JPH1082275A - Method and device for detecting position - Google Patents

Abstract

PROBLEM TO BE SOLVED: To resolve the problem of influence on magnetic field and minimize measurement error, by providing an AC voltage-applying means, an electromotive force-measuring means, and a selective connection means, in both first and second coils respectively. SOLUTION: A distance from a measuring base point provided in a vertical shaft to the rearmost point of a Hume pipe is measured to calculate the position in the thrusting direction of the head. Next, the right-angled position against the thrusting direction of the head is measured by a head position detector. The first coil is connected to the first AC electric source and the second coil is connected to the second voltmeter. Then, the second coil is moved reciprocally to obtain a point showing the maximum value of the second voltmeter. And the second coil is connected to the second AC electric source and the second coil is moved reciprocally to obtain a point showing the maximum value of the first voltmeter. And the mid-point of both points is calculated. And this is regarded as the detected position in the right-angled direction to decide the head position. In this way, the measuring accuracy is increased and the positional control is facilitated and the high accuracy is effectively realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting method and an apparatus for measuring the horizontal position of an object such as an underground shield excavator from the ground in a shield method, a propulsion method, etc. using civil engineering technology and surveying technology. More particularly, the present invention relates to a position detection method and an improvement of a position detection method in a type using a pair of coils based on the principle of electromagnetic induction.

[0002]

2. Description of the Related Art As a conventional position detecting device of this kind,
What utilizes what is called the principle of electromagnetic induction is used.
This position detecting device is, for example, as shown in FIG.
On the ground, the first coil 101 is installed so that the coil core is horizontal, while on the ground, the second coil 102 is configured to be movable in the horizontal direction while maintaining the positional relationship where the coil cores are parallel to each other. The AC voltage from the AC power supply 101a is applied to the first coil 101, and at the same time, the induced voltage generated in the second coil 102 is measured by the voltmeter 102a.

In this case, the magnetic field 103 generated by the first coil 101 is, in principle, the first coil 10
Since the magnetic field 103 is generated symmetrically with respect to the point A located directly above the center A, the magnetic field 103 is horizontal at the point A, and only the magnetic field component in the horizontal direction in the second coil 102 generates an induced voltage. At point A, the induced voltage will show a maximum value.

Therefore, in the ideal state, the point at which the induced voltage in the second coil 102 is maximized while moving the second coil 102 to the left and right is obtained by finding the point located immediately above the first coil 101. This usually means that the horizontal position of the first coil 101 will be accurately measured by this method.

However, as shown in FIG. 7 (b), a magnetic material such as a manhole or an iron pipe or a conductor 104 exists around a site where a pipe or the like is actually constructed. In this case, the magnetic field 103 generated by the first coil 101 is distorted by the influence of these magnetic substances or conductors 104, and as a result, the point at which the magnetic field 105 supposed to be located at the point A becomes horizontal is a point. B, since only the horizontal component generates an induced voltage in the second coil 102, the induced voltage of the second coil 102 shows the maximum value at the point B, which is inaccurate accordingly. There are inconveniences.

The present inventors have repeated research and experiments to solve such inconveniences. As a result, when a magnetic material or a conductor is present in the periphery, the position of the first coil and the magnetic material or the conductor is reduced. When the relationship is fixed, when the magnetic field generated by the first coil is measured by the second coil which is movable in the horizontal direction, the position where the induced voltage becomes maximum is shifted from the position directly above the first coil. However, when the same device is used to measure the magnetic field generated by the second coil that can move in the horizontal direction with the first coil, the position where the induced voltage is maximum is shifted on the opposite side from the former. Found that the principle of becoming

More specifically, the case where a magnetic material is present in the peripheral portion will be described in detail. As shown in FIG. 8, the generation of the first coil 111 located at the point A by the application of an AC voltage from an AC power supply 111a is performed. When measuring the magnetic field 113 with the voltmeter 112a of the second coil 112,
Assuming that the generated magnetic field 113 does not include the magnetic body 114,
At the point B located on the coil core 112b of the second coil 112 and directly above the first coil 111, the horizontal component will be the largest, but since the magnetic material 114 exists, the inside of the magnetic material 114 Due to the generated magnetic field 113 passing through, the magnetic body 114 is oriented in the direction of the magnetic field 113 (arrow 11 in the figure).
5a), and an induced magnetic field 115 is generated.

Then, the induction magnetic field 115 and the generated magnetic field 11
3 are in the same direction, the magnetic field 113 is strengthened near the magnetic body 114, and the magnetic field 113 generated by the first coil 111 and the induced magnetic field 11 by the magnetic body 114 are increased.
5, that is, the second coil 1
The point on the twelve coil cores 112b where the horizontal component of the magnetic field is the largest is located closer to the magnetic body 114 than the center point of the first coil 111 when the magnetic body 114 is not present. Therefore, the point at which the induced voltage by the second coil 112 becomes maximum on the ground is shifted to the point C which is closer to the magnetic body 114 than the point B.

However, as shown in FIG. 9, when the first coil 111 is located at the point A which is the same position as in FIG. An AC voltage is applied to generate a generated magnetic field 116, and the generated voltage 116 is applied to the first coil 11.
Considering the case where the measurement is performed at 1, the same as in the case of FIG.
The magnetic field 116 generated by the coil 112 magnetizes the magnetic body 114 in the direction of the magnetic field 116 (the direction of the arrow 117a in the drawing) to generate an induced magnetic field 117. In the case of FIG. 9, the generated magnetic field 116 and the induced magnetic field are used. Since the point that is the center of the sum of the second coil 117 and the second coil 112 is required to be the point A, the second coil 112 is opposite to the point B located immediately above the first coil 111, which is opposite to the case of FIG. The induced voltage measured by the voltmeter 111a at the point D on the opposite side of a certain magnetic body 114 shows the maximum value.

[0010] The case where a conductor is present in the peripheral portion will be specifically described. As shown in FIG. 10, a generated magnetic field generated in a first coil 121 located at a point A by application of an AC voltage from an AC power supply 121a. When measuring 123 with the voltmeter 122a of the second coil 122, the generated magnetic field 123 is on the coil core 122b of the second coil 122 and the first coil 1
The point B located directly above the point 21 has the largest horizontal component. However, since the conductor 124 is present, the conductor 124 generates an eddy current (arrow 125a in FIG. ), And the eddy current 125 a generates an induced magnetic field 125.

Then, the induction magnetic field 125 and the generated magnetic field 12
3 are opposite to each other, the generated magnetic field 123 around the conductor 124 is weakened, and the generated magnetic field 123 by the first coil 121 and the induced magnetic field 12 by the magnetic body 124 are reduced.
5, that is, the second coil 1
The point on the 22 coil core 122b where the horizontal component of the magnetic field is the largest is located on the opposite side of the conductor 124 from the center point of the first coil 121 when the conductor 124 is not present. To become
On the ground, the point at which the induced voltage by the second coil 122 becomes maximum is shifted to a point C which is on the opposite side of the conductor 124 as compared with the point B.

However, as shown in FIG. 11, when the first coil 121 is located at a point A which is the same position as in FIG. 10, the AC power supply 122c of the second coil 122 reverses the case of FIG. Generated magnetic field 1 by applying AC voltage
26, and the generated voltage 126 is measured by the first coil 121, the second coil 122
The eddy current 127a generates an induced magnetic field 127 while the eddy current 127a is generated in the conductor 124 in the direction opposite to that of FIG. In this case, the point at which the center of the sum of the generated magnetic field 126 and the induction magnetic field 127 is required to be the point A, so that the second coil 122 is compared with the point B located directly above the first coil 121. 10, the induced voltage measured by the voltmeter 121a at the point D on the side of the magnetic body 124 opposite to that of FIG. 10 shows the maximum value.

[0013]

Accordingly, the present invention is based on the principle described above, and eliminates the influence of a magnetic substance or conductor on the magnetic field when a magnetic substance or conductor is present in the surroundings, thereby reducing the measurement error. It is an object of the present invention to provide a position detection method and a position detection method that can be minimized and have high measurement accuracy.

[0014]

That is, as shown in FIG. 1, the position detecting method according to the present invention is applied to a case where an AC voltage is applied to the first coil 1 whose coil core S1 is set horizontally or vertically. , A second coil 2 having a coil core S2 held in a positional relationship parallel to the coil core S1
Is moved in the horizontal direction, the induced electromotive force of the second coil 2 is maximized, or the second coil 2 having the coil core S2 held in a positional relationship perpendicular to the coil core S1 is moved in the horizontal direction. Measuring the first position of the second coil 2 so as to minimize the induced electromotive force of the second coil 2 when moving to; and applying an AC voltage to the second coil 2, Second coil 2 having coil core S2 held in a positional relationship parallel to core S1
Is moved in the horizontal direction, the induced electromotive force of the first coil 1 is maximized, or the second coil 2 having the coil core S2 held in a position perpendicular to the coil core S1 is moved in the horizontal direction. Measuring the second position of the second coil 2 that minimizes the induced electromotive force of the first coil 1 when moving to a position between the first position and the second position. Setting the detection position of the first coil 1.

Further, as shown in FIG. 1, the apparatus invention embodying such a position detecting method uses a magnetic field formed by a first coil 1 in which a coil core S1 is set horizontally or vertically. The first coil 1 is received and received by the second coil 2 which is horizontally movable while maintaining a positional relationship where S2 is parallel or perpendicular to the coil core S1 of the first coil 1.
In the position detecting device for detecting the horizontal position of the first coil 1, the first coil 1 has a first AC voltage applying means 3 for applying an AC voltage to the first coil 1 and a first AC voltage applying means 3 for measuring the magnitude of the induced electromotive force of the coil. Electromotive force measuring means 4 and first AC voltage applying means 3
Or first selection connecting means 5 for selecting one of the first electromotive force measuring means 4 and connecting to the first coil 1, wherein the second coil 2 has a second AC Voltage applying means 6, second electromotive force measuring means 7 for measuring the magnitude of the induced electromotive force of the coil, and second AC voltage applying means 6
Alternatively, a second selection connection means 8 for selecting one of the second electromotive force measurement means 7 and connecting to the second coil 2 is provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the accompanying drawings.

Embodiment 1 FIG. 2 is an explanatory view showing a construction state in a case where Embodiment 1 of the present invention is applied to the site of a fume pipe laying construction by a propulsion method in an urban area. FIG. 2A is a front view, and FIG. 2B is a longitudinal sectional view.

In the figure, reference numeral 11 denotes a shaft which has been subjected to a predetermined shoring method, foundation crushed stone 11a and leveling concrete 11b, and 12 has been cured after being cast in advance for the purpose of securing a reaction force against propulsion. The back concrete 13 having a predetermined strength is provided with a plurality of main push jacks 13a for applying a propulsive force, interposed between the main push jack 13a and the propulsion pipe, and fixed to the tip of the main push jack 13a. Placed on the pressure plate 13b and the H steel gantry 13d,
A main pushing device 14 includes a guide 13c that guides the propulsion pipe and regulates the direction of movement of the pressure plate 13b. Reference numeral 14 denotes a steel entrance that plays a role of stopping water, reinforcing the wellhead, and guiding the propulsion pipe.

Reference numeral 15 denotes a hollow cylindrical propulsion humid tube, and 16 denotes a propelling tube disposed at the front end, and a head 16a,
And a main body 16b, a head cutter 16c is provided at the front of the head 16a to cut a face while rotating and to take in earth and sand, and a head cutter 16c is provided between the head 16a and the main body 16b. In the meantime,
A direction control jack 16d for controlling the propulsion direction is provided, and the head 16a is tilted left and right or up and down, and the propulsion direction is regulated by the side on which the head is tilted.

The process of laying the propulsion hume pipe 15 using such technical means is performed by suspending the propulsion hume pipe 15 using an overhead crane (not shown) or the like.
After being placed on the c, the original push jack 13a is extended, and the rear end of the propulsion tubing 15 in the propulsion direction is pressed via the pressure-resistant plate 13b to apply the propulsion force to the propulsion machine 16. The propulsion machine 16 itself inserts the propulsion machine 16 and the existing propulsion hume tube 15 into the ground by one length of the propulsion hume tube 15 by taking the face while rotating the head 16a. The process for inserting a new propulsion hume tube 15 is repeated again.

By the way, as a matter of course, when the laying process of the propulsion tubing 15 is performed, the direction in which the propulsion machine 16 should excavate is measured and set, and a stake is installed underground. In this embodiment, a head position detecting device 17 capable of accurately and easily detecting the horizontal position of the head 16a on the ground is provided.

The head position detecting device 17 includes a head 1
The first coil 21 includes a first coil 21 disposed in an accurate positional relationship with respect to the head 16a in the interior of the measuring box 22a, and a second coil 22 disposed inside the measuring box 22d on the ground.

The first coil 21 can be selectively connected to an AC voltage from a first AC power supply 21a or a first voltmeter 21b for measuring an induced electromotive force of the first coil 21 itself via a switch 21c. And the first AC power supply 2
When the AC voltage according to 1a is selected and applied, an induced magnetic field based on the principle of electromagnetic induction is generated in the first coil 21.

As shown in FIG. 3, the first coil 21 is provided with a gimbal 31 having two degrees of freedom around the X axis and Y axis.
The first coil 21 is supported so as to be rotatable around its axis, and the coil core is always kept horizontal by the weight of the first coil 21.

On the other hand, the second coil 22 is
2a or a second voltmeter 22b for measuring the induced electromotive force of the second coil 22 itself.
2c is selectively connectable via the second AC power supply 22a. When an AC voltage is selected and applied by the second AC power supply 22a, an induced magnetic field based on the principle of electromagnetic induction is generated in the second coil 22. It has become.

As shown in FIG. 3, the second coil 22 is rotatably supported by a gimbal 32 having two degrees of freedom around the X-axis and the Y-axis, similarly to the first coil 21. The configuration is such that the coil core always keeps a horizontal state by the weight of the two coils 22.

According to the head position detecting device 17 having such a configuration, the position in the direction perpendicular to the propulsion direction (Y direction in the figure) can be measured, and the position in the propulsion direction (X direction in the figure) can be measured in the conventional manner. Will be measured by the method described above.

Next, a head position detecting process performed by the head position detecting device 17 according to this embodiment will be described with reference to FIGS.

(1) Work before Position Detection Prior to starting the position detection process, the worker must determine the point A, which is the center of the first coil 21 that should be detected by the head 16a and the head position detection device 17, The positional relationship of the head 16a is detected by measuring the point A by actual measurement or the like in advance.

To detect the position of the head 16a,
The operator of the propulsion machine 16 has the original pushing jack 13a.
Is stopped so as to prevent a measurement error from occurring due to the position of the head 16a moving at the timing of position detection. The rotation of the head cutter 16c is not stopped from the viewpoint of preventing a situation in which the earth and sand around the propulsion machine 16 are tightened and the propulsion machine 16 cannot be propelled (cannot move).

(2) Measurement of the position of the head in the propulsion direction After the work to be performed before the position detection is completed, the position of the head 16a in the propulsion direction (X direction in the drawing, the same applies hereinafter) is measured by a known measuring method as follows. I will ask for it.

That is, the operator measures the distance from the survey reference point installed in the shaft in advance to the end of the propulsion tube 15 and recognizes the position of the end of the propulsion tube 15 and the already installed propulsion tube. The position of the head 16a in the propulsion direction is calculated from the total length of the installation propulsion hyume tube 15 calculated from the total number of the hyume tubes 15 and the length of the propulsion machine 16.

In this case, since the propulsion tubing 15 is a secondary product of concrete, the length dimension per rod is extremely accurate, but the actual total extension when these are joined is the same as the propulsion tubing 15. It is a concern whether the numerical value obtained by calculation in consideration of the joint is taken into consideration in the total number, but in the propulsion method, the connected propulsion pipe 15 is used.
Since a very large pressing force is applied to the rear end of the joint, there is no problem because the joint dimensions do not vary.

(3) Position detection in the direction perpendicular to the propulsion direction of the head Next, the position in the direction perpendicular to the propulsion direction (Y direction in the drawing, the same applies hereinafter) is measured by the head position detection device 17 of the present invention. First, the switch 21c of the first coil 21 and the switch 22c of the second coil 22 are operated so that the magnetic field generated by the first coil 21 is detected by the second coil 22, so that the first coil 21 is connected to the first AC power supply 21a. At the same time, the second coil 22 is connected to the second voltmeter 22b.

Then, the second coil 22 is connected to the measuring box 2
By reciprocating in the X direction every 2d, a point B on the coil core of the second coil 22 at which the second voltmeter 22b shows the maximum value is obtained.

At this time, the head 16a in which the first coil 21 is disposed, and the measuring box 22d in which the second coil 22 is disposed, have the former with a substantially designed gradient of the propulsion hume tube 15 to be laid. In the latter case, the state of the ground on which the measurement box 22d is to be moved is inclined or the inclination state is also changed.
The two-degree-of-freedom gimbals 31 and 32 that rotatably support the first and second coils 22 around the X axis and the Y axis respectively function effectively, so that the horizontal state of the coil core is always maintained. Therefore, the position is not affected by the inclination when detecting the position.

The point B is a point immediately above the center point of the first coil 21 when there is no magnetic material and conductor around it, whereas the point B is the first coil 2 when there is a magnetic material.
1 is shifted to the magnetic body side when viewed from a point directly above the center point, and when a conductor is present, it is shifted to a side opposite to the conductor when viewed from a point immediately above the center point of the first coil 21. .

Next, when the magnetic field generated by the second coil 22 is detected by the first coil 21, the switches 21c and 22c
, The first coil 21 is connected to the first voltmeter 21b, and the second coil 22 is connected to the second AC power supply 22a.

Then, the second coil 22 is connected to the measuring box 2
By reciprocating in the X direction every 2d, a point on the coil core of the second coil 22 and the first coil 21
The point C at which the voltmeter 21b indicates the maximum value is obtained.

At this time, when the detection position of the point B deviates from the point immediately above the first coil 21 due to the influence of a magnetic material or a conductor around the point C, the point C is the point immediately above the first coil 21. As a result, it is shifted to the opposite side to point B. Note that there is no magnetic substance or conductor around the periphery, and the detection position of the point B is the first position.
When the point is directly above the coil 21, the detection position of the point C is also a point immediately above the first coil 21 that is the same as the point B.

Then, the midpoint between the points B and C is calculated as a point D, and the point D is set as a detection position in a direction perpendicular to the propulsion direction of the head 16a.

(4) Determination of Head Position Finally, the position of the head 16a in the propulsion direction measured in (2) is set as the position in the X direction in the figure, and the propulsion direction of the head 16a detected and calculated in (3) is determined. The position of the head 16a is determined by setting the position in the right angle direction as the position in the Y direction in the figure.

Second Embodiment FIG. 4 shows a second embodiment of the head position detecting device to which the present invention is applied. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted.

The basic structure of the head position detecting device according to the second embodiment is substantially the same as that of the first embodiment, but is different from the first embodiment in that the first coil 41 is provided in the head 16a and the coil core is vertical. The second coil 42 is disposed in the measurement box 22d such that its coil core is in the vertical direction. In the second embodiment, the first coil 41 and the second coil 42
Is held irrespective of the inclined state of the head 16a and the measurement box 22d. The process of detecting the position of the head 16a in the direction perpendicular to the propulsion direction using such technical means is as follows. In addition, about the position of the head 16a in the propulsion direction,
It is determined by the same method as in the first embodiment.

First, the first AC power supply 21 is connected to the first coil 41.
a, when the second voltmeter 22b is connected to the second coil 42,
While the first coil 21 generates a magnetic field G,
The induced voltage of the second coil 22 due to the magnetic field G is detected by the second voltmeter 22b, and the coil core 42a of the second coil 42
When the center line of the magnetic field G coincides with the center line, the maximum value is shown.

That is, when there is no magnetic substance or conductor around, the magnetic field G is symmetrical and the direction on the coil core indicates vertical.
By moving 2d along the Y direction, the second voltmeter 22
The point B at which b has the maximum value is located immediately above the point A which is the center of the first coil 21. On the other hand, when a magnetic material is present, the point A which is the center of the first coil 21 is provided. Is shifted toward the magnetic body when viewed from a point directly above the antenna, and when a conductor is present, the conductor is shifted to the opposite side from the conductor when viewed from a point immediately above the point A which is the center of the first coil 21.
As with the first coil 21 and the second coil 22, the same result as in the case where the horizontal state is maintained is shown.

Next, by switching the switches 21c and 22c, the first coil 21 is connected to the first voltmeter 21b, and the second coil 22 is connected to the second AC power supply 22a.
And the second coil 22 is reciprocated in the Y direction together with the measurement box 22d, and is a point on the coil core of the second coil 22 and the first voltmeter 2 of the first coil 21.
A point C at which 1b shows the maximum value is obtained.

At this time, when the detection position of the point B deviates from the point immediately above the first coil 21 due to the influence of a magnetic substance or a conductor around the point C, the point C is immediately above the point A which is the center of the first coil 21. Is shifted to the opposite side to the point B when viewed from the point of.
Can be used as the detection position in the direction perpendicular to the propulsion direction of the head 16a.

Third Embodiment FIG. 5 shows a third embodiment of the head position detecting device to which the present invention is applied. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted.

The basic configuration of the head position detecting device according to the third embodiment is substantially the same as that of the first embodiment, but unlike the first embodiment, the second coil 5 is provided in the measurement box 22d.
1 is disposed such that the coil core 51a is in the vertical direction. Note that, in this embodiment, the first coil 21 in the head 16a is disposed so that the coil core 21d is horizontal, as in the first embodiment. The vertical state of the second coil 52 is maintained regardless of the tilted state of the head 16a and the measurement box 22d.

The process of detecting the position of the head 16a in the direction perpendicular to the propulsion direction using such technical means is as follows. The position of the head 16a in the propulsion direction is obtained by the same method as in the first embodiment.

First, the first AC power supply 21 is connected to the first coil 21.
a, when the second voltmeter 22b is connected to the second coil 51,
The first coil 21 generates a magnetic field G. When the horizontal component of the magnetic field G is maximum, the vertical component is minimum. Therefore, the measurement box 22d is moved within a certain range along the Y direction. Move the second voltmeter 22b
Is located just above point A, which is the center of the first coil 21 when there is no magnetic material or conductor around it, whereas point B where the magnetic material exists Is shifted toward the magnetic body when viewed from a point directly above the point A which is the center of the first coil 21, and when a conductor is present, from the point immediately above the point A which is the center of the first coil 21 As a result, it will be shifted to the opposite side from the conductor.

Next, by switching the switches 21c and 22c, the first coil 21 is connected to the first voltmeter 21b, and the second coil 51 is connected to the second AC power supply 22a.
And the second coil 51 is reciprocated within a certain range along the Y direction together with the measurement box 22d, and a point on the coil core of the second coil 51 and the first coil 21 of the first coil 21 The point C at which the voltmeter 21b indicates the minimum value is obtained.

At this time, when the detection position of the point B deviates from the point immediately above the first coil 21 due to the influence of a magnetic substance or a conductor around the point C, the point C is immediately above the point A which is the center of the first coil 21. Is shifted to the opposite side to the point B when viewed from the point of. Therefore, if the midpoint D of the points B and C is calculated, the point D
Can be used as the detection position in the direction perpendicular to the propulsion direction of the head 16a.

Fourth Embodiment FIG. 6 shows a fourth embodiment of the head position detecting device to which the present invention is applied. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted.

The basic structure of the head position detecting device according to the fourth embodiment is substantially the same as that of the first embodiment, but, unlike the first embodiment, the first coil 61 in the head 16a is replaced by the coil core 61a. It is arranged to be vertical.
In this embodiment, the second coil 22 in the measurement box 22d has the same coil core 2 as in the first embodiment.
2e, and is arranged so that the vertical state of the first coil 21 and the horizontal state of the second coil 22 are maintained regardless of the inclined state of the head 16a and the measurement box 22d. I have.

The process of detecting the position of the head 16a in the direction perpendicular to the propulsion direction using such technical means is as follows. The position of the head 16a in the propulsion direction is obtained by the same method as in the first embodiment.

First, the first AC power supply 21 is connected to the first coil 61.
a, When the second voltmeter 22b is connected to the second coil 22,
The first coil 61 generates a magnetic field G. When the vertical component of the magnetic field G is maximum, the horizontal component is minimum. Therefore, the measurement box 22d is moved within a certain range along the Y direction. Move the second voltmeter 22b
Is located just above point A, which is the center of the first coil 21 when there is no magnetic material or conductor around it, whereas point B where the magnetic material exists Is shifted toward the magnetic body when viewed from a point directly above the point A which is the center of the first coil 21, and when a conductor is present, from the point immediately above the point A which is the center of the first coil 21 As a result, it will be shifted to the opposite side from the conductor.

Next, by switching the switches 21c and 22c, the first coil 61 is connected to the first voltmeter 21b, and the second coil 22 is connected to the second AC power supply 22a.
And the second coil 22 is reciprocated within a certain range along the Y direction together with the measurement box 22d, and a point on the coil core 22e of the second coil 22 The point C at which the one voltmeter 21b shows the minimum value is obtained.

At this time, when the detection position of the point B deviates from the point immediately above the first coil 21 due to the influence of a magnetic substance or a conductor around the point C, the point C is immediately above the point A which is the center of the first coil 21. Is shifted to the opposite side to the point B when viewed from the point of.
Can be used as the detection position in the direction perpendicular to the propulsion direction of the head 16a.

[0061]

As described above, according to the present invention,
The magnetic field formed by the first coil whose coil core is horizontal or vertical is received by the second coil that is movable in the horizontal direction while maintaining the parallel or vertical positional relationship with the first coil, and the horizontal position of the first coil is determined. The first coil is provided with a first AC voltage applying means, a first electromotive force measuring means, and a first selection connecting means for selecting and connecting any one of them to the first coil. Means for applying a second AC voltage to the coil,
Since the configuration includes the second electromotive force measurement means and the second selection connection means for selecting one of them, a measurement error due to the influence of the magnetic field due to the surrounding magnetic material, conductor, or the like is eliminated. In addition to being able to increase measurement accuracy, it is also effective in facilitating position control of a propulsion machine and the like and improving accuracy.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a position detection method and apparatus according to the present invention.

FIG. 2 is a schematic diagram of a head position detecting device according to Embodiment 1 of the present invention.

FIG. 3 is a detailed view of mounting a first coil or a second coil according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of a position detecting method and a position detecting device according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a position detecting method and a position detecting device according to a third embodiment of the present invention.

FIG. 6 is an explanatory diagram of a position detecting method and a position detecting device according to a fourth embodiment of the present invention.

FIG. 7 is a schematic view of a conventional position detection method and apparatus.

FIG. 8 is an explanatory diagram showing a conventional position detection method and a detection principle of the device.

FIG. 9 is an explanatory diagram showing the position detection method and the detection principle of the apparatus that were experimented by the present inventors.

FIG. 10 is an explanatory diagram showing a conventional position detection method and a detection principle of the apparatus.

FIG. 11 is an explanatory diagram showing a position detection method and a detection principle of the apparatus which were experimented by the present inventors.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st coil 2 ... 2nd coil 3 ... 1st AC voltage application means 4 ... 1st electromotive force measurement means 5 ... 1st connection connection means 6 ... 2nd AC voltage application means 7 ... 2nd electromotive force measurement means 8 ... second selection connection means 11 ... shaft 12 ... back concrete 13 ... main pushing device 14 ... steel entrance 15 ... propulsion hyume pipe 16 ... propulsion machine 16a ... head 17 ... head position detection device 21 ... first coil 21a ... first AC power supply 21b first voltmeter 21c switch 22 second coil 22a second AC power supply 22b second voltmeter 22c switch 22d measurement box 22e coil core 31 two-degree-of-freedom gimbal 41 first Coil 41a Coil core 42 Second coil 42a Coil core 51 Second coil 51a Coil core 61 First coil 61a Coil core S1 Le core S2 ... coil core G ... field

Claims (2)

[Claims] 1. A coil maintained in a positional relationship parallel to the coil core (S1) when an AC voltage is applied to the first coil (1) whose coil core (S1) is set horizontally or vertically. When the second coil (2) having the core (S2) is moved in the horizontal direction, the induced electromotive force of the second coil (2) is maximized or the positional relationship is perpendicular to the coil core (S1). When the second coil (2) having the coil core (S2) held in the horizontal direction is moved in the horizontal direction, the first electromotive force of the second coil (2) is minimized. And a second coil having a coil core (S2) held in a positional relationship parallel to the coil core (S1) when an AC voltage is applied to the second coil (2). When (2) is moved in the horizontal direction, Either maximize the induced electromotive force of the first coil (1), or move the second coil (2) having the coil core (S2) held in a positional relationship perpendicular to the coil core (S1) in the horizontal direction. When the first move
Measuring a second position of the second coil (2) that minimizes the induced electromotive force of the coil (1); and setting a first point at a midpoint between the first position and the second position.
Setting the detection position of the coil (1). 2. A magnetic field formed by a first coil (1) whose coil core (S1) is set to be horizontal or vertical, and a coil core (S2) is formed by a coil core (S1) of a first coil (1). In a position detecting device for receiving a horizontal position of a first coil (1) by receiving a horizontal position while maintaining a parallel or vertical positional relationship, the first coil (1) ) Includes first AC voltage applying means (3) for applying an AC voltage to the first coil (1), and first electromotive force measuring means (4) for measuring the magnitude of the induced electromotive force of the coil.
And first selection connection means (5) for selecting one of the first AC voltage application means (3) and the first electromotive force measurement means (4) and connecting to the first coil (1), The second coil (2) includes second AC voltage applying means (6) for applying an AC voltage to the coil, second electromotive force measuring means (7) for measuring the magnitude of the induced electromotive force of the coil, and (2) a second selection connection means (8) for selecting one of the AC voltage application means (6) and the second electromotive force measurement means (7) and connecting to the second coil (2). Position detecting device.