JPH0885922A - On-road information sensing device - Google Patents

Abstract

PURPOSE: To prevent missensing by sensing the inter-extremal period, from the maximum to minimum, of the magnetic field horizontal component of a magnetic substance laid on a road and also the peak time of the vertical magnetic field, and emitting a sensing signal only when the peak value lies within the inter-extremal period. CONSTITUTION: The horizontal component and vertical component of a magnetic field formed by a magnetic flux generated by a magnetic substance are sensed by a horizontal magnetic field sensing coil 13H and a vertical magnetic field sensing coil 13V. The inter-extremal period from the time, when the sensing signal of the coil 13H shows the maximum, to the time it shows the minimum is sensed by inter-extremal period sensing parts 20, 22-25, 27, 28. The peak value of the sensing signal given by the coil 13V is sensed by peak time sensing parts 21, 29. If the peak time lies within the inter-extremal period, an output pulse forming part 31 judges the applicable signal is a proper signal not containing any noise component and emits a sensing output signal. Thereby noise included in the sensing signal can be excluded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road information detecting device which is mounted on a vehicle and detects a magnetic substance arranged as a road information supplying medium on a road on which the vehicle runs.

[0002]

2. Description of the Related Art For a vehicle traveling on a general road, it has been proposed to install various driving operation support systems for assisting a driving operation by an occupant of the vehicle in order to obtain a safer and more comfortable driving state. Has been done. As one of such driving operation support systems, various road markings drawn on the road surface on which a vehicle travels, such as lane markings, pedestrian crossing warning markings, speed limit markings, etc., are automatically detected by visual detection means. In some cases, an occupant of the vehicle is provided with information output according to the detected road marking. For example,
In Japanese Patent Laid-Open No. 5-310058, an advance notice road marking or the like in the vicinity of an intersection is imaged using an imaging device, image processing is performed based on an imaging output signal obtained from the imaging device, and a specific object such as an intersection is displayed. There is disclosed a collision prevention device that measures a distance from a vehicle and informs the result to the occupant of the vehicle with, for example, an alarm.

As another type of the driving operation support system, a magnetic substance arranged on the road is detected on the assumption that the magnetic substance is embedded as a road information supply medium on the road on which the vehicle runs. It has also been proposed to provide a magnetic detection unit for reproducing the information represented by the magnetic body detected by the magnetic detection unit and providing the reproduced information to an occupant of the vehicle. In such a case, the magnetic substance arranged as a road information supply medium on the road on which the vehicle travels is, for example, as shown in FIG.
, The number of them, for example, 4 (M
1, M2, M3 and M4) are arranged along the traveling direction of the vehicle indicated by the arrow V when viewed from above the road surface. Each of the four magnetic bodies M1, M2, M3, and M4 has a predetermined width W (not necessarily constant), and a predetermined mutual pitch D (not necessarily constant).
Further, the magnetization direction is such that the N pole is directed upward, or the S pole is directed upward. Then, preset information is represented by various combinations of the width W, the pitch D, the magnetizing direction, the magnetizing strength, and the like.

The magnetic detection means for detecting the magnetic substance arranged on the road in this way is formed by, for example, an electromagnetic coil, is attached to a portion of the vehicle facing the road surface, and is formed by the magnetic flux generated by each magnetic substance. It is supposed to detect the magnetic field. Then, the magnetic field detection output signal obtained from the magnetic detection means is subjected to various kinds of processing to reproduce the information represented by the magnetic material arranged on the road.

[0005]

As described above, the magnetic detecting means for detecting the magnetic substance arranged on the road is provided, and the information represented by the magnetic substance detected by the magnetic detecting means is reproduced to the occupant of the vehicle. In the driving operation support system to be provided, the magnetic field detection signal obtained from the magnetic detection means is supplied to, for example, a signal extraction unit in which a predetermined threshold value is set, and a portion exceeding the threshold value is extracted as an information reproduction signal. It is assumed that the magnetic material is used for reproducing information.

However, various noise components are mixed in the magnetic field detection signal obtained from the magnetic detection means, and a situation in which pulse noise having a relatively large amplitude is contained in these noise components occasionally occurs. Such pulse-like noise having a relatively large amplitude exceeds a predetermined threshold value set in the signal extraction unit, and as a result, there is a possibility that it may be mixed into an information reproduction signal obtained from the signal extraction unit. Therefore, if it is mixed in the information reproducing signal, the magnetic substance placed on the road may be erroneously detected. When an erroneous detection of a magnetic substance placed on the road occurs, a false information reproducing signal obtained from the signal extraction unit is obtained even if the magnetic substance placed on the road is not actually detected. Will be used to reproduce the information represented by the magnetic material, and accordingly, the information represented by the magnetic material arranged on the road will not be reproduced properly.

In view of such a point, the present invention detects a magnetic body mounted on a vehicle and arranged as a road information supply medium on a road on which the vehicle travels, and reproduces information represented by the detected magnetic body. It is supposed to be used for driving operation support systems etc. that are provided to vehicle occupants, and the noise component that mixes the detection of the magnetic substance placed as a road information supply medium on the road on which the vehicle travels into the detection signal of the magnetic substance. It is an object of the present invention to provide a road information detection device that can be properly performed while avoiding erroneous detection caused by the above.

[0008]

In order to achieve the above-mentioned object, a road information detecting apparatus according to the present invention is a horizontal component of a magnetic field formed by a magnetic flux generated by a magnetic body arranged on a road as a road information supply medium. And the first and second magnetic field detection units for respectively detecting the vertical components, and the maximum from the time when the detection signal obtained from the first magnetic field detection unit has the maximum value or the minimum value to the time when the detection signal has the minimum value or the maximum value. An inter-extreme period detection unit for detecting an inter-value period, a peak value time point detection unit for detecting a peak value time point when the detection signal obtained from the second magnetic field detection unit has a positive or negative peak value, and a peak A determination unit that determines whether or not the peak value time point detected by the value time point detection unit is within the extreme value period detected by the extreme value period detection unit, and the peak value time point is determined by the determination unit as the extreme value period. Determined to be within When, and an output unit that emits a detection output signal of which is arranged in the road magnetic material.

[0009]

In the road information detecting apparatus according to the present invention having the above-described structure, the detection signal obtained from the first magnetic field detecting unit is the magnetic substance arranged on the road as the road information supplying medium. When properly obtained based on the horizontal component of the magnetic field formed by the generated magnetic flux, depending on the magnetization direction of the magnetic substance, the maximum value is taken first and then the minimum value is taken, or the minimum value is taken first. Is assumed to have a maximum value. Further, the detection signal obtained from the second magnetic field detection unit is
When it is properly obtained based on the vertical component of the magnetic field formed by the magnetic flux generated by the magnetic substance arranged on the road as the on-road information supply medium, the peak value of the positive polarity or The peak value of the negative polarity is taken at a time point between the time point when the detection signal obtained from the first magnetic field detection unit takes the maximum value or the minimum value and the time point when the detection signal takes the minimum value or the maximum value.

Then, the detection signal obtained from the first magnetic field detection unit is not properly obtained based on the horizontal component of the magnetic field formed by the magnetic flux generated by the magnetic body arranged on the road, but is a noise component. And consists of a second
When the detection signal obtained from the magnetic field detection unit of is not properly obtained based on the vertical component of the magnetic field formed by the magnetic flux emitted by the magnetic body arranged on the road, it is composed of noise components. Indicates that the detection signal obtained from the second magnetic field detection section has a positive peak value or a negative peak value, and the detection signal obtained from the first magnetic field detection section has a maximum value or a minimum value and a minimum value. The situation that will be taken between the time when the value or the maximum value is taken is
It usually does not occur.

Therefore, the determination unit determines that the peak value time point is within the inter-extreme period, which means that the detection signal obtained from the first magnetic field detection unit is placed on the road as the road information supply medium. The magnetic field generated by the magnetic body disposed on the road as the on-road information supply medium is properly detected based on the horizontal component of the magnetic field formed by the magnetic flux generated by the magnetic body, and the detection signal obtained from the second magnetic field detection unit is generated. It is in a state where it can be properly obtained based on the vertical component of the magnetic field formed by, and therefore, the magnetic substance arranged on the road as the road information supply medium is in a state where it is properly detected. That is, the detection output signal for the magnetic material placed on the road, which is obtained from the output unit when the determination unit determines that the peak value time point is within the inter-extreme period, is not obtained as a result of erroneous detection. , Always proper.
Therefore, the detection of the magnetic substance arranged as the on-road information supply medium on the road on which the vehicle is traveling is properly performed while avoiding erroneous detection caused by the noise component mixed in the detection signal of the magnetic substance. Will be done.

[0012]

FIG. 2 is a block diagram of an example of a road information detecting apparatus according to the present invention, which detects a magnetic substance arranged as a road information supplying medium on a road on which a vehicle travels, and detects the detected magnetic substance. 11 equipped with a driving operation support system for reproducing the information represented by
Indicates that the vehicle is running on the road. A road information detecting device 12, which is an example of the road information detecting device according to the present invention, used in the driving operation support system mounted on the vehicle 11, is arranged in a lower front portion of the vehicle 11.

A plurality of magnetic bodies M as road information supply media are embedded in the road on which the vehicle 11 is traveling.
These magnetic bodies M are the four magnetic bodies M shown in FIG.
Like M1, M2, M3, and M4, they are arranged and arranged along the traveling direction of the vehicle 11 represented by the arrow V, and each has a predetermined width (not necessarily constant).
And having a predetermined mutual pitch (not necessarily constant), and the direction of magnetization is such that the N pole is directed upward or the S pole is directed upward. It is said that The width of each of the plurality of magnetic bodies M,
Preliminarily set information is represented by various combinations such as the magnetization direction and the magnetization intensity, and the mutual pitches of the plurality of magnetic bodies M.

As shown in FIG. 3, the on-road information detecting device 12 is arranged at a position facing a road surface of a road on which a plurality of magnetic bodies M as an on-road information supply medium are arranged, and the plurality of magnetic bodies M are arranged. The magnetic substance detection part 13 which detects each of these is provided. The magnetic body detection unit 13 is formed by a horizontal magnetic field detection coil 13H forming a first magnetic field detection unit that detects a horizontal component of a magnetic field formed by the magnetic flux generated by the magnetic body M, and a magnetic flux generated by the magnetic body M. And a vertical magnetic field detection coil 13V forming a second magnetic field detection unit for detecting the vertical component of the generated magnetic field.

The horizontal magnetic field detecting coil 13H forming the first magnetic field detecting section is wound in a plane substantially orthogonal to the road surface of the road on which the magnetic body M is arranged. The vertical magnetic field detection coil 13V forming the second magnetic field detection unit is wound in a plane substantially parallel to the road surface of the road on which the magnetic body M is arranged.
Therefore, the horizontal magnetic field detection coil 13H and the vertical magnetic field detection coil 13V are wound in the planes orthogonal to each other. Then, the horizontal magnetic field detection coil 13
The detection signal GH is derived from H, and the detection signal GV is derived from the vertical magnetic field detection coil 13V.

The magnetic material detection unit 13 that moves with the traveling vehicle 11 passes above the magnetic material M arranged on the road, and the magnetic material detection unit 13 detects the magnetic material M. At this time, the detection signal GH derived from the horizontal magnetic field detection coil 13H is obtained by detecting the horizontal component of the magnetic field formed by the magnetic flux generated by the magnetic body M, and the vertical magnetic field detection coil 13V. The detection signal GH derived from is obtained by detecting the vertical component of the magnetic field formed by the magnetic flux generated by the magnetic body M.

For example, as shown in FIG. 4, the magnetic body M is magnetized uniformly in the direction along the traveling direction of the vehicle 11 represented by the arrow V, and the direction from the S pole to the N pole. Is directed substantially orthogonal to the road surface of the road and is placed in a state of generating magnetic flux as indicated by a plurality of broken line arrows in FIG. Then, above the magnetic body M along the traveling direction of the vehicle 11, the magnetic body detection unit 1
When the magnetic substance M is detected by the magnetic substance detection unit 13 after passing 3, the detection signal GH derived from the horizontal magnetic field detection coil 13H and the detection signal GV derived from the vertical magnetic field detection coil 13V are respectively detected. , A horizontal component of the magnetic field formed by the magnetic flux generated by the magnetic body M is detected and obtained, and a vertical component of the magnetic field formed by the magnetic flux generated by the magnetic body M is detected. 5 or an amplitude change close to the amplitude change as shown in FIG. The horizontal axis in FIG. 5 represents time t, and the time point to represents the time point at which the magnetic material detection unit 13 passes through the central portion of the magnetic material M in the direction along the traveling direction of the vehicle 11.

In the amplitude change shown in FIG. 5, the detection signal GH has the level LH as the reference level and the time point to.
It takes a maximum value at an earlier time point tb and a minimum value at a time point ta after the time point to, and the detection signal GV has a positive polarity at the time point to with the level LV as a reference level. It is supposed to take the peak value. In the amplitude change close to the amplitude change as shown in FIG. 5, the detection signal GH changes at the time point tb.
In addition to the maximum value at the time point ta and the minimum value at the time point ta, the detection signal GV has a positive peak value at a time point between the time points tb and ta.

In this way, when the magnetic body M is detected by the magnetic body detector 13, the horizontal magnetic field detecting coil 1
The detection signal GH derived from 3H has a maximum value and a minimum value, and the vertical magnetic field detection coil 13
The detection signal GV derived from V is assumed to have a positive peak value, and the detection signal GV takes a positive peak value at least at a minimum value from the time when the detection signal GH takes a maximum value. It will be within the period until the time of taking.

The magnetic body M is uniformly magnetized in the direction along which the vehicle 11 travels, and the direction from the S pole to the N pole is downward and substantially orthogonal to the road surface of the road. In such a case, the detection signal GH derived from the horizontal magnetic field detection coil 13H changes the detection signal GH shown in FIG. Is assumed to have a minimum value and a maximum value, which are equivalent to those with the polarity reversed.
Further, the detection signal GV derived from the vertical magnetic field detection coil 13V has a negative peak value corresponding to the polarity of the detection signal GV shown in FIG. 5 inverted with respect to the level LV. .

As shown in FIG. 1, the road information according to the present invention is provided with the horizontal magnetic field detecting coil 13H and the vertical magnetic field detecting coil 13V which are formed as described above to form the magnetic substance detecting portion 13 for detecting the magnetic substance M. The structure of the road information detection device 12 which is an example of a detection device is shown.

In the on-road information detecting device 12 shown in FIG. 1, the detection signal GH derived from the horizontal magnetic field detecting coil 13H is supplied to the differentiating circuit 20 and the detection signal GH derived from the vertical magnetic field detecting coil 13V. The signal GV is supplied to the differentiating circuit 21. And the horizontal magnetic field detection coil 13H
The differential output signal GH ′ obtained by differentiating the detection signal GH is derived from the differentiating circuit 20 to which the detection signal GH is supplied, and is supplied to the zero cross detection circuit 22. In the zero cross detection circuit 22, a zero cross point in the differential output signal GH 'is detected, and if the detected zero cross point is a point changing from positive to negative, it is regarded as positive and is detected. When the zero crossing point is a point changing from negative to positive, the pulse signal PH having a negative polarity is issued at the time point corresponding to the detected zero crossing point.

The pulse signal PH obtained from the zero-cross detection circuit 22 is supplied to the comparison terminal in the level comparison circuit 23 and the polarity inversion circuit 24. An inverted pulse signal PHI obtained by inverting the polarity of the pulse signal PH is derived from the polarity inversion circuit 24, and is supplied to the comparison terminal in the level comparison circuit 25.

Level comparison circuit 23 and level comparison circuit 2
The reference level setting unit 26
A voltage signal VR having a reference level from is supplied.
Then, in the level comparison circuit 23, the pulse signal P
A level comparison between H and the voltage signal VR is performed, and a portion of the pulse signal PH that is equal to or higher than the level of the voltage signal VR is derived as the pulse signal PX. Further, in the level comparison circuit 25, the inverted pulse signal PHI and the voltage signal VR are obtained. Are compared with each other, and a portion of the inverted pulse signal PHI that is equal to or higher than the level of the voltage signal VR is derived as the pulse signal PXI.

The pulse signal PX derived from the level comparison circuit 23 and the pulse signal PXI derived from the level comparison circuit 25 are combined in the adder circuit 27. Then, the pulse signal PX and the pulse signal PX are output from the adding circuit 27.
A pulse signal PT formed by combining I and
Is obtained, which is a flip-flop circuit (FF).
28 trigger terminals. F. F. 28 performs the inversion operation every time the pulse signal PT from the adder circuit 27 is supplied to its trigger terminal, and the F.28. F. At the output terminal Q of 28, the pulse signal PQ formed by the inverting operation is obtained.

On the other hand, the detection signal GV is supplied from the differentiating circuit 21 to which the detection signal GV from the vertical magnetic field detection coil 13V is supplied.
Differentiated output signal GV 'obtained by differentiating V
Is derived and supplied to the zero-cross detection circuit 29. In the zero cross detection circuit 29, the differential output signal G
A zero cross point at V ′ is detected, and if the detected zero cross point is a point changing from positive to negative, it is regarded as a positive polarity, and the detected zero cross point changes from negative to positive. If it is a point, the pulse signal P that is of negative polarity
V is emitted at the time corresponding to the detected zero crossing point.

The pulse signal PV obtained from the zero-cross detection circuit 29 is supplied to the gate circuit 30. The control terminal of the gate circuit 30 has an F. F. The pulse signal PQ obtained is supplied to the output terminal Q of 28, and the gate circuit 30
The ON state is set only during the pulse width period of the pulse signal PQ.

When the pulse signal PV obtained from the zero-cross detection circuit 29 is supplied to the gate circuit 30, the gate circuit 30 outputs the F.S. F. When it is turned on by the pulse signal PQ from 28, the pulse signal PV passes through the gate circuit 30 and is supplied to the output pulse forming unit 31. On the other hand, when the pulse signal PV obtained from the zero-cross detection circuit 29 is supplied to the gate circuit 30, the pulse signal PV cannot pass through the gate circuit 30 when the gate circuit 30 is in the off state. , Is not supplied to the output pulse forming unit 31.

The output pulse forming section 31 includes a gate circuit 30.
When the pulse signal PV that has passed through is detected, it is detected and an output pulse PO corresponding to the detected pulse signal PV is emitted, and the output pulse PO is used as a detection output signal for the magnetic body M, and the control unit 32 Supply to. In the control unit 32, the output pulse PO, which is a detection output signal for the magnetic body M, is subjected to predetermined processing.

Under the above circumstances, the magnetic substance M is detected by the magnetic substance detector 13, and the detection signal GH derived from the horizontal magnetic field detection coil 13H has a maximum value and a minimum value. In addition, the detection signal GV derived from the vertical magnetic field detection coil 13V has a positive peak value, and the detection signal GH takes a maximum value at the time when the detection signal GV takes a positive peak value. During the period from the time point to the time point when the minimum value is reached, the horizontal magnetic field detection coil 13H causes the magnetic body detection unit 13 to follow the traveling direction of the vehicle 11 on the magnetic body M as shown in A of FIG. Time point before and after time point to passing through the central portion in the direction
The detection signal GH having the maximum value and the minimum value at b and ta, respectively, is supplied to the differentiating circuit 20, and from the vertical magnetic field detection coil 13V, as shown in A of FIG. 7, from time tb to time ta. Time point within the period, for example,
Detection signal GV having a positive peak value at time to
Are supplied to the differentiating circuit 21.

As a result, the differentiating circuit 20 has a zero-cross point that changes from positive to negative at the time point tb when the detection signal GH takes a maximum value as shown in FIG. 6B, and the detection signal GH. At the time point ta at which takes a minimum value, a differential output signal GH ′ is obtained which has a zero crossing point changing from negative to positive. Accordingly, it is obtained from the zero-cross detection circuit 22 as having a positive polarity at the time point tb as shown in C of FIG. 6, and
At the time point ta, the pulse signal PH obtained by being made negative is derived, and further, from the polarity inversion circuit 24,
As shown in D of FIG. 6, an inverted pulse signal PHI obtained by being made negative in polarity at time tb and being positive in polarity at time ta is derived.

At this time, the voltage of the positive pulse signal PH obtained at time tb of the pulse signals PH obtained from the zero cross detection circuit 22 as shown in C of FIG. A portion above the level of the signal VR is derived as the pulse signal PX, and
From the level comparison circuit 25, the level of the voltage signal VR in the positive polarity inversion pulse signal PH obtained at the time point ta of the inversion pulse signal PHI obtained as shown in D of FIG. Is derived as a pulse signal PXI. As a result, as shown in E of FIG. 6, based on the pulse signal PX obtained from the level comparison circuit 23 at the time point tb and the pulse signal PXI obtained from the level comparison circuit 25 at the time point ta from the addition circuit 27. , Time point tb and time point ta
Of the pulse signal PT obtained in each of
They are F. F. 28 trigger terminals.

As a result, the F. F. From the output terminal Q of 28, an inversion operation according to the pulse signal PT obtained at the time point tb and an inversion operation according to the pulse signal PT obtained at the subsequent time point ta are formed, as shown in F of FIG. A pulse signal PQ having a pulse width corresponding to the period from time tb to time ta is obtained. Then, in this way, F. Since the pulse signal PQ obtained from 28 has a pulse width corresponding to the period from the time point tb to the time point ta, the gate circuit 30 is in the ON state in the period from the time point tb to the time point ta. It is said that

Under such a condition, the differentiating circuit 20, the zero-cross detecting circuit 22, the level comparing circuits 23 and 25, the polarity inverting circuit 24, the adding circuit 27 and the F.D. F. 28 is a pulse corresponding to the detected inter-extreme period, which detects the inter-extreme period from the time point tb when the detection signal GH obtained from the horizontal magnetic field detection coil 13H takes the maximum value to the time point ta when the detection signal GH takes the minimum value. This means that an inter-extreme period detection unit that generates a signal (pulse signal PQ) is formed. Further, among them, the level comparing circuits 23 and 25, the polarity inverting circuit 24, and the adding circuit 27.
And F. F. Numeral 28 forms a pulse generating means for generating a pulse signal (pulse signal PQ) having a width corresponding to the period between the zero cross points at the time points tb and ta detected successively by the zero cross detection circuit 22. Will be there.

On the other hand, from the differentiating circuit 21, as shown in FIG. 7B, at the time point to when the detection signal GV takes the positive peak value, the zero crossing point changes from positive to negative. A differential output signal GV 'is obtained. Along with this, the zero-cross detection circuit 29 derives a pulse signal PV that is obtained as a positive polarity at the time point to as shown in C of FIG. Therefore, the differentiating circuit 21 and the zero-cross detecting circuit 29 detect the peak value time point (time point to) at which the detection signal GV obtained from the vertical magnetic field detecting coil 13V has a positive peak value, and the detected peak value time point. Therefore, a peak value time point detection unit that generates a pulse signal (pulse signal PV) according to the above is formed.

The pulse signal PV obtained from the zero-cross detection circuit 29 at the time point to is supplied to the gate circuit 30. At this time, the gate circuit 30 starts from the time point to as shown in D of FIG. The pulse signal PQ having a pulse width corresponding to the period from the previous time point tb to the time point ta after the time point to is supplied, and thereby turned on. Therefore, the pulse signal PV passes through the gate circuit 30 and reaches the output pulse forming unit 31.

Accordingly, in the gate circuit 30, the peak value time point detected by the peak value time point detecting section formed by the differentiating circuit 21 and the zero-cross detection circuit 29, that is,
At the time point to, the differentiating circuit 20, the zero-cross detecting circuit 22, the level comparing circuits 23 and 25, the polarity inverting circuit 24, the adding circuit 27 and the F.D. F. It is determined whether or not it is within the inter-extreme period detected by the inter-extreme period detection unit formed by 28, that is, within the period from time tb to time ta, and the peak value time is within the inter-extreme period. When it is determined that the pulse signal PV from the zero-cross detection circuit 29 reaches the output pulse formation unit 31, a determination unit is formed.

The pulse signal PV is output from the output pulse forming unit 31 to which the pulse signal PV from the gate circuit 30 arrives.
Accordingly, the output pulse PO having the leading edge at the time point to, as shown in FIG. 7E, is obtained as the detection output signal for the magnetic body M. Therefore, the output pulse forming unit 31 outputs the detection pulse of the magnetic material M when the determination unit formed by the gate circuit 30 determines that the peak value time point is within the inter-extreme period. This means that the output section that emits PO is formed.

In the above-mentioned state, when the magnetic body M is magnetized uniformly in the direction along the traveling direction of the vehicle 11, and the magnetized direction is such that the N pole is directed upward. What is obtained is that in the case where the magnetic body M is uniformly magnetized in the direction along the traveling direction of the vehicle 11 and the magnetizing direction is such that the S pole is directed upward. When the detection by the magnetic substance detection unit 13 is appropriately performed, the detection signal GH having the minimum value and the maximum value at the time points tb and ta before and after the time point to, respectively, is differentiated from the horizontal magnetic field detection coil 13H. The voltage is supplied to the circuit 20, and from the vertical magnetic field detection coil 13V, a time point within the period from the time point tb to the time point ta, for example,
Detection signal GV having a negative peak value at time point to
Will be supplied to the differentiating circuit 21.

As a result, the differentiating circuit 20, the zero-cross detecting circuit 22, the level comparing circuits 23 and 25, the polarity inverting circuit 24, the adding circuit 27 and the F.D. F. 28 detects a period between extreme values from a time point tb when the detection signal GH obtained from the horizontal magnetic field detection coil 13H has a minimum value to a time point ta when it has a maximum value, and a pulse corresponding to the detected period between extreme values. An inter-extreme value period detection unit that generates a signal (pulse signal PQ) will be formed. Further, the differentiating circuit 21 and the zero-cross detecting circuit 29 detect a peak value time point (time point to) at which the detection signal GV obtained from the vertical magnetic field detecting coil 13V has a negative peak value, and the detected peak value time point. Will form a peak value time point detection unit that generates a pulse signal (pulse signal PV) according to the above.

In this way, the F. F. The output pulse PO is obtained from the output pulse forming section 31 only when the pulse signal PV is obtained from the zero cross detection circuit 29 while the gate circuit 30 is turned on by the pulse signal PQ obtained from 28. As a result, the detection output signal for the magnetic body M is detected, so that the detection output signal for the magnetic body M is actually detected by the magnetic body detection unit 13 to detect the horizontal magnetic field detection coil 13H. And the detection signal GV from the vertical magnetic field detection coil 13V are derived by detecting the horizontal and vertical components of the magnetic field formed by the magnetic flux generated by the magnetic body M, respectively. Therefore, the magnetic substance detection unit 13 does not detect the magnetic substance M, and the detection signal GH and the drop signal derived from the horizontal magnetic field detection coil 13H are obtained. Detection signals GV derived from the magnetic field detection coil 13V
Is regarded as a noise component, even if the pulse signal PH based on the noise component is derived from the zero-cross detection circuit 22 and the pulse signal PV based on the noise component is derived from the zero-cross detection circuit 29, A detection output signal for the magnetic body M cannot be obtained. Therefore, erroneous detection of the magnetic body M will not occur.

It is also conceivable that the magnetic body M has a predetermined inclination angle θ with respect to the road surface of the road in the direction from the S pole to the N pole as shown in FIG.
In such a case, the magnetic body detection unit 13 passes above the magnetic body M along the traveling direction of the vehicle 11, and the magnetic body detection unit 13
When the magnetic substance M is detected by, for example, the detection signal GH from the horizontal magnetic field detection coil 13H forming the magnetic substance detection unit 13 is detected by the magnetic substance detection unit 13 as shown in FIG. At time t'before the time to 'when passing through the central portion in the direction along the traveling direction of the vehicle 11 at
This means that the point symmetry between the maximum value side portion taken at b ′ and the minimum value side portion taken at the time point ta ′ after the time point to ′ is further broken. Therefore,
Such a detection signal G from the horizontal magnetic field detection coil 13H
The inclination angle θ of the magnetic body M in the magnetizing direction can be estimated from H, and thereby the information represented by the magnetic body M can be diversified.

[0043]

As is apparent from the above description, in the road information detecting device according to the present invention, the detection signal obtained from the first magnetic field detecting unit is arranged on the road as the road information supplying medium. When it is properly obtained based on the horizontal component of the magnetic field formed by the magnetic flux generated by the magnetic substance, the maximum value is taken first and then the minimum value is given, or the minimum value is given first, depending on the magnetization direction of the magnetic substance. Then, the detection signal obtained from the second magnetic field detection unit is the magnetic field formed by the magnetic flux generated by the magnetic substance arranged on the road as the road information supply medium. When it is properly obtained based on the vertical component of the magnetic field, the peak value of the positive polarity or the peak value of the negative polarity is set to the maximum value or the maximum value of the detection signal obtained from the first magnetic field detection unit according to the magnetization direction of the magnetic body. Local minimum It is assumed to take at the time between the time point to take time and the minimum value or maximum value taken.

Accordingly, the determination unit determines that the peak value time point is within the inter-extreme period, which means that the detection signal obtained from the first magnetic field detection unit is placed on the road as the road information supply medium. The magnetic field generated by the magnetic body disposed on the road as the on-road information supply medium is properly detected based on the horizontal component of the magnetic field formed by the magnetic flux generated by the magnetic body, and the detection signal obtained from the second magnetic field detection unit is generated. It is in a state where it can be properly obtained based on the vertical component of the magnetic field formed by, and therefore, the magnetic substance arranged on the road as the road information supply medium is in a state where it is properly detected.

That is, it is obtained from the output unit when the determination unit determines that the peak value time point is within the period between extreme values.
The detection output signal of the magnetic material arranged on the road is not obtained as a result of erroneous detection and is always proper. Therefore, according to the road information detection device of the present invention, the detection of the magnetic substance arranged as the road information supply medium on the road on which the vehicle travels is caused by the noise component mixed in the detection signal of the magnetic substance. It will be performed properly while avoiding erroneous detection that occurs.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a road information detection device according to the present invention.

FIG. 2 is a diagram showing a state in which a vehicle equipped with a driving operation support system configured by using an example of a road information detection device according to the present invention is traveling on a road.

FIG. 3 is a conceptual diagram provided for explaining a magnetic substance detection unit included in an example of the road information detection device according to the present invention.

FIG. 4 is a conceptual diagram provided for explaining an example of a magnetic body detected by an example of the road information detection apparatus according to the present invention.

FIG. 5 is a waveform diagram provided for explaining a detection signal of an example of a magnetic body according to an example of the road information detection apparatus according to the present invention.

FIG. 6 is a waveform diagram provided for explaining a magnetic body detection operation by an example of the road information detection device according to the present invention.

FIG. 7 is a waveform diagram provided for explaining a magnetic substance detection operation by an example of the road information detection apparatus according to the present invention.

FIG. 8 is a conceptual diagram provided for explaining another example of the magnetic body detected by the example of the road information detection apparatus according to the present invention.

FIG. 9 is a waveform diagram provided for explaining detection signals of another example of the magnetic body according to the example of the road information detection apparatus according to the present invention.

FIG. 10 is a conceptual diagram used for explaining a magnetic body arranged as a road information supply medium on a road on which a vehicle travels.

[Explanation of symbols]

 11 vehicle 12 road information detection device 13 magnetic substance detection unit 13H horizontal magnetic field detection coil 13V vertical magnetic field detection coil 20,21 differentiation circuit 22,29 zero cross detection circuit 23,25 level comparison circuit 24 polarity reversal circuit 27 addition circuit 28 F. F. 30 Gate Circuit 31 Output Pulse Forming Section 32 Control Unit M, M1, M2, M3, M4 Magnetic Material

Claims (5)

[Claims] 1. A first magnetic field detector for detecting a horizontal component of a magnetic field formed by a magnetic flux generated by a magnetic body arranged on a road as a road information supply medium, and a second magnetic field detector for detecting a vertical component of the magnetic field. A magnetic field detection unit and an inter-extreme period detection unit for detecting an inter-extreme period from the time when the detection signal obtained from the first magnetic field detection unit has a maximum value or a minimum value to the time point when the detection signal has a minimum value or a maximum value. And a peak value time point detection unit for detecting a peak value time point when the detection signal obtained from the second magnetic field detection unit has a positive or negative polarity peak value, and a peak value detected by the peak value time point detection unit. A determination unit that determines whether the time point is within the inter-extremum period detected by the inter-extremum period detection unit, and the determination unit determines that the peak value time point is within the inter-extreme period period. Above when magnetized Road information detecting device configured and an output unit that emits a detection output signal for. 2. The first magnetic field detecting section is formed by including coil means wound in a plane substantially orthogonal to the road surface of the road on which the magnetic body is arranged, and the second magnetic field is formed. 2. The road information detecting device according to claim 1, wherein the detecting unit is formed to include a coil means wound in a plane substantially parallel to the road surface of the road on which the magnetic body is arranged. 3. An inter-extreme value period detecting section differentiates a detection signal obtained from the first magnetic field detecting section, and zero-cross detection detecting a zero-cross point of a differential output signal obtained from the differentiating means. Means for generating pulse signals having a width corresponding to a period between two zero-cross points which are successively detected by the zero-cross detecting means. The road information detection device described in 1 or 2. 4. A peak value time point detecting section detects and detects a differentiating means for differentiating the detection signal obtained from the second magnetic field detecting section and a zero cross point of the differential output signal obtained from the differentiating means. 3. The road information detection device according to claim 1, wherein the road information detection device is formed by including pulse generation means for generating a pulse signal corresponding to a zero cross point. 5. An inter-extreme value period detecting section detects a zero-cross point of a differential output signal obtained from the differentiating means and a differentiating means obtained by differentiating the detection signal obtained from the first magnetic field detecting section. Means and a pulse generating means for generating a first pulse signal having a width corresponding to a period between two zero cross points successively detected by the zero cross detecting means, and a peak value. The time point detecting section detects a zero-cross point of the differential output signal obtained from the differentiating means obtained from the second magnetic field detecting section and the differentiating means, and detects the zero-cross point corresponding to the detected zero-cross point. Pulse generating means for generating two pulse signals, and when the determination section receives the second pulse signal during a period corresponding to the pulse width of the first pulse signal, the determining section determines the second pulse signal. 2 pulse signals Road information detecting apparatus according to claim 1 or 2 wherein, characterized in that it is formed to include a gate means for.