WO2016017580A1

WO2016017580A1 - Three-dimensional space coordinate measurement device

Info

Publication number: WO2016017580A1
Application number: PCT/JP2015/071245
Authority: WO
Inventors: 裕明杉原; 純一原田
Original assignee: シナノケンシ株式会社
Priority date: 2014-07-31
Filing date: 2015-07-27
Publication date: 2016-02-04
Also published as: JP2016035453A

Abstract

In order to accurately measure a three-dimensional location even when a measurement wave is obstructed by an obstacle, this three-dimensional coordinate measurement device 1 is provided with a transmission device 11 acting as a displacement body that transmits radio waves, and with a reception device 12 acting as a stationary body that receives said radio waves. The coordinates of the transmission device 11 are calculated, by means of propagation path distance difference, using a reception unit 31 having a plurality of reception unit pairs in the reception device 12, and when the reception device 12 has moved, a location for which coordinates have been ascertained is measured again on the basis of movement information, and the coordinates of the reception device 12 are corrected on the basis of the measured coordinate change.

Description

Three-dimensional spatial coordinate measuring device

The present invention relates to a three-dimensional spatial coordinate measuring apparatus.

There is a technology that uses motion sensing technology to continuously acquire spatial coordinates as numerical data and use them to measure three-dimensional spatial coordinates. Such techniques include various methods such as using radio waves, and other types such as sound wave, light, magnetic type, mechanical type, and the like. Patent Document 1 discloses a technique having a relatively high resolution for an on-vehicle radar.

JP 2002-357656 A

However, when using the technique disclosed in Patent Document 1 for measurement of three-dimensional spatial coordinates, the electromagnetic wave transmitted from the radar is reliably reflected at a plurality of target points to be measured to the radar receiver. The electromagnetic wave must be returned. Therefore, when there is an obstacle between the object to be measured and the measuring apparatus and the radar is blocked by the obstacle, the three-dimensional spatial coordinates of the object cannot be measured.

On the other hand, instead of the method of Patent Document 1, the receiving unit is installed at a position away from the measurement object, and a three-dimensional spatial coordinate is measured by bringing a transmission device separate from the receiving unit into contact with the measurement object. It is being considered. Even in such a case, when there is an obstacle between the receiving unit and the transmission device, the obstacle obstructs a measurement wave such as electromagnetic waves and sound waves, and a blind spot that cannot be measured correctly occurs. There is a problem.

The present invention was made under such a background, and its purpose is to correctly measure a three-dimensional position even when a measurement wave is obstructed by an obstacle. An object of the present invention is to provide a three-dimensional spatial coordinate measuring apparatus capable of

The present invention has a stationary body and a displacement body, and a physical action for coordinate measurement is transmitted from the stationary body to the displacement body, or from the displacement body to the stationary body. It is a three-dimensional spatial coordinate measuring apparatus that is fixed to specific coordinates in a three-dimensional spatial coordinate system in which measurement is performed, and the fixed specific coordinates can be changed by following a specific procedure.

More specifically, the present invention is a transmission device that is a displacement body and transmits radio waves, a plurality of reception units that are stationary bodies and receive radio waves, light, or ultrasonic waves transmitted by the transmission device, and a plurality of reception units. A plurality of receiving unit pairs each including at least two receiving units, and based on radio waves, light, or ultrasonic waves received by the receiving units included in the receiving unit pair, the first of the receiving unit pairs from the transmitting device. A propagation path distance difference calculation unit for calculating a propagation path distance difference that is a difference between a distance from the receiving unit to a second receiving unit of the receiving unit pair and a plurality of receiving unit pairs. The coordinates of the transmitting device that calculates the coordinates of the transmitting device based on the propagation path distance difference and the movement information that indicates that the movement has been performed when the receiving unit has moved. Measure the current position again and repeat Based on the movement correction value calculated by the movement correction value calculation unit and the movement correction value calculation unit that calculates the movement correction value from the coordinate change of the reception unit obtained by measurement, either before or after the movement of the reception unit And a movement correction unit that corrects the coordinates of the three-dimensional space coordinate measuring device.

For example, the movement correction value calculation unit adds the movement correction value to the coordinates of the transmitter measured after the movement of the reception unit. Alternatively, the movement correction value calculation unit may subtract the movement correction value from the coordinates of the transmission device measured before the movement of the reception unit.

Further, it is preferable that the movement information is transmitted from the transmission device by pressing the switch means.

Alternatively, the transmission device and the movement correction value calculation unit are provided separately, and movement information is transferred to the movement correction value calculation unit by pressing a switch unit provided in the same housing as the movement correction value calculation unit. It may be transmitted.

Also, the radio wave or light can be a sine wave with a beat signal superimposed on it.

According to the present invention, it is possible to correctly measure a three-dimensional position in a three-dimensional spatial coordinate measuring apparatus even when a measurement wave is blocked by an obstacle.

1 is an overall configuration diagram of a three-dimensional spatial coordinate measuring apparatus according to an embodiment of the present invention. It is a figure which shows the structural example of a transmission apparatus among the three-dimensional space coordinate measuring apparatuses of FIG. It is a figure which shows the example of the sweep of the electromagnetic wave transmitted from a transmitter. It is a principal block block diagram of the three-dimensional coordinate measuring apparatus of FIG. It is a figure which shows the image of the position specification of the transmitter by several receiving parts. It is a figure which shows arrangement | positioning of the curved surface and receiving part which satisfy | fill Formula (12). It is a figure which shows the specific structural example mainly of a propagation path distance difference calculation part among the transmission apparatuses and receiving parts of FIG. It is a figure which shows the electromagnetic wave received by the receiving part pair, the synthetic wave which synthesize | combined the electromagnetic wave, and a beat signal. 3 is a flowchart illustrating an operation of the transmission device in FIG. 1. 2 is a flowchart showing an operation of the receiving apparatus of FIG. It is a figure which shows a mode that the dimension of a desk is measured by the three-dimensional space coordinate measuring apparatus of FIG. 1, and is a figure which shows the example in which an obstruction intervenes between a transmitter and a receiver. It is a figure which shows a mode that a receiving part is moved in the measurement of FIG. It is a figure explaining the concept of the correction | amendment of coordinate information by the movement correction | amendment part of FIG. 7, and is a figure which shows the example which adds a correction value to the coordinate after the movement of a receiver. It is a figure explaining the concept of the correction | amendment of coordinate information by the movement correction part of FIG. 7, and is a figure which shows the example which subtracts a correction value from the coordinate before the movement of a receiver.

Before describing the present invention in detail, terms used in this specification will be defined here.

A stationary object is one that is not moved during a series of measurement operations in the three-dimensional spatial coordinate measurement apparatus of the present invention. A local coordinate system is temporarily assumed in the vicinity of the area where the stationary body is installed, and the relative values of the stationary body and the displacement body indicate what coordinate values the displacement body described later has in this local coordinate system. Acquiring based on the positional relationship is an outline of coordinate measurement. The temporary local coordinate system is determined by the position and orientation of the stationary object.

For example, when finding the area of a land of a certain triangle, install a stationary object near this land, measure the coordinates of the three vertices of the triangle, and calculate the area based on these three coordinate values. Can do. If the stationary object is moved before such a series of measurement operations (for example, the calculation of the area as described above) is completed, the local coordinate system will be distorted. deep.

The displacement body has a function of indicating a point where coordinate measurement is desired in the three-dimensional spatial coordinate measurement apparatus of the present invention. As described above, since a point that requires coordinate measurement is specified for the purpose of calculating a specific physical quantity, the measurer moves it by holding it in his hand.

The physical action means that the transmission is performed from the stationary body to the displacement body or, conversely, from the displacement body to the stationary body of the three-dimensional spatial coordinate measurement apparatus of the present invention, and is intended for coordinate measurement. Specifically, electromagnetic waves such as radio waves and light, ultrasonic waves, and the like are not necessary. In short, the relative positional relationship is known by the physical action between the stationary body and the displacement body. The direction of transmission of physical action is either “stationary to displacement” or “displacement to stationary”, but it can also be used in both directions to improve the accuracy of coordinate measurement and increase the versatility of the equipment. It is.

“Specific procedure” means that when performing the above-mentioned series of measurement operations, if the point where coordinate measurement is attempted becomes a blind spot where measurement cannot be performed for some reason, the stationary object is moved. This is a process with a displacement body or a stationary body that is performed when the blind spot is resolved.

For example, before moving the stationary body, an arbitrary point in the local coordinate system is recognized as a “identification point for moving the stationary body” by the displacement body (= coordinate measurement), and then the stationary body is moved. This movement causes the local coordinate system to become inconsistent before and after the movement of the stationary body, but the previous identification point is indicated by the displacement body, and in this state, “the same point as the identification point measured earlier is currently indicated. The coordinate value measured before moving the stationary body is converted into the local coordinate system after moving the stationary body. Thereby, it is possible to avoid the inability to measure coordinates due to blind spots. The procedure as in the above example is a “specific procedure”.

A three-dimensional spatial coordinate measuring apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings. Hereinafter, the three-dimensional spatial coordinate measuring device 1 is simplified and referred to as a coordinate measuring device 1.

<About the configuration of the coordinate measuring apparatus 1>
As shown in FIG. 1, the coordinate measuring device 1 includes a transmission device 11 and a reception device 12. When a measurement person installs the receiving device 12 at a position away from the object to be measured and brings the transmitting device 11 into contact with the object to be measured, a predetermined radio wave is transmitted and received between the transmitting device 11 and the receiving device 12. The three-dimensional space coordinates of the measurement object can be measured.

FIG. 2 shows an internal configuration example of the transmission device 11. The transmission device 11 includes an antenna 21, a radio wave generation unit 22, a retransmission mode switch 23,

interface units

24 and 26, a measurement switch 25, a control unit 27, and a memory 28. The transmission device 11 transmits a predetermined radio wave when the measurement switch 25 is pressed by touching the measurement object or when the retransmission mode switch 23 is operated.

The antenna 21 radiates radio waves into space. The radio wave generator 22 includes an oscillator, an amplifier, a frequency multiplier, a filter, a modulator, and the like (not shown), and generates a radio wave transmitted from the antenna 21.

The retransmission mode switch 23 is provided, for example, on the casing of the transmission device 11. When the retransmission mode switch 23 is pressed with, for example, a measurer's finger, a signal indicating that the retransmission mode switch 23 has been pressed is transmitted to the control unit 27 via the interface unit 24.

The measurement switch 25 is provided, for example, at the tip of the transmission device 11. When the measurement switch 25 is pressed by, for example, a measurer contacting the measurement object, a signal indicating that the measurement switch 25 is pressed is transmitted to the control unit 27 via the interface unit 26.

The control unit 27 performs various controls in the transmission device 11 by executing a predetermined processing program 28 a stored in the memory 28. For example, when the measurement switch 25 is pressed, the control unit 27 controls the radio wave generation unit 22 based on the sweep pattern information 28b shown in FIG. 3 stored in the memory 28 to sweep the sine wave. Transmit as radio waves. In this embodiment, sweeping is to change the frequency of a sine wave based on a certain pattern over time. In the present embodiment, it means that the frequency of a radio wave to be transmitted is changed with the elapse of time within a predetermined frequency range centering on the fundamental frequency.

The sweep pattern information 28b includes information indicating a transmission start time (timing), a sweep time, a transmission end time (timing), a fundamental frequency, and a frequency corresponding to the sweep time. In the sweep pattern information 28b, it is assumed that there are a plurality of sweep patterns in which the known fundamental frequency, sweep time, and sweep frequency width of the sweep sine wave are appropriately set, and the control unit 27 uses the plurality of sweep patterns. It may be possible to switch the sweep pattern.

Alternatively, sweep pattern switching means (not shown) may be provided so that the sweep pattern can be switched by an external instruction. As an instruction from the outside, RS-232C, I2C, USB (registered trademark) or the like is preferable for wired communication, and Bluetooth (registered trademark) or ZigBee (registered trademark) is preferable for wireless communication.

Furthermore, a sweep pattern changing means (not shown) may be provided to change the sweep pattern itself so that the sweep pattern can be changed by an external instruction. As an instruction from the outside, like the sweep pattern switching means, RS-232C, I2C, USB (registered trademark) or the like is preferable for wired communication, and Bluetooth (registered trademark) or ZigBee (registered trademark) is preferable for wireless communication.

Here, in the present embodiment, the radio wave radiated from the antenna 21 is a sine wave, and the sine wave that is swept around a specific frequency is referred to as a “swept sine wave”. Further, in the following description, the coordinate means a coordinate in an orthogonal coordinate system in a three-dimensional (three-dimensional) space unless otherwise specified.

Further, when the re-transmission mode switch 23 is pressed, the control unit 27 controls the radio wave generation unit 22 to generate a signal indicating that and transmits the signal via the antenna 21. In order to distinguish the signal generated at this time from the signal for measuring the coordinate position, for example, the frequency is different from that of the signal for measuring the coordinate position, or the modulation is different even though the frequency is the same.

Next, the receiving device 12 will be described with reference to FIG. The reception device 12 includes four reception units 31a to 31d, a propagation path distance difference calculation unit 32, a transmission device coordinate calculation unit 33, a transmission device coordinate storage unit 34, a movement correction value calculation unit 35, and a movement correction unit 36. Yes. The receiving device 12 calculates the three-dimensional spatial coordinates of the measurement object based on the radio wave transmitted from the transmitting device 11. The position where the receiving device 12 is first placed becomes a reference point for coordinate position measurement. In the configuration of the transmission apparatus 11 illustrated in FIG. 4, the

interface units

25 and 26, the control unit 5, and the memory 28 are not illustrated.

The receiving units 31a to 31d receive the radio waves transmitted by the transmission device 11, respectively. The receiving units 31a to 31d have antennas 41a to 41d and receivers 42a to 42d, respectively. In the following description, when it is not necessary to distinguish between the receiving units 31a to 31d, the antennas 41a to 41d, and the receivers 42a to 42d, the receiving unit 31, the antenna 41, and the receiver 42 are simply described. Called.

Also, a pair of two receiving units 31 is referred to as a receiving unit pair. Since four receiving units 31a to 31d are provided, the receiving unit 31a and the receiving unit 31b, the receiving unit 31a and the receiving unit 31c, the receiving unit 31a and the receiving unit 31d, the receiving unit 31b and the receiving unit 31c, and the receiving unit 31b The receiving unit 31d, the receiving unit 31c, and the receiving unit 31d form a receiving unit pair. In this example, there are six receiving unit pairs.

In the example of FIG. 4, four receiving units 31a to 31d are provided, but a receiving unit 31 may be further provided. In addition, here, the two receiving units 31 are used as a receiving unit pair, but three or more receiving units 31 can be used as one group (receiving unit group).

As shown in FIG. 5, the propagation path distance difference calculation unit 32 has a difference in distance between each reception unit 31 and the transmission device 11, so that one reception unit constituting a reception unit pair for each reception unit pair. 31 and a propagation path distance difference, which is a difference between the distance between the transmission device 11 and the one reception unit 31 and the distance between the transmission device 11 and the other reception unit 31, based on the radio waves respectively received by the reception unit 31 and the other reception unit 31. To do. Details of the method of calculating the propagation path distance difference will be described later.

The transmission device coordinate calculation unit 33 calculates the coordinates of the transmission device 11 based on the propagation path distance difference calculated for the reception unit 31 using the position of the reception device 12 as a reference point for coordinate position measurement, and stores the transmission device coordinate storage. Stored in the unit 34.

An outline (details will be described later) of the coordinate calculation method of the transmission device 11 will be described. The coordinates (curved surface on the three-dimensional coordinate system) at which the propagation path distance difference between the transmission device 11 and the two reception units 31 is a constant value are candidates for the coordinate solution of the transmission device 11. The curved surface represented by the mesh in FIG. 6 is the propagation path distance difference (distance difference between TP and TQ) for the transmitter 11 and the two receivers 31a (P in the figure) and 31B (Q in the figure). Is a curved surface with a constant value. The transmission device coordinate calculation unit 33 obtains the curved surface for the six combinations of the reception unit pairs, and calculates the point where they intersect as the position of the transmission device 11. Note that this may be configured such that the transmitter coordinate calculation unit 33 can appropriately switch and connect six reception unit pairs to one propagation path distance difference calculation unit 32 (FIG. 4). A dedicated propagation path distance difference calculation unit 32 may be provided for each part pair, and all the calculation results may be connected to the transmitter coordinate calculation unit 33 at the same time.

The transmission device coordinate calculation unit 33 receives propagation path distance differences for the six reception unit pairs, and the known four reception units 31a (P), 31b (Q), 31c (R), and 31d (S). Based on the coordinates and the propagation path distance difference values for the six receiver pairs, the coordinates of the transmission device 11 (T) can be calculated using equations (18) to (32) described later.

Although FIG. 4 shows that the receiving unit pair including the receiving units 31a to 31d and the propagation path distance difference calculating unit 32 are integrated, the present invention is not limited to this. Although not shown in the figure, the transmitter coordinate calculation unit 33 may be integrated with or separate from the reception unit pair and the propagation path distance difference calculation unit 32.

The movement correction value calculation unit 35 is calculated by the transmission device coordinate calculation unit 33 at a position immediately before the movement when the reception device 12 (reception unit 31) is moved when measuring the measurement object for the reason described later. The movement correction value is calculated on the basis of the predetermined coordinates and the coordinates calculated by the transmitter coordinate calculation unit 33 at the position after the movement after receiving the radio wave again after the movement.

The movement correction unit 36 corrects the coordinates measured by the transmission device 11 after the movement of the reception unit 31 based on the movement correction value calculated by the movement correction value calculation unit 35. Thereby, it becomes possible to take consistency with the coordinates of the transmission device 11 measured before the movement of the reception unit 31. In the present embodiment, the movement correction value is a three-dimensional position difference before and after the movement of the reception unit 31 and is added to the coordinates of the transmission device 11 measured after the movement of the reception unit 31. That is, processing for adjusting the position after movement to the coordinates before movement is performed.

In addition, you may make it correct | amend the coordinate used as the reference | standard position of the receiving part 31 after a movement. Also in this case, it is substantially the same as adding the movement correction value to the coordinates of the transmission device 11 measured after the movement of the receiving unit 31.

When correcting the coordinates that become the reference position of the receiving unit 31 after the movement, the coordinates of the measurement points of the transmission apparatus 11 that have already been measured are corrected, and the coordinates of the transmission apparatus 11 that are measured after the movement of the reception apparatus 12 are moved. It shall not be corrected with the correction value. When the coordinates of each measurement point of the transmitter 11 that has already been measured are corrected, the subsequent measurement results at the transmitter 11 can be used as they are. In this case, the movement correction unit 36 corrects the coordinates of each measurement point of the transmitter 11 that has already been measured based on the measurement result of the movement correction value in the movement correction value calculation unit 35.

<Details of Configuration of Propagation Route Distance Difference Calculation Unit 32>
The configuration of the propagation path distance difference calculation unit 32 will be described with reference to FIG. FIG. 7 shows a configuration corresponding to the receiving unit pair (receiving

units

31 a and 31 b) among the configurations of the propagation path distance difference calculating unit 32. Since the other receiving unit pairs (receiving

units

31c and 31d) are the same, the description thereof is omitted.

The propagation path distance difference calculation unit 32 corresponds to the reception unit pair (

reception units

31a and 31b), and includes

multiplexers

51a and 51b,

power detectors

52a and 52b,

low frequency amplifiers

53a and 53b, and an A / D converter 54a. , 54b, a beat frequency calculation unit 55, and a distance difference calculation unit 56.

The radio wave received by the receiving unit 31a and the radio wave received by the receiving unit 31b are combined by the multiplexer 51a to become a combined wave. The intensity of the combined wave combined by the multiplexer 51a is detected by the power detector 52a. The detection result of the power detector 52a is an envelope waveform of a composite wave, which is a low frequency analog signal. The analog signal that is the envelope waveform of the synthesized wave is amplified by the low-frequency amplifier 53a. The envelope waveform of the composite wave amplified by the low frequency amplifier 53 a is converted into a digital signal by the A / D converter 54 a and supplied to the beat frequency calculation unit 55.

The radio wave received by the receiving unit 31b and the radio wave received by the receiving unit 31a are combined in the multiplexer 51b with a phase delayed by 90 degrees from the combined wave of the combined wave in the multiplexer 51a. The intensity of the combined wave combined by the multiplexer 51b is detected by the power detector 52b. The detection result of the power detector 52b is an envelope waveform of a composite wave, which is a low frequency analog signal. The analog signal that is the envelope waveform of the synthesized wave is amplified by the low-frequency amplifier 53b. The envelope waveform of the synthesized wave amplified by the low frequency amplifier 53 b is converted into a digital signal by the A / D converter 54 b and supplied to the beat frequency calculation unit 55.

The beat frequency calculation unit 55 calculates a frequency analysis beat frequency by FFT (Fast Fourier Transform) based on the signal converted from the analog signal to the digital signal by the A / D converter 54a and the A / D converter 54b. It is possible to generate a beat signal from signals generated by the multiplexer 51a, the power detector 52a, the low frequency amplifier 53a, and the A / D converter 54a. In this example, however, FFT (Fast Fourier Transform) is used. ) To obtain the frequency of the beat signal, and in order to improve the accuracy of the FFT, a signal whose phase is shifted by 90 degrees is used.

The distance difference calculation unit 56 calculates the distance difference based on the beat frequency output from the beat frequency calculation unit 55. This distance difference calculation unit 56 obtains a propagation path distance difference by substituting the above-described beat signal frequency into Equation (1) described later. Note that the sweep time and sweep frequency width of the swept sine wave are known.

FIG. 8 shows, from above, examples of radio waves received by the receiver 31a, radio waves received by the receiver 31b, synthesized waves generated by the multiplexer 51a, and beat signals calculated by the beat frequency calculator 55. Show.

The radio waves transmitted from the transmission device 11 are received by the

reception units

31a and 31b (FIG. 7). At this time, the “distance from the transmission device 11 to the reception unit 31a” and the “transmission device 11 to the reception unit 31b”. If there is a difference in “distance to”, a time difference will occur in the arrival of radio waves by the time obtained by dividing this distance difference by the speed of light. Here, the radio wave transmitted from the transmitter 11 is a swept sine wave. Accordingly, when the radio waves received by the receiving unit 31a and the receiving unit 31b are combined by the multiplexer 51a, the sweep is performed by an amount corresponding to the difference in time when the radio waves arrived at the receiving unit 31a and the receiving unit 31b. This is a composite of a swept sine wave with a frequency offset of minutes. That is, as a result of the synthesis by the

multiplexers

51a and 51b, a beat whose amplitude varies with the frequency difference between the two waves before synthesis as a period is observed. The frequency of the beat signal is called the beat frequency.

<Principle of Coordinate Calculation Method of Transmitter 11>
Next, the principle of the coordinate calculation method of the transmission device 11 in the transmission device coordinate calculation unit 33 will be described.

From the above equation (1), the distance difference d, which is the difference between the “distance between the transmitter 11 and the receiver 31a” and the “distance between the transmitter 11 and the receiver 31b”, can be determined if the beat frequency of the synthesized wave is known. This d is the propagation path distance difference.

In addition, in the spatial coordinates of the transmission device 11, the reception unit 31a, and the reception unit 31b as shown in FIG. 5, as shown in FIG. 6, a curved surface that is a distance difference d can be determined based on these coordinates. It is located somewhere on this curved surface.

In order to measure the spatial coordinates of the transmitter 11 that transmits a swept sine wave, a plurality of receiver pairs are used to calculate a distance difference to determine a plurality of curved surfaces, and a point where all the curved surfaces intersect is transmitted. This is the coordinates where the device 11 exists.

Details of the coordinate measuring method of the transmission device 11 by the four receiving units 31a to 31d are described below.

The origin of the three-dimensional coordinate system is set to an arbitrary point, the transmission device 11 is represented by T, the reception unit 31a is represented by Q, the reception unit 31b is represented by P, the reception unit 31c is represented by S, and the reception unit 31d is represented by R. The coordinates of the transmitting device 11 existing in the coordinates are (x, y, z), and the three-dimensional coordinates of the

respective receiving units

31a, 31b, 31c, 31d are (□ .x, □ .y, □ .z) (where P, Q, R, and S are included in □), the expressions representing the distances between the transmitter 11 and the receiving

units

31a, 31b, 31c, and 31d are the following expressions (2) to (2) to Equation (5) is obtained.

In addition, the difference in distance between the transmission device 11 and each receiving unit 31 is defined as follows using Equations (6) to (11).

The four receiving units 31 have combinations of six receiving unit pairs. Therefore, the following six relational expressions (12) to (17) can be derived between the six reception unit pairs and the transmission device 11.

For reference, TQP. The xyz satisfying the equation (12) for d is plotted on the three-dimensional coordinates to represent the curved surface portion represented by the mesh in FIG. In this way, the coordinates at which the propagation path distance difference (TQP.d: distance difference between TP and TQ) is constant for the transmitter 11 and the two receivers 31 (in this case, P and Q) are three-dimensional. On the coordinate system, a curved surface is represented by the mesh in FIG. 6, and this curved surface is a candidate group of coordinate solutions of the transmission device 11. As described above, the transmission device 11 (T) is located somewhere on the curved surface of the mesh.

Obtaining a point where a plurality of curved surfaces as described above intersect means obtaining an expression for each of xyz, which is the coordinates of the transmission device 11 (T), based on Expressions (2) to (17). “Coordinates of four receiving units 31a (P), 31b (Q), 31c (R), 31d (S)” and “propagation path distance difference for each of six receiving unit pairs” are substituted into the obtained formula. As a result, xyz is determined. For the convenience of expressing the formulas, A1 to A3, B1 to B3, C1 to C3, and D1 to D3 are defined as formulas (18) to (29), and using this, the transmission apparatus Expressions (30) to (32) represent the coordinates xyz of 11 (T).

In this way, the known coordinates of the four receivers 31a (P), 31b (Q), 31c (R), 31d (S), the propagation path distance differences measured in each of the six receiver pairs, Is substituted into equations (18) to (32) to obtain the coordinates of the transmitter 11 (T). When the coordinates of the receivers 31a (P), 31b (Q), 31c (R), 31d (S) are, for example, a triangular pyramid shape as shown in FIG. Although it is suitable, it is not limited to this.

The reason for sweeping the sine wave transmitted from the transmission device 11 will be described. The radio wave transmitted from the transmitting device 11 reaches the receiving

units

31a, 31b, 31c, and 31d of the receiving unit pair with a time difference. In simple terms, if this time difference is measured, it is theoretically possible to determine the propagation path distance difference by multiplying the measured time by the speed of light.

However, when the radio waves transmitted from the same transmitter 11 are received by the receiving unit pair, the propagation path distance difference does not exceed the linear distance of the receiving units 31a to 31d of the receiving unit pair. However, since the speed of light travels 1 m at about 3.3 nsec, it is necessary to measure the time difference in the nsec order range in order to measure the arrival time difference of the radio waves received by the receiving units 31a to 31d of the receiving unit pair. In order to realize this measurement, expensive parts are required, which is contrary to economic efficiency, and it is practically difficult to perform highly accurate measurement.

On the other hand, by measuring the radio wave transmitted from the transmitter 11 as a swept sine wave, the measurement of the propagation path distance difference is changed from “highly difficult minute time measurement” to “low difficulty and relatively low frequency beat signal. Can be replaced by "frequency measurement". As a result, measurement of the propagation path distance difference can be realized with a simple apparatus configuration and technique as in the present embodiment. In addition, by changing the setting of the sweep time and sweep frequency width of the swept sine wave, “the linear distance of the receiver pair”, “the range of the assumed distance from the transmitter 11 to the receiver 31” and “measurement” It becomes possible to perform coordinate measurement of the transmission device 11 in conformity with conditions such as “accuracy”.

<About the measuring method of the coordinate measuring apparatus 1>
Next, the operation of the control unit 27 of the transmission apparatus 11 is shown in the flowchart of FIG. The START condition in FIG. 9 is a condition that a power switch (not shown) of the transmission apparatus 11 is in an ON state. Note that the processing from START to END in the flowchart of FIG. 9 is processing for one cycle, and the processing is restarted if the START condition is satisfied when the processing for one cycle is completed (END). .

In step S1, the control unit 27 determines whether or not the measurement switch 25 is ON (pressed). If it is determined in step S1 that the measurement switch 25 is ON, the process proceeds to step S2. On the other hand, if it is determined in step S1 that the measurement switch is not ON, the process repeats step S1.

In step S2, the control unit 27 causes the radio wave generation unit 22 to generate a radio wave based on the sweep pattern information 28b and cause the antenna 21 to transmit the radio wave. When the process of step S2 is completed, the process proceeds to step S3.

In step S3, the control unit 27 determines whether or not the retransmission mode switch 23 is ON (pressed). If it is determined in step S3 that the retransmission mode switch 23 is ON, the process proceeds to step S4. On the other hand, if it is determined in step S3 that the retransmission mode switch is not ON, the process returns to step S1.

In step S4, the control unit 27 causes the radio wave generation unit 22 to generate a radio wave for notification of retransmission, and transmits the radio wave for notification of retransmission from the antenna 21. When the process of step S4 is completed, the process for one cycle is ended (END).

Next, the operation of the receiving device 12 is shown in the flowchart of FIG. The START condition in FIG. 10 is that the power switch (not shown) of the receiving device 12 is in the ON state. Note that the processing from START to END in the flowchart of FIG. 10 is processing for one cycle, and processing is restarted if the START condition is satisfied when processing for one cycle is completed (END). .

In step S <b> 10, the propagation path distance difference calculation unit 32 determines whether or not the radio wave from the transmission device 11 has been received. If it is determined in step S10 that the radio wave from the transmission device 11 has been received, the process proceeds to step S11. On the other hand, if it is determined in step S10 that the radio wave from the transmission device 11 is not received, the process repeats step S10.

In step S11, the propagation path distance difference calculation unit 32 calculates the propagation path distance difference of the transmission device 11, and the process proceeds to step S12.

In step S12, the transmission device coordinate calculation unit 33 calculates the coordinates of the transmission device 11, and the transmission device coordinate storage unit 34 stores the coordinates of the transmission device 11 calculated by the transmission device coordinate calculation unit 33. Proceed to step S13.

In step S13, the movement correction value calculation unit 35 determines whether or not there is a retransmission notification. If it is determined in step S13 that there is a retransmission notification, the process proceeds to step S14. On the other hand, if it is determined in step S13 that there is no retransmission notification, the process returns to step S10.

In step S14, the movement correction value calculation unit 35 reads the coordinates of the transmission device 11 calculated immediately before from the transmission device coordinate storage unit 34, and the process proceeds to step S15.

In step S15, the movement correction value calculation unit 35 determines whether or not the transmission device coordinate calculation unit 33 has calculated the coordinates of the transmission device 11. If it is determined in step S15 that the coordinates of the transmission device 11 have been calculated, the process proceeds to step S16. On the other hand, if it determines with the coordinate of the transmitter 11 not being calculated in step S15, a process will repeat step S15.

In step S16, the movement correction value calculation unit 35 calculates the difference between the coordinates of the transmission device 11 read from the transmission device coordinate storage unit 34 in step S14 and the coordinates of the transmission device 11 calculated by the transmission device coordinate calculation unit 33 in step S15. Is calculated as a movement correction value, and the process proceeds to step S17.

In step S <b> 17, the movement correction value calculation unit 35 adds the movement correction value to the coordinates of the transmission device 11 after receiving the retransmission notification among the coordinate information of the transmission device 11 stored in the transmission device coordinate storage unit 34. The process to start is started.

Next, the measurement method using the coordinate measuring apparatus 1 will be described more specifically with reference to FIGS. 11 and 12.

FIG. 11 shows how the dimensions of the desk 90 are measured using the transmitter 11 and the receiver 12. As shown in FIG. 11, when the measurer causes the measurement switch 27 of the transmission device 11 to contact the desk 90 (step S1 in FIG. 9), the transmission device 11 transmits radio waves from the reception device 12 (in FIG. 9). In step S2), the four receiving units 31a to 31d of the receiving device 12 receive radio waves (step S10 in FIG. 10).

In the example of FIG. 11, the transmission device 11 first transmits a radio wave to the reception device 12 at the position P1 on the upper surface of the desk 90, whereby the reception device 12 has the position P1 calculated by the transmission device coordinate calculation unit 33. Coordinate information is memorize | stored in the transmitter coordinate memory | storage part 34 (step S12 of FIG. 10). Thereafter, the measurer similarly transmits the radio wave at the position P2 on the upper surface of the desk 90 and the position P3 on the lower side of the desk 90, respectively, and the transmitter coordinate calculation unit 33 calculates the radio wave in the receiving apparatus 12. The coordinate information of the position P2 and the position P3 is stored in the transmitter coordinate storage unit 34, respectively.

Incidentally, as shown in FIG. 11, at the position P <b> 4 below the desk 90, even if the transmission device 11 tries to transmit radio waves to the reception device 12, the radio waves reach the reception device 12 because the top plate of the desk 90 becomes an obstacle. do not do. Alternatively, although the radio wave reaches the receiving device 12, the reached radio wave is a radio wave reflected on the floor or wall after being reflected on the upper plate of the desk 90, and includes many measurement errors. It should be noted that the presence of an obstacle between the transmission device 11 and the reception device 12 can usually be recognized visually by a measurer who is measuring the dimensions of the desk 90.

Therefore, the measurer performs the measurement by moving the position of the receiving device 12 as shown in FIG. In this moved position, the receiving device 12 can directly and satisfactorily receive the radio wave of the transmitting device 11 at the position P4 of the desk 90, and the receiving device 12 directly receives the radio wave of the transmitting device 11 at the position P3. A position that can be received well (no obstacles).

After the movement, the measurer presses the retransmission mode switch 23 of the transmission device 11 (step S5 in FIG. 9). Then, the control unit 27 causes the radio wave generation unit 22 to generate a mode switching signal (step S6 in FIG. 9). The mode switching signal generated by the radio wave generator 22 is transmitted from the antenna 21. Then, the receiving device 12 receives the mode switching signal. At this time, the movement correction value calculation unit 35 determines that the mode switching signal has been received (corresponding to the case of Yes in step S13 in FIG. 10).

In FIG. 10, when it is determined that the movement correction value calculation unit 35 has not received the mode switching signal (in the case of No), the processing returns to step S10.

In the receiving device 12, the mode switching signal is input to the movement correction value calculation unit 35. Then, the movement correction value calculation unit 35 reads the coordinates of the transmission device 11 calculated immediately before from the transmission device coordinate storage unit 34 (step S14 in FIG. 10).

Next, the measurer transmits the radio wave of the transmission device 11 again from the position P3 measured immediately before operating the retransmission mode switch 23 in the ON state. At this time, the movement correction value calculation unit 35 is in a state where it is determined whether or not the transmission device coordinate calculation unit 33 has calculated the coordinates of the transmission device 11 (step S15 in FIG. 10). For this reason, when a radio wave is received by the receiving unit 31 (in the case of Yes), the process proceeds to the next step S16, but if the radio wave is not received, the process of step S15 is repeated.

When the radio wave is received, the movement correction value calculation unit 35 receives the coordinates of the same position P3, that is, the coordinate information output from the transmitter coordinate calculation unit 33 after receiving the mode switching signal, and before receiving the mode switching signal. A difference from the coordinate information measured and stored in the transmitter coordinate storage unit 34 is calculated, and the difference is set as a movement correction value (step S16 in FIG. 10). Then, the movement correction value calculation unit 35 outputs the calculated movement correction value to the movement correction unit 36.

Then, the movement correction unit 36 adds the movement correction value calculated by the movement correction value calculation unit 35 to the coordinates of the transmission device 11 to be measured later (step S17 in FIG. 10). Thereby, the consistency of the coordinates of the transmission device 11 before and after the reception device 12 moves is taken.

That is, in the case shown in FIG. 12, the transmission device 11 transmits a radio wave to the reception device 12 at a position P4 below the desk 90, and the coordinate information of the position P4 is stored in the transmission device coordinate storage unit 34. Also at this time, the movement correction unit 36 adds the movement correction value to the coordinates of the transmission device 11 measured at the position P4.

Thus, even when the measurer moves the position of the receiving device 12, the coordinate information of the transmitting device 11 stored in the transmitting device coordinate storage unit 34 can be corrected according to the movement.

FIG. 13 and FIG. 14 are diagrams showing the concept of correction of coordinate information by the movement correction unit 36. As shown in FIG. 13, when the movement correction value α is obtained at the position P3, the movement correction value α is added to the actual measurement value in the subsequent measurement of the coordinates of the positions P4, P5, and P6. Thereby, the coordinate information is matched before and after the movement of the receiving device 12.

When the position after the movement is matched with the coordinates before the movement, the movement correction value α is added to the coordinates obtained after the movement as shown in FIG. 13, but the position of the receiving unit 31 after the movement is used as a reference. In this case, as shown in FIG. 14, when the movement correction value α is obtained at the position P3, the movement correction value α is subtracted from the coordinate information of the previous positions P1, P2, and P3. As a result, the coordinate information is matched before and after the movement of the receiving device 12.

Note that the correction of the coordinate information shown in FIG. 13 or FIG. 14 may be performed during the measurement or after the measurement is completed. In particular, the correction method shown in FIG. 14 may be performed after the measurement ends because the stored contents of the transmitter coordinate storage unit 34 are traced back to the past.

In this way, the coordinate measuring device 1 can measure the coordinates of the transmitting device 11 even if the measurer moves the receiving device 12 during the measurement. According to this, it is possible to measure coordinates while moving the receiving device 12 to an optimal position as viewed from the transmitting device 11. That is, the receiving unit 31 can receive the radio wave from the transmission device 11 directly and satisfactorily. For this reason, the receiving unit 31 does not need to be highly sensitive, and can be reduced in cost and size. Moreover, since the output required for the transmission apparatus 11 does not need to be large, the antenna of the transmission apparatus 11 can be reduced in size, and the radio wave generation unit 22 and the like can be reduced in cost. Furthermore, when receiving the radio wave transmitted from the transmission device 11, the reception unit 31 can directly receive the radio wave from the transmission device 11, so that the coordinate measurement accuracy can be improved without being affected by the reflected wave or the like. it can.

<About modification>
The present invention has been described with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. Of course.

In the above-described embodiment, the mode switching signal is a radio wave transmitted from the antenna 21 via the radio wave generator 22. However, the mode switching signal may be other signals. For example, the mode switching signal may be another method such as a method using infrared rays, a method using other light, or a region using radio waves but deviating from the frequency shown in FIG. Moreover, it is good also as a system which generates a mode switching signal by the receiver 12 side instead of the system which transmits a mode switching signal from the transmitter 11 side. For example, when the receiving device 12 is moved, a mode switching signal may be generated by pressing a predetermined button provided on the receiving device 12.

In the above-described embodiment, after the retransmission mode switch 23 is operated to the ON state, the coordinate information of the transmission device 11 stored at the latest time stored in the transmission device coordinate storage unit 34 is read. However, the coordinate information of the transmission device 11 read from the transmission device coordinate storage unit 34 at this time may be arbitrarily selected by the measurer.

Further, in the configuration of FIG. 1, only one transmitter 11 is shown. However, the reception unit 31 selects and receives the swept sine wave transmitted from the transmission device 11 for each frequency band so that radio waves transmitted from the plurality of transmission devices 11 using different frequency bands can be distinguished and handled. May be possible.

In the above-described embodiment, an example in which radio waves are used as measurement waves has been described. However, the present invention can be similarly implemented by using light (light waves) or ultrasonic waves (sound waves). In the case of light, light on which a beat signal with a low frequency is superimposed can be used as in the above example.

In the above-described embodiment, the measurement of the three-dimensional spatial coordinates has been described. In this case, only one receiving unit pair is required.

DESCRIPTION OF SYMBOLS 1 ... Coordinate measuring apparatus, 11 ... Transmission apparatus, 12 ... Reception apparatus, 23 ... Retransmission mode switch, 25 ... Measurement switch, 31 ... Reception part, 32 ... Propagation path distance difference calculation part, 33 ... Transmission apparatus coordinate calculation part, 35: Movement correction value calculation unit, 36: Movement correction unit

Claims

In a three-dimensional spatial coordinate measuring apparatus having a stationary body and a displacement body,
A physical action for coordinate measurement is transmitted from the stationary body to the displacement body, or from the displacement body to the stationary body,
The stationary body is
During a series of measurement operations, it is fixed at a specific coordinate in the three-dimensional spatial coordinate system where the measurement is performed,
The fixed specific coordinates can be changed by following a specific procedure.
A three-dimensional spatial coordinate measuring device.
In the three-dimensional space coordinate measuring device according to claim 1,
A transmitter that is the displacement body and transmits radio waves, light, or ultrasonic waves;
A plurality of receiving units that are the stationary body and receive radio waves, light, or ultrasonic waves transmitted by the transmission device;
Among the plurality of receiving units, the transmitting device has a plurality of receiving unit pairs each including at least two receiving units, and based on radio waves, light, or ultrasonic waves received by the receiving unit included in the receiving unit pair A propagation path distance difference calculation unit that calculates a propagation path distance difference that is a difference between a distance from the receiving unit pair to the first receiving unit and a distance from the transmitting device to the second receiving unit of the receiving unit pair When,
A transmission device coordinate calculation unit that calculates coordinates of the transmission device based on the propagation path distance difference calculated for each of the plurality of reception unit pairs;
When the receiving unit moves, based on movement information indicating that the movement has been performed, the position where the coordinates are already known is measured again, and the coordinate change of the receiving unit obtained by the re-measurement A movement correction value calculation unit for calculating a movement correction value from
Based on the movement correction value calculated by the movement correction value calculation unit, a movement correction unit that corrects any coordinates before or after the movement of the reception unit;
A three-dimensional spatial coordinate measuring apparatus comprising:
The three-dimensional spatial coordinate measuring device according to claim 2,
The movement correction value calculation unit adds the movement correction value to the coordinates of the transmission device measured after movement of the reception unit,
A three-dimensional coordinate measuring apparatus characterized by that.
The three-dimensional spatial coordinate measuring device according to claim 2,
The movement correction value calculation unit subtracts the movement correction value from the coordinates of the transmission device measured before the reception unit moves.
A three-dimensional coordinate measuring apparatus characterized by that.
In the three-dimensional space coordinate measuring device of any one of Claim 2 to 4,
The movement information is transmitted from the transmission device by pressing a switch means.
A three-dimensional coordinate measuring apparatus characterized by that.
In the three-dimensional space coordinate measuring apparatus of any one of Claim 2 to 5,
The transmission device and the movement correction value calculation unit are provided separately, and the movement information is obtained by pressing the switch means provided in the same housing as the movement correction value calculation unit. Sent to the calculator,
A three-dimensional coordinate measuring apparatus characterized by that.