JP2003042798A - Vehicle position estimator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle position estimator in which the estimated inclination of a vehicle can be corrected utilizing an optical beacon. SOLUTION: Estimated inclination of a vehicle 1 may be shifted significantly from an actual inclination as shown by an arrow M even when the vehicle 1 is traveling on a lane 2 due to gradual shift of its estimated position. Passage of the vehicle 1 through the receiving area A of a signal from an optical beacon transmitter is detected (when the optical beacon receiver mounted on the vehicle 1 receives a signal from the optical beacon transmitter), and the estimated position of the vehicle 1 is corrected to fall within the receiving area A based on its ID information and the estimated inclination is corrected to be in parallel with the lane 2 as indicated in an arrow N. In place of correcting the estimated inclination to be in parallel with the lane 2, it can be corrected to an angle within a predetermined correction range of inclination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle position estimating device for estimating a traveling position of a vehicle using an optical beacon.

[0002]

2. Description of the Related Art Conventionally, as a method of estimating the traveling position of a vehicle for cargo handling / transportation in a yard such as a factory, a yaw rate sensor, a vehicle speed sensor (motor rotation sensor), a tire angle sensor, etc. are attached to the vehicle. By knowing the snake angle from the output of the tire angle sensor, knowing the yaw rate from the output of the yaw rate sensor, and knowing the vehicle speed from the output of the vehicle speed sensor,
It is known to comprehensively judge them and estimate the traveling position of a vehicle on a preset coordinate system.

However, the estimated position may shift due to the error of the above-mentioned sensor, disturbance, etc. Therefore, in order to secure sufficient positional accuracy, it is necessary to take some measures against the shift of the estimated position. As an example of such means, it has been proposed to correct the estimated position using an optical beacon. That is, an optical beacon transmitter is installed at a key point in the traveling path of the vehicle, and when the vehicle passes under it, position information corresponding to the optical beacon transmitter is given to forcibly correct the estimated position. It was done like this.

[0004]

In carrying out the above-mentioned position estimation, in which direction on the road surface the vehicle is inclined with respect to the direction of the traveling passage (which direction on the road surface it is facing). Information indicating the
Is also very important. If the estimated tilt is wrong, it is impossible to correct the tilt itself even if the position is corrected by the optical beacon as described above.

Therefore, there is a problem in that once the estimated tilt becomes incorrect, the position cannot be accurately estimated thereafter. For example, in a system that displays a running locus of a vehicle based on an estimated position, if the tilt is wrong, a totally random running locus is obtained, which is a serious problem.

In view of the above conventional problems, the present invention provides a vehicle position estimating device capable of correcting an estimated inclination of a vehicle using an optical beacon, and an actual inclination of a vehicle using an optical beacon. An object of the present invention is to provide a vehicle position estimating device capable of knowing a vehicle position.

[0007]

In order to solve the above problems, the present invention is configured as follows. That is, the present invention has an optical beacon transmitter installed in a key part of the traveling path of the vehicle, and an optical beacon receiver mounted on the vehicle to receive a signal transmitted from the optical beacon transmitter, It is applied to the vehicle position estimation device that estimates the traveling position of the vehicle based on the signal received by the optical beacon receiver,
The feature is that the vehicle is provided with a tilt correction means for correcting the estimated tilt of the vehicle with respect to the traveling path based on the received signal of the optical beacon receiver when the vehicle passes through the reception area of the optical beacon transmitter. That is.

By providing the inclination correcting means as described above, even if the estimated inclination is distorted, the estimated inclination is corrected by the vehicle passing through the reception area of the optical beacon transmitter. Is fixed. Therefore, accurate position estimation can be performed without deviation.

Various concrete correction methods by the inclination correction means are considered. One example is to correct the estimated tilt of the vehicle to a predetermined tilt corresponding to each optical beacon transmitter. More specifically, when the vehicle passage width is almost equal to the vehicle width, for example, it is desirable to correct the estimated inclination of the vehicle so that it is parallel to the traveling passage in which the optical beacon transmitter is installed. . If the vehicle passage width is relatively wider than the vehicle width, a range of inclination that does not require correction is determined in advance as the inclination correction range, and if the estimated inclination of the vehicle is within the inclination correction range, Is not corrected, and on the other hand, when the estimated tilt of the vehicle is not within the tilt correction range, it is desirable to correct the tilt within the tilt correction range. If the inclination correcting means corrects the estimated inclination in consideration of the actual traveling direction of the vehicle and the vehicle speed as well, the correction can be performed more accurately.

Further, the inclination correcting means has an inclination detecting means for detecting an actual inclination of the vehicle with respect to the traveling path on the basis of the signal received by the optical beacon receiver, and the inclination of the vehicle is detected according to the inclination detected by the inclination detecting means. It is also possible to correct the estimated slope. By doing so, the estimated inclination can be made to match the actual inclination, so that more accurate position estimation can be performed.

The inclination detected by such inclination detecting means does not necessarily have to be used for inclination correction, but may be used for other purposes. Such configurations are also within the scope of the invention. Here, since the optical beacon transmitter irradiates an optical signal including its own position information toward the traveling path, the area where the optical beacon can be received by the optical beacon receiver (that is, the receiving area) Are formed on the traveling passage. This receiving area has a very sharp boundary line, so if the shape and arrangement position etc. are modified, the direction of which point in the receiving area the vehicle will see based on the signal received by the optical beacon receiver. It is possible to know almost exactly whether the vehicle has passed through, and thus the actual inclination of the vehicle with respect to the traveling path can be known.

For example, the reception area is composed of at least two areas arranged at regular intervals in the traveling passage direction,
Both of these two regions have an asymmetric shape in the traveling passage width direction. In this case, the tilt detection means
From each passage time when the vehicle passes each of the two areas, the coordinates in the traveling passage width direction at each vehicle passage point in each of the two areas are obtained, and the actual vehicle is calculated based on the coordinates and the interval. It is possible to detect the inclination.

As another example, the reception area is composed of a plurality of regions which are arranged in at least two stages at regular intervals in the traveling passage direction and arranged in a plurality of rows at regular intervals in the traveling passage width direction. To In this case, the tilt detection means
It is possible to detect the actual tilt of the vehicle based on which of the plurality of areas the vehicle has passed.

As still another example, the reception area is made up of one rectangular area having a constant width in the traveling path direction. In this case, the inclination detection means can detect the actual inclination of the vehicle based on the distance between the passage start point and the passage end point of the rectangular area and the width.

Further, if the inclination detecting means can detect not only the actual inclination of the vehicle but also the traveling direction of the vehicle, the inclination can be corrected more accurately by using these. . Note that the present invention is applied to a vehicle position estimation device that uses an optical beacon, but the vehicle itself that is the object of position estimation is the cargo handling and
It may be a vehicle for transportation, or may be an ordinary automobile running on a general road. Such a vehicle position estimating device, when the detection target is a vehicle on the premises, a system for managing the operation route of a manned vehicle (for example, a system for displaying a running locus) or an automatic driving (unmanned driving) of an unmanned vehicle. When the detection target is a general vehicle, it can be used in a vehicle navigation system on a road traffic network or the like.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. <First Embodiment of the Present Invention> FIG. 1 is a diagram showing the principle of inclination correction in the first embodiment of the present invention.

As shown in the figure, an optical beacon transmitter (not shown) is installed at a key location along the traveling passage 2 of the vehicle 1.
On the other hand, the vehicle 1 is equipped with an optical beacon receiver (not shown) that receives an optical signal emitted from the optical beacon transmitter. The optical signal includes the installation position information (ID information) of the optical beacon transmitter itself, and by irradiating the traveling path 2 with this optical signal, the traveling path 2 is provided with the optical signal. A reception area A, which is an area receivable by the optical beacon receiver, is formed.

Here, the ID information is different for each optical beacon transmitter, that is, if the receiving area A through which the vehicle 1 passes is different, the ID information included in the received signal of the optical beacon receiver is also different. come. Therefore, when the vehicle 1 passes through any of the reception areas A, the current traveling position of the vehicle 1 can be known from the ID information received by the optical beacon receiver at that time.

On the other hand, various sensors (vehicle speed sensor, yaw rate sensor, tire angle sensor, etc.) are attached to the vehicle 1, and the traveling position of the vehicle 1 is estimated based on the output signals from these sensors. Then, when the vehicle 1 passes through the reception area A, the estimated position of the vehicle 1 is also corrected based on the position information obtained from the received signal of the optical beacon receiver. As for a specific method of estimating and correcting the traveling position, existing technologies such as autonomous navigation can be adopted, and therefore detailed description thereof is omitted here.
It should be noted that such estimation and correction of the traveling position, tilt correction, tilt detection, etc., which will be described later, are data processing circuits using a microcomputer, a personal computer, etc., provided for processing the received signals of the optical beacon receiver. Executed by.

In the first embodiment, in addition to the above-described estimation and correction of the traveling position, the vehicle 1 for the traveling passage 2 is
The process of correcting the estimated inclination of is executed. In the example of FIG.
The black circles are the estimated positions of the vehicle 1 at each time, and the polygonal lines connecting the black circles with straight lines are the traveling loci (estimated loci). That is, as the estimated position of the vehicle 1 gradually shifts, the estimated inclination of the vehicle 1 may also deviate considerably from the actual inclination as shown by the arrow M in FIG. 1 has passed through the reception area A (that is, when the optical beacon receiver receives a signal from the optical beacon transmitter), and the estimated position of the vehicle 1 is set within the reception area A based on the ID information. In addition to the correction, the estimated inclination is corrected so as to be parallel to the traveling passage 2 as indicated by an arrow N.

Below, regarding the above-described inclination correction processing,
A more specific description will be given with reference to FIG. First, based on the output of the vehicle speed sensor, it is determined whether the current vehicle speed (spd) of the vehicle 1 is zero (step a1). If the vehicle speed is zero, it is determined that the vehicle 1 is stopped, and the process ends. To do.

When it is determined in step a1 that the vehicle speed is not zero, that is, the vehicle 1 is running, the vehicle speed (spd) is saved, and then it is determined whether or not a signal is received by the beacon receiver. (Step a2),
If no signal is received, the process ends. If vehicle 1 is moving forward, spd> 0. If vehicle 1 is moving backward, spd> 0.
<0.

When the signal is received in step a2, that is, it is determined that the vehicle 1 is passing through the reception area A, the traveling direction (dire) of the vehicle 1 at that time is determined.
c), that is, which direction the vehicle 1 is traveling on the traveling path 2 is determined and stored (step a3). The determination of the traveling direction can be performed based on, for example, a plurality of past coordinate value changes. If the vehicle 1 is traveling on the traveling passage 2 in one direction (for example, the X direction in FIG. 1), direc> 0 is set, and if the vehicle 1 is traveling in the other direction (for example, the −X direction in FIG. 1). d
Set irec <0.

Subsequently, the ID information is read from the received signal of the optical beacon receiver, and it is determined which position the ID indicates (step a4). For example, if a number (1, 2, 3, ...) Is associated with the ID of each optical beacon transmitter, the tilt setting corresponding to the ID is set based on which ID is received. Perform processing (step a5)
a7, steps a8 to a10, ...). That is, the traveling path direction at that position may differ depending on the installation location of the optical beacon transmitter, and therefore, processing corresponding to each ID is performed.

For example, as shown in FIG. 3A, the Y direction on the entire coordinate system displaying the traveling locus of the vehicle 1 is 0.
, −X direction is 90 °, −Y direction is 180 °, and X direction is 270 °. Then, depending on the installation location of the optical beacon transmitter, the traveling passage 2 may be traveling in the Y direction and the −Y direction as shown in FIG. 3B, or may be traveling as shown in FIG. 3C. The passage 2 may run in the X direction and the −X direction.

Therefore, I determined in step a4 above
Regardless of which number D is, first, it is determined whether the multiplication value of the vehicle speed (spd) and the traveling direction (direc) is positive (spd * direc> 0) (steps a5 and a8). Here, when the vehicle 1 is moving forward in the X direction or the Y direction and when the vehicle 1 is moving backward in the -X direction or the -Y direction, spd * direc> 0, In all other cases, spd * direc <0.

Then, for each ID, a tilt setting process corresponding to the ID is performed. That is, for example, when ID = 1, the reception area A corresponding to the ID is, for example, as shown in FIG.
It is assumed that it is formed on the traveling passage 2 extending in the Y direction and the -Y direction as shown in (b). Then, in this case, if it is determined in step a5 that spd * direc> 0, is the vehicle 1 moving forward in the Y direction?
Or since it is retreating toward the -Y direction,
In this case, the estimated inclination is 0 according to the Y direction of the traveling passage 2.
Set to °. On the other hand, in step a5 above, spd * direc
If it is determined to be <0, it means that the vehicle 1 is moving forward in the −Y direction or is moving backward in the Y direction.
Set to 180 ° according to the Y direction.

When ID = 2, the reception area A corresponding to the ID is X as shown in FIG. 3C, for example.
It is assumed that it is formed on the traveling passage 2 extending in the direction and the -X direction. Then, in this case, in step a8, s
If it is determined that pd * direc> 0, it means that the vehicle 1 is moving forward in the X direction or is moving backward in the −X direction. It is set to 270 ° according to the X direction (step a9). On the other hand, if it is determined in step a8 that spd * direc <0, it means that the vehicle 1 is moving forward in the -X direction or moving backward in the X direction. Is set to 90 ° in accordance with the −X direction of the traveling passage 2 (step a10).

For other IDs, the inclination setting process corresponding to that ID is similarly performed. According to the first embodiment of the present invention described above, the vehicle 1 can pass through any one of the reception areas A on the travel passage 2 even when the estimated inclination is incorrect. Then, the estimated inclination is corrected so as to be parallel to the traveling passage 2. Moreover,
Since the inclination is corrected in consideration of the vehicle speed and the traveling direction, it is possible to correct the inclination accurately. As a result, very accurate position estimation can be realized without any error.

In the first embodiment, particularly when the actual inclination of the vehicle 1 is substantially parallel to the traveling passage 2,
For example, when the width of the traveling passage 2 is substantially equal to the width of the vehicle 1, it is possible to obtain a very desirable result. Alternatively, the same desirable result can be expected by installing the optical beacon transmitter at a position where the actual inclination of the vehicle 1 can be considered to be substantially parallel to the traveling passage 2. <Second Embodiment of the Present Invention> FIG. 4 is a diagram showing the principle of inclination correction in the second embodiment of the present invention.

In the second embodiment, in addition to the estimation and correction of the traveling position shown in the description of the first embodiment, a process of correcting the estimated inclination of the vehicle 1 with respect to the traveling passage 2 is performed. Run. Also in the example of FIG. 4, the black circles are the estimated positions of the vehicle 1 at that time, as in the case of FIG. 1, and the polygonal line connecting the black circles with straight lines is the traveling locus (estimated locus). That is, as the estimated position of the vehicle 1 gradually shifts, the estimated inclination of the vehicle 1 also changes from the arrow m in FIG.
In some cases, the actual tilt may deviate considerably from the actual tilt as shown in. Therefore, it is detected that the vehicle 1 has passed through the reception area A, the estimated position of the vehicle 1 is corrected within the reception area A based on the ID information, and the estimated tilt is within the preset tilt correction range B. If out of range, arrow n
As shown by, the estimated tilt is corrected so as to match the boundary angle of the tilt correction range B (angle of the boundary of the tilt range B).

Below, regarding the above-described inclination correction processing,
A more specific description will be given with reference to FIG. First, based on the output of the vehicle speed sensor, it is determined whether the current vehicle speed (spd) of the vehicle 1 is zero (step b1). If the vehicle speed is zero, it is determined that the vehicle 1 is stopped, and the process ends. To do.

When it is determined in step b1 that the vehicle speed is not zero, that is, the vehicle 1 is traveling, the vehicle speed (spd) is saved, and then it is determined whether or not a signal is received by the beacon receiver. (Step b2),
If no signal is received, the process ends. If vehicle 1 is moving forward, spd> 0. If vehicle 1 is moving backward, spd> 0.
<0.

When the signal is received in step b2, that is, it is determined that the vehicle 1 is passing through the reception area A, the traveling direction (dire) of the vehicle 1 at that time is determined.
c), that is, which direction the vehicle 1 is traveling on the traveling passage 2 is determined and stored (step b3). The determination of the traveling direction can be performed based on, for example, a plurality of past coordinate value changes. If the vehicle 1 is traveling on the traveling passage 2 in one direction (for example, the X direction in FIG. 4), direc> 0 is set, and if the vehicle 1 is traveling in the other direction (for example, the −X direction in FIG. 4). d
Set irec <0.

Then, the ID information is read from the received signal of the optical beacon receiver and it is determined which position the ID indicates (step b4). For example, if a number (1, 2, 3, ...) Is associated with the ID of each optical beacon transmitter, the tilt setting corresponding to the ID is set based on which ID is received. Perform processing (step b5 to
b9, steps b10 to b14, ...). That is,
Depending on the location where the optical beacon transmitter is installed, the direction of the traveling passage 2 at that location may be different.
The processing corresponding to each D is performed.

That is, no matter which ID is determined in step b4, first, the multiplication value of the vehicle speed (spd) and the traveling direction (direc) is positive (spd * direc> 0).
It is determined whether or not (steps b5 and b10). Here, when the vehicle 1 is moving forward in the X direction or the Y direction and when the vehicle 1 is moving backward in the -X direction or the -Y direction, spd * direc> 0, In all other cases, spd * direc <0.

Then, for each ID, a tilt setting process corresponding to the ID is performed. That is, for example, when ID = 1, the reception area A corresponding to the ID is, for example, as shown in FIG.
It is assumed that it is formed on the traveling passage 2 extending in the Y direction and the -Y direction as shown in (b). Then, in this case, if it is determined in step b5 that spd * direc> 0, is the vehicle 1 moving forward in the Y direction?
Or since it is retreating toward the -Y direction,
In this case, the estimated tilt is within a predetermined tilt correction range B (FIG. 4)
It is judged whether or not it is outside (step b6). Here, the tilt correction range B is a range of tilt that does not require correction, and is determined in advance for each ID. Here, it is assumed that the tilt correction ranges B are provided at positions that are 180 ° symmetrical along the traveling passage direction.

In step b6, if the estimated inclination is within the inclination correction range B, the processing is terminated without performing inclination correction, while if the estimated inclination is outside the inclination correction range B, the above spd * According to the fact that direc> 0, for example, as shown in FIG. 6A, the estimated inclination indicated by the arrow C is corrected to an angle within the inclination correction range B on the 0 ° side as indicated by the arrow D (step S). b7). FIG. 6A shows an example in which the estimated inclination is corrected to match the boundary angle of the inclination correction range B on the 0 ° side (the closer one of the two boundaries). The angle may be corrected to another angle (for example, parallel to the traveling passage 2) as long as it is within the tilt correction range.

On the other hand, in step b5 above, spd * direc
If it is determined to be <0, it means that the vehicle 1 is moving forward in the −Y direction or moving backward in the Y direction. Therefore, in this case as well, the estimated tilt is first within the tilt correction range B. It is judged whether or not it is outside (step b8).
If the estimated inclination is within the inclination correction range B, the processing is terminated without performing the inclination correction. On the other hand, if the estimated inclination is outside the inclination correction range B, it follows that spd * direc <0. For example, as shown in FIG. 6A, the estimated tilt indicated by arrow C is corrected to an angle within the tilt correction range B on the 180 ° side as indicated by arrow E (step b9). Also in this case, the corrected tilt may match the boundary angle of the tilt correction range B on the 180 ° side (the closer one of the two boundaries) or the tilt correction range B on the 180 ° side. It may be some angle.

When ID = 2, the reception area A corresponding to the ID is X as shown in FIG. 3C, for example.
It is assumed that it is formed on the traveling passage 2 extending in the direction and the -X direction. Then, in this case, in step b10
If it is determined that spd * direc> 0, vehicle 1 is X
Since the vehicle is moving forward in the direction or moving backward in the -X direction, it is first determined in this case whether the estimated inclination is outside the inclination correction range B (step b11). If the estimated inclination is within the inclination correction range B, the processing is terminated without performing the inclination correction, while if the estimated inclination is outside the inclination correction range B, the above spd * direc>
According to the fact that it is 0, for example, as shown in FIG.
The estimated tilt indicated by arrow F is
The angle is corrected within the tilt correction range B on the 0 ° side (step b12). Also in this case, the corrected tilt is the boundary angle of the tilt correction range B on the 270 ° side (the closer one of the two boundaries).
May be the same, or may be some angle within the tilt correction range B on the 270 ° side.

On the other hand, in step b10, spd * direc
If it is determined to be <0, it means that the vehicle 1 is moving forward in the -X direction or moving backward in the X direction. Therefore, in this case as well, the estimated inclination is first within the inclination correction range B. Determine if it is outside (step b1)
3). If the estimated inclination is within the inclination correction range B, the process is terminated without performing the inclination correction, while if the estimated inclination is outside the inclination correction range B, according to the above spd * direc <0, For example, as shown in FIG. 6B, the estimated tilt indicated by the arrow F is corrected to an angle within the tilt correction range B on the 90 ° side as indicated by the arrow H (step b14).
In this case also, the corrected tilt is the tilt correction range B on the 90 ° side.
May be the same as the boundary angle (closer to the two boundaries), or may be some angle within the tilt correction range B on the 90 ° side.

For other IDs, the inclination setting process corresponding to that ID is similarly performed. According to the second embodiment of the present invention described above, the vehicle 1 can pass through any of the reception areas A on the travel passage 2 even if the estimated inclination is incorrect. Then, the estimated inclination is corrected within the inclination correction range B. Moreover, since the inclination is corrected in consideration of the vehicle speed and the traveling direction, the inclination can be corrected accurately. As a result, very accurate position estimation can be realized without any error. For example, FIG. 7 shows a display example of the traveling locus of the vehicle when the inclination correction according to the second embodiment is applied. In this case, the optical beacon transmitters 11 to 15 are installed at various places in the traveling passage 2 to perform the tilt correction, so that even if the estimated position gradually deviates, the optical beacon transmitters are not provided. Since a normal estimated position and estimated inclination are obtained each time the vehicle passes under 11 to 15, the traveling locus can be normally returned.

In the first embodiment, the traveling passage 2 is used.
Is suitable for the case where the width of the vehicle 1 is substantially equal to the width of the vehicle 1, etc., but the second embodiment is particularly preferable when the actual inclination of the vehicle 1 is not always parallel to the traveling passage 2. For example, when the width of the traveling passage 2 is considerably wider than the width of the vehicle 1, it is possible to obtain a very desirable result. <Other Embodiments> The present invention is not limited to the above embodiments, and various configurations can be adopted within the scope described in each claim. For example, the following configuration changes are possible.

(1) In the first and second embodiments described above, the inclination is corrected each time the vehicle 1 passes under one optical beacon transmitter. However, for example, two optical beacon transmitters are used. Are installed relatively close to each other and tilt correction is performed only when signals from them are received in a predetermined order (that is, when the vehicle 1 passes under the two optical beacon transmitters in a predetermined order). It is also possible to do so.

In this way, since the traveling direction of the vehicle 1 can be clearly determined, even if the estimated position and the estimated inclination are out of order, the values are returned to normal values. be able to. For example, in FIG.
In the display example of the traveling locus shown in FIG. 7, an example of the traveling locus in which the inclination is corrected only when the vehicle passes under the two optical beacon transmitters 15 and 14 in that order Is. As is clear from this figure, the vehicle passing under the optical beacon transmitters 15, 14 in that order corrects the totally random estimated position (J) to the normal position (K), and It can be seen that the estimated inclination has also returned to the normal inclination along the traveling passage 2.

(2) The embodiment described above is the vehicle 1
This makes it possible to bring the estimated tilt closer to the actual tilt without detecting the actual tilt, and enables accurate tilt correction with a relatively simple process. However, a means for detecting the actual inclination of the vehicle 1 is further provided,
If the estimated tilt of the vehicle 1 is corrected according to the detected tilt, the tilt correction with higher accuracy can be realized. The principle of such inclination detection is shown in FIG.
It shows in (a)-(i).

In the example of FIG. 9 (a), the reception area A has two areas A1 arranged at a constant interval L in the traveling path direction.
, A2, and these two regions A1 and A2 both have an asymmetrical shape (for example, trapezoidal) in the width direction of the traveling passage. It should be noted that the above two areas A1 and A2
Are formed by different optical beacon transmitters, and have different IDs. Also,
The distance L corresponds to the distance between the optical beacon transmitters, and is a distance between the central positions (positions indicated by ID) in the traveling path direction in the two areas A1 and A2.

In this case, the vehicle has two areas A1 and A2.
The position in the travel passage width direction at that time is specified by measuring each passing time when passing each of the above. Specifically, since the same signal is repeatedly transmitted from the optical beacon transmitter in a constant cycle, by measuring the number of times of reception, the passing points T1 and T2 of the areas A1 and A2 are measured.
The position coordinates in the travel passage width direction at (the central position in the travel passage direction) can be specified. Then, the distance W in the traveling passage width direction is obtained from the coordinates of T1 and T2, and the distance W
And the above-described distance L in the traveling path direction, the actual inclination θ of the vehicle is calculated. At this time, the traveling direction of the vehicle can be determined from the order of the received IDs.

In the example shown in FIG. 9B, the reception area A is made up of two areas A1 and A2 arranged at a constant interval L in the direction of the traveling passage, as in the case of FIG. 9A. Each of the two regions A1 and A2 has an asymmetrical shape (for example, a trapezoidal shape) in the travel passage width direction. However, in this example, the lengths of the two regions A1 and A2 in the traveling passage direction are different from each other, and the lower side of the trapezoid matches the traveling passage width direction. The two areas A1 and A2 are formed by the same optical beacon transmitter and have the same ID.

Also in this case, as in the example of FIG. 9A, the distance W in the traveling passage width direction is obtained from the coordinates of the passing points T1, T2 of the vehicle, and the distance W in the traveling passage direction is used to determine the vehicle distance. The actual inclination θ is calculated. On the other hand, two areas A1
, A2 have different lengths in the traveling path direction,
The traveling direction of the vehicle is determined based on the difference in the passing times (the number of times of reception).

In the example of FIG. 9 (c), the reception areas A are arranged in two steps at a constant interval L in the traveling path direction, and each step has a plurality of smaller rectangular areas A1 to A5. A
6 to A10 are arranged at a constant interval V in the traveling passage width direction. These areas A1 to A10 are all formed by different optical beacon transmitters and have different IDs.

In this case, since the area where the vehicle has passed can be determined from the IDs that are sequentially received when the vehicle passes,
The actual inclination θ of the vehicle is calculated from the deviation (an integer multiple of V) in the width direction of the traveling passage and the distance L in the traveling passage direction between the first-stage region and the second-stage region. On the other hand, the traveling direction of the vehicle is
Judgment is made from the order of the received IDs.

In the example of FIG. 9D, as in the example of FIG. 9C, the receiving area A has a plurality of smaller areas A1 to A5.
, A6 to A10, but the first-stage area A1
~ A5 and the second-stage areas A6 to A10 are a set of those located at the same position in the width direction of the traveling passage (the area surrounded by the dotted line in the figure) and have the same ID. ing. Since the areas of the set having the same ID can be formed by dividing the signal from the same optical beacon transmitter into two, the number of optical beacon transmitters is reduced to half compared to the example of FIG. 9C. be able to.

In this case, the positional deviation in the traveling passage width direction (an integral multiple of V) is obtained from the IDs sequentially received when the vehicle passes, and the actual inclination of the vehicle is calculated from this and the distance L in the traveling passage direction. Calculate θ. However, it is necessary to determine the traveling direction by another method. For example, as shown in FIG. 9 (e), if another area A11 having a width that can cover the traveling passage width and a completely different ID is provided at another position in the traveling passage direction, It is possible to determine the traveling direction depending on whether the ID is received first or later.

In the example of FIG. 9 (f), the receiving area A has a constant distance L1 and L2 (L1>) in the traveling path direction.
L2) are arranged in three stages, and each stage has a plurality of smaller rectangular regions A1 to A5, A6 to A10, A.
11 to A15 are arranged at a constant interval V in the width direction of the traveling passage. Among these areas, those at the same position in the traveling passage width direction (areas surrounded by dotted lines in the figure) form one set, and these have the same ID.

In this case, the calculation of the inclination θ is the same as in the example of FIG. 9 (d). On the other hand, in the traveling direction, L1> L2 at each stage
Since the IDs are arranged in, it is possible to determine from the reception time intervals of the IDs that are sequentially received. In the example of FIG. 9G, the reception area A is one rectangular area having a constant width L in the traveling path direction.

In this case, the reception start point T11 and the reception end point T12 when the vehicle passes through the reception area A are detected, and the distance L'between them is measured based on the vehicle speed and the number of signal receptions. Then, the actual inclination θ of the vehicle is calculated from L and L ′. However, it is necessary to determine the traveling direction by another method. For example, as shown in FIG. 9H, a region A1 similar to FIG. 9G is added to a region A2 and A3 similar to FIG. 9A.
By using a combination of the above as the reception area A, not only the inclination θ but also the traveling direction can be detected. That is,
The slope θ is calculated using the area A1, and the areas A2 and A are calculated.
Use 3 to determine the direction of travel. In this case,
It is assumed that the areas A1, A2, and A3 have different IDs.

In the example of FIG. 9 (i), the reception area A is composed of two areas A1 arranged at a constant interval L in the traveling path direction.
, A2, and these two areas A1,
Two sides of A2 adjacent to each other and facing each other are parallel to each other, and both of these two sides are orthogonal to the traveling passage direction. It should be noted that these two adjacent and opposing sides have a constant distance L.
Is set to.

In this case, the traveling distance L'between the reception end point T21 of the first area A2 and the reception start point T22 of the next area A1 due to the passage of the vehicle is obtained, and the example of FIG. 9 (g) is obtained. The actual inclination θ of the vehicle is calculated in the same manner as in.
On the other hand, the traveling direction of the vehicle is determined from the order of the received ID. In this example, the number of optical beacon transmitters can be reduced by one compared with the example of FIG. 9 (h).

The example shown in FIG. 9 is only one example of the inclination detecting means, and the present invention is not limited to this. Further, the inclination detected by such inclination detecting means does not necessarily have to be used for inclination correction, and it is also within the scope of the present invention to use it for other purposes.

[0061]

According to the present invention, even when the estimated inclination of the vehicle is distorted, the estimated inclination is more appropriate because the vehicle passes through the reception area of the optical beacon transmitter. Since the angle is corrected to a different angle, highly accurate position estimation can be realized.

Further, by further providing inclination detecting means for detecting the actual inclination of the vehicle and correcting the estimated inclination to the detected inclination, the position can be estimated with higher accuracy. Of course, such inclination detecting means can be used for various purposes other than inclination correction.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle of inclination correction according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a tilt correction process according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between directions and angles on a coordinate system.

FIG. 4 is a diagram showing a principle of inclination correction according to the second embodiment of the present invention.

FIG. 5 is a flowchart showing a tilt correction process according to the second embodiment of the present invention.

FIG. 6 is a diagram showing an example of inclination correction according to the second embodiment of the present invention.

FIG. 7 is a diagram showing a display example of a traveling locus of a vehicle when the inclination correction according to the second embodiment of the present invention is applied.

FIG. 8 is a diagram showing a display example of a traveling locus of a vehicle when tilt correction is applied in another embodiment of the present invention.

FIG. 9 is a diagram showing the principle of tilt detection in another embodiment of the present invention.

[Explanation of symbols]

1 vehicle 2 runway 11, 12, 13, 14, 15 Optical beacon transmitter A reception area B Tilt correction range

Claims (11)

[Claims] 1. An optical beacon transmitter installed in a key part of a traveling path of a vehicle, and an optical beacon receiver mounted on the vehicle for receiving a signal transmitted from the optical beacon transmitter, In a vehicle position estimation device that estimates the traveling position of the vehicle based on a received signal at an optical beacon receiver, based on a received signal of the optical beacon receiver when the vehicle passes through a reception area by the optical beacon transmitter ,
A vehicle position estimating device comprising inclination correcting means for correcting an estimated inclination of the vehicle with respect to the traveling path. 2. The vehicle position estimating apparatus according to claim 1, wherein the inclination correcting means corrects the estimated inclination of the vehicle to a predetermined inclination corresponding to each optical beacon transmitter. 3. The vehicle position according to claim 2, wherein the inclination correcting means corrects the estimated inclination of the vehicle so as to be parallel to a traveling path in which the optical beacon transmitter is installed. Estimator. 4. The tilt correcting means does not correct when the estimated tilt of the vehicle is within a predetermined tilt correction range, while the estimated tilt of the vehicle is not within the predetermined tilt correction range. In this case, the vehicle position estimating device according to claim 2, wherein the vehicle position estimating device corrects the inclination within the predetermined inclination correcting range. 5. The vehicle according to claim 2, wherein the inclination correction means corrects the estimated inclination in consideration of an actual traveling direction and a vehicle speed of the vehicle. Position estimation device. 6. The tilt correcting means has a tilt detecting means for detecting an actual tilt of the vehicle with respect to the traveling path based on a signal received by the optical beacon receiver, and the tilt detected by the tilt detecting means. The vehicle position estimating apparatus according to claim 1, wherein the estimated inclination of the vehicle is corrected according to the above. 7. An optical beacon transmitter installed in a key part of a traveling path of the vehicle, and an optical beacon receiver mounted on the vehicle to receive a signal transmitted from the optical beacon transmitter, In a vehicle position estimation device that estimates the traveling position of the vehicle based on a received signal at an optical beacon receiver, based on a received signal of the optical beacon receiver when the vehicle passes through a reception area by the optical beacon transmitter ,
A vehicle position estimating device comprising inclination detecting means for detecting an actual inclination of the vehicle with respect to the traveling path. 8. The reception area is composed of at least two regions arranged at regular intervals in the traveling passage direction, each of the two regions having an asymmetric shape in the traveling passage width direction, and the inclination detection. The means obtains coordinates in the travel passage width direction at each vehicle passage point in each of the two areas from each passage time when the vehicle passes each of the two areas, and based on the coordinates and the interval, The vehicle position estimating device according to claim 7, wherein an actual inclination is detected. 9. The reception area is composed of a plurality of areas which are arranged in at least two stages at regular intervals in the traveling passage direction and are arranged in a plurality of rows at regular intervals in the traveling passage width direction. 8. The vehicle position estimating device according to claim 7, wherein the detecting means detects the actual inclination based on which area of the plurality of areas the vehicle has passed. 10. The reception area is composed of one rectangular area having a certain width in a traveling path direction, and the inclination detecting means is arranged such that a distance between a passage start point and a passage end point of the rectangular area. The vehicle position estimating device according to claim 7, wherein the actual inclination is detected based on the width and the width. 11. The vehicle position estimating device according to claim 7, wherein the inclination detecting unit detects not only the actual inclination but also a traveling direction of the vehicle.