estimated that some abnormality has occurred in the position detection device. Therefore, next, it is necessary to judge which component of the position detecting device has an abnormality.

As a result of the above judgment, when it is judged that the position deviation rate is out of the allowable range, the second judging means judges whether the abnormality occurrence rate of the azimuth sensor is outside the predetermined range. . As a result, when it is determined that the abnormality occurrence rate of the azimuth sensor is out of the predetermined range, it can be estimated that an abnormality has occurred in the azimuth sensor. On the other hand, when it is determined that the abnormality occurrence rate is not outside the predetermined range, it can be estimated that the azimuth sensor has no abnormality.

Further, as a result of the above judgment, when it is judged that the position deviation rate is out of the allowable range, it is determined whether or not the matching rate between the current position of the vehicle and the road network data is out of a predetermined range. It is judged by the judging means. As a result, when it is determined that the matching rate is out of the predetermined range, it can be estimated that the road network data has an abnormality. On the other hand, if it is determined that the matching rate is not outside the predetermined range, it can be estimated that the road network data is normal.

The second and third judgment results are recorded by the recording means. For this reason, it is possible to predict which component has an abnormality, so that it is possible to easily evaluate and review the design of the position detection device.

[0012]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a basic configuration of a navigation device to which a position detecting device according to an embodiment of the present invention is applied. This navigation device is mounted on a vehicle and is used to determine the estimated position of the vehicle based on the outputs of a geomagnetic sensor 1 for detecting the earth's magnetic field, a vehicle speed sensor 2, and a gyro 3 for detecting the turning angular velocity of the vehicle. The position is calculated by the position detection unit 4, and the calculated estimated position is displayed on a display unit 5 including a CRT, a liquid crystal display element, and the like, together with a road map around the display. That is, the position detection unit 4 reads road network data in the vicinity of the estimated position from the road map memory 6 configured by a CD-ROM or the like via the CD driver 7, and displays the read data and the estimated position on the display unit. 5 is displayed.

A clock 9 is connected to the position detector 4. As will be described later, this clock 9 measures the time from the previous setting of the current position of the vehicle to the present resetting,
It is used when measuring the time from the previous detection of the gyro offset value to the current detection of the offset value. The position detecting section 4 is further provided with a RAM (random access memory) 10 which functions as a work area or the like. In the storage area of the RAM 10, counters C1 and C4 for the geomagnetic sensor and a counter C for the gyro are provided.
2, C5 and matching counters C3, C6 are provided.

A keyboard 8 operated by a user or the like is connected to the display section 5. The keyboard 8 is used by the user to reset the current position of the vehicle when, for example, the initial position of the vehicle is set or a displacement occurs, and the position of the keyboard 8 can be set via the display unit 5. It is for inputting these position information to the detection unit 4. That is, the keyboard 8 functions as a position reset means. With the above-mentioned configuration, the position detection device is
The processing performed to determine the abnormality will be described with reference to FIGS. FIG. 2 is a flowchart for resetting the current position of the vehicle. This behavior is
This is performed when the user or the like finds that the estimated position of the vehicle displayed on the display unit 4 does not match the actual vehicle position, so that the operation is interrupted even if another operation is performed.

First, the user or the like estimates the estimated position of the vehicle and the actual position.
If it finds that the vehicle position does not match, the keyboard
The estimated position is corrected by operating the switch 8 (step S
1). That is, the current position of the vehicle is reset. This and
The corrected vehicle position coordinate K _i， Before it is modified
Position K_i-1, The mileage D since the last modification and
Position information such as time T measured by the clock 9 when
Information is stored in the ring buffer as shown in Table 1 below.
(Step S2).

[0016]

[Table 1]

FIG. 3 is a flow chart showing the operation for obtaining the data necessary for calculating the abnormality rate of the geomagnetic sensor 1. This operation is performed every time the vehicle travels a predetermined distance. The vehicle is the distance ΔL (for example, ΔL = 2m)
When the vehicle travels (step n1), the output signal (x, y) from the geomagnetic sensor 1 is output (step n2). When the output signal (x, y) is output, the geomagnetic counter C4
The count value K4 of 1 is counted (step n3).
Then, the radius of the geomagnetic azimuth circle of the geomagnetic sensor 1 is expanded or reduced based on the output signal (x, y), the predetermined magnetization amount (x ₀ , y ₀ ) of the vehicle body, and the geomagnetic level R ₀ (constant). The rate KS is obtained from the following equation (1) (step n4), and it is determined whether the obtained enlargement / reduction rate KS is outside the range of 0.8 to 1.2 (step n5).

[0018]

[Equation 1]

As a result, if the enlargement / reduction rate KS is out of the above range, the count value K1 of the geomagnetic counter C1 is counted by one (step n6). That is, the scaling factor KS in the normal case is 1, but the scaling factor KS changes greatly due to the influence of disturbance, and if the change becomes too large, the geomagnetic sensor 1 deteriorates in its function as a sensor.
Therefore, if the enlargement / reduction rate KS is outside the above range, which is a range in which the function as a sensor is hardly deteriorated even if the enlargement / reduction rate KS changes, it may be considered that an abnormality has occurred in the geomagnetic sensor 1. That is, the count value K1 serves as an index for determining the abnormality of the geomagnetic sensor 1.

FIG. 4 is a flow chart showing an operation for obtaining data for calculating the matching rate between the current position of the vehicle and the road network data. The following operations
This is performed every time the vehicle travels the distance ΔL. The vehicle is the distance ΔL
When the vehicle travels (step q1), the current position of the vehicle is estimated (step q2). When the current position of the vehicle is estimated, the count value K6 of the matching counter C6 is counted by one (step q3). Then, as a result of estimating the current position of the vehicle and performing pattern matching with the road network data (step q4), when the current position is obtained on the road (step q5), the count value of the matching counter C3 One K3 is counted (step q6). That is, when the current position is obtained on the road, the current position and the road network data may be regarded as accurate. That is, the count value K3 is an index indicating that the road network data is accurate.

FIG. 5 is a flow chart showing the operation for obtaining data for calculating the gyro 3 abnormality rate. This operation is performed every time the vehicle stops. When the vehicle stops (step m1), the offset value α _{i of the} gyro 3 is
Is output (step m2). When the offset value α _i of the gyro 3 is output, the count value K5 of the gyro counter C5 is counted by 1 (step m3). Next, the change of the offset value per time, that is, the offset drift OF per time is obtained from the following equation (2) (step m4).

[0022]

[Equation 2]

In the above equation (2), α_i-1Stopped last time
Offset value output at time T ₀Is measured with clock 9
From the previous stop to the current stop
Represents the time taken. Offset value α_iIs generally around
It has a property that changes with temperature, so-called drift
And offset value α_iWhen drifts too much
Accurate turning angular velocity cannot be detected. Therefore, (2) above
Offset drift OF obtained by the formula is too large
If so, the performance of the gyro 3 will be reduced, so obtain from the above equation (2).
Offset drift OF is out of a predetermined allowable range
It is determined whether or not to exist (step m5). As a result,
If the lift is judged to be outside the allowable range, the gyro
The count value K2 of the counter C2 is counted by 1 (step
M6). That is, the count value K2 is the abnormality of the gyro 3
Will be used as an index for judgment.

FIG. 6 is a flow chart for obtaining the normality / abnormality of the position detecting device and its components based on the data obtained by the operations of FIGS. This operation is performed every time the vehicle travels the distance NΔL. N is a predetermined natural number. Vehicle is distance N
When running ΔLm (step p1), step S in FIG.
The position deviation rate I is calculated by the following equation (3) based on the position coordinates K _i , K _i-1 and the traveling distance D, which are the position information stored in the ring buffer in step 2 (step p2).

[0025]

[Equation 3]

Further, based on the count values K1 and K4, the geomagnetic sensor abnormality rate TJ, which is the abnormal frequency of the geomagnetic sensor 1 with respect to the number of times the output signal (x, y) from the geomagnetic sensor 1 is output, is given by (4) ) Formula (step p
3).

[0027]

[Equation 4]

Further, based on the count values K2 and K5, the gyro abnormality ratio J, which is the number of abnormalities of the gyro 3 with respect to the number of times the offset drift OF is calculated, is calculated by the following equation (5) (step p4).

[0029]

[Equation 5]

Based on the count values K3 and K6, the matching rate M, which is the number of times the vehicle is obtained on the road with respect to the number of times the current position of the vehicle is estimated, is calculated by the following equation (6) ( Step p5).

[0031]

[Equation 6]

The data obtained as described above is R
It is stored in the AM 10 (step p6). Then, this data is displayed on the display unit 4 (step p7). Judgment of normality / abnormality of the position detecting device and its components from the displayed data can be divided into the following five cases. When the positional deviation rate I is negligible, the position detection error in this case is determined to be within the error range that the position detection device necessarily has. When the position deviation rate I is too high to be ignored and the geomagnetic sensor abnormality rate TJ is too high to be ignored, the position detection error in this case is determined to be incorrect because the geomagnetic sensor 1 is abnormal. When the position deviation rate I is too high to be ignored and the gyro abnormality rate J is too high to be ignored, the position detection error in this case is determined to be incorrect because the gyro 3 is abnormal. The positional deviation rate I is too high to be ignored, and the geomagnetic sensor abnormality rate TJ and the gyro abnormality rate J are negligible.
Moreover, when the matching rate M is too low to be ignored, the position detection error in this case is normal because the orientation sensor is
It is determined that the current position does not match because the road network data is abnormal. When any of the above items (1) to (4) does not apply, the position detection error in this case is determined to be unknown.

However, in step p7, the display on the display unit 4 is not performed every time the data is obtained, but is performed as needed. That is, for example, even if the user resets the current position of the vehicle, it is sufficient if the message is displayed when the position shift occurs again and the dealer is requested to repair. As described above, in addition to the display section 4, for example, an LED (light emitting diode) element or the like is attached at an arbitrary position of the vehicle, and when the positional deviation rate is too high to ignore, the LED element emits light so that it can be ignored. In some cases, the light may not be emitted. That is, it can be determined that the position detection device and its components are normal if the LED element is not emitting light, and abnormal if the LED device is emitting light.

As described above, in the navigation device of this embodiment, the position shift rate I is calculated to judge whether the position detecting device is normal or abnormal. When it is determined that the position detection device is abnormal, the geomagnetic sensor abnormality rate T is used to determine which component of the position detection device is abnormal.
J, gyro abnormality rate J and matching rate M are calculated. Then, by displaying these relationships on the display unit 4 or the like, the position detecting device itself determines which component is abnormal.

Therefore, when the user receives a complaint that "the current position does not match", the dealer can easily determine whether or not the position detecting device is abnormal, and it is easy to determine which component is abnormal. Can judge. For this reason, it is not necessary to inspect each of the constituent parts, and much labor and cost are unnecessary. Therefore, it is possible to easily evaluate and review the design of the position detection device.

Besides, it is possible to make various design changes within the scope of the present invention.

[0037]

As described above, in the position detecting device of the present invention, the first judging means judges whether the position detecting device is normal or abnormal, and the second and third judging means determines which component of the position detecting device. Is abnormal. Therefore, when it is determined that the position detecting device is abnormal, the position detecting device itself determines which component is abnormal, and therefore it is not necessary to inspect each component.
For this reason, much labor and cost are not required, which enables quick repair and facilitates evaluation and review of the position detection device design.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a navigation device to which a position detection device according to an embodiment of the present invention is applied.

FIG. 2 is a flowchart showing an operation of resetting a current position of a vehicle.

FIG. 3 is a flowchart showing an operation for obtaining data necessary for calculating a geomagnetic sensor abnormality rate.

FIG. 4 is a flowchart showing an operation for obtaining data necessary for calculating a matching rate.

FIG. 5 is a flowchart showing an operation for obtaining data necessary for calculating a gyro abnormality rate.

FIG. 6 is a flowchart for obtaining normality / abnormality of the position detection device and its components.

[Explanation of symbols]

 1 Geomagnetic sensor 3 Gyro 4 Position detector 10 RAM C1, C2, C3, C4, C5, C6 Counter

Claims (1)

[Claims] 1. A moving body mounted and used, a moving distance and a moving direction of the moving body are detected by a distance sensor and a direction sensor, respectively, to estimate a current position of the moving body, and the estimated current position of the moving body. A map matching type position detection device that compares the position and the road network data obtained from the road map memory and detects the current position of the moving object based on the comparison result Whether the position resetting means for resetting the current position of the moving body and the position deviation rate between the estimated current position of the moving body and the current position reset by the position resetting means are outside the allowable range. The first determination means for determining and the abnormality determination rate of the azimuth sensor are predetermined when the position determination rate is determined to be outside the predetermined range by the first determination means. The second determination means for determining whether the vehicle is out of the predetermined range and the first determination means determines that the position deviation rate is out of the predetermined range. The third judgment means for judging whether or not the matching rate between the position and the road network data is out of a predetermined range, and the results judged by the second and third judgment means are recorded. And a recording means for performing the position detection device.