JPH09189506A - Position detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a position detection device which is suited for detecting a relative position between adjacent bridge girders. SOLUTION: In a position detection device for indirectly detecting a relative position by providing a transmission device 10 which is mounted to one of bridge girders and a reception device 20 which is mounted to the other, the transmission device 10 has a transmission coil 12 and transmits a magnetic signal with a specific frequency. Also, the reception device 20 has at least three reception coils 21, 22, and 23 and means 25-27 for measuring a level for a reception signal via the reception coils and the reception coils 21, 22, and 23 are arranged at different sites.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device, and more particularly to a position detecting device suitable for detecting and measuring a relative position between adjacent bridge girders on an elevated road or a connecting bridge.

[0002]

2. Description of the Related Art Conventionally, as a position detecting device, there has been known a device for precisely measuring a distance between two objects by utilizing a laser beam, a microwave or an ultrasonic wave.

Further, there is also known one which comprises a coil and a metal plate in which an eddy current is induced by the current of the coil, and which simply measures the distance between the coil and the metal plate according to the magnitude of the eddy current. .

[0004]

However, in such a conventional position detecting device, a precision measuring device is expensive even though it has high accuracy. On the other hand, in the case of simple measurement, not only the accuracy is not ensured but also a large power is required to drive the coil current in order to obtain a desired detection distance.
The price will not be so cheap. In addition, these devices
Since it is intended to detect the distance in the direction, if the position in two or three directions is to be detected, basically two or three devices are required, which further increases the cost.

On the other hand, in detecting and measuring the relative position between adjacent bridge girders, several mm is applied over a range of several cm (for example, about 5 cm) in three directions of front, rear, left and right, and up and down.
It is necessary to perform detection with an accuracy of (for example, about ± 3 mm). Then, on the premise that such a condition is satisfied, it is an object to reduce the device cost.

The present invention has been made to solve the above problems, and an object thereof is to realize a position detecting device suitable for detecting a relative position between adjacent bridge girders.

[0007]

In order to solve such a problem, according to the present invention, when a coil is used for transmission and reception, reception is performed according to the distance between the transmission coil and the reception coil and the amount of deviation. If the level changes and if three or more receiving coils are used, the relationship between each receiving level and the position in the three directions is determined to be one-to-one in almost all areas. Based on the fact that it is possible to sufficiently detect a received signal using the above, etc., a transmitting device that sends out a predetermined oscillation signal as a magnetic signal and a receiving device that receives the magnetic signal are configured. . Then, attach a transmitter to one of the bridge girders,
The receiving device is attached to the other bridge girder in opposition to this, and the absolute level or level change of the received signal necessary for position detection is measured.

The first structure is (the claim 1 at the beginning of the application)
(As described in 1.), a transmitter attached to one of a pair of measuring objects such as a bridge girder and a receiving device attached to the other, to indirectly determine the relative position between the measuring objects. The position detecting device for automatically detecting, the transmitting device includes a transmitting coil, and transmits a magnetic signal of a predetermined frequency through the transmitting coil, and the receiving device has three or more receiving the magnetic signals. Of the receiving coil and level measuring means for measuring the level of a received signal obtained through the receiving coil, and the receiving coil is arranged at different portions. It is a thing.

Here, the above "predetermined frequency" is several cm.
It means a frequency suitable for non-contact transmission / reception by electromagnetic coupling between a distant transmission coil and a reception coil, and is selected from the range of several hundred Hz to several MHz according to the usage environment. Also,
Examples of the shape of each “coil” include a polygon such as a triangle and a quadrangle, a circle, a spiral, and a cylinder.

In the position detecting device having the first structure as described above, the reception levels of the respective receiving coils are determined approximately in a one-to-one correspondence with the relative position between the pair of measuring objects. This makes it possible to indirectly detect the relative position by performing a back calculation process or the like from the level of each received signal obtained by measurement. In addition, the reception level changes sufficiently beyond the measurable level for changes of 1 mm or less in the relative position.

Therefore, according to the present invention, it is possible to realize a position detecting device suitable for detecting the relative position between adjacent bridge girders.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Regarding the position detecting device of the present invention,
The second configuration is (as described in claim 2 at the beginning of the application),
When indirectly detecting the relative position between the measurement objects by receiving a magnetic signal of a predetermined frequency from a transmitter attached to one of the pair of measurement objects such as a bridge girder, the measurement signal is attached to the other of the measurement objects. A wearable position detecting device, comprising three or more receiving coils arranged at different parts for receiving the magnetic signals, and level measuring means for measuring a level of a received signal obtained through these coils. Characterize.

In the position detecting device having the second structure, the characteristic structure of the receiving device in the position detecting device having the first structure is completed. Therefore, by combining with a simple transmitting device, at a reasonable cost and accuracy,
The relative position between adjacent bridge girders can be detected.

With regard to the position detecting device of the present invention, the concrete third configuration is (as described in claim 3 at the beginning of the application),
The position detecting device having the above-mentioned second configuration, wherein each element is provided for each receiving coil, each element is associated with each relative position between the transmitting device and the corresponding coil, and the receiving level obtained in advance at that position. , A search means for accessing these three-dimensional array structures to search for an element whose value substantially matches the value measured by the level measurement means, and a part of this search means Or separately provided, and an arithmetic means for calculating the relative position between the measurement objects from the address in the array of the retrieved element.

Here, the above-mentioned "three-dimensional array structure" is structure data of the array allocated to the memory,
The address in the array of each element is uniquely determined by the triple of the index. Further, the above-mentioned "substantially coincident" means that the sum of absolute values or the root mean square of the difference between the measured value of each receiving coil and the value of the corresponding element of each array is sufficient from the viewpoint of ensuring accuracy. It means small. It is typical to match when the difference is minimal.

In the position detecting device having the third structure as described above, the information on the relative position between the measuring objects is obtained from the received signal level by searching the three-dimensional array structure corresponding to each receiving coil. It is obtained in a direct form. Moreover, since the size of the three-dimensional array structure does not have to be so large under the required detection range and detection accuracy, the storage capacity and the search processing procedure can be made small and simple.

Therefore, according to the present invention, it is possible to realize the position detecting device for detecting the relative position between adjacent bridge girders and calculating the position information at a reasonable cost and accuracy.

In a position detecting device according to the present invention, a further concrete fourth structure is the position detecting device of the above-mentioned third structure (as described in claim 4 at the beginning of the application). Four or more coils are provided, and two or more coils are arranged so that two or more coils are placed on each of the two orthogonal straight lines, and the search means includes the two orthogonal straight lines of the three-dimensional array structure. One of the three-dimensional array structures corresponding to the receiving coil arranged for one of the three-dimensional array structures is searched for, and the remaining three-dimensional array of the three-dimensional array structure is searched according to the search result. It is characterized in that it limits the access range for searching a structure.

In the position detecting device having such a fourth structure, since the receiving coils are arranged so as to correspond to the two orthogonal directions, the three-dimensional value is substantially equal to the value measured by the level measuring means. The element of the array structure is obtained as a common element of both candidate groups obtained by independently accessing the three-dimensional array structure corresponding to each direction. Therefore, even if the three-dimensional array structure corresponding to each direction is sequentially accessed, it is still obtained as a common element of both candidate groups. At that time, for the elements other than the candidate elements narrowed down by the previous access, the result is not affected even if the elements are accessed at the later access.

By limiting the access range at the time of search based on such characteristics, the speed of the search processing can be improved. Therefore, according to the present invention, it is possible to realize a position detecting device that detects the relative position between adjacent bridge girders and the like and calculates position information with reasonable cost and accuracy and quickly.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific configuration of the first embodiment of the position detecting device of the present invention will be described with reference to the drawings. FIG. 1 is a block showing its circuit configuration, and FIG. 2 is a layout diagram of its receiving coil.

The position detecting device is composed of a pair of transmitting unit (transmitting device) 10 and a receiving unit (receiving device; position detecting device) 20.

The transmitting unit 10 has an oscillating circuit 11 which oscillates at a constant frequency of several hundreds of kHz to generate an oscillating signal, and also has a transmitting coil 12 which receives a drive current corresponding to this oscillating signal. A magnetic signal of a predetermined frequency is transmitted from 12 to the outside.

The receiving unit 20 has three receiving coils 21, 22, 23 which are arranged at different vertex positions of an equilateral triangle on the same plane. The receiving coil 21 and the like are formed in a spiral pattern with the ferrite core 28, or are formed by winding a coil wire around the ferrite core 28, and a receiving signal is induced by receiving a magnetic signal from the transmitting coil 12. Is. The receiving coil 2
A bolt hole 29 is bored on the surface on which 1 and the like are arranged, and the receiving unit 20 is attached to the mounting surface and the like with bolts.

The receiving unit 20 includes receiving coils 21 and 2.
Selector 24 for selectively inputting the received signals of 2, 23
And an amplifier 25 for receiving and amplifying the output of the selector 24
An A / D conversion circuit 26 for inputting an analog signal whose output from the amplifier 25 is smoothed and digitizing the analog signal;
The controller 27 has a controller 27 which takes in the outputs (a, b, c) of the D conversion circuit 26, whereby the level of each received signal is sequentially measured in time division.

The controller 27 is connected to the cable 30 of the simplified network and has a function of sending a report message of the measured values (a, b, c) to the cable 30.

The usage and operation of the position detecting device of the first embodiment will be described.

FIG. 3 is a diagram showing a state of application to an elevated road. In this state, the transmission unit 1 is set to the pair of bridge girders (measurement object) 42 adjacent to each other on the bridge pile 41.
0 and the receiving unit 20 are attached. The transmitting unit 10 is attached to one bridge girder 42, and the receiving unit 2
0 is attached to the other bridge girder 42, but in each case, the bridge girder 4
It is fixed to the bridge girder 42 via the angle 43 below the end of 2 and the coil surfaces thereof face each other. In addition, the position detection device is similarly attached to other adjacent portions of the bridge girder.

Then, the cable 30 is connected to the bridge girder 4
When power is supplied from a power source for an illuminating lamp (not shown) on the above 2, the transmitting unit 10 operates to transmit a magnetic signal of a predetermined frequency. Further, the receiving unit 20 operates to sequentially obtain a measured value a corresponding to the mutual inductance between the transmitting coil 12 and the receiving coil 21, and a measured value b corresponding to the mutual inductance between the transmitting coil 12 and the receiving coil 22. Is required, and the transmitting coil 12 and the receiving coil 23
A measured value c corresponding to the mutual inductance between and is also obtained. The measured values (a, b, c) thus obtained are sent to the data collecting device or the like via the cable 30 at a constant cycle.

In this state, when the bridge girder 42 expands and contracts, moves, or drops in extreme cases, the transmitter coil 1
The distance between 2 and the receiving coils 21, 22, 23 changes, and the mutual inductance also changes. Therefore, the measured value (a, b, c) is changed according to the change in the relative position between the adjacent bridge girders 42.
Also change. Thus, although it is an indirect form of expression,
The relative position between the adjacent bridge girders 42 is detected.

By using this detection result, it is possible to estimate with a practically effective accuracy whether the bridge girder 42 is normal or whether there is an abnormality in the bridge girder 42 or the like to make it impossible to pass through. Of.

The configuration of the second embodiment of the position detecting device of the present invention will be described.

FIG. 4 is a layout view of the receiving coil,
FIG. 5 is a block diagram of the controller. The second embodiment is different from the first embodiment in these receiving coils and controllers, and therefore these differences will be mainly described below.

Four receiving coils are provided and are symmetrically arranged in the upper, lower, left and right directions (U, D, L, R), and two receiving coils are provided in each of two orthogonal straight lines of the upper and lower y directions and the left and right x directions. Is aboard.

The controller 270, which corresponds to the controller 27 in the first embodiment, has an array U, D, L, R as a three-dimensional array structure in its memory.
Also, data such as limit values X, Y, Z are stored.
Further, for the processing by the MPU (microprocessor), it also has a program for performing a process such as a search as a search unit and a calculation unit, and a program for reporting an alarm instead of the raw information of the detected position. Further, in response to the number of receiving coils becoming four, four measured values u, d, l and r are taken in from the A / D conversion circuit 26.

The array U is a three-dimensional array consisting of 50 × 50 × 50 elements and is provided corresponding to the upper receiving coil (U). In each of the elements, the relative position between the counterpart transmitting coil and the corresponding receiving coil is set in advance in the x direction,
5 cm while changing in y and z directions in increments of 1 mm
The level value of the received signal measured over the entire range of x5 cm x 5 cm is set. As a result, each element is associated with each relative position between the transmitter and the corresponding coil. Note that the reception level value at this time is subjected to statistical processing such as local averaging in order to remove the influence of noise and the like. The arrays D, L, R are also three-dimensional arrays having the same structure, and the values of the reception levels measured in advance corresponding to the respective reception coils (D, L, R) are set. .

The limit value X is a limit value that can be said to be safe if the deviation (x) in the x direction between the bridge girders 42 is less than that, and is set based on design conditions and the like.
The limit values Y and Z are also the same with respect to the shifts (y, z) in the y and z directions.

The retrieval processing is to access the arrays U, D, L and R and retrieve the elements whose element values are closest to the measured values u, d, l and r. Process in stages. That is, first, all the elements of the arrays U and L are accessed to search for the element closest to the measured values u, l. Next, the arrays D and R are accessed, but only the two-dimensional partial array whose y-direction address matches the previous search element is accessed, and the element closest to the measured values d and r is searched from among these. . As a result, the controller 270
Of the three-dimensional array structure accesses the three-dimensional array structure corresponding to the receiving coil arranged on one of the two orthogonal straight lines to perform a search, and limits the access range according to the search result. Then, the remaining three-dimensional array structure of the three-dimensional array structure is searched.

Further, in this search processing, in order to calculate the relative position between the bridge girders from the array address of the searched element, a calculation such as adding or subtracting a predetermined offset value to the array address value is performed. The detection positions x, y, z obtained by this are in a direct expression format in mm units.

The alarm process compares the detection positions x, y and z with the limit values X, Y and Z, respectively, and if any of the detection positions exceeds the corresponding limit value, the alarm process is performed via the cable 30. It sends an alarm message.

The usage and operation of the position detecting device of the second embodiment will be described. The description will be focused on the points related to the above-mentioned characteristic points.

The transmitter coil 12 and the four receiver coils (U,
When the measured values u, d, l, r corresponding to the mutual inductance with (D, L, R) are obtained, the controller 270 performs a search process for the arrays U, D, L, R.
At this time, since the search range is limited to two sequences and two partial sequences, it can be completed in a shorter time than a simple search procedure of searching the entire three sequences.

Then, the detection position x, y, of the processing result is obtained.
If z exceeds the limit values X, Y, and Z, the alarm processing reports that fact. In this way, if there is an abnormality between adjacent bridge girders such as an elevated road, it can be automatically detected and appropriate measures can be taken immediately.

[0044]

As is apparent from the above description, in the first position detecting device according to the present invention, the receiving level of each receiving coil is approximately one-to-one according to the relative position between the pair of measuring objects. Since there is an advantage in that the position detection device suitable for detecting the relative position between adjacent bridge girders can be realized with reasonable cost and accuracy.

Further, in the second position detecting device according to the present invention, by combining it with the transmitting device, it is possible to detect the relative position between adjacent bridge girders with reasonable cost and accuracy. Play.

Further, in the third position detecting device according to the present invention, by searching the three-dimensional array structure,
There is an advantageous effect that the relative position can be detected and the position information can be calculated between the adjacent bridge girders with reasonable cost and accuracy.

Further, in the fourth position detecting device according to the present invention, by limiting the access range at the time of search, the relative position between adjacent bridge girders and the like can be detected with reasonable cost and accuracy and quickly. There is an advantageous effect that the position information can be calculated.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a first embodiment of a position detecting device of the present invention.

FIG. 2 is a layout view of the receiving coil.

FIG. 3 is a diagram showing the installation status.

FIG. 4 is a layout view of a receiving coil of a second embodiment of the position detecting device of the invention.

FIG. 5 is a block diagram of the controller.

[Explanation of symbols]

 10 oscillator unit 11 oscillator circuit 12 transmitter coil 20 receiver unit 21 receiver coil 22 receiver coil 23 receiver coil 24 selector 25 amplifier 26 A / D converter circuit 27 controller 28 ferrite core 29 bolt hole 30 cable 41 bridge pile 42 bridge girder 43 angle 270 controller x , Y, z Detection position X, Y, Z Limit value u, d, l, r Measurement value U, D, L, R array

Claims (4)

[Claims] 1. A position detector for indirectly detecting a relative position between the measuring objects, comprising a transmitting device attached to one of the pair of measuring objects and a receiving device attached to the other. In the device, the transmitting device includes a transmitting coil and transmits a magnetic signal of a predetermined frequency through the transmitting coil, and the receiving device includes three or more receiving coils that receive the magnetic signal and the receiving coils. And a means for measuring the level of the received signal obtained by the above, the receiving coil,
A position detecting device characterized in that they are arranged in different parts. 2. When the relative position between the measuring objects is indirectly detected by receiving a magnetic signal of a predetermined frequency from a transmitter attached to one of the pair of measuring objects, the other measuring object is detected. A position detecting device to be attached, comprising three or more receiving coils arranged at different parts for receiving the magnetic signals, and means for measuring a level of a received signal obtained through these coils. Position detection device. 3. An element provided corresponding to each of the receiving coils is associated with each relative position between the transmitter and the corresponding coil, and holds a value of a reception level obtained in advance at that position. A three-dimensional array structure and a search means for accessing these three-dimensional array structures to search for an element whose value substantially matches the value measured by the level measuring means;
The position detecting device according to claim 2, further comprising a calculating unit that calculates a relative position between the measurement objects from the searched address in the array of the elements. 4. The receiving coil is provided with four or more coils and is arranged in such a manner that two or more coils are placed on each of two orthogonal straight lines, and the search means is the three-dimensional array structure. Of the two orthogonal lines, the three-dimensional array structure corresponding to the receiving coil is accessed and searched, and the access range is limited according to the search result. The position detecting apparatus according to claim 3, wherein the remaining three-dimensional array structure of the structures is searched.