JP3982215B2 - Vehicle position estimation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle position estimation device that estimates a travel position of a vehicle using an optical beacon.
[0002]
[Prior art]
Conventionally, as a method of estimating the traveling position of a vehicle for cargo handling / transportation in a premises 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 and the output of the tire angle sensor From the output of the yaw rate sensor, the yaw rate from the output of the vehicle speed sensor, and the vehicle speed from the output of the vehicle speed sensor. It is known to estimate.
[0003]
However, since the estimated position may be shifted due to an error or disturbance of the sensor, it is necessary to take some measures against the estimated position shift in order to ensure sufficient position accuracy. 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 of the vehicle's travel path, and when the vehicle passes below, position information corresponding to the optical beacon transmitter is given to forcibly correct the estimated position. It is what I did.
[0004]
[Problems to be solved by the invention]
In executing the position estimation described above, inclination information (hereinafter referred to as “estimation”) indicates in which direction the vehicle is inclined on the road surface (which direction is on the road surface) with respect to the traveling path direction. “Slope” is also very important. If the estimated inclination is distorted, it is impossible to correct the inclination itself even if the position is corrected by the optical beacon as described above.
[0005]
For this reason, there has been a problem in that once the estimated inclination is deviated, the position cannot be estimated accurately thereafter. For example, in a system that displays the travel locus of a vehicle based on the estimated position, if the inclination is distorted, a very unusual travel locus is obtained, which is a serious problem.
[0006]
In view of the above-described conventional problems, the present invention provides a vehicle position estimation device that can correct an estimated inclination of a vehicle using an optical beacon and an actual inclination of the vehicle using an optical beacon. It is an object of the present invention to provide a vehicle position estimation device capable of performing the following.
[0007]
[Means for Solving the Problems]
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 at a key point of a traveling path of a vehicle, and an optical beacon receiver that is mounted on a vehicle and receives a signal transmitted from the optical beacon transmitter. The present invention is applied to a vehicle position estimation device that estimates a traveling position of a vehicle based on a signal received by the optical beacon receiver, and the feature is that the vehicle passes through a reception area by the optical beacon transmitter. Inclination correcting means for correcting the estimated inclination of the vehicle with respect to the travel path based on the received signal of the optical beacon receiver at the time When the estimated inclination of the vehicle is within a predetermined inclination correction range (inclination range that does not require correction) corresponding to the optical beacon transmitter that forms the reception area through which the vehicle passes. Is not corrected, and on the other hand, when the estimated inclination of the vehicle is not within the predetermined inclination correction range, it is corrected to the inclination within the predetermined inclination correction range. That is.
[0008]
By providing such a tilt correcting means, even if the estimated tilt is out of order, the estimated tilt is reduced when the vehicle passes through the reception area of the optical beacon transmitter. To tilt within the specified tilt correction range Will be corrected. Such inclination correction can be applied even when the vehicle passage width is relatively wide compared to the vehicle width. Therefore, accurate position estimation without any deviation is possible.
[0009]
Various specific correction methods by the inclination correction means are conceivable. As an example, the estimated inclination of the vehicle Match the boundary angle of the predetermined tilt correction range It can be corrected. Also When the vehicle passage width is substantially 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 where the optical beacon transmitter is installed. . Na If the inclination correcting means corrects the estimated inclination in consideration of the actual traveling direction of the vehicle and the vehicle speed, a more accurate correction can be made.
[0010]
In addition, the inclination correcting means has inclination detecting means for detecting the actual inclination of the vehicle with respect to the travel path based on the received signal of the optical beacon receiver, and the estimated inclination of the vehicle is determined according to the inclination detected by the inclination detecting means. It is also possible to modify. By doing so, the estimated inclination can be matched with the actual inclination, so that more accurate position estimation can be performed.
[0011]
Note that the inclination detected by such an inclination detecting means is not necessarily used for the inclination correction, and may be used for other purposes. Such a configuration is also within the scope of the present invention.
Here, since the optical beacon transmitter emits an optical signal including its own position information toward the traveling path, an area where this optical signal can be received by the optical beacon receiver (that is, a reception area) Is formed on the travel path. This reception area has a very sharp boundary line, so if you devise its shape, placement, etc., the vehicle will go to which point in the reception area and in what direction based on the received signal from the optical beacon receiver. It is possible to know almost exactly whether or not the vehicle has passed, and thus the actual inclination of the vehicle with respect to the travel path can be known.
[0012]
For example, the reception area is composed of at least two regions arranged at a constant interval in the traveling passage direction, and these two regions have an asymmetric shape in the traveling passage width direction. In this case, the inclination detecting means obtains coordinates in the traveling path width direction at each vehicle passing point in the two areas from each passing time when the vehicle passes through each of the two areas. Based on the above, it is possible to detect the actual inclination of the vehicle.
[0014]
other As an example, the reception area is made up of one rectangular area having a certain 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.
[0015]
Further, if the inclination detecting means can detect not only the actual inclination of the vehicle but also the traveling direction of the vehicle, it becomes possible to correct the inclination more accurately by using these.
Although the present invention is applied to a vehicle position estimation device using an optical beacon, the vehicle itself that is the position estimation target may be a cargo handling / transportation vehicle used on the premises. It may be a normal car traveling on a general road. Such a vehicle position estimation device is a system for managing the operation route of a manned vehicle (for example, a system that displays a travel locus, etc.) or an automatic driving of an unmanned vehicle (automatic driving) when the detection target is a local vehicle. It can be used in a system or the like, and when the detection target is a general vehicle, it can be used in an automobile navigation system or the like on a road traffic network.
[0016]
DETAILED DESCRIPTION OF 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.
[0017]
As shown in the figure, an optical beacon transmitter (not shown) is installed at an important point along the traveling path 2 of the vehicle 1, while the vehicle 1 receives an optical signal emitted from the optical beacon transmitter. An optical beacon receiver (not shown) is mounted. The optical signal includes the installation position information (ID information) of the optical beacon transmitter itself. When the optical signal is irradiated onto the traveling path 2, the optical signal is transmitted onto the traveling path 2. A reception area A that is an area that can be received by the optical beacon receiver is formed.
[0018]
Here, the ID information is different for each optical beacon transmitter. That is, if the reception area A through which the vehicle 1 passes is different, the ID information included in the reception signal of the optical beacon receiver is also different. Therefore, when the vehicle 1 passes through one 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.
[0019]
On the other hand, various sensors (a vehicle speed sensor, a yaw rate sensor, a tire angle sensor, and the like) are attached to the vehicle 1, and the traveling position of the vehicle 1 is estimated based on output signals from these sensors. And when the vehicle 1 passes through the reception area A, the estimated position of the vehicle 1 is corrected based on the position information obtained from the reception signal of the optical beacon receiver. With regard to a specific method for estimating and correcting such a traveling position, a technique such as existing autonomous navigation can be employed, and thus detailed description thereof is omitted here. In addition, such a travel position estimation and correction, inclination correction described later, inclination detection, and the like are provided for processing the received signal of the optical beacon receiver, a data processing circuit using a microcomputer, a personal computer, or the like. It is executed by.
[0020]
In the first embodiment, in addition to the above-described estimation and correction of the travel position, processing for correcting the estimated inclination of the vehicle 1 with respect to the travel path 2 is executed. In the example of FIG. 1, black circles are the estimated positions of the vehicle 1 from time to time, and a broken line formed by connecting the black circles with a straight line is a traveling locus (estimated locus). That is, as the estimated position of the vehicle 1 gradually shifts, the estimated tilt of the vehicle 1 may also shift considerably from the actual tilt as indicated by the arrow M in FIG. 1 is detected to pass 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 in the reception area A based on the ID information. At the same time, as shown by the arrow N, the estimated inclination is corrected to be parallel to the travel path 2.
[0021]
Hereinafter, the above-described tilt correction process will be described more specifically with reference to FIG.
First, based on the output of the vehicle speed sensor, it is determined whether or not the current vehicle speed (spd) of the vehicle 1 is zero (step a1). If the vehicle speed is zero, the vehicle 1 is stopped and the process is terminated. To do.
[0022]
If it is determined in step a1 that the vehicle speed is not zero, that is, the vehicle 1 is traveling, the vehicle speed (spd) is stored, and then it is determined whether a signal is received by the beacon receiver (step a2). ) If no signal is received, the process is terminated. Note that spd> 0 when the vehicle 1 is moving forward, and spd <0 when the vehicle is moving backward.
[0023]
When a signal is received in step a2, that is, when it is determined that the vehicle 1 is passing through the reception area A, the traveling direction (direc) of the vehicle 1 at that time, that is, the vehicle 1 is on the traveling path 2 It is determined in which direction the direction of the travel is proceeding, and this is stored (step a3). The determination of the traveling direction can be made based on, for example, a plurality of past coordinate value changes. If the vehicle 1 is traveling in one direction (for example, the X direction in FIG. 1) on the traveling path 2, set direc> 0, and if traveling in the other direction (for example, the −X direction in FIG. 1). Let direc <0.
[0024]
Subsequently, the ID information is read from the received signal of the optical beacon receiver, and it is determined which position indicates the ID (step a4). For example, if a number (1, 2, 3,...) Is associated with each ID for each optical beacon transmitter, an inclination setting corresponding to the ID is set based on what number is received. Processing is performed (steps a5 to a7, steps a8 to a10,...). In other words, depending on the installation location of the optical beacon transmitter, there may be a case where the traveling path direction at that position is different, so that processing corresponding to each ID is performed.
[0025]
For example, as shown in FIG. 3A, the Y direction is 0 °, the −X direction is 90 °, the −Y direction is 180 °, and the X direction is 270 ° on the entire coordinate system for displaying the travel locus of the vehicle 1. Think of it as corresponding to Then, depending on the installation location of the optical beacon transmitter, the traveling path 2 may be traveling in the Y direction and the −Y direction as illustrated in FIG. 3B, or as illustrated in FIG. The passage 2 may run in the X direction and the −X direction.
[0026]
Therefore, regardless of the ID determined in step a4, first, it is determined whether the product of the vehicle speed (spd) and the traveling direction (direc) is positive (spd * direc> 0) (step a5, 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 toward the -X direction or the -Y direction, spd * direc> 0, Otherwise, spd * direc <0.
[0027]
Thereafter, for each ID, an inclination setting process corresponding to the ID is performed. That is, for example, when ID = 1, it is assumed that the reception area A corresponding to the ID is formed on the traveling path 2 extending in the Y direction and the −Y direction as shown in FIG. 3B, for example. Then, in this case, if it is determined in step a5 that spd * direc> 0, the vehicle 1 is moving forward in the Y direction or moving backward in the -Y direction. In this case, the estimated inclination is set to 0 ° in accordance with the Y direction of the travel path 2. On the other hand, if it is determined in step a5 that spd * direc <0, the vehicle 1 is moving forward in the -Y direction or moving backward in the Y direction. The inclination is set to 180 ° in accordance with the −Y direction of the travel path 2.
[0028]
Further, when ID = 2, it is assumed that the reception area A corresponding to the ID is formed on the traveling path 2 extending in the X direction and the −X direction as shown in FIG. 3C, for example. Then, in this case, if it is determined in step a8 that spd * direc> 0, the vehicle 1 is moving forward in the X direction or moving backward in the -X direction. Sets the estimated inclination to 270 ° in accordance with the X direction of the travel path 2 (step a9). On the other hand, if it is determined in step a8 that spd * direc <0, 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 travel path 2 (step a10).
[0029]
In the case of other IDs, the tilt setting process corresponding to the ID is similarly performed.
According to the first embodiment of the present invention described above, the vehicle 1 passes through one of the reception areas A on the travel path 2 even if the estimated inclination is incorrect. Thus, the estimated inclination is corrected to be parallel to the travel path 2. In addition, 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, a very accurate position estimation without any deviation can be realized.
[0030]
The first embodiment is applied particularly when the actual inclination of the vehicle 1 is substantially parallel to the traveling path 2, for example, when the width of the traveling path 2 is substantially equal to the width of the vehicle 1. In this way, very desirable results can be obtained. Alternatively, a desirable result can be similarly expected by installing an optical beacon transmitter at a point where the actual inclination of the vehicle 1 can be regarded as being substantially parallel to the traveling path 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.
[0031]
In the second embodiment, processing for correcting the estimated inclination of the vehicle 1 with respect to the travel path 2 is executed in addition to the estimation and correction of the travel position shown in the description of the first embodiment. Also in the example of FIG. 4, as in FIG. 1, black circles are the estimated positions of the vehicle 1 from time to time, and a broken line connecting the black circles with straight lines is a travel locus (estimated locus). That is, when the estimated position of the vehicle 1 is gradually shifted, the estimated tilt of the vehicle 1 may be considerably shifted from the actual tilt as indicated by the arrow m in FIG. Therefore, it is detected that the vehicle 1 has passed through the reception area A, and the estimated position of the vehicle 1 is corrected in the reception area A based on the ID information, and the estimated inclination is within a preset inclination correction range B. When it is out of the range, the estimated inclination is corrected so as to coincide with the boundary angle of the inclination correction range B (the angle of the boundary of the inclination range B) as indicated by an arrow n.
[0032]
Hereinafter, the above-described tilt correction process will be described more specifically with reference to FIG.
First, based on the output of the vehicle speed sensor, it is determined whether or not the current vehicle speed (spd) of the vehicle 1 is zero (step b1). If the vehicle speed is zero, the vehicle 1 is stopped and the process is terminated. To do.
[0033]
If 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 stored, and then it is determined whether a signal is received by the beacon receiver (step b2). ) If no signal is received, the process is terminated. Note that spd> 0 when the vehicle 1 is moving forward, and spd <0 when the vehicle is moving backward.
[0034]
When a signal is received in step b2, that is, when it is determined that the vehicle 1 is passing the reception area A, the traveling direction (direc) of the vehicle 1 at that time, that is, the vehicle 1 is on the traveling path 2 It is determined in which direction the direction of travel is proceeding, and this is stored (step b3). The determination of the traveling direction can be made based on, for example, a plurality of past coordinate value changes. If the vehicle 1 is traveling in one direction (for example, the X direction in FIG. 4) on the traveling path 2, direc> 0, and if traveling in the other direction (for example, the −X direction in FIG. 4). Let direc <0.
[0035]
Subsequently, ID information is read from the received signal of the optical beacon receiver, and it is determined which position indicates the ID (step b4). For example, if a number (1, 2, 3,...) Is associated with each ID for each optical beacon transmitter, an inclination setting corresponding to the ID is set based on what number is received. Processing is performed (steps b5 to b9, steps b10 to b14,...). That is, depending on the installation location of the optical beacon transmitter, there may be a case where the direction of the traveling path 2 at that position is different, so that processing corresponding to each ID is performed.
[0036]
That is, regardless of the number of the ID determined in step b4, first, it is determined whether the product of the vehicle speed (spd) and the traveling direction (direc) is positive (spd * direc> 0) (step b5, 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 toward the -X direction or the -Y direction, spd * direc> 0, Otherwise, spd * direc <0.
[0037]
Thereafter, for each ID, an inclination setting process corresponding to the ID is performed. That is, for example, when ID = 1, it is assumed that the reception area A corresponding to the ID is formed on the traveling path 2 extending in the Y direction and the −Y direction as shown in FIG. 3B, for example. Then, in this case, if it is determined in step b5 that spd * direc> 0, the vehicle 1 is moving forward in the Y direction or moving backward in the -Y direction. In the case, it is determined whether or not the estimated inclination is outside the predetermined inclination correction range B (FIG. 4) (step b6). Here, the inclination correction range B is an inclination range that does not require correction, and is determined in advance for each ID. Here, it is assumed that the inclination correction ranges B are provided at positions that are 180 ° symmetrical along the traveling path direction.
[0038]
In step b6, if the estimated inclination is within the inclination correction range B, the process is terminated without correcting the inclination. On the other hand, if the estimated inclination is outside the inclination correction range B, the above spd * direc> 0 Accordingly, 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 b7). FIG. 6A shows an example in which the estimated inclination is corrected so as to coincide with the boundary angle of the inclination correction range B on the 0 ° side (the closer of the two boundaries). If it is within the inclination correction range, it may be corrected to other angles (for example, parallel to the travel path 2).
[0039]
On the other hand, if it is determined in step b5 that spd * direc <0, the vehicle 1 is moving forward in the -Y direction or moving backward in the Y direction. First, it is determined whether or not the estimated inclination is outside the inclination correction range B (step b8). If the estimated inclination is within the inclination correction range B, the process is terminated without performing the inclination correction. On the other hand, if the estimated inclination is outside the inclination correction range B, spd * direc <0 is satisfied. 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 180 ° side as indicated by the arrow E (step b9). Also in this case, the corrected inclination may coincide with the boundary angle of the inclination correction range B on the 180 ° side (the closer of the two boundaries), or within the inclination correction range B on the 180 ° side. It may be at some angle.
[0040]
Further, when ID = 2, it is assumed that the reception area A corresponding to the ID is formed on the traveling path 2 extending in the X direction and the −X direction as shown in FIG. 3C, for example. Then, in this case, if it is determined in step b10 that spd * direc> 0, the vehicle 1 is moving forward in the X direction or moving backward in the -X direction. First, it is determined whether or not the estimated inclination is outside the inclination correction range B (step b11). If the estimated inclination is within the inclination correction range B, the process is terminated without performing the inclination correction. On the other hand, if the estimated inclination is outside the inclination correction range B, spd * direc> 0 is satisfied. For example, as shown in FIG. 6B, the estimated inclination indicated by the arrow F is corrected to an angle within the inclination correction range B on the 270 ° side as indicated by the arrow G (step b12). Also in this case, the corrected inclination may be coincident with the boundary angle of the inclination correction range B on the 270 ° side (the closer one of the two boundaries) or within the inclination correction range B on the 270 ° side. It may be at some angle.
[0041]
On the other hand, if it is determined in step b10 that spd * direc <0, the vehicle 1 is moving forward in the -X direction or moving backward in the X direction. First, it is determined whether or not the estimated inclination is outside the inclination correction range B (step b13). If the estimated inclination is within the inclination correction range B, the process is terminated without performing the inclination correction. On the other hand, if the estimated inclination is outside the inclination correction range B, spd * direc <0 is satisfied. For example, as shown in FIG. 6B, the estimated inclination indicated by the arrow F is corrected to an angle within the inclination correction range B on the 90 ° side as indicated by the arrow H (step b14). In this case, the corrected inclination may coincide with the boundary angle of the inclination correction range B on the 90 ° side (the closer of the two boundaries) or within the inclination correction range B on the 90 ° side. It may be at some angle.
[0042]
In the case of other IDs, the tilt setting process corresponding to the ID is similarly performed.
According to the second embodiment of the present invention described above, the vehicle 1 passes through any one of the reception areas A on the travel path 2 even if the estimated inclination is incorrect. Thus, the estimated inclination is corrected within the inclination correction range B. In addition, 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, a very accurate position estimation without any deviation can be realized. For example, FIG. 7 shows a display example of the traveling locus of the vehicle when the inclination correction in the second embodiment is applied. In this case, the optical beacon transmitters 11 to 15 are installed at various locations in the travel path 2 so that the inclination is corrected, so that even if the estimated position gradually goes out of order, the optical beacon transmitter Since a normal estimated position and estimated inclination are obtained each time the vehicle passes under 11 to 15, the traveling locus can be returned to normal.
[0043]
Although the first embodiment is suitable when the width of the travel path 2 is substantially equal to the width of the vehicle 1, the second embodiment is particularly suitable when the actual inclination of the vehicle 1 travels. When it is not always parallel to the passage 2, for example, when the width of the traveling passage 2 is considerably wider than the width of the vehicle 1, a very desirable result can be obtained.
<Other embodiments>
The present invention is not limited to the above-described embodiment, and various configurations can be adopted within the scope described in each claim. For example, the following configuration changes are possible.
[0044]
(1) In the first and second embodiments, the inclination correction is performed each time the vehicle 1 passes under one optical beacon transmitter. For example, two optical beacon transmitters are compared with each other. So that the inclination is corrected only when the signals from them are received in a predetermined order (that is, when the vehicle 1 passes under the two optical beacon transmitters in the predetermined order). It is also possible to do.
[0045]
In this way, since the traveling direction of the vehicle 1 can be clearly determined, even when the estimated position and the estimated inclination are completely out of order, they can be returned to normal values. . For example, FIG. 8 is a travel locus in the case where the inclination correction is performed only when the vehicle passes under the two optical beacon transmitters 15 and 14 in that order in the display example of the travel locus shown in FIG. An example is shown. As is clear from this figure, the vehicle passes under the optical beacon transmitters 15 and 14 in that order, so that the estimated position (J), which was completely random, is corrected to the normal position (K), and It can be seen that the estimated inclination has returned to the normal inclination along the traveling path 2.
[0046]
(2) The embodiment described above makes it possible to bring the estimated inclination closer to the actual inclination without detecting the actual inclination of the vehicle 1, and is accurate with relatively simple processing. The tilt can be corrected. However, if a means for detecting the actual inclination of the vehicle 1 is further provided and the estimated inclination of the vehicle 1 is corrected in accordance with the detected inclination, a more accurate inclination correction can be realized. The principle of such inclination detection is shown in FIGS.
[0047]
In the example of FIG. 9A, the reception area A is composed of two areas A1 and A2 arranged at a constant interval L in the traveling path direction, and these two areas A1 and A2 are both in the traveling path width direction. It has an asymmetric shape (for example, a trapezoidal shape). The two areas A1 and A2 are formed by different optical beacon transmitters and have different IDs. The interval L corresponds to the interval between the optical beacon transmitters, and is the distance between the central positions (positions indicated by the IDs) in the traveling path direction in the two areas A1 and A2.
[0048]
In this case, the position in the traveling passage width direction at that time is specified by measuring each passing time when the vehicle passes through the two regions A1 and A2, respectively. Specifically, since the same signal is repeatedly transmitted from the optical beacon transmitter at a constant period, by measuring the number of times of reception, the passing points T1 and T2 of the areas A1 and A2 (in the traveling path direction) The position coordinate in the traveling passage width direction at the center position) can be specified. Then, an interval W in the travel path width direction is obtained from the coordinates of T1 and T2, and the actual inclination θ of the vehicle is calculated from the interval W and the interval L in the travel path direction. At this time, the traveling direction of the vehicle can be determined from the order of the received IDs.
[0049]
In the example of FIG. 9B, the reception area A is composed of two areas A1 and A2 arranged at a constant interval L in the direction of the traveling path, as in the case of FIG. 9A. Both A1 and A2 have an asymmetric shape (for example, a trapezoidal shape) in the traveling passage width direction. However, in this example, the lengths in the traveling path direction in the two regions A1 and A2 are made different, and the lower side of the trapezoid coincides with the traveling path width direction. The two areas A1 and A2 are formed by the same optical beacon transmitter, and have the same ID.
[0050]
In this case as well, as in the example of FIG. 9A, the distance W in the travel path width direction is obtained from the coordinates of the vehicle passing points T1, T2, and the actual inclination of the vehicle is determined from this and the distance L in the travel path direction. θ is calculated. On the other hand, since the lengths of the two areas A1 and A2 in the traveling path direction are different, the traveling direction of the vehicle is determined from the difference in the passing time (number of receptions).
[0051]
In the example of FIG. 9C, the reception area A is arranged in two stages at a constant interval L in the traveling path direction, and each stage has a plurality of smaller rectangular areas A1 to A5 and A6 to A10. Are arranged at a constant interval V in the traveling passage width direction. These areas A1 to A10 are all formed by separate optical beacon transmitters and have different IDs.
[0052]
In this case, since the area through which the vehicle has passed can be determined from the IDs sequentially received when the vehicle passes, the shift in the traveling path width direction in the first-stage area and the second-stage area (integer multiple of V) The actual inclination θ of the vehicle is calculated from the distance L in the traveling path direction. On the other hand, the traveling direction of the vehicle is determined from the order of the received IDs.
[0053]
In the example of FIG. 9D, the reception area A is composed of a plurality of smaller areas A1 to A5 and A6 to A10 as in the example of FIG. 9C, but the first area A1 to A5 and In the second-stage areas A6 to A10, the ones at the same position in the travel path width direction (areas surrounded by dotted lines in the figure) form one set, and these have the same ID. Since a pair of regions having the same ID can be formed by dividing a signal from the same optical beacon transmitter into two, the number of optical beacon transmitters is reduced by half compared to the example of FIG. be able to.
[0054]
In this case, the positional deviation in the traveling passage width direction (integer multiple of V) is obtained from the ID sequentially received when the vehicle passes, and the actual inclination θ of the vehicle is calculated from this and the interval L in the traveling passage direction. To do. However, the traveling direction needs to be determined by another method. For example, as shown in FIG. 9 (e), if another region A11 having a completely different ID and a width that can cover the width of the traveling path is provided at another position in the traveling path direction, The direction of travel can be discriminated based on whether the ID is received first or later.
[0055]
In the example of FIG. 9 (f), the reception area A is arranged in three stages at regular intervals L 1 and L 2 (L 1> L 2) in the traveling path direction, and each stage has a plurality of smaller rectangular shapes. Regions A1 to A5, A6 to A10, and A11 to A15 are arranged at a constant interval V in the traveling passage width direction. Among these areas, those located at the same position in the traveling passage width direction (area surrounded by a dotted line in the figure) form one set, and they have the same ID.
[0056]
In this case, the calculation of the inclination θ is the same as in the example of FIG. On the other hand, the traveling direction can be determined from the reception time intervals of the IDs that are sequentially received because each stage is arranged such that L1> L2.
In the example of FIG. 9G, the reception area A is one rectangular region having a certain width L in the traveling path direction.
[0057]
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, the traveling direction needs to be determined by another method. For example, as shown in FIG. 9 (h), an area A1 similar to FIG. 9 (g) combined with areas A2 and A3 similar to FIG. It is possible to detect not only the direction of travel. That is, the inclination θ is calculated using the area A1, and the traveling direction is determined using the areas A2 and A3. In this case, the areas A1, A2, and A3 are assumed to have different IDs.
[0058]
In the example of FIG. 9 (i), the reception area A is composed of two areas A1 and A2 arranged at a constant interval L in the traveling path direction, and these two areas A1 and A2 are adjacent to each other. One side is parallel and both these two sides are perpendicular to the direction of the travel path. Note that these two adjacent opposing sides are set at a constant interval L.
[0059]
In this case, the travel distance L ′ between the reception end point T21 of the first area A2 and the reception start point T22 of the next area A1 associated with the passage of the vehicle is obtained, and the same as in the example of FIG. Based on the idea, the actual inclination θ of the vehicle is calculated. On the other hand, the traveling direction of the vehicle is determined from the order of the received IDs. In this example, the number of optical beacon transmitters can be reduced by one compared to the example of FIG.
[0060]
Note that the example shown in FIG. 9 is only an example of the inclination detecting means, and the present invention is not limited to these. In addition, the inclination detected by such an inclination detecting means is not necessarily used for correcting the inclination, and those used for other purposes are within the scope of the present invention.
[0061]
【The invention's effect】
According to the present invention, even if the estimated inclination of the vehicle is out of order, the estimated inclination is corrected to a more appropriate angle by the vehicle passing through the reception area of the optical beacon transmitter. Therefore, very accurate position estimation can be realized.
[0062]
Further, if an inclination detecting means for detecting the actual inclination of the vehicle is further provided and the estimated inclination is corrected to the detected inclination, the position can be estimated with higher accuracy. Of course, such a tilt detection means can be used for various purposes other than tilt correction.
[Brief description of the drawings]
FIG. 1 is a diagram showing the principle of inclination correction in a first embodiment of the present invention.
FIG. 2 is a flowchart showing an inclination correction process in the first embodiment of the present invention.
FIG. 3 is a diagram illustrating a relationship between a direction on a coordinate system and an angle.
FIG. 4 is a diagram illustrating a principle of inclination correction in a second embodiment of the present invention.
FIG. 5 is a flowchart showing an inclination correction process in the second embodiment of the present invention.
FIG. 6 is a diagram showing an example of inclination correction in the second embodiment of the present invention.
FIG. 7 is a diagram illustrating a display example of a traveling locus of a vehicle when applying an inclination correction according to the second embodiment of the present invention.
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 inclination detection in another embodiment of the present invention.
[Explanation of symbols]
1 vehicle
2 travel path
11, 12, 13, 14, 15 Optical beacon transmitter
A Reception area
B Inclination correction range

Claims (8)

An optical beacon transmitter installed at a key point of a traveling path of the vehicle, and an optical beacon receiver that is mounted on the vehicle and receives a signal transmitted from the optical beacon transmitter; In the vehicle position estimation device for estimating the traveling position of the vehicle based on the received signal of
Based on a reception signal of the optical beacon receiver when the vehicle passes through a reception area by the optical beacon transmitter, comprising an inclination correction means for correcting an estimated inclination of the vehicle with respect to the travel path ;
The inclination correction means does not perform correction when the estimated inclination of the vehicle is within a predetermined inclination correction range corresponding to the optical beacon transmitter forming the reception area through which the vehicle passes, The vehicle position estimation apparatus, wherein when the estimated inclination of the vehicle is not within the predetermined inclination correction range, the vehicle is corrected to an inclination within the predetermined inclination correction range . When the estimated inclination of the vehicle is not within the predetermined inclination correction range, the inclination correction means corrects the estimated inclination of the vehicle so as to coincide with a boundary angle of the predetermined inclination correction range. The vehicle position estimation apparatus according to claim 1. When the estimated inclination of the vehicle is not within the predetermined inclination correction range, the inclination correcting means is configured to change the estimated inclination of the vehicle to the optical beacon transmitter that forms a reception area through which the vehicle passes . The vehicle position estimating apparatus according to claim 1 , wherein the vehicle position estimating apparatus is corrected so as to be parallel to the installed traveling path. The vehicle position estimation apparatus according to any one of claims 1 to 3 , wherein the inclination correction unit corrects the estimated inclination in consideration of an actual traveling direction and a vehicle speed of the vehicle. The inclination correction means includes inclination detection means for detecting an actual inclination of the vehicle with respect to the travel path based on a reception signal of the optical beacon receiver, and the estimated inclination of the vehicle is within the predetermined inclination correction range. 2. The vehicle position estimation apparatus according to claim 1, wherein when there is no vehicle, the estimated inclination of the vehicle is corrected in accordance with the inclination detected by the inclination detecting means. An optical beacon transmitter installed at a key point of a traveling path of the vehicle, and an optical beacon receiver that is mounted on the vehicle and receives a signal transmitted from the optical beacon transmitter; In the vehicle position estimation device for estimating the traveling position of the vehicle based on the received signal of
Inclination detecting means for detecting an actual inclination of the vehicle with respect to the travel path based on a reception signal of the optical beacon receiver when the vehicle passes through a reception area by the optical beacon transmitter.
The reception area is composed of at least two regions arranged at a constant interval in the traveling passage direction, both of which have an asymmetric shape in the traveling passage width direction,
The inclination detection means obtains coordinates in the traveling path width direction at each vehicle passing point in the two areas from each passing time when the vehicle passes through each of the two areas. based on the actual vehicle both position estimation device you and detecting the inclination. An optical beacon transmitter installed at a key point of a traveling path of the vehicle, and an optical beacon receiver that is mounted on the vehicle and receives a signal transmitted from the optical beacon transmitter; In the vehicle position estimation device for estimating the traveling position of the vehicle based on the received signal of
Inclination detecting means for detecting an actual inclination of the vehicle with respect to the travel path based on a reception signal of the optical beacon receiver when the vehicle passes through a reception area by the optical beacon transmitter.
The reception area is composed of one rectangular area having a certain width in the direction of the travel path,
It said inclination detecting means, wherein the actual vehicle both position estimation device you and detects the inclination based distance and the said width between passage start point and passing the end point of該矩shaped region. The vehicle position estimation apparatus according to claim 6 or 7 , wherein the inclination detection unit detects a traveling direction of the vehicle in addition to the actual inclination.

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