JP2007132689A - Magnetic marker detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic marker capable of effectively performing trouble recognition. <P>SOLUTION: The magnetic sensor 3 for detecting the magnetic field emitted from the magnetic markers M laid on the running route 11 is provided with a plurality of magnetic detection parts which are parallel arranged in a prescribed direction of the vehicle 2. The magnetic marker detecting device recognizes the center position of a region containing the magnetic detection part satisfying the predetermined magnetic field intensity condition among the plurality of magnetic detection parts as the position of the marker M to the vehicle 2. By comparing the center position of the region with the center position of the region where the magnetic detection parts satisfying the predetermined magnetic field intensity condition in the region continue without intermission, if both the center positions are different, it is determined that there is a defective magnetic detection part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic marker detection device, and more specifically, a magnetic detection unit provided to detect the position of a magnetic marker that emits a magnetic field, and a plurality of magnets arranged in a predetermined direction of a moving body. The present invention relates to a magnetic marker detection device that recognizes a failure in a detection unit.

  2. Description of the Related Art Conventionally, there has been known a failure recognition method for a magnetic sensor that uses a magnetic detection unit such as a magnetoresistive element to detect the position of a magnetic marker that emits a magnetic field embedded at a predetermined interval on a road (for example, patent literature) 1).

  FIG. 1 is a configuration diagram for explaining a traveling system of a vehicle equipped with a magnetic sensor. Magnetic markers M are installed on the travel path 11 at predetermined intervals, and the magnetic sensor 3 performs magnetic detection between any predetermined positions on the travel path 11 between the predetermined magnetic markers M. An installed reference marker Mx (an N pole reference marker Mxn magnetized to the N pole and an S pole reference marker Mxs magnetized to the S pole) is installed. The magnetic sensor 3 has a plurality of magnetic detection elements arranged in a line in the vehicle width direction of the vehicle. When the magnetic marker M or the reference marker Mx is detected, the magnetic sensor 3 detects the magnetism. Only the magnetic detection element is turned on.

  Therefore, in order to recognize the position in the vehicle width direction of the magnetic marker M with respect to the vehicle 2 (in other words, the position in the vehicle width direction of the vehicle 2 with respect to the magnetic marker M), the magnetic marker M is turned on. What is necessary is just to calculate the center position of the region including the magnetic detection element.

Further, when the vehicle 2 passes the reference marker Mx, all the magnetic detection elements must be in an ON state if they are normal. Therefore, when the vehicle 2 passes the reference marker Mx, each of the magnetic detection elements is detected. By reading the state, if there is a magnetic detection element that is not in the on state, it is possible to recognize that the magnetic detection element has an off failure.
Japan Society for Invention and Innovation Open Technical Report 2005-500058

  However, in the above-described prior art, the position recognition process for calculating the center position of the region including the magnetic detection element that is in the ON state and the detection state of each magnetic detection element when the vehicle passes the reference marker are read. Since the failure recognition process for detecting a failure is performed independently of each other, the memory capacity and processing time are increased.

  Accordingly, an object of the present invention is to provide a magnetic marker detection device that can efficiently perform fault recognition.

In order to solve the above problems, according to one aspect of the present invention,
A plurality of magnetic detectors that are arranged side by side in a predetermined direction of the moving body and detect a magnetic field emitted by a magnetic marker laid on the road,
A magnetic marker detection device for recognizing a center position of a region including a magnetic detection unit that satisfies a predetermined magnetic field strength condition among a plurality of magnetic detection units as a position of the magnetic marker with respect to the moving body,
The center position of the region is compared with the center position of a continuous region of the region where the magnetic detection condition satisfying the predetermined magnetic field strength is not interrupted. A magnetic marker detection device is provided that determines that there is.

  According to this aspect, since the failure recognition is performed from the result of the position recognition process for the magnetic marker with respect to the moving object, the ROM capacity and the processing time can be saved without simultaneously operating the position recognition process and the failure recognition process.

  Here, in this aspect, at least one or more of the magnetic markers are arranged so that all the magnetic detection units can satisfy the predetermined magnetic field strength condition no matter where the moving body passes. A reference magnetic marker is desirable. This is because when the end portions of a plurality of magnetic detection units arranged side by side are out of order, the calculation results of the two center positions are equal and there is a possibility that the failure cannot be recognized.

  Further, comparison may be performed with respect to both the center positions only when passing through the reference magnetic marker. When the moving body passes through the reference magnetic marker as described above, if all the magnetic detection units are normal, all the magnetic detection units must satisfy a predetermined magnetic field strength condition. This is because if the failure is determined, the failure determination is performed for all the magnetic detection units even if the failure is not recognized when passing through a magnetic marker other than the reference magnetic marker.

  If the number of magnetic detection units satisfying the predetermined magnetic field strength is all or almost all (assuming several failures), it can be determined that the reference magnetic marker has passed, If the number of magnetic detectors satisfying the magnetic field strength is smaller than when passing through the reference magnetic marker, it can be determined that the magnetic marker other than the reference magnetic marker has passed. It is preferable to determine whether or not the reference magnetic marker has passed according to the number of detection units.

  According to the present invention, failure recognition can be performed efficiently.

  The best mode for carrying out the present invention will be described below with reference to the drawings. As shown in FIG. 1, the system of the present embodiment includes a travel path 11 as an infrastructure facility, and the vehicle 2 travels on the travel path 11. A magnetic marker M is laid on the travel path 11 at predetermined intervals along the center thereof. Each magnetic marker M of the present embodiment is formed of a magnetic nail having an upper portion with an N pole and a lower portion with an S pole, and generates a magnetic field around the magnetic nail. Further, a reference magnetic marker Mx, that is, an N pole reference marker Mxn or an S pole reference marker Mxs is laid between predetermined magnetic markers M on the travel path 11. The N pole reference marker Mxn and the S pole reference marker Mxs are detected by the magnetic detection unit of the magnetic sensor 3 regardless of the position of the vehicle 2 on the traveling path 11 in the vertical direction of the drawing (in the vehicle width direction). It is installed so that it can.

  The magnetic sensor 3 is installed at the bottom of the vehicle body, for example. FIG. 2 is a diagram illustrating a positional relationship between the magnetic marker M and the magnetic sensor 3 when the vehicle 2 passes the magnetic marker M. 2A shows a diagram when the positional relationship is seen from above the vehicle, and FIG. 2B shows a diagram when the positional relationship is seen from the rear of the vehicle. The magnetic sensor 3 includes, for example, 59 magnetic detectors arranged in a line in the vehicle width direction (also referred to as an array type magnetic sensor). Although FIG. 2 shows only one row, of course, a plurality of rows may be provided in parallel. Each magnetic detection unit detects the vertical magnetic field strength and outputs a voltage corresponding to the vertical magnetic field strength. In this embodiment, the reference numerals of the magnetic detection units are # 0, # 1,..., # 58 in order from the left side of the vehicle body.

  FIG. 3 is a diagram for explaining the relationship between the distribution of the vertical magnetic field strength of the magnetic field generated by the magnetic marker M and the detection state of each magnetic detection unit of the magnetic sensor 3. The vertical magnetic field strength of the magnetic field generated by the magnetic marker M is approximately the same on a concentric circle, and decreases as the distance from the center position increases. FIG. 3A is a relationship diagram between the distribution of the vertical magnetic field strength of the magnetic field generated by one magnetic marker M and the detection state of each magnetic detection unit of the magnetic sensor 3. For example, when the threshold value for determining the detection / non-detection of magnetism is set at the position shown in FIG. 3A, the magnetic detection units # 2 to 5 that detect the perpendicular magnetic field strength equal to or higher than the threshold value detect the magnetism. It will be determined that On the other hand, FIG. 3B is a relationship diagram between the distribution of the vertical magnetic field strength of the magnetic field generated by the N pole reference marker Mxn or the S pole reference marker Mxs and the detection state of each magnetic detection unit of the magnetic sensor 3. For example, when the threshold value for determining the detection / non-detection of magnetism is set at the position shown in FIG. 3B, all the magnetic detection units # 0 to # 58 that detect the perpendicular magnetic field strength equal to or greater than the threshold value are set. It is determined that magnetism is detected.

  Each magnetic detection unit of the magnetic sensor 3 outputs a voltage corresponding to the strength of the magnetic field that circulates in the vertical direction. In this embodiment, each magnetic detection unit outputs a larger voltage as the strength of the circulating vertical magnetic field increases. That is, the output voltage of the magnetic detection unit increases as the magnetic detection unit approaches the position where the magnetic marker M passes, and decreases as the position from the position through which the magnetic marker M passes. Therefore, in order to recognize which position of the traveling path 11 the vehicle 2 is traveling on, the value of the output voltage of each magnetic detection unit is used.

  FIG. 4A shows a block diagram of the magnetic marker detection device 10 of the first embodiment. The magnetic marker detection device 10 according to the first embodiment includes a magnetic sensor 3, a comparator 22, a control unit 7, and the like.

  FIG. 5A is a diagram illustrating an example of output voltage characteristics with respect to the vertical magnetic field strength of each magnetic detection unit of the magnetic sensor 3 of the magnetic marker detection device 10 according to the first embodiment. As shown in FIG. 5A, the output voltage Vc increases as the vertical magnetic field strength increases.

The control unit 7 performs predetermined control based on the output voltage of each magnetic detection unit of the magnetic sensor 3, but the comparator 22 controls the magnetic detection unit of the magnetic sensor 3 as shown in FIG. It is provided between the unit 7. The magnetic marker detection device 10 according to the first embodiment includes comparators 22 corresponding to the magnetic detection units # 0 to # 58 in the magnetic sensor 3, respectively. Incidentally, the comparator 22 respectively corresponding to the magnetic detection unit # 0 through # 58, referred to as the comparator _{22 0-22 58.}

Each magnetic detection unit is connected to the non-inverting input terminal of each comparator 22. The output voltage of each magnetic detection unit is input to each comparator 22. Further, a power supply 24 that generates a variable voltage is connected to the inverting input terminal of each comparator 22. The comparator 22 compares the output voltage Vc of the magnetic detection unit with a voltage generated by the power supply 24 (hereinafter, this value is referred to as Vref), and outputs a Hi signal or a Lo signal according to the magnitude relationship between the two. Specifically, the output terminal S0~S58 of the comparator _{22 0-22 58,} when Vc ≧ Vref is satisfied and outputs to the control unit 7 a Hi signal, while, when Vc ≧ Vref is not satisfied The Lo signal is output to the control unit 7. The voltage Vref generated by the power supply 24 functions as a threshold value of the output voltage Vc of the magnetic detection unit for determining whether or not the vertical magnetic field strength is equal to or higher than a predetermined value. This Vref corresponds to the threshold shown in FIG.

The control unit 7 shown in FIG. 4 (a), Hi / Lo signal output from the output terminal S0~S58 of the comparator _{22 0-22 58} is input. The control unit 7 also includes a ROM that stores the program according to the present invention, a RAM that is a work area of the program, a CPU that calculates the program, and the like. Execute.

  The control unit 7 determines that the magnetic detection unit corresponding to the comparator 22 that has output the Hi signal is a magnetic detection unit that is magnetically detected, and the magnetic detection unit corresponding to the comparator 22 that has output the Lo signal detects the magnetic detection. It is determined that the magnetic detection unit is not.

  Here, the control unit 7 of the magnetic marker detection device 10 according to the first embodiment is from the magnetic detection unit # 0 side (the vehicle body left side in this embodiment) to the magnetic detection unit # 58 side (the vehicle body right side in this embodiment). In turn, it is determined whether or not each magnetic detection unit is detecting a magnetic field, and the magnetic detection unit that has first determined that magnetic detection has been performed is set as “the leftmost element position (LEDG) where the magnetic detection is performed”. Then, the magnetic detection unit immediately before the magnetic detection unit determined not to detect the magnetism first on the magnetic detection unit # 58 side of the LEDG is set as “the rightmost element position (REDG) where the magnetic detection is performed” or When there is no magnetic detection unit that determines that no magnetic detection is performed up to the magnetic detection unit # 58, the magnetic detection unit # 58 is set to “the right end element position (REDG) where the magnetic detection is performed”. Using the LEDG and REDG set in this way, the control unit 7 calculates the lateral position based on the arithmetic expression “lateral position = (LEDG + REDG) / 2”.

  That is, the “lateral position” corresponds to the center position between the left end element position (LEDG) in which magnetic detection is performed and the right end element position (REDG) in which magnetic detection is performed. It is possible to recognize which position on the travel path 11 is traveling.

  For example, when the vehicle 2 passes the magnetic marker M, as shown in FIG. 6A, since LEDG = # 2 and REDG = # 5, “lateral position = 3.5”. When the vehicle 2 passes the reference marker Mx, as shown in FIG. 6C, since LEDG = # 0 and REDG = # 58, “lateral position = 29.0”. Therefore, the control unit 7 is installed so that the reference marker Mx can detect the magnetism no matter where the vehicle 2 travels on the travel path 11, so that “lateral position = 3.5”. Sometimes, it can be recognized that the vehicle 2 is traveling at a position deviated by 25.5 (= 29.0−3.5) from the center position of the travel path 11.

  Next, the failure determination of the magnetic detection part by the control part 7 of the magnetic marker detection apparatus 10 is demonstrated.

  For example, as shown in FIG. 6D, when the vehicle 2 passes the reference magnetic marker Mx in a state where the magnetic detection unit # 7 is out of order, LEDG = # 0 and REDG = # 6. “Horizontal position = 3.0”. Therefore, the control unit 7 always calculates the horizontal position as 29.0 when passing the reference marker Mx, whereas it calculates each magnetic detection when the value of 3.0 is calculated as the horizontal position. It can be determined that a part related to magnetic detection such as a detection path to the control unit 7 or the control unit 7 has failed.

  Further, as shown in FIG. 6E, the vehicle 2 sets the reference magnetic marker Mx in a state where the magnetic detection unit # 0 which is the end of the plurality of magnetic detection units arranged side by side is out of order. When passing, LEDG = # 1 and REDG = # 58, so “lateral position = 29.5”. Therefore, the control unit 7 always calculates the horizontal position as 29.0 when passing through the reference marker Mx, whereas when the value of 29.5 is calculated as the horizontal position, each magnetic detection It can be determined that a part related to magnetic detection such as a detection path to the control unit 7 or the control unit 7 has failed.

  That is, as described above, the position recognition process for calculating the lateral position and the failure recognition process for recognizing the failure of the magnetic detection part are performed by the same calculation method, and by detecting the change in the calculated value, the magnetic detection part Recognize the failure.

  Note that the control unit 7 can also specify the failure position of the magnetic detection unit in accordance with the value of the lateral position calculated when passing through the reference marker Mx. For example, if the magnetic detection unit # 7 is out of order, the lateral position is 3.0, and if the magnetic detection unit # 11 is out of order, the lateral position is 5.0. This is because the failure positions of the detection units correspond one-on-one.

  In addition, in order to recognize that the vehicle 2 has passed the reference marker Mx, the control unit 7 passes the reference marker Mx when it is determined that almost all the magnetic detection units have detected magnetism. We recognize that we did. This is because the reference marker Mx is laid so that all the magnetic detection units can perform magnetic detection when the vehicle 2 passes the reference marker Mx regardless of the position in the vehicle width direction. It should be noted that “almost all” is considered that a part of the magnetic detection unit or a part of the reference marker Mx is out of order, so that the passage of the reference marker Mx is recognized due to several failures. This is to prevent it from becoming impossible.

  Further, in order to recognize that the vehicle 2 has passed the reference marker Mx, it is predetermined that the N-pole reference marker Mxn or the S-pole reference marker Mxs is laid next to the magnetic marker M having a predetermined number. May be. For example, as shown in FIG. 7A, it is determined in advance that an N-pole reference marker Mxn is laid next to the 524th magnetic marker M, and the control unit 7 detects the magnetic marker M each time. It is possible to recognize that the magnetism detected next to the 524th magnetic marker M is the magnetism generated by the N pole reference marker Mxn.

  Now, the control operation of the control unit 7 of the magnetic marker detection device 10 will be described with reference to FIG. FIG. 8 shows an operation flow of the control unit 7 of the magnetic marker detection device 10. As described above, the control unit 7 sequentially determines whether or not each magnetic detection unit is performing magnetic detection from the magnetic detection unit # 0 side toward the magnetic detection unit # 58 side, “Element position (LEDG)” is specified (step 2), “right end element position being magnetically detected (REDG)” is specified (step 4), and the lateral position is calculated (step 6). The controller 7 determines whether or not the magnetism detected in Steps 2 to 6 is due to the passage of the reference marker Mx (Step 10). When the control unit 7 determines that the detected magnetism is not the magnetism due to the passage of the reference marker Mx, the control unit 7 recognizes that the vehicle 2 is traveling on the traveling path 11 in the lateral position calculated in Step 6, and this flow. Ends. On the other hand, when the control unit 7 determines that the detected magnetism is the magnetism due to the passage of the reference marker Mx, the control unit 7 determines whether the lateral position calculated in step 6 is 29.0 (step 14). If the lateral position is 29.0, the control unit 7 recognizes that there is no failure in the magnetic detection part, and this flow ends. If the lateral position is not 29.0, it is recognized that the magnetic detection site has an off failure. At this time, the element number ## of the magnetic detection unit recognized as a failure may be recorded.

  Therefore, according to the above description of the first embodiment, since the failure recognition is performed based on the calculation result of the lateral position, which is information necessary for driving the vehicle, the position recognition process for calculating the lateral position. And failure recognition processing for recognizing failures in magnetic detection parts can be processed in sequence without operating at the same time, and the position recognition processing and failure recognition processing are combined with the same arithmetic expression, thus saving ROM capacity and processing time it can. In addition, no special failure detection circuit is required.

  By the way, by providing the N pole reference marker Mxn and the S pole reference marker Mxs on the travel path 11, it is not simply the off fault recognition of the magnetic detection part as described above, but the off fault recognition of the north pole detection and the south pole detection. It becomes possible to determine a detected failure for the magnetic pole, such as off-failure recognition.

  FIG. 4B is a block diagram of the magnetic marker detection device 10 according to the second embodiment. The magnetic marker detection apparatus 10 according to the second embodiment includes a magnetic sensor 3, comparators 104 and 106, a control unit 7, and the like in order to determine a failure in N pole detection or a failure in S pole detection.

  FIG. 5B is a diagram illustrating an example of output voltage characteristics of each magnetic detection unit of the magnetic sensor 3 of the magnetic marker detection device 10 according to the second embodiment. The output voltage is positive in the case of the vertical magnetic field strength on the N pole side, the output voltage is negative in the case of the vertical magnetic field strength on the S pole side, and the absolute value of the output voltage increases as the vertical magnetic field strength increases. .

The control unit 7 performs predetermined control based on the output voltage of each magnetic detection unit of the magnetic sensor 3, but the comparators 104 and 106 are connected to the magnetic detection unit of the magnetic sensor 3 as shown in FIG. And the control unit 7. The magnetic marker detection device 10 according to the second embodiment includes a first comparator 104 and a second comparator 106 corresponding to the magnetic detection units # 0 to # 58 in the magnetic sensor 3, respectively. The first comparator 104 and the second comparator 106 corresponding to the magnetic detection units # 0 to # 58, respectively, are referred to as first comparators 104 _{0 to} 104 ₅₈ and second comparators 106 _{0 to} 106 ₅₈ , respectively.

  Each magnetic detection unit is connected to the non-inverting input terminal of each first comparator 104 and the inverting input terminal of each second comparator 106. The output voltage of each magnetic detection unit is input to each of the first and second comparators 104 and 106. In addition, a first power supply 108 that generates a voltage of 3 V, for example, is connected to the inverting input terminal of each first comparator 104. In addition, a second power supply 110 that generates a voltage of 2 V, for example, is connected to the non-inverting input terminal of each second comparator 106. The first and second comparators 104 and 106 include an output voltage Vb of the magnetic detection unit, a voltage generated by the first power supply 108 (hereinafter referred to as Vthn) or a voltage generated by the second power supply 110 (hereinafter referred to as this value). Is referred to as Vths), and a Hi signal or a Lo signal is output according to the magnitude relationship between the two.

  Specifically, the first comparator 104 outputs a Hi signal when Vb ≧ Vthn is satisfied, and outputs a Lo signal when Vb ≧ Vthn is not satisfied. The second comparator 106 outputs a Hi signal when Vths ≧ Vb is satisfied, and outputs a Lo signal when Vths ≧ Vb is not satisfied. The voltage Vthn generated by the first power supply 108 is used as a first threshold value of the output voltage Vb of the magnetic detection unit for determining whether or not the magnetic pole is an N pole, and the voltage Vths generated by the second power supply 110 is Is used as a second threshold value of the output voltage Vb of the magnetic detection unit for determining whether or not is the S pole. It is assumed that Vthn ≧ Vths holds. That is, the relationship between the output voltage Vb of the magnetic detection unit and the threshold values Vthn and Vths as shown in FIG. 5C is created.

  The Hi / Lo signal output from the output terminals of the first and second comparators 104 and 106 is input to the control unit 7 shown in FIG. The control unit 7 also includes a ROM that stores the program according to the present invention, a RAM that is a work area of the program, a CPU that calculates the program, and the like, and the predetermined control according to the present invention based on the Hi / Lo signal described above. Execute.

  The control unit 7 determines that the magnetic detection unit corresponding to the first comparator 104 that has output the Hi signal is a magnetic detection unit that has detected the N pole, and the magnetic unit corresponding to the second comparator 106 that has output the Hi signal. The detection unit determines that it is a magnetic detection unit detecting the S pole, and the magnetic detection unit corresponding to the first and second comparators 104 and 106 that output the Lo signal is a magnetic detection unit that does not detect magnetism. Judge that there is.

  Here, the control unit 7 of the magnetic marker detection device 10 of the second exemplary embodiment determines whether or not each magnetic detection unit detects the N pole from the magnetic detection unit # 0 side to the magnetic detection unit # 58 side. Are determined in order, and the magnetic detection unit that first determines that the N pole is detected is set as “the left end element position (LEDG) that is magnetically detected”, and the NG is first detected on the magnetic detection unit # 58 side of the LEDG. If the magnetism detection unit immediately before the magnetism detection unit determined not to detect the pole is set as “right end element position (REDG) where magnetism is detected” or N pole detection is not performed until the magnetism detection unit # 58. When there is no magnetic detection unit to be determined, the magnetic detection unit # 58 is set as “the right end element position (REDG) where the magnetic detection is performed”. Alternatively, the control unit 7 of the magnetic marker detection device 10 according to the second embodiment determines whether or not each magnetic detection unit detects the south pole from the magnetic detection unit # 0 side toward the magnetic detection unit # 58 side. The magnetic detection unit determined in order and first determined that the south pole is detected is set as “the leftmost element position (LEDG) where the magnetic detection is performed”, and the south pole is first detected on the magnetic detection unit # 58 side of the LEDG. The magnetic detection unit immediately before the magnetic detection unit that is determined not to be detected is set to “right end element position (REDG) where magnetic detection is performed”, or it is determined that the south pole is not detected until the magnetic detection unit # 58. When there is no magnetic detection unit to be performed, the magnetic detection unit # 58 is set as “the right end element position (REDG) where the magnetic detection is performed”. Using the LEDG and REDG set in this way, the control unit 7 calculates the lateral position based on the arithmetic expression “lateral position = (LEDG + REDG) / 2”.

  That is, the “lateral position” corresponds to the center position of the left end element position (LEDG) where the N pole is detected and the right end element position (REDG) where the N pole is detected, or the left end where the S pole is detected. This corresponds to the center position of the element position (LEDG) and the right end element position (REDG) detected at the S pole. By calculating this lateral position, which position of the travel path 11 the vehicle 2 is traveling on is calculated. Can be recognized.

  Therefore, the control unit 7 of the magnetic marker detection device 10 of the second embodiment example performs the calculation of the lateral position and the failure determination of the magnetic detection part for each of the N pole and the S pole in the case of the above first embodiment example. If it carries out similarly to, in determining the detection failure about a magnetic pole, such as N pole detection failure and S pole detection failure, the effect similar to 1st Embodiment can be acquired.

  In the case of the second embodiment, it is possible to distinguish between the N pole and the S pole. Therefore, in order for the control unit 7 to recognize that the vehicle 2 has passed the reference marker Mx, the reference marker Mx. It may be determined in advance that the polarity of the magnetic marker M before this is different from the polarity of the other magnetic markers M. For example, as shown in FIG. 7B, by changing the polarity of the 524th magnetic marker M from the N pole to the S pole, the control unit 7 detects the S pole next. It can be recognized that the detected north pole is the north pole of the north pole reference marker Mxn.

  In the second embodiment, each magnetic detection unit is configured to detect both the N pole and the S pole, but includes a magnetic detection unit dedicated to N pole detection and a magnetic detection unit dedicated to S pole detection. May be. In that case, for example, in FIG. 2, among the 59 magnetic detectors arranged in series, # 0 and the even-numbered magnetic detector are dedicated to the N-pole dedicated magnetic detector, and the odd-numbered magnetic detector is dedicated to the S-pole. The magnetic detection unit. Alternatively, 59 N pole dedicated magnetic detectors arranged in series and 59 S pole dedicated magnetic detectors arranged in series may be installed on the bottom of the vehicle in parallel.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, unlike the control unit 7 of the magnetic marker detection device 10 of the first embodiment, the magnetic detection unit # 0 to # 58 are located closest to the magnetic detection unit # 0 (that is, the left side of the vehicle body). A magnetic marker with respect to the vehicle 2 is a central position between the position of the magnetic detection unit detecting the magnetic force and the position of the magnetic detection unit detecting the magnetism closest to the magnetic detection unit # 58 (that is, the right side of the vehicle body). It is detected as a position where M has passed. For example, as shown in FIG. 6A, when the vehicle 2 passes the magnetic marker M, the position where the magnetic marker M passes with respect to the vehicle 2 is detected as “(2 + 5) /2=3.5”. Is done. 6B, when the vehicle 2 passes the magnetic marker M while the magnetic detection unit # 4 is out of order, the position where the magnetic marker M has passed with respect to the vehicle 2 is “(2 + 5) /2=3.5” is detected. However, in the case of FIG. 6B, when the lateral position is calculated based on the above-described arithmetic expression “lateral position = (LEDG + REDG) / 2”, LEDG = # 2 and REDG = # 3. = 2.5 ”. Therefore, since the position “3.5” where the magnetic marker M has passed with respect to the vehicle 2 is different from the lateral position “2.5” with respect to the vehicle 2, the control unit 7, It can be determined that a part related to magnetic detection has failed.

  Similarly, in the case of the control unit 7 of the magnetic marker detection device 10 according to the second embodiment, the position of the magnetic marker M with respect to the vehicle 2 is compared with the lateral position, so that each magnetic It can be determined that a part related to magnetic detection such as a detection path to the detection unit or the control unit 7 has failed. To explain below, among the magnetic detection units # 0 to # 58, the position of the magnetic detection unit located closest to the magnetic detection unit # 0 detecting the N pole and the most magnetic detection unit # detecting the N pole A central position with respect to the position of the magnetic detection unit located on the 58 side is detected as “a position where the magnetic marker M of the N-pole magnetic field passes through the vehicle 2”. Or, among the magnetic detection units # 0 to # 58, the position of the magnetic detection unit located on the most magnetic detection unit # 0 side detecting the S pole and the most magnetic detection unit # 58 side detecting the S pole The position of the center of the magnetic detection unit located at is detected as “the position where the magnetic marker M of the S-pole magnet passes through the vehicle 2”. Then, the control unit 7 calculates the lateral position based on the above-described arithmetic expression “lateral position = (LEDG + REDG) / 2”. As a result, the control unit 7 determines that the “position where the magnetic marker M of N-pole magnetic field M has passed with respect to the vehicle 2” and the “lateral position” are different, or “magnetic of S-pole magnetic field with respect to the vehicle 2”. When the “position where the marker M has passed” and the “lateral position” are different, it can be determined that a part related to magnetic detection, such as a detection path to each magnetic detection unit or the control unit 7, has failed.

It is a block diagram for demonstrating the travel system of the vehicle carrying a magnetic sensor. FIG. 3 is a diagram illustrating a positional relationship between the magnetic marker M and the magnetic sensor 3 when the vehicle 2 passes the magnetic marker M. 4 is a diagram for explaining the relationship between the distribution of the vertical magnetic field strength of the magnetic field generated by the magnetic marker M and the detection state of each magnetic detection unit of the magnetic sensor 3. FIG. 1 is a block diagram of a magnetic marker detection device 10 according to first and second embodiments. FIG. It is a figure for demonstrating the relationship between the output voltage of each magnetic detection part of the magnetic sensor 3, and a perpendicular magnetic field intensity. It is a figure showing a detection state when the vehicle 2 passes the magnetic marker M or the reference marker Mx. It is a figure for demonstrating the passage recognition of the reference | standard marker Mx. The operation | movement flow of the control part 7 of the magnetic marker detection apparatus 10 is shown.

Explanation of symbols

2 Vehicle 3 Magnetic sensor 11 Travel path M Magnetic marker Mxn N pole reference marker Mxs S pole reference marker

Claims (4)

A plurality of magnetic detectors that are arranged side by side in a predetermined direction of the moving body and detect a magnetic field emitted by a magnetic marker laid on the road,
A magnetic marker detection device for recognizing a center position of a region including a magnetic detection unit that satisfies a predetermined magnetic field strength condition among a plurality of magnetic detection units as a position of the magnetic marker with respect to the moving body,
The center position of the region is compared with the center position of a continuous region of the region where the magnetic detection condition satisfying the predetermined magnetic field strength is not interrupted. A magnetic marker detection device that determines that there is a magnetic marker.   At least one or more of the magnetic markers are reference magnetic markers arranged so that all the magnetic detection units can satisfy the predetermined magnetic field strength condition no matter where the moving body passes. Item 2. A magnetic marker detection device according to Item 1.   The magnetic marker detection device according to claim 2, wherein the comparison is made with respect to both the center positions only when passing through the reference magnetic marker.   The magnetic marker detection device according to claim 3, wherein it is determined whether or not the reference magnetic marker has passed according to the number of magnetic detection units that satisfy the predetermined magnetic field strength condition.

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