JPH04311209A - Device for detecting position of mobile vehicle - Google Patents

Abstract

PURPOSE:To winden the detectable range of a device without lowering the detecting accuracy of the relative position between a mobile vehicle and storage medium. CONSTITUTION:On the mobile vehicle for which a coil 3 for supplying power by electromagnetic induction is provided on a storing medium B installed on the ground, 15 pieces of pickup coils Cmn are arranged in a five-row three- column matrix for calculating the relative position between the vehicle and medium B from the strength distribution of a magnetic field formed by the coil 3. A processing means selects one out of three small three-row three-column matrixes included in the above-mentioned matrix and calculates the relative positions in the direction of the rows and columns based on the detected values of nine pickup coils Cmn in the small matrixes. Out of the turee small matrixes, the matrix having the smallest total sum of the detected values of the 9 pieces of pickup coils Cmn in the matrix is selected.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a power supply coil for supplying power to a storage medium installed on the ground side by electromagnetic induction in a mobile vehicle, and the strength of the magnetic field formed by the power supply coil. A plurality of pickup coils for detecting the distribution are arranged at predetermined intervals, and processing means is provided for calculating the relative position of the moving vehicle and the storage medium based on the detection values from the pickup coils. The present invention relates to a position detection device for a moving vehicle.

0002

[Prior Art] As a conventional example of such a position detecting device for a moving vehicle, Japanese Patent Application No. 145207 filed earlier by the present applicant is known.
There are some listed in the issue. In this conventional example, the storage medium is installed along the traveling route of the moving vehicle, and stores the driving control to be applied to the moving vehicle. It also includes communication means for performing close proximity wireless communication with the moving vehicle using electromagnetic induction. This storage medium does not have a built-in battery, and its power consumption is supplied non-contact by electromagnetic induction from the moving vehicle. As the moving vehicle approaches the storage medium, it supplies power to the storage medium and reads the stored information through communication. Based on that information, subsequent driving control is performed. Therefore, the mobile vehicle is equipped with a power supply coil and a communication coil, and the storage medium is equipped with a power reception coil and a communication coil.

Specifically, as shown in FIG. 5, a storage medium B is buried in the road surface of a moving vehicle, and the moving vehicle is equipped with a power supply coil 3 wound in a rectangular loop shape when viewed from above. It is being Five pickup coils 5a, 5b, .

[0004] The induced voltage generated in each pickup coil is the smallest when the central portion of the storage medium B is located directly below the pickup coil. Therefore, the relative position between the power feeding coil 3 and the storage medium B, that is, the relative position between the mobile vehicle and the storage medium B, can be detected from the induced voltage generated in these pickup coils. For example, a pair of pickup coils 5a and 5b in the figure
The relative position in the left and right direction can be determined from the difference in the induced voltage. Note that the central pickup coil 5e is provided to compensate for the decrease in sensitivity of each pickup coil when the power feeding coil 3 is located directly above the storage medium B.

[0005] Also, in order to be able to quantitatively detect the relative positions in the left and right directions and the relative positions in the front and back directions even when the positional relationship between the moving vehicle and the storage medium B is diagonally deviated,
As shown in Figure 6, 9 pickup coils are arranged in 3 rows and 3
It is conceivable to arrange them in a matrix of columns.

[0006]

[Problems to be Solved by the Invention] The relative position between the moving vehicle and the storage medium can be quantitatively detected by the conventional example shown in FIG. It is almost limited to cases within a cross-shaped range up to the picked-up coil. Moreover, in the case of FIG. 6, it is almost limited to a rectangular range connecting eight surrounding pickup coils.

On the other hand, if an attempt is made to widen the interval between adjacent pickup coils in order to widen the relative position detection range, the induced voltage of each pickup coil will no longer change linearly according to the relative position, resulting in a decrease in detection accuracy. do. The present invention has been made in view of the above circumstances, and its purpose is to widen the relative position detection range without reducing detection accuracy.

[0008]

[Means for Solving the Problems] A position detecting device for a mobile vehicle according to the present invention is provided with a power supply coil for supplying power to a storage medium installed on the ground side by electromagnetic induction in the mobile vehicle; A plurality of pickup coils are arranged at predetermined intervals to detect the intensity distribution of the magnetic field formed by the coils, and the relative relationship between the moving vehicle and the storage medium is determined based on the detected values from the pickup coils. A processing means for calculating the position is provided, the first
The characteristic configuration is that a larger number of the pickup coils than necessary for calculating the relative position are arranged,
The processing means selects a necessary number of adjacent pickup coils to calculate the relative position based on the detection values from all the pickup coils, and selects the detection values from the plurality of selected pickup coils. The present invention is configured to calculate the relative position based on .

A second characteristic configuration is that in the first characteristic configuration, all the pickup coils are arranged in a two-dimensional matrix, and the relative positions in the row direction and the column direction of the matrix are A plurality of small matrices constituted by the number of pickup coils necessary for calculating the position are included in the matrix, and the processing means calculates the number of the plurality of small matrices based on the detected values from all the pickup coils. The device is configured to select one of the matrices and calculate the relative position in the row direction and the relative position in the column direction based on detected values from a plurality of pickup coils in the selected small matrix. It is in the point that it is.

The third characteristic configuration specifies one specific configuration in the second characteristic configuration, in which 15 pickup coils are arranged in a matrix of 5 rows and 3 columns, and the processing means , 3 included in the matrix
It is configured to select one of three small matrices of three rows and three columns.

[0011] The fourth characteristic configuration specifies a preferable specific configuration for implementing the second characteristic configuration, in which the processing means, for each of the plurality of small matrices, processes all of the small matrices. Detected values from the pickup coils are summed, the sums are compared between the small matrices, and the small matrix with the smallest sum is selected.

0012

[Operation] According to the first characteristic configuration, for example, if the number of pickup coils required to calculate the relative position is three, four or more pickup coils are arranged, and the processing means , selects the three most suitable adjacent pickup coils for calculating the relative position based on the detected values from all the pickup coils. Generally speaking, M pickup coils are arranged at predetermined intervals, and K adjacent pickup coils are selected. There are (M-K+1) pickup coil sets made up of K pickup coils, and to select one of them, for example, select the pickup coil set with the smallest sum of detection values from the pickup coils. good. Based on the detected values from the K adjacent pickup coils selected as described above, the relative position is basically calculated as described in "Prior Art".

According to the second characteristic configuration, in order to calculate the two-dimensional relative position, for example, nine pickup coils arranged in a matrix (small matrix) of 3 rows and 3 columns are required. Then either the row or column or both will be 4.
Twelve or more pickup coils are arranged in the above matrix. Then, the processing means selects the one most suitable for detecting the relative position of the moving vehicle and the storage means at that time from among the plurality of small matrices based on the detection values from all the pickup coils. Generally speaking, M×N pickup coils are arranged in a matrix of M rows and N columns, and a small matrix of K rows and L columns included therein is selected. There are (M-K+1)×(N-L+1) small matrices, and to select one of them, for example, there is a method shown in the fourth feature configuration. Then, the relative position in the row direction and the relative position in the column direction are calculated based on the detected values from the K×L pickup coils in the selected small matrix.

According to the third characteristic configuration, as shown in FIG. 1, 15 pickup coils are arranged in a matrix of 5 rows and 3 columns. This matrix has 3 rows 3
Contains three small matrices of columns. The processing means selects one of the three small matrices and determines the relative position in the row direction and the relative position in the column direction based on the detected values from the nine pickup coils in the selected small matrix. Calculate the position.

According to the fourth characteristic configuration, when selecting one of the plurality of small matrices in the second characteristic configuration, the control means selects one of the plurality of small matrices such that the sum of detected values from the pickup coils in the small matrix is the minimum. Select a small matrix with .

[0016]

[Effects of the Invention] According to the first characteristic configuration, the number of adjacent pickup coils can be increased without changing the interval between them, so the relative position detection range can be expanded without reducing detection accuracy. It has become possible. According to the second characteristic configuration, it is possible to expand the detection range when calculating a two-dimensional relative position. According to the third characteristic configuration,
Compared to the case where nine pickup coils are arranged in three rows and three columns, it is now possible to obtain about twice the detection range in the row direction as long as the spacing between the pickup coils is the same. According to the fourth characteristic configuration, since one of the plurality of small matrices can be selected by simple calculations of addition and comparison, the processing load on the control means is light, and the pickup coils in the small matrix can be selected. Since the selection is based on the sum of detected values from the matrix, it is now possible to select the optimal small matrix while suppressing the influence of noise.

As described above, it has become possible to accurately perform travel control, steering control, and stop control of a moving vehicle based on a wide range of two-dimensional relative position data obtained in real time.

[0018]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. As shown in FIG. 4, a storage medium B is embedded in the road surface on which a mobile vehicle A travels. The storage medium B is provided at a plurality of locations along the travel route of the moving vehicle A, and has its address, address,
Travel control information such as addresses, branching directions, distances, etc. of adjacent storage media are stored. When the mobile vehicle A approaches the storage medium B, the communication device 11 performs close proximity wireless communication with the storage medium B and reads out the stored information. Then, based on the read travel control information, the vehicle autonomously travels to the next storage medium and travels along a predetermined travel route by sequentially tracing the plurality of storage media.

The moving vehicle A is provided with running wheels 14 on the front, rear, left and right sides which are propelled by a running motor 12 and also serve as steering wheels which are steered and driven by a steering motor 13. Each running wheel 14 is provided with an encoder 15 that generates a number of pulses proportional to the number of rotations. As shown in Figure 2,
The moving vehicle A is equipped with a processing means 4 equipped with a microcomputer, and the processing means 4 calculates the travel control information, the travel distance and travel speed determined from the pulses of the encoder 15, and the relative position of the storage medium to be described later. Based on information etc., the running motor 12 and steering motor 1 of each running wheel 14
3 to drive autonomously.

As shown in FIGS. 1 and 3, the storage medium B has a surface exposed to the road surface covered with a tile surface plate 16 of about 300 mm square, and a rectangular loop-shaped receiving coil underneath. 17, transmission coil 18, and power reception coil 19
are arranged sequentially from the center to the outside. Receiving coil 1
7 and the transmitting coil 18 are for performing close proximity wireless communication with the moving vehicle A, and are tuned to radio waves in the VHF band. The power receiving coil is for contactlessly receiving power supplied from mobile vehicle A using electromagnetic waves of about 25 KHz. In other words, storage medium B does not include a battery, and its power consumption is supplied from mobile vehicle A. Since the storage medium B is energized only when the moving vehicle A approaches, and otherwise is not energized, a nonvolatile IC memory is used as the storage element provided in the storage medium main body 20.

As shown in FIG. 1, the communication device 11 of the mobile vehicle A is provided with a transmitting coil 1 and a receiving coil 2 facing the receiving coil 17 and transmitting coil 18 of the storage medium B, respectively. There is. Transmitting coil 1 and receiving coil 2
As shown in FIG.
and exchange data.

A power feeding coil 3 is provided outside the receiving coil 2. The power feeding coil 3 is configured in a rectangular loop shape that is longer in the left and right direction than the power receiving coil 19 of the storage medium B in order to expand the position detection range described below in the left and right direction. As shown in FIG. 1, 15 pickup coils Cmn (m=
1 to 5, n=1 to 3) are arranged at predetermined intervals d in a matrix of 5 rows and 3 columns.

An induced voltage is generated in each pickup coil Cmn by the magnetic field formed by the power supply coil 3. As shown in Fig. 2, each induced voltage is amplified by the signal processing circuit 6, passed through a bandpass filter, rectified and smoothed to become a DC voltage, and converted into a digital value by an A/D converter. and is input to the processing means 4.

The induced voltage generated in the pickup coil Cmn is generated between the power feeding coil 3 and the power receiving coil 1 of the storage medium B.
It changes depending on the strength of electromagnetic coupling with 9. In other words, the closer the electromagnetic coupling between the two, the more the magnetic flux distribution will change between the feeding coils 3 and 3.
The lower part is denser and the upper part is sparser, and as a result, the induced voltage generated in the pickup coil Cmn becomes lower.

When the power feeding coil 3 of the mobile vehicle A is located directly above the storage medium B as shown in FIG. 1, for example, the induced voltage of the pickup coil C22 and the induced voltage of the pickup coil C24 decrease equally. However, if moving vehicle A
If is displaced to the right, the voltage induced in the pickup coil C22 will decrease more than the voltage induced in the pickup coil C24.

Therefore, to put it simply, the processing means 4 calculates the difference (P22-
P24), the relative position of the moving vehicle A and the storage medium B in the left-right direction can be calculated. In practice, the following arithmetic processing is performed in order to correct the effects of vertical positional deviation and obtain more accurate quantitative values of the left and right relative positions.

First, the pickup coil Cm due to variations in the vertical distance between the moving vehicle A and the storage medium B
In order to correct the change in the detected value from n, the difference in the detected value is divided by the amount of change in the sum of the detected values. That is, (P22-
P24)/(2-(P22+P24)) However, each detected value is normalized so that the value when the power feeding coil 3 is not electromagnetically coupled to the storage medium B is 1.

Second, when the power feeding coil 3 of the mobile vehicle A is located directly above the storage medium B, each pickup coil Cmn
Since the sensitivity of the sensor decreases, it is compensated for by the detected value P23 from the pickup coil C23 provided at the center. That is, (P2
2-P24)/(3-(P22+P23+P24))

Thirdly, if the moving vehicle A and the storage medium B are also out of alignment in the front-back direction, the left and right pickup coils C2
The difference (P22-P24) between the detected values of C2 and C24 no longer changes linearly with respect to the relative position in the left-right direction. Therefore, in order to correct the influence of positional deviation in the front-rear direction, three pickup coils C arranged in the front-rear direction (column direction)
Three values obtained by adding detected values Pmn from mn (m=2 to 4, n=1 to 3) for each row are used. That is, P0
2=P12+P22+P32 P03=P13+P23+P33 P04=P14+P24+P34 Using the three values P02, P03, and P04, the relative position X in the left-right direction is determined by the following formula.

[0030]

[Math 1]

[0031] However, C and D are offset constants.

[0032] The relative position Y in the front-rear direction is also determined in the same manner. That is, the three values P1c obtained by adding the detection values Pmn from the three pickup coils Cmn (m=2 to 4, n=1 to 3) arranged in the left-right direction (row direction) for each column.
=P12+P13+P14 P2c=P22+P23+P24 P3c=P32+P33+P34 It is determined by the following formula.

[0033]

[Math 2]

However, E and F are offset constants.

The above relative position calculation is performed using the 15 pickup coils C arranged in a matrix of 5 rows and 3 columns.
mn (m=1-5, n=1-3), both end rows (m=
The nine pickup coils Cmn (m
= 2 to 4, n = 1 to 3). When the deviation from the positional relationship in which the power feeding coil 3 of the moving vehicle A is directly above the storage medium B (hereinafter simply referred to as the positional deviation between the moving vehicle A and the storage medium B) is less than or equal to the pickup coil spacing d, As mentioned above, nine pickup coils Cmn (m=2~
4, n=1 to 3) can be used to calculate the relative position.

When the positional deviation between the moving vehicle A and the storage medium B exceeds the pickup coil spacing d in either the left or right direction, the nine pickup coils arranged in a matrix of 3 rows and 3 columns in the center are no longer used. pickup coil Cmn (m=2~4,
It is not possible to calculate the relative position using n=1 to 3). In such a case, the position detection device of this embodiment shifts the nine pickup coils used for relative position detection by one line to the left or right. That is, a matrix of 3 rows and 3 columns (hereinafter,
By shifting the small matrix) to the left and right, the detectable range of the relative position is expanded to the left and right.

For example, if the moving vehicle A is shifted to the right with respect to the storage medium B by a distance exceeding d but not exceeding 2d, the nine pickup coils Cmn (m=1 to Detected value Pm from 3, n=1 to 3)
The relative position can be calculated using n. That is, P
01=P11+P21+P31 P02=P12+P22+P32 P03=P13+P23+P33 Then, the relative position X in the left-right direction can be determined by the following formula.

[0038]

[Math 3]

Similarly, if the moving vehicle A is shifted to the left with respect to the storage medium B by a distance exceeding d but not exceeding 2d, the nine pickup coils Cmn (m=3 ~5, n=1~3) detected value Pm
The relative position can be calculated using n. That is, P
03=P13+P23+P33 P04=P14+P24+P34 P05=P15+P25+P35 Then, the relative position X in the left and right direction can be determined by the following formula.

[0040]

[Math 4]

As described above, the detection range of the relative position in the left and right direction is the center nine pickup coils Cmn (m=
2 to 4, n = 1 to 3) is used, whereas it is ±d, whereas the value of Cmn for all 15 pickup coils (m =
1 to 5, n=1 to 3), the range is expanded to ±2d.

The determination as to which of the three small matrices should be selected to calculate the relative position is made as follows. First, the detected values from the nine pickup coils Cmn are summed for each of the three small matrices. Then, the total sum is compared among the three small matrices, and the small matrix with the smallest sum is selected. This is because the smallest sum means the largest drop in induced voltage and means that the center of the storage medium B is located below within the small matrix.

Regarding the relative positions in the front-rear direction, even when the left and right small matrices are selected, the nine pickup coils Cmn (m=2 to 4,
It is calculated in the same way as when using n=1 to 3). In this embodiment, the detection range of the relative position in the front-rear direction is not expanded, and the range is ±d in the front-rear direction, but it can be expanded in the same manner as the detection range of the relative position in the left-right direction.

Furthermore, in the left and right direction, the number of lines is not limited to five, but it is also possible to further increase the number of lines to further expand the relative position detection range. Generally speaking, M rows N
(M×N) pickup coils Cmn (m=1 to M, n=1 to N) are arranged in a matrix of rows, and (M−2)×(N−2) pickup coils are included in the matrix. It is possible to select one of the small matrices of 3 rows and 3 columns, and calculate the relative positions in the front-rear direction and the left-right direction based on the detected values from the nine pickup coils in the small matrix.

As a method for selecting one small matrix, in addition to the method of the above embodiment, detection values from all pickup coils are compared, and a small matrix having the pickup coil with the smallest detection value as the central element is selected. There are other ways to choose. However, the small matrix is not limited to a matrix with 3 rows and 3 columns, but may be a matrix with 2 rows and 2 columns or a matrix with 4 rows and 4 columns, for example. In the case of these even matrices, the method of the above embodiment in which the sums of detection values from the pickup coils in the small matrices are compared is suitable.

[0046] The above explanation centered on the embodiment was about expanding the detection range of relative positions in the left-right direction and front-back direction in two-dimensional relative position detection, but the same applies to one-dimensional relative position detection. Needless to say, the detection range can be expanded by In this case, it is simpler, and for example, three adjacent pickup coils (hereinafter referred to as a pickup coil group) are selected from among M pickup coils Cm (m=1 to M) arranged in a row at predetermined intervals. , and calculate the relative position based on the detected values from the three pickup coils.

In this case, as in the two-dimensional case, the method for selecting one of the (M-2) pickup coil sets is to select the one that has the smallest sum of detection values from the three pickup coils. There is a method of selecting a pickup coil set, and a method of selecting a pickup coil set consisting of the pickup coil with the smallest detection value among all the pickup coils and the pickup coils on both sides of the pickup coil.

[0048] Although reference numerals are written in the claims for convenience of comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram of a pickup coil, etc. in a position detection device for a moving vehicle according to an embodiment of the present invention.

[Figure 2] Similarly, a block diagram of the position detection device

[Fig. 3] Partial cross-sectional view of a storage medium in plan view

FIG. 4 is a schematic side view showing a moving vehicle and a traveling road surface according to an embodiment of the present invention.

[Fig. 5] Layout diagram of pickup coils, etc. in a conventional mobile vehicle position detection device

[Fig. 6] Layout diagram of pickup coils, etc. in a position detection device for a moving vehicle according to another conventional example.

[Explanation of symbols]

3 Power feeding coil 4 Processing means Cmn Pick-up coil A
Mobile vehicle B storage medium

Claims (4)

[Claims] Claim 1: A power feeding coil (3) for feeding power to a storage medium (B) installed on the ground side by electromagnetic induction.
) is provided on the mobile vehicle (A), and the power feeding coil (3)
A plurality of pickup coils (Cmn) are arranged at predetermined intervals to detect the strength distribution of the magnetic field formed by the moving vehicle (A). ) and the storage medium (B), the position detection device for a moving vehicle is provided with a processing means (4) for calculating the relative position between the storage medium (B) The pickup coil (Cmn) is arranged, and the processing means (4) processes a necessary number of adjacent pickups to calculate the relative position based on the detection values from all the pickup coils (Cmn). A position detecting device for a moving vehicle configured to select a coil (Cmn) and calculate the relative position based on detected values from the selected plurality of pickup coils (Cmn). [Claim 2] All the pickup coils (Cm
n) are arranged in a two-dimensional matrix, and are composed of a number of pickup coils (Cmn) necessary to calculate the relative position in the row direction and the relative position in the column direction of the matrix. are included in the matrix, and the processing means (4) selects one of the plurality of small matrices based on the detected values from all the pickup coils (Cmn), and 2. The device according to claim 1, wherein the relative position in the row direction and the relative position in the column direction are calculated based on detected values from a plurality of pickup coils (Cmn) within a selected small matrix. Position detection device for moving vehicles. [Claim 3] 15 pickup coils (Cmn
) are arranged in a matrix of 5 rows and 3 columns, and the processing means (4) is configured to select one of the three small matrices of 3 rows and 3 columns included in the matrix. The position detection device for a moving vehicle according to claim 2. 4. The processing means (4) sums up detection values from all pickup coils (Cmn) within the plurality of small matrices for each of the plurality of small matrices, and compares the sums between the small matrices. 3. The position detection device for a moving vehicle according to claim 2, wherein the device is configured to select the small matrix whose sum is the smallest.