JP2021177137A - Radiation shield, 2d space measurement system, and control method of 2d space measurement system - Google Patents

Abstract

To provide a small size and lightweight radiation shield capable of being used for a 2D measuring instrument.SOLUTION: A radiation shield in an embodiment is a radiation shield used for a 2D measuring instrument. The 2D measuring instrument is an instrument for grasping the position of surrounding objects using reflected waves from an object of the irradiation waves scanned to a two-dimensional space. The 2D measuring instrument has a shielding wall capable of covering the whole thereof, and a slit that for allowing irradiation waves from the 2D measuring instrument covered with the shield wall to pass therethrough for scanning toward the outside of the above shield wall.SELECTED DRAWING: Figure 1

Description

The present invention relates to a radiation shield, a two-dimensional space measurement system, and a control method for a two-dimensional space measurement system.

When transporting radioactive waste in a radioactive waste storage with a high radiation level, the radiation level in the storage may be high and workers may not be able to enter. In such a harsh environment, radioactive waste may be transported unmanned. As such an automatic guided vehicle, a system including a rail or an electromagnetic induction device embedded in a floor surface so that the vehicle can move on a predetermined track and a camera capable of visually recognizing the front of the vehicle is known. ..

If the above camera is mounted on a transport vehicle as it is, it causes a problem due to radiation, so it is necessary to shield the radiation. As such a radiation-resistant camera, one having a radiation shielding member that shields radiation to an image sensor is known, and a robot equipped with this radiation-resistant camera has been proposed (see JP-A-2019-124747). ).

The conventional radiation-resistant camera captures an image of the subject, an image pickup optical system that forms an image of the subject, relays the image, and changes the traveling direction of light on the way, and the relayed image. The image pickup optical system and the image pickup element are arranged in an internal space provided inside the shielding main body.

In the radiation-resistant camera, the shielding main body has a hemispherical portion so that the amount of radiation reaching the image sensor or the like from all directions is equal. The radiation-resistant camera is fixed to the robot by a shaft-shaped support member. Further, the robot has a rotation mechanism that can rotate around an axis, and by rotating this support member, it is possible to take a picture of the surroundings.

JP-A-2019-124747

When the conventional radiation-resistant camera is used, a rotating mechanism is required to check the surroundings, and radiation to the rotating mechanism itself needs to be shielded, so that the weight tends to increase.

Further, in recent years, as an unmanned transport system, there is a demand for a system in which a transport vehicle recognizes its own position and flexibly transports the vehicle without determining a track. In order for the transport vehicle to recognize its own position, it is necessary to grasp an object (obstacle) in a two-dimensional space. In the above-mentioned conventional radiation-resistant camera, the rotation speed of the rotation mechanism may be insufficient and the object may not be sufficiently grasped in the two-dimensional space. On the other hand, if a sufficient rotation speed is to be obtained, the size and weight of the rotation mechanism will further increase.

The present invention has been made based on the above circumstances, and is a small and lightweight radiation shield that can be used for a two-dimensional measuring instrument, a two-dimensional space measurement system using this radiation shield, and the present invention. An object of the present invention is to provide a control method for a two-dimensional space measurement system.

The radiation shield according to one aspect of the present invention is a radiation shield used for a two-dimensional measuring instrument, and is surrounded by a reflected wave of an object in the irradiation wave scanned by the two-dimensional measuring instrument in a two-dimensional space. The position of the object is grasped, and the shielding wall capable of covering the entire two-dimensional measuring instrument and the irradiation wave of the two-dimensional measuring instrument covered with the shielding wall are passed and directed toward the outside of the shielding wall. It is equipped with a slit that enables scanning.

In the radiation shield, the slit allows the irradiation wave of the two-dimensional measuring instrument to pass through and scan toward the outside of the shield wall, so that the position of the object can be grasped in the two-dimensional space without rotating the shield wall. can do. Therefore, the radiation shielding body can be easily reduced in size and weight because the radiation resistance can be improved only by covering the entire two-dimensional measuring instrument with the shielding wall.

It is preferable that the shielding wall is a hollow columnar shape, the slit is provided on the side surface of the shielding wall, and the opening angle formed by the slit around the central axis of the shielding wall is 60 degrees or more. By setting the opening angle formed by the slit to be equal to or greater than the above lower limit, it is possible to easily grasp the position of an object around the transport vehicle with a small number of two-dimensional measuring instruments.

The irradiation wave is a laser beam, and the two-dimensional measuring instrument projects the laser beam and receives the reflected light of the object, and the laser beam projected from the light emitting and receiving unit forms the slit. It has a reflecting plate that changes its traveling direction so that it can pass through, and when the shielding wall covers the two-dimensional measuring instrument, the light emitting and receiving portion is configured to be located at the blind spot of the slit. It is good to be there. In a two-dimensional measuring instrument in which the irradiation wave is a laser beam, the light emitting and receiving part is a part that is easily affected by radiation, and by locating the light emitting and receiving part in the blind spot of the slit, the radiation dose that the light receiving and receiving part is directly exposed to. Can be reduced. Therefore, it is possible to suppress the occurrence of a failure due to radiation of the two-dimensional measuring instrument and extend the life of the two-dimensional measuring instrument when it is used in a radiation environment.

The two-dimensional space measurement system according to another aspect of the present invention measures the radiation dose of the radiation shield of the present invention, the two-dimensional measuring device stored in the radiation shield, and the radiation dose of the two-dimensional measuring device. It includes a radiation measuring instrument, the two-dimensional measuring instrument, and a control unit that controls the radiation measuring instrument.

Since the two-dimensional space measurement system uses the radiation shield of the present invention, the exchange cycle due to exposure to the radiation of the two-dimensional measuring instrument is relatively long. Further, in the two-dimensional space measurement system, since the radiation dose to be exposed to the two-dimensional measuring instrument is measured by the radiation measuring instrument, the necessity of replacing the two-dimensional measuring instrument can be grasped from the accumulated absorbed dose. Therefore, the two-dimensional space measurement system can stably grasp the position of the object in the two-dimensional space while reducing the number of exchanges of the two-dimensional measuring instrument.

The control method of the two-dimensional space measurement system according to still another aspect of the present invention is the control method of the two-dimensional space measurement system of the present invention, which includes the step of measuring the actual air dose with the radiation measuring instrument and the above. In the step of measuring the actual operating time of the two-dimensional measuring instrument, the step of calculating the actual accumulated dose from the actual air dose obtained in the dose measuring step and the actual operating time obtained in the time measuring step, and the calculation step. It is provided with a step of monitoring that the obtained actual accumulated dose does not exceed a predetermined upper limit value.

In the control method of the two-dimensional space measurement system, the necessity of replacing the two-dimensional measuring instrument can be grasped by the above-mentioned process. Therefore, by using the control method of the two-dimensional space measurement system, it is possible to stably grasp the position of the object in the two-dimensional space while reducing the number of exchanges of the two-dimensional measuring instrument.

Here, the "wave" includes light in addition to waves such as sound waves and electromagnetic waves. "Covering the entire 2D measuring instrument" means that at least a part thereof is shielded from irradiation in any direction, and that the 2D measuring instrument is sealed by a shielding wall. It's not something to do.

As described above, the radiation shield of the present invention can be used for a two-dimensional measuring instrument, and is compact and lightweight. Further, the control method of the two-dimensional space measurement system of the present invention and the two-dimensional space measurement system of the present invention is stable while reducing the number of replacements of the two-dimensional measuring instrument by using the radiation shield of the present invention. It is possible to grasp the position of an object in a two-dimensional space.

FIG. 1 is a schematic side view of a radiation shield according to an embodiment of the present invention. FIG. 2 is a schematic horizontal cross-sectional view of the radiation shield of FIG. 1 as viewed from above along line II-II. FIG. 3 is a schematic side sectional view of the radiation shield of FIG. 1 as viewed from the side. FIG. 4 is a schematic plan view showing the configuration of the two-dimensional space measurement system according to the embodiment of the present invention. FIG. 5 is a schematic side view showing the configuration of the two-dimensional space measurement system of FIG. FIG. 6 is a flow chart showing a control method of the two-dimensional space measurement system according to the embodiment of the present invention. FIG. 7 is a schematic side view of a radiation shield different from that of FIG. FIG. 8 is a schematic horizontal cross-sectional view of the radiation shield of FIG. 7 viewed from above along line VIII-VIII.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[First Embodiment]
[Radiation shield]
The radiation shield 10 shown in FIGS. 1, 2 and 3 is a radiation shield used for a laser scanner which is a two-dimensional measuring instrument 20. The radiation shield 10 includes a shielding wall 11 and a slit 12. The two-dimensional measuring instrument grasps the position of a surrounding object by the reflected wave of the object in the irradiation wave scanned in the two-dimensional space.

<Laser scanner>
In the present embodiment, in the two-dimensional measuring instrument 20, the irradiation wave is a laser beam. The laser scanner, which is the two-dimensional measuring instrument 20, passes through a light emitting / receiving unit 21 that projects the laser light and receives the reflected light of the object, and the laser light projected from the light receiving / receiving unit 21 passes through a slit 12 described later. It has a reflector 22 that changes the traveling direction thereof, and a housing 23 that houses the light emitting / receiving unit 21 and the reflector 22.

In the two-dimensional measuring instrument 20, the light emitting / receiving unit 21 has a laser and a light receiving element. In the two-dimensional measuring instrument 20, the laser light emitted from the laser of the light emitting / receiving unit 21 is reflected by the reflector 22 and changes its traveling direction. This laser beam passes through the slit 12 and is emitted to the outside, and if there is an object in the traveling direction, the laser light is reflected by the object. The reflected light passes through the slit 12 again, is directed by the reflector 22 in the traveling direction toward the light receiving element of the light emitting and receiving unit 21, and is detected by the light receiving element. It is possible to know the distance to the reflected object from the time difference until the laser beam is emitted from the laser and detected by the light receiving element. On the other hand, the laser beam that has passed through the slit 12 and is emitted to the outside does not return the reflected light unless there is an object in the traveling direction, so that it can be seen that the object does not exist.

The reflector 22 is configured to be rotatable at a constant speed by, for example, a motor or the like. The reflector 22 may rotate 360 degrees in one direction, or may reciprocate within a certain angle range (opening angle). Further, even when the reflector 22 is rotated 360 degrees, the irradiation may be performed only in a certain angle range.

<Shielding wall>
The shielding wall 11 can cover the entire two-dimensional measuring instrument 20. Specifically, the shielding wall 11 is a hollow columnar shape.

The shielding wall 11 is composed of a shielding body that attenuates radiation. The thickness of the shielding wall 11 is appropriately determined from the attenuation rate and the radiation dose to be exposed, but from the viewpoint of weight reduction, the radiation dose reaching the two-dimensional measuring instrument 20 is within a range of a desired magnitude or less. The thinner the better.

It is preferable that the shielding wall 11 is configured such that the light emitting / receiving portion 21 is located at the blind spot of the slit 12 when the two-dimensional measuring instrument 20 is covered. That is, as shown in FIG. 3, the light emitting / receiving unit 21 is arranged at a position where the radiation passing straight through the slit 12 does not directly hit. Since the radiation is transmitted through the relatively thin reflector 22, the amount of radiation reflected by the reflector 22 and substantially directly hits the light emitting / receiving unit 21 is small. Further, the radiation reflected by the shielding wall 11 and indirectly hitting the light emitting / receiving unit 21 is attenuated. Therefore, by locating the light emitting / receiving unit 21 in the blind spot of the slit 12, the radiation dose to the light receiving / receiving unit 21 can be reduced. In the two-dimensional measuring instrument 20 in which the irradiation wave is laser light, the light emitting / receiving unit 21 is a portion that is easily affected by radiation. Therefore, by reducing the radiation dose that the light emitting / receiving unit 21 is exposed to, the two-dimensional measuring instrument 20 It is possible to suppress the occurrence of a failure due to radiation and extend the life of the two-dimensional measuring instrument 20 when used in a radiation environment.

<Slit>
The slit 12 allows the irradiation wave of the two-dimensional measuring instrument 20 coated on the shielding wall 11 to pass through and scan toward the outside of the shielding wall 11. Specifically, the slit 12 is provided on the side surface of the shielding wall 11. The slit 12 is linear with respect to the horizontal direction and has a fan shape in a plan view.

The lower limit of the opening angle (θ in FIG. 2) formed by the slit 12 around the central axis of the shielding wall 11 is preferably 60 degrees, more preferably 90 degrees, and even more preferably 120 degrees. If the opening angle θ formed by the slit 12 is less than the above lower limit, the range that the two-dimensional measuring instrument 20 can scan with respect to the two-dimensional space is limited, which may make it difficult to grasp the position of surrounding objects or the surroundings. A large number of two-dimensional measuring instruments 20 may be required to grasp the position of an object. On the other hand, the upper limit of the opening angle θ is not particularly limited.

The opening angle θ formed by the slit 12 preferably coincides with the scan angle range of the two-dimensional measuring instrument 20 (the angle range in which the reflector 22 rotates). When the opening angle θ formed by the slit 12 is less than the scan angle range of the two-dimensional measuring instrument 20, the position of the object is grasped by using the entire range that the two-dimensional measuring instrument 20 can scan with respect to the two-dimensional space. Can't be done. On the contrary, when the opening angle θ formed by the slit 12 exceeds the scan angle range of the two-dimensional measuring instrument 20, the radiation dose that passes through the slit 12 and enters the inside of the shielding wall 11 unnecessarily increases, and the two-dimensional measuring instrument The life of 20 may be shortened.

<Advantage>
In the radiation shield 10, the slit 12 allows the irradiation wave of the two-dimensional measuring instrument 20 to pass through and scan toward the outside of the shield wall 11, so that the shield wall 11 does not rotate in the two-dimensional space. The position of the object can be grasped. Therefore, the radiation shielding body 10 can be easily reduced in size and weight because the radiation resistance can be improved only by covering the entire two-dimensional measuring instrument 20 with the shielding wall 11.

[Two-dimensional space measurement system]
The two-dimensional space measurement system shown in FIGS. 4 and 5 includes a radiation shield 10 according to an embodiment of the present invention shown in FIGS. 1 to 3, a two-dimensional measuring instrument 20 housed in the radiation shield 10, and a two-dimensional measuring instrument 20. It includes a radiation measuring instrument 30 that measures the radiation dose that the two-dimensional measuring instrument 20 is exposed to, and a control unit (not shown) that controls the two-dimensional measuring instrument 20 and the radiation measuring instrument 30.

The two-dimensional space measurement system is used, for example, in a transport vehicle X that transports waste L in a radiation waste storage. In the examples of FIGS. 4 and 5, four sets of the radiation shield 10, the two-dimensional measuring instrument 20, and the radiation measuring instrument 30 are mounted. The control unit may be provided individually for each radiation shield 10, the two-dimensional measuring instrument 20, and the radiation measuring instrument 30, or one may be provided in common.

<Radiation shield and 2D measuring instrument>
Since the radiation shield 10 and the two-dimensional measuring instrument 20 are the same as those described above, individual description thereof will be omitted.

The arrangement of the radiation shield 10 in which the two-dimensional measuring instrument 20 is stored is determined in consideration of the angle range in which the stored two-dimensional measuring instrument 20 can be scanned, the range in which the transport vehicle X itself cannot be seen, and the like. However, as shown in FIG. 4, for example, it is preferable that the transport vehicle X is arranged on the front side, the rear side, and the left and right sides of the transport vehicle X. By arranging in this way, the positions of surrounding objects can be grasped in all directions.

<Radiation measuring instrument>
The radiation measuring instrument 30 is arranged in the vicinity of the radiation shielding body 10, or more accurately, in the vicinity of the two-dimensional measuring instrument 20 housed in the radiation shielding body 10.

The radiation measuring instrument 30 may be provided with one radiation measuring instrument 30 in common for the four two-dimensional measuring instruments 20, but as shown in FIGS. 4 and 5, each of the two-dimensional measuring instruments 20 is located in the vicinity. It is preferable to provide a radiation measuring instrument 30. As shown in FIGS. 4 and 5, the transport vehicle X transports the radioactive waste L, but since the amount of radiation exposure depends on the distance and direction from the waste L, the four two-dimensional measuring instruments 20 are the same. Not always exposed to a large amount of radiation. Therefore, by providing a radiation measuring instrument 30 in the vicinity of each of the two-dimensional measuring instruments 20, it is possible to improve the measurement accuracy of the radiation dose exposed to the two-dimensional measuring instrument 20. On the other hand, when one radiation measuring instrument 30 is provided in common for the four two-dimensional measuring instruments 20, the two-dimensional space measuring system can be made smaller and lighter.

Since the radiation measuring instrument 30 itself has high radiation resistance, it is not always necessary to dispose of the radiation measuring instrument 30 in the shielding body as shown in FIGS. 4 and 5, and the radiation measuring instrument 30 can be directly mounted on the transport vehicle X. By mounting the radiation measuring instrument 30 directly in this way, the radiation measuring instrument 30 and thus the two-dimensional space measuring system can be made smaller and lighter. In this case, since the radiation dose measured by the radiation measuring instrument 30 is the dose in the real space outside the radiation shielding body 10, the two-dimensional measuring instrument 20 takes into consideration the attenuation of the radiation when passing through the radiation shielding body 10. The radiation dose to be exposed to the radiation will be measured. Specifically, for example, the control unit may multiply the actual measured value by the attenuation coefficient. Alternatively, the actual measured value can be used directly. Since the actual measured value is the value obtained by multiplying the radiation dose of the two-dimensional measuring instrument 20 by the proportional coefficient (the inverse of the attenuation coefficient), even if the actual measured value is used, the radiation dose of the two-dimensional measuring instrument 20 is substantially calculated. Equivalent to measuring. In this case, it is not necessary to calculate the damping coefficient.

Alternatively, the radiation measuring instrument 30 may be covered with a shield equivalent to the radiation shield 10. In this configuration, since the radiation measuring instrument 30 measures the radiation dose inside the shield, it is not necessary to adjust the measured value with an attenuation coefficient or the like. Further, since the radiation measuring instrument 30 and the radiation shielding body 10 in which the two-dimensional measuring instrument 20 is housed are separate bodies, the degree of freedom of arrangement when mounting the radiation measuring instrument X on the transport vehicle X is increased.

Alternatively, the radiation measuring instrument 30 may be included in the radiation shield 10 itself. According to this configuration, the radiation dose exposed to the two-dimensional measuring instrument 20 can be measured more accurately.

The result of the radiation dose measured by the radiation measuring instrument 30 is transferred to the control unit.

<Control unit>
The control unit calculates the actual accumulated dose by time integration of the radiation dose measured by the radiation measuring instrument 30, and monitors until the actual accumulated dose reaches a predetermined upper limit value. When the upper limit is reached, the control unit issues a warning prompting, for example, replacement of the two-dimensional measuring instrument 20. When the control unit detects that the two-dimensional measuring instrument 20 has been replaced, it initializes the actual accumulated dose and continues monitoring the replaced two-dimensional measuring instrument 20.

The control method of the two-dimensional space measurement system by the control unit will be described in detail below.

<Control method of 2D space measurement system>
The control method of the two-dimensional space measurement system shown in FIG. 6 is the control method of the two-dimensional space measurement system of the present invention. The control method of the two-dimensional space measurement system includes a dosimetry step S1, a time measurement step S2, an integrated dose calculation step S3, and a monitoring step S4.

(Dosimetry process)
In the dose measurement step S1, the actual air dose is measured by the radiation measuring instrument 30.

The measured dose of the radiation measuring instrument 30 is sent to the control unit. Further, when the radiation measuring instrument 30 measures the dose in the real space outside the radiation shield 10 as described above, the value obtained by multiplying the attenuation coefficient by the radiation shield 10 may be used as the actual air dose. The actual air dose itself may be used as an index of the radiation dose to be exposed to the two-dimensional measuring instrument 20.

This actual air dose increases, for example, when the transport vehicle X approaches the stored waste L, and increases remarkably when the waste L is lifted. Therefore, it is necessary to measure the actual air dose sequentially. The sequential measurement includes the case of intermittent measurement at regular time intervals.

(Time measurement process)
In the time measurement step S2, the actual operating time of the two-dimensional measuring instrument 20 is measured. This step is performed simultaneously with the dosimetry step S1.

It is considered that the two-dimensional measuring instrument 20 is operating when the transport vehicle X is movable, that is, when the system power of the transport vehicle X is turned on. On the other hand, when the system power of the transport vehicle X is not turned on, the transport vehicle X is in a dormant state, and it is considered that the transport vehicle X does not normally pause in a state of being exposed to radiation. Therefore, the actual operating time of the two-dimensional measuring instrument 20 You can exclude it from.

The time measurement step S2 may be performed by the control unit. It is easy to correspond the measured time with the actual air dose measured in the dose measurement step S1, and the accumulated dose can be easily calculated in the integrated dose calculation step S3, which is the next step.

(Accumulated dose calculation process)
In the accumulated dose calculation step S3, the actual accumulated dose is calculated from the actual air dose obtained in the dose measurement step S1 and the actual operating time obtained in the time measurement step S2.

Specifically, the actual accumulated dose can be calculated by numerically integrating the actual air dose expressed as a function of the time measured in the time measurement step S2. This real air dose approximates the radiation dose received by the two-dimensional measuring instrument 20.

(Monitoring process)
In the monitoring step S4, it is monitored that the actual accumulated dose obtained in the calculation step S3 does not exceed a predetermined upper limit value.

The upper limit value can be determined by confirming the accumulated dose that normally operates by performing an irradiation test using radiation on the two-dimensional measuring instrument 20 in advance. This upper limit may be a fixed value regardless of the intensity of the radiation received, but may be a different upper limit depending on the average dose per unit time (for example, per hour). The actual average dose can be calculated by dividing the actual accumulated dose calculated in the accumulated dose calculation step S3 by the total operating time obtained in the time measurement step S2. Therefore, it is possible to set an upper limit from this actual average dose and monitor it.

In the two-dimensional space measurement systems shown in FIGS. 4 and 5, this monitoring is performed independently for each two-dimensional space measurement system because a radiation measurement device 30 is provided for each two-dimensional measurement device 20. be able to. On the other hand, when one radiation measuring instrument 30 is provided for the plurality of two-dimensional measuring instruments 20, the plurality of two-dimensional measuring instruments 20 are monitored as one group.

When the upper limit is reached, the control unit may issue a warning to prompt the replacement of, for example, the two-dimensional measuring instrument 20 as described above. By replacing the two-dimensional measuring instrument 20 based on this warning, it is possible to suppress the occurrence of a failure due to radiation.

<Advantage>
Since the two-dimensional space measurement system uses the radiation shield 10 of the present invention, the exchange cycle due to exposure to the radiation of the two-dimensional measuring instrument 20 is relatively long. Further, in the two-dimensional space measurement system, since the radiation dose to be exposed to the two-dimensional measuring instrument 20 is measured by the radiation measuring instrument 30, the necessity of replacing the two-dimensional measuring instrument 20 can be grasped from the accumulated absorbed dose. Therefore, the two-dimensional space measurement system can stably grasp the position of the object in the two-dimensional space while reducing the number of exchanges of the two-dimensional measuring instrument 20.

Further, in the control method of the two-dimensional space measurement system, the necessity of replacing the two-dimensional measuring instrument 20 can be grasped by the above-mentioned steps. Therefore, by using the control method of the two-dimensional space measurement system, it is possible to stably grasp the position of the object in the two-dimensional space while reducing the number of exchanges of the two-dimensional measuring instrument.

[Second Embodiment]
[Radiation shield]
The radiation shield 40 shown in FIGS. 7 and 8 is a radiation shield used in the laser scanner which is the two-dimensional measuring instrument 20. The radiation shield 40 includes a shielding wall 41 and a slit 42. Since the two-dimensional measuring instrument 20 is the same as the two-dimensional measuring instrument 20 in the first embodiment, the same reference numerals are given and the description thereof will be omitted.

In the radiation shielding body 40, the slit 42 is provided over the entire circumference except for the four columns 41a forming a part of the shielding wall 41. In other words, the slit 42 is configured as a slit having an opening angle of 360 degrees separated by four columns 41a.

The support column 41a has a plate shape. If the slit having an opening angle of 360 degrees is configured as it is, the shielding wall 41 will be completely divided into upper and lower parts, and the shape of the radiation shielding body 40 cannot be maintained. The support column 41a is provided to maintain the shape of the radiation shield 40 even in a slit having an opening angle of 360 degrees. Even if the opening angle does not reach 360 degrees, for example, if the opening angle exceeds 180 degrees, the strength of the shielding wall 41 may be insufficient and the slit portion may be easily crushed in the height direction. Even in such a case, it is preferable to provide a support column 41a in a part of the slit to reinforce it.

The four columns 41a are arranged radially from the rotation axis of the reflector 22 so as to form an angle of 90 degrees with the adjacent columns 41a, that is, at equal intervals. By arranging in this way, the support column 41a is unlikely to interfere with the irradiation of the laser beam, which is the irradiation wave of the two-dimensional measuring instrument 20, while maintaining the shape of the shielding wall 41. In the radiation shielding body 40 shown in FIGS. 7 and 8, the shape of the shielding wall 41 is maintained by the four columns 41a, but the number of columns 41a may be three or five or more. ..

Since the shielding wall 41 and the slit 42 can be configured in the same manner as the shielding wall 11 and the slit 12 in the first embodiment except for the above-described configuration, other description will be omitted.

In the radiation shield 40, since the slit 42 is provided over the entire circumference except for the support column 41a, it can be effectively used for the two-dimensional measuring instrument 20 that irradiates the entire circumference (360 degrees).

[Other Embodiments]
The present invention is not limited to the above embodiment.

In the above embodiment, the case where the two-dimensional measuring instrument is a laser scanner has been described, but the two-dimensional measuring instrument is not limited to the laser scanner. The scanner may use another light source, or may use other waves such as sound waves and X-rays.

In the above embodiment, the case where the shielding wall is columnar has been described, but the shape of the shielding wall is not limited to the columnar shape. Other shapes such as a square columnar shape may be adopted for the shielding wall.

In the above embodiment, the case where the slit is provided on the side surface of the shielding wall has been described, but the slit is provided at a position where the irradiation wave of the two-dimensional measuring instrument can pass, and the position is limited to the side surface of the shielding wall. It's not a thing.

The radiation shield of the present invention can be used for a two-dimensional measuring instrument, and is compact and lightweight. Further, the control method of the two-dimensional space measurement system of the present invention and the two-dimensional space measurement system of the present invention is stable while reducing the number of replacements of the two-dimensional measuring instrument by using the radiation shield of the present invention. It is possible to grasp the position of an object in a two-dimensional space.

10 Radiation shield 11 Shield wall 12 Slit 20 Two-dimensional measuring instrument 21 Light receiving part 22 Reflector 23 Housing 30 Radiation measuring instrument 40 Radiation shield 41 Shield wall 41a Strut 42 Slit X Transport vehicle L Waste

Claims (5)

A radiation shield used for two-dimensional measuring instruments.
The above-mentioned two-dimensional measuring instrument grasps the position of surrounding objects by the reflected wave of the object in the irradiation wave scanned in the two-dimensional space.
A shielding wall that can cover the entire 2D measuring instrument,
A radiation shield provided with a slit that allows the irradiation wave of the two-dimensional measuring instrument covered with the shield wall to pass through and scan toward the outside of the shield wall. The shielding wall is a hollow columnar
The slit is provided on the side surface of the shielding wall,
The radiation shield according to claim 1, wherein the opening angle formed by the slit around the central axis of the shield wall is 60 degrees or more. The above irradiation wave is a laser beam,
The above two-dimensional measuring instrument
The light emitting and receiving unit that projects the laser light and receives the reflected light of the object,
It has a reflector that changes the traveling direction of the laser beam projected from the light receiving / receiving unit so as to pass through the slit.
The radiation shield according to claim 1 or 2, wherein when the shielding wall covers the two-dimensional measuring instrument, the light emitting / receiving portion is located at the blind spot of the slit. The radiation shield according to claim 1, claim 2 or claim 3 and
The two-dimensional measuring instrument stored in the radiation shield and
A radiation measuring instrument that measures the radiation dose that the above two-dimensional measuring instrument is exposed to,
A two-dimensional space measurement system including the two-dimensional measuring instrument and a control unit for controlling the radiation measuring instrument. The control method for the two-dimensional space measurement system according to claim 4.
The process of measuring the actual air dose with the above radiation measuring instrument and
The process of measuring the actual operating time of the above two-dimensional measuring instrument and
A step of calculating the actual accumulated dose from the actual air dose obtained in the dosimetry step and the actual operating time obtained in the time measurement step, and
A control method for a two-dimensional space measurement system including a step of monitoring that the actual accumulated dose obtained in the above calculation step does not exceed a predetermined upper limit value.

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