Air flow measurement device and air flow measurement method

Abstract

An air flow measuring device is provided that can minimize the amount of displacement of an air flow measuring unit in the Y-axis direction caused by a displacement unit. [Solution] A control unit of an air volume measuring device moves a traveling carriage to a first position below an air outlet, calculates a first amount of deviation between the center of the air outlet and the center of the backing plate from an image captured by an imaging unit at the first position, and rotates the traveling carriage so that its traveling direction points toward the center of the air outlet. The control unit moves the traveling carriage to a second position forward in the traveling direction by the first amount of deviation, and rotates the traveling carriage at the second position so that its traveling direction coincides with the X-axis direction. The control unit calculates a second amount of deviation in the Y-axis direction between the center of the air outlet and the center of the backing plate from an image captured by the imaging unit at the second position, and displaces a displacement unit in the Y-axis direction by the second amount of deviation.

Description

[Technical Field]

[0001] The present disclosure relates to an air flow measurement device and an air flow measurement method, and more particularly to an air flow measurement device and an air flow measurement method for measuring the volume of air blown out from a long air outlet arranged in one direction next to an air intake in a system ceiling. [Background technology]

[0002] An example of this type of airflow measurement device, an airflow measurement robot, is disclosed in, for example, Patent Document 1 below. This airflow measurement robot includes a carriage unit, which is a traveling carriage; an airflow measurement unit having a hood; a lifting unit that raises and lowers the airflow measurement unit; a horizontal displacement unit; a ceiling condition detection unit that detects the condition of the ceiling surface; and a control unit. The control unit moves the carriage unit below an air vent, which is an air outlet, and then controls the operation of the carriage unit and the horizontal displacement unit based on the condition of the ceiling surface to adjust the position of the airflow measurement unit relative to the air vent. A partition plate is attached to the upper end of the hood as a backing plate that covers the gap (inlet) around the air vent (air outlet). An opening corresponding to the shape of the air vent is formed in this partition plate, preventing communication between the gap and the air vent. In other words, attaching the partition plate prevents communication between the inside of the hood and the gap, which would otherwise reduce the accuracy of airflow measurement.

[0003] Another airflow measurement device, an inspection device for an air vent, is disclosed, for example, in Patent Document 2. This inspection device includes a pantograph-type lifting unit and an XY moving unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2025-24970 [Patent Document 2] Japanese Patent Publication No. 2023-150033 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, the longitudinal direction of the air duct is defined as the X-axis direction, and the direction perpendicular to the X-axis direction and the up-down direction is defined as the Y-axis direction. The horizontal displacement unit is operated in the Y-axis direction to displace the airflow measurement unit in the Y-axis direction. If the displacement of the airflow measurement unit in the Y-axis direction is large, the center of gravity of the horizontal displacement unit and the airflow measurement unit will shift in the Y-axis direction. If the center of gravity shifts, when the airflow measurement unit is raised, the partition plate will shift in the Y-axis direction relative to the air duct due to deflection of the lifting unit caused by a bending moment (= load of the airflow measurement unit × displacement in the Y-axis direction). Because the gap and the air duct are arranged side by side in the Y-axis direction, it is necessary to minimize the positional deviation in the Y-axis direction as much as possible. To achieve this, it is desirable to minimize the displacement of the airflow measurement unit in the Y-axis direction caused by the horizontal displacement unit.

[0006] Furthermore, the pantograph-type lifting unit employed in Patent Document 2 has a larger expansion / contraction ratio than lifting units that use hydraulic or electric mechanisms, making it easier to transport to and from the site, but it is also more prone to bending. When employing such a pantograph-type lifting unit, it is particularly necessary to minimize the amount of displacement in the Y-axis direction.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an air flow measurement device and an air flow measurement method that can minimize the amount of displacement of an air flow measurement unit in the Y-axis direction caused by a displacement unit. [Means for solving the problem]

[0008] The present disclosure relates to an airflow measurement device that measures the volume of air blown out from a longitudinal air outlet installed next to an air inlet in a system ceiling. The airflow measurement device includes an airflow measurement unit having a hood with an upper opening larger than the air outlet and an airflow sensor that measures the volume of air guided by the hood, a lifting unit that supports the airflow measurement unit so that it can be raised and lowered, a unidirectionally movable and rotatable traveling cart on which the lifting unit is mounted, a displacement unit that can displace the airflow measurement unit in the Y-axis direction, where the longitudinal direction of the air outlet is the X-axis direction and the direction in which the air outlet and the air inlet are arranged side by side, which is perpendicular to the X-axis direction and the up-down direction, is the Y-axis direction, an imaging unit that images the air outlet through the hood, and a control unit that controls the lifting unit, the traveling cart, and the displacement unit. A backing plate that covers the air inlet is attached to the upper end of the hood, and an opening corresponding to the shape of the air outlet is formed in the backing plate. The control unit is configured to perform the following operations: running the traveling carriage to a first position below the air outlet; calculating a first deviation amount between the air outlet center, which is the center of the air outlet, and the backing plate center, which is the center of the backing plate, from an image captured by the imaging unit at the first position; rotating the traveling carriage so that the traveling direction of the traveling carriage is directed toward the air outlet center, and running the traveling carriage to a second position forward in the traveling direction by the first deviation amount; rotating the traveling carriage at the second position so that the traveling direction of the traveling carriage coincides with the X-axis direction; calculating a second deviation amount in the Y-axis direction between the air outlet center and the backing plate center from the image captured by the imaging unit at the second position; and displacing the displacement unit by the second deviation amount in the Y-axis direction.

[0009] In the present disclosure, the control unit is configured to repeatedly rotate the traveling carriage at the first position, travel to the second position, and rotate the traveling carriage at the second position until the first deviation amount falls within a threshold value.

[0010] In the present disclosure, the control unit is further configured to determine two intersection points of the frame of the system ceiling from the image captured at the first position, and to determine the center of the air outlet from the two intersection points.

[0011] In the present disclosure, the control unit is further configured to adjust at least one of the brightness and contrast of the image when the two intersection points cannot be determined from the image captured at the first position.

[0012] The present disclosure relates to an air flow measurement method for measuring the air flow rate blown out from the air outlet using the air flow measurement device. The air flow measurement method includes the steps of: moving the traveling vehicle to the first position; and correcting the position of the air flow measurement unit after moving the traveling vehicle to the first position. The position correction step includes the steps of: capturing an image of the air outlet through the hood with the imaging unit at the first position; calculating, from the image captured at the first position, a first rotation angle for orienting the traveling direction of the traveling vehicle toward the center of the air outlet, the first offset amount, and a second rotation angle for aligning the traveling direction of the traveling vehicle with the X-axis direction; rotating the traveling vehicle by the first rotation angle at the first position; moving the traveling vehicle rotated by the first rotation angle to the second position forward in the traveling direction by the first offset amount; and rotating the traveling vehicle by the second rotation angle at the second position; capturing an image of the air outlet through the hood with the imaging unit at the second position; 2 and displacing the displacement unit in the Y-axis direction by the second displacement amount. [Effects of the Invention]

[0013] According to the present disclosure, the traveling carriage is moved to a first position, and then rotated at the first position so that the traveling carriage is directed toward the center of the air outlet. After rotating, the traveling carriage is moved to a second position, which is a first offset amount forward in the traveling direction from the first position. By moving the traveling carriage obliquely from the first position to the second position in this manner, the second offset amount in the Y-axis direction between the center of the air outlet and the center of the backing plate at the second position can be made smaller than the offset amount in the Y-axis direction at the first position. Therefore, it is possible to minimize the displacement amount of the air flow measuring unit in the Y-axis direction due to the displacement unit. This suppresses the change in the Y-axis direction of the displacement unit and the center of gravity of the air flow measuring unit. Therefore, when the air flow measuring unit is raised, deflection of the lifting unit due to the bending moment (= load of the air flow measuring unit × displacement amount in the Y-axis direction) can be suppressed. As a result, it is possible to prevent the backing plate from being displaced in the Y-axis direction relative to the air outlet. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing an air flow measurement device according to an embodiment; [Figure 2] FIG. 2 is a block diagram showing a control system of the air flow measuring device. [Figure 3] 1(a) is a schematic cross-sectional view showing an example of a ceiling against which a hood of an airflow measuring device is pressed, and FIG. 1(b) is a schematic plan view of the ceiling. [Figure 4] 1A is a schematic plan view showing a state in which the amount of misalignment of the backing plate with respect to the air outlet in the Y-axis direction is within the allowable range, and FIG. 1B is a schematic plan view showing a state in which the amount of misalignment of the backing plate with respect to the air outlet in the Y-axis direction exceeds the allowable range. [Figure 5] 10 is a schematic diagram for explaining a method of correcting the position of an opening 231 relative to an air outlet 13, separately for the traveling carriage side and the Y displacement unit side. FIG. [Figure 6] 10 is a flowchart showing a routine of an air volume measurement method. [Figure 7] 7 is a flowchart showing a routine for position correction executed in step S2 of FIG. 6. [Figure 8] 10A and 10B are diagrams illustrating a method for calculating a first turning angle, a movement amount of a traveling carriage, and a second turning angle. [Figure 9] Graph (a) shows the relationship between the amount of movement of the backing plate in the Y-axis direction and the measured air flow rate, and graph (b) shows the relationship between the amount of movement of the backing plate in the X-axis direction and the measured air flow rate. [Figure 10] 10 is a flowchart showing a routine of a modified example of position correction. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments will be described with reference to the drawings. Common or corresponding elements in each drawing are designated by the same reference numerals, and descriptions thereof will be simplified or omitted. In each drawing, illustration of some components may be omitted for convenience of drawing.

[0016] Fig. 1 is a schematic diagram showing an air flow measurement device according to an embodiment, and Fig. 2 is a block diagram showing a control system of the air flow measurement device.

[0017] As shown in FIG. 1, the air flow measurement device 1 includes an air flow measurement unit 2, a lifting unit 3, a traveling carriage 4, a displacement unit 5, an imaging unit 6, and a control unit .

[0018] The airflow measurement unit 2 includes a hood 21 having an upper opening larger than the air outlet 13 (described later) and an airflow sensor 22 that measures the airflow rate of the air guided by the hood 21. The hood 21 is composed of a base 211 and a duct 212 formed integrally with the base 211. At least one airflow sensor 22 is disposed inside the base 211. A known Pitot tube can be used as the airflow sensor 22, and further explanation of its installation method and airflow measurement principle will be omitted. The duct 212 is formed to gradually widen from bottom to top (in other words, to gradually narrow from top to bottom) and collects the air blown out from the air outlet 13 and guides it to the airflow sensor 22. A backing plate 23 (described later) is attached to the upper end of the hood 21 (i.e., the upper end of the duct 212). The hood 21 may be provided with a ceiling contact sensor 24 (see FIG. 2) that detects contact of the hood 21 with the ceiling 10. A known limit switch can be used as the ceiling contact sensor 24. Alternatively, an infrared optical sensor or the like may be provided to measure the distance between the hood 21 and the ceiling 10, thereby detecting contact of the hood 21 with the ceiling 10.

[0019] The lifting unit 3 includes an upper plate 31, a lower plate 32, and a lifter 33. The upper plate 31 movably supports the Y-displacement unit 5 (described later) on its upper surface, thereby supporting the airflow measurement unit 2 connected to the Y-displacement unit 5. The lifter 33 is interposed between the upper plate 31 and the lower plate 32. By extending and retracting the lifter 33 in the vertical direction, the airflow measurement unit 2 can be raised and lowered between a raised position (airflow measurement position) where the hood 21 abuts against the ceiling 10 around the air outlet 13 and a lowered position where the hood 21 is separated from the air outlet 13. The lifter 33 is not limited to the pantograph-shaped one shown in the figure, and can be, for example, a hydraulic mechanism or an electric mechanism. As described above, the pantograph-type lifter 33 has a larger extension ratio than those using hydraulic or electric mechanisms, making it easier to transport to and from the site, but it is also more likely to bend. A pair of link mechanisms 331 constituting the lifter 33 are arranged opposite each other with a gap in the Y-axis direction, and the lifter 33 is provided so that the rotation axis of the joint 332 of each link mechanism 331 extends along the Y-axis direction. This makes it possible to suppress deflection of the lifter 33 compared to when the pair of link mechanisms 331 are arranged opposite each other with a gap in the X-axis direction. The lifting unit 3 is placed on a traveling cart 4.

[0020] The traveling carriage 4 is capable of traveling in one direction and of turning. The traveling carriage 4 can travel along a travel route from a position (hereinafter referred to as a "first position") directly below the air outlet 13 that has been previously taught as described below. The traveling carriage 4 has, for example, a pair of drive wheels 41 spaced apart in a width direction perpendicular to the traveling direction, a pair of driven wheels 42 arranged ahead of the drive wheels 41 in the traveling direction, and a pair of driven wheels 43 arranged behind the drive wheels 41 in the traveling direction. A known AMR (Autonomous Mobile Robot) can be used as this traveling carriage 4. By rotating the pair of drive wheels 41 in opposite directions, the traveling carriage 4 can turn on the spot. The driven wheels 43 can be, for example, swivel casters. This type of traveling carriage 4 is not designed to travel with high positional accuracy. Therefore, when the traveling carriage 4 is moved to the first position (teaching position), the position of the contact plate 23 (hood 21) inevitably shifts relative to the air outlet 13, as will be described later.

[0021] Y displacement unit 5 is capable of displacing air volume measurement unit 2 in the Y-axis direction. For example, a Y-stage can be used as Y displacement unit 5. As the Y-stage, a known device having a motor, motor driver, or gear mechanism such as a rack and pinion for moving base 211 of hood 21 in the Y-axis direction can be used, and therefore further description, including illustrations of these, will be omitted.

[0022] The imaging unit 6 is disposed outside the hood 21. The imaging unit 6 is supported at the tip of a support frame 61 fixed to the upper plate 31 of the lifting unit 3. The imaging unit 6 captures an image of the ceiling 10 through the hood 21. An RGB-D camera capable of simultaneously acquiring color images (RGB) and depth information (D) can be used as the imaging unit 6. Therefore, the imaging unit 6 can measure the distance to the ceiling 10 in addition to capturing the image. Since a known RGB-D camera can be used, further explanation will be omitted. The fixed position of the support frame 61 of the imaging unit 6 is not particularly limited, and the support frame 61 may be fixed to, for example, the Y displacement unit 5, the lower plate 32, or the control unit 7.

[0023] The control unit 7 comprehensively controls various aspects of the air volume measurement device 1, such as the operation of the lifter 33 of the lifting unit 3, the operation of the traveling carriage 4 (including travel and rotation), the operation of the Y-displacement unit 5, and the operation of the imaging unit 6. The control unit 7 performs alignment control, which will be described later, to correct misalignment of the backing plate 23 with respect to the air outlet 13. A processing circuit including a processor 71 and a memory 72 can be used as the control unit 7. The processor 71 reads and executes a program stored in the memory 72, thereby performing the various controls described above. Alternatively, a programmable logic controller (PLC) can be used as the control unit 7.

[0024] FIG. 3(a) is a schematic cross-sectional view showing an example of a ceiling against which the hood of the airflow measuring device is pressed, and FIG. 3(b) is a schematic plan view of the ceiling. The system ceiling 10 against which the hood 21 (backing plate 23) is pressed is, for example, a grid-type system ceiling. This system ceiling 10 includes a frame 11, which is a lattice framework, and boards 12, each fitted into a grid defined by the frame 11. The length of one side of each grid is, for example, 600 mm or 640 mm. In the illustrated system ceiling 10 example, a rectangular air outlet 13 elongated in the X-axis direction is incorporated in the center of the board 12 in the Y-axis direction, and lighting fixtures 14 are incorporated on both sides of the air outlet 13 in the Y-axis direction. A mounting surface 150 to which the lighting fixture 14 is attached using a mounting fixture (not shown) has slits that serve as air inlets (also called "vents") 15. That is, the air outlet 13 and air inlets 15 of the system ceiling 10 are arranged side by side and adjacent to each other in the Y-axis direction. Because the upper opening of hood 21 is larger than air outlet 13, if hood 21 is simply pressed against air outlet 13, the air blown into hood 21 from air outlet 13 will be sucked in through air inlet 15. Therefore, a backing plate 23 that closes air inlet 15 is attached to the upper end of hood 21. An opening 231 that corresponds to the shape of air outlet 13 is formed in backing plate 23.

[0025] Here, while air inlets 15 are not disposed outside air outlet 13 in the X-axis direction, air outlet 13 and air inlets 15 are disposed close to each other in the Y-axis direction as described above, and therefore high accuracy is required in the Y-axis direction for aligning backing plate 23 (opening 231) with respect to air outlet 13. That is, the allowable error in the Y-axis direction for aligning opening 231 of backing plate 23 with opening 131 of air outlet 13 (see FIG. 2(a)) is small. For example, if the Y-axis dimension W1 of air outlet 13 is 205 mm to 250 mm, and the Y-axis dimension W2 of opening 131 of air outlet 13 and opening 231 of backing plate 23 are 180 mm to 220 mm, the allowable error We in the Y-axis direction for opening 231 of backing plate 23 aligned with opening 131 of air outlet 13 is approximately 12 mm to 15 mm. As shown in Fig. 4(a), if the amount of misalignment of opening 231 relative to air outlet 13 in the Y-axis direction is within the range of allowable error We, air inlet 15 does not face opening 231, and therefore air flow sensor 22 can measure the air flow with high accuracy. On the other hand, as shown in Fig. 4(b), if the amount of misalignment of opening 231 relative to air outlet 13 in the Y-axis direction is outside the range of allowable error We, air inlet 15 faces opening 231, and therefore air flow sensor 22 cannot measure the air flow with high accuracy (see the experiment shown in Fig. 8(a) described later). Note that air inlet 13 and air inlet 15 are not close to each other in the X-axis direction, and therefore high alignment accuracy is not required in the X-axis direction (see the experiment shown in Fig. 8(b) described later).

[0026] Hereinafter, an air volume measurement method using the air volume measurement device 1 will be described with reference to Figs. 5 to 8. The air volume measurement method includes correcting the position of the air volume measurement unit 2 relative to the air outlet 13, and thereby correcting the position of the backing plate 23 (opening 231) relative to the air outlet 13. Fig. 5 is a schematic diagram explaining the method of correcting the position of the opening 231 relative to the air outlet 13, dividing it into the traveling carriage side and the Y displacement unit side. Fig. 6 is a flowchart showing a routine of the air volume measurement method. Fig. 7 is a flowchart showing a position correction routine executed in step S2 of Fig. 6, which will be described later. Fig. 8 is a diagram for explaining a method of calculating the first rotation angle θ1, the movement amount R, and the second rotation angle θ2.

[0027] Prior to inspecting (measuring airflow) the multiple air outlets 13 provided in the system ceiling 10, map data (not shown) of the floor on which the air conditioning equipment construction work has been performed is acquired, and teaching of each of the air outlets 13 to be inspected is performed on the acquired map data. Teaching not only includes setting the position (X and Y coordinates) directly below each air outlet 13 by actually driving the traveling cart 4 or using a GUI (Graphical User Interface) on computer software, but also includes setting the travel route of the traveling cart 4 (the inspection sequence of the multiple air outlets 13). The taught map data is stored in the memory 72 of the control unit 7. Known map data and teaching methods can be used, so further explanation will be omitted.

[0028] The control unit 7 reads out the taught map data from the memory 72. As a result, the control unit 7 acquires the travel route of the traveling carriage 4 and also acquires a first position (teaching position) corresponding to the air outlet 13 where the first inspection is to be performed on the travel route. The control unit 7 moves (travels) the traveling carriage 4 to the acquired first position (step S1).

[0029] When the traveling carriage 4 stops at the first position, that is, when the traveling carriage 4 reaches the first position directly below the air outlet 13, the position of the air volume measuring unit 2 is corrected (step S2). In this step S2, a position correction routine shown in FIG. 7 is executed.

[0030] According to this routine, first, the imaging unit 6 captures an image of the ceiling 10 through the hood 21 at a first position. The control unit 7 calculates the first rotation angle θ1, the movement amount R, and the second rotation angle θ2 at the first position from the image captured at the first position (step S11). The first rotation angle θ1 is the rotation angle required for the traveling direction of the traveling carriage 4 to be oriented toward the air outlet center 13c. The movement amount R is the amount of straight movement of the traveling carriage 4 after the traveling carriage 4 has been rotated by the first rotation angle θ1. This movement amount R is the amount of deviation (hereinafter referred to as the "first deviation amount") between the center 13c of the air outlet 13 (hereinafter referred to as the "air outlet center") and the center 23c of the backing plate 23 (hereinafter referred to as the "backing plate center"). When calculating this movement amount (first deviation amount) R, the control unit 7 identifies the air outlet center 13c indicated by a white circle in Fig. 5 and the backing plate center 23c indicated by a black circle in Fig. 5. The second rotation angle θ2 is the rotation angle required to align the traveling direction of the traveling carriage 4 with the X-axis direction after the traveling carriage 4 has been moved straight by the movement amount R. In other words, the second rotation angle θ2 is the rotation angle required to align the longitudinal direction of the air outlet 13 with the longitudinal direction of the opening 231 of the backing plate 23.

[0031] FIG. 7 is a diagram for explaining a method for calculating the first turning angle θ1, the movement amount R, and the second turning angle θ2. As shown in FIG. 7, the positions (X L ,Y L ),(X R ,Y R ) and calculate the midpoint (X M ,Y M ) is calculated from these positions. M0 ,Y M0 ) is calculated. The position of the backing plate center (XF0, YF0) is also known. Using this position information and equations (1) to (3) shown in the figure, the first rotation angle θ1, the movement amount (straight movement amount) R, and the second rotation angle θ2 can be calculated. In this way, by extracting two intersections of the bar members of the frame 11 arranged in a lattice pattern, the position of the backing plate center 23c can be calculated. Therefore, it is sufficient that these two intersections fall within the angle of view of the imaging unit 6, and there is some leeway in the placement of the imaging unit 6.

[0032] Depending on the captured image, the two intersection points may not be found. This is particularly likely to occur when the air outlet 13 is located next to a window and the image is bright. In this case, the control unit 7 can adjust at least one of the brightness and contrast of the image to find the two intersection points. Note that the automatic exposure function of the imaging unit 6 may also be used.

[0033] If the amount of movement (first deviation amount) R calculated in step S11 above is smaller than the threshold value Rth (Yes in step S12), it is determined that position correction of the air volume measurement unit 2 is not necessary, and the process proceeds to step S17. Due to the accuracy of the traveling carriage 4, the amount of movement (first deviation amount) R is generally equal to or greater than the threshold value Rth, and the process normally proceeds to step S13. In step S13, it is determined whether the number of times N that steps S14 to S16 described below have been repeated is greater than a threshold value Nth. If the number of repetitions N in step S13 is greater than the threshold value Nth, the process also proceeds to step S17. In this case, an alarm may be issued to indicate that the position correction of the air volume measurement unit 2 is not possible. On the other hand, if the number of repetitions N is less than the threshold value Nth, the process proceeds to step S14.

[0034] In step S14, the control unit 7 rotates the pair of drive wheels 41 of the traveling carriage 4 in opposite directions to each other, thereby turning the traveling carriage 4 by the first turning angle θ1 calculated in step S11. As a result, the traveling carriage 4 points toward the air outlet center 13c.

[0035] Next, in step S15, the control unit 7 rotates the pair of drive wheels 41 of the traveling carriage 4 in the same direction, thereby moving the traveling carriage 4 straight toward the air outlet center 13c by the movement amount (straight movement amount) R calculated in step S11. As a result, the traveling carriage 4 reaches a second position, which is forward in the traveling direction by the movement amount R from the first position.

[0036] Next, in step S16, the control unit 7 rotates the pair of drive wheels 41 of the traveling carriage 4 in opposite directions to each other, thereby rotating the traveling carriage 4 by the second rotation angle θ2 calculated in step S11. This aligns the orientation of the opening 131 of the air outlet 13 with the orientation of the opening 231 of the backing plate 23. In other words, the longitudinal direction of the air outlet 13 and the longitudinal direction of the opening 231 of the backing plate 23 coincide with each other.

[0037] When the processing of step S16 is completed, the process returns to step S11, where the imaging unit 6 captures an image of the ceiling 10 through the hood 21, and the first rotation angle θ1, the movement amount R, and the second rotation angle θ2 are recalculated. When the recalculated movement amount (first deviation amount) R becomes smaller than the threshold value Rth (Yes in step S12), the process proceeds to step S17.

[0038] In step S17, at the second position of the traveling carriage 4, the imaging unit 6 captures an image of the ceiling 10 through the hood 21. From this captured image, the air outlet center 13c and the backing plate center 23c are identified using the method described above, and the Y-axis component Y of the amount of deviation between these two centers 13c, 23c (hereinafter referred to as the "second amount of deviation") is calculated.

[0039] Next, the Y displacement unit 5 is operated to displace the air volume measurement unit 2 in the Y-axis direction by the second displacement amount Y calculated in step S17 (step S18). Because the control precision of the Y displacement unit 5 is high, the Y displacement unit 5 is operated only once for each air outlet 13. After that, this routine ends, and the process proceeds to step S3 in FIG. 6.

[0040] In step S3, the distance Z from the airflow measurement unit 2 to the ceiling 10, obtained when the imaging unit 6 is at the second position, is acquired. Next, the lifter 33 of the elevation unit 3 is extended to raise the airflow measurement unit 2 by the distance Z (step S4). This causes the hood 21 (backing plate 23) to abut against the ceiling 10. The abutment of the hood 21 against the ceiling 10 can be confirmed by a signal from the limit switch, which is the ceiling contact sensor 24. In this state, the airflow sensor 22 measures the airflow blown out from the air outlet 13 using a known method (step S5). Since any known method can be used to measure the airflow using the airflow sensor 22, a description thereof will be omitted here. When the airflow measurement is completed, the lifter 33 of the elevation unit 3 is retracted to lower the airflow measurement unit 2 (step S6).

[0041] Next, the control unit 7 determines whether travel along the travel route has been completed, i.e., whether air volume measurements have been completed for all of the air outlets 13 (step S7). If air volume measurements have not been completed for all of the air outlets 13, the travel carriage 4 is moved to a first position corresponding to the next air outlet 13 on the travel route (step S8). Thereafter, the process returns to step S2. On the other hand, if air volume measurements have been completed for all of the air outlets 13, this routine ends.

[0042] As described above, high alignment accuracy is not required in the X-axis direction between the air outlet 13 and the opening 231 of the backing plate 23. Therefore, in steps S17 and S18, the X-axis component of the amount of deviation between the two centers 13c, 23c at the second position is ignored, and only the second deviation amount Y, which is the Y-axis component, is considered, and the second deviation amount Y is corrected by operating the Y displacement unit 5.

[0043] Here, the inventors conducted the following experiment to confirm the required alignment accuracy in the Y-axis and X-axis directions. Specifically, the backing plate 23 was intentionally moved by a predetermined amount in the Y-axis or X-axis direction, and the change in the air volume measured by the air volume sensor 22 was confirmed. FIG. 9(a) is a graph showing the relationship between the amount of movement of the backing plate 23 in the Y-axis direction and the measured air volume. FIG. 9(b) is a graph showing the relationship between the amount of movement of the backing plate 23 in the X-axis direction and the measured air volume. As shown in FIG. 9(a), it was confirmed that the measured air volume significantly decreased when the backing plate 23 was moved in the Y-axis direction by more than −15 mm or more than +15 mm. From the viewpoint of air volume measurement accuracy, the allowable range of positional deviation in the Y-axis direction between the air outlet center 13c and the backing plate center 23c is set to −15 mm to +15 mm. On the other hand, as shown in Fig. 9(b), it was confirmed that the measured air volume significantly decreased when the backing plate 23 was moved in the X-axis direction by more than -50 mm or more than +60 mm. Therefore, from the viewpoint of air volume measurement accuracy, the allowable range of positional deviation in the X-axis direction between the air outlet center 13c and the backing plate center 23c is set to -50 mm to +60 mm. This experiment revealed that while high accuracy is required in the Y-axis direction for aligning the backing plate 23 (opening 231) with the air outlet 13, such high accuracy is not required in the X-axis direction.

[0044] As described above, in this embodiment, after traveling to a first position, traveling carriage 4 is rotated by first rotation angle θ1 at the first position so that traveling carriage 4 is oriented toward air outlet center 13c. After the rotation, traveling carriage 4 is moved to a second position, which is forward in the traveling direction from the first position by a movement amount (first displacement amount) R. By traveling traveling carriage 4 obliquely from the first position to the second position in this manner, the amount of displacement in the Y-axis direction between air outlet center 13c and backing plate center 23c at the second position can be made smaller than the amount of displacement in the Y-axis direction at the first position. Therefore, it is possible to minimize the displacement of the air volume measurement unit in the Y-axis direction by Y displacement unit 5. This suppresses changes in the Y-axis direction of the center of gravity of the Y-displacement section 5 and the air volume measuring section 2, thereby suppressing deflection of the lifting section 3 due to bending moment (= load of the air volume measuring section 2 x displacement in the Y-axis direction) when the air volume measuring section 2 is raised, and as a result, it is possible to prevent the support plate 23 from shifting in position in the Y-axis direction relative to the air outlet 13.

[0045] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure. For example, in FIG. 7, conditions are set for the movement amount (first shift amount) R and the number of repetitions N (steps S12 and S13), but as shown in FIG. 10, conditions may be set for the second shift amount Y and the number of repetitions Ny. In other words, a configuration may be adopted in which the Y displacement unit 5 can be operated multiple times for one air outlet 13. FIG. 10 is a flowchart showing a routine of a modified position correction. According to this routine, after calculating the second shift amount Y in step S17, if the calculated second shift amount Y is smaller than the threshold value Yth (Yes in step S21), the routine ends without operating the Y displacement unit 5. On the other hand, if the second shift amount Y is equal to or greater than the threshold value Yth, the routine proceeds to step S22. If the number of repetitions Ny, which is the number of times the displacement unit 5 is operated, is equal to or less than the threshold value Nyth (No in step S22), the process proceeds to step S18, where the Y displacement unit 5 is operated to displace the air volume measurement unit 2 in the Y-axis direction by the second deviation amount Y calculated in step S17. When the processing of step S18 is completed, the process returns to step S21. On the other hand, if the number of repetitions Ny is greater than the threshold value Nyth (Yes in step S22), the Y displacement unit 5 is not operated and this routine is terminated. According to this modified example, by minimizing the number of times the Y displacement unit 5 is operated, the time required for position correction and therefore the time required for air volume measurement can be shortened. [Explanation of symbols]

[0046] 1...air flow measuring device, 10...ceiling, 11...frame, 12...board, 13...air outlet, 13c...air outlet center, 14...lighting, 15...intake port, 150...mounting surface, 2...air flow measuring unit, 21...hood, 211...base, 212...duct, 22...air flow measuring sensor, 23...backing plate, 23c...backing plate center, 231...opening, 3...lifting unit, 31...upper plate, 32...lower plate, 33...lifter, 331...link mechanism, 332...joint, 4...traveling carriage, 41...drive wheel, 42, 43...driven wheel, 5...Y displacement unit, 6...imaging unit, 61...support frame

Claims

1. An air flow measuring device that measures the air flow rate blown out from a longitudinal air outlet that is installed in parallel with an air intake port on a system ceiling, an air volume measuring unit having a hood with an upper opening larger than the air outlet and an air volume sensor that measures the volume of airflow guided by the hood; a lifting unit that supports the airflow measurement unit so that the airflow measurement unit can be raised and lowered; a traveling carriage on which the lifting unit is placed, capable of traveling in one direction, and capable of turning; a displacement unit that can displace the air volume measurement unit in the Y-axis direction, where the longitudinal direction of the air outlet is defined as an X-axis direction and the direction in which the air outlet and the air inlet are arranged side by side, which is perpendicular to the X-axis direction and the up-down direction, is defined as a Y-axis direction; an imaging unit that images the air outlet through the hood; a control unit that controls the lifting unit, the traveling carriage, and the displacement unit, A backing plate is attached to the upper end of the hood to close the air inlet, and an opening corresponding to the shape of the air outlet is formed in the backing plate, The control unit moving the traveling carriage to a first position below the air outlet; calculating a first deviation amount between a center of the air outlet that is a center of the air outlet and a center of the backing plate that is a center of the backing plate from the image captured by the imaging unit at the first position; turning the traveling carriage so that the traveling direction of the traveling carriage is directed toward the center of the air outlet, and causing the traveling carriage to travel to a second position forward in the traveling direction by the first deviation amount; turning the traveling carriage so that a traveling direction of the traveling carriage coincides with the X-axis direction at the second position; calculating a second deviation amount in the Y-axis direction between the center of the air outlet and the center of the backing plate from the image captured by the imaging unit at the second position; displacing the displacement portion in the Y-axis direction by the second displacement amount; An air flow measurement device configured to perform the above.

2. The air flow measuring device according to claim 1, The control unit is configured to repeatedly rotate the traveling carriage at the first position, travel to the second position, and rotate the traveling carriage at the second position until the first deviation amount falls below a threshold value.

3. The air flow measuring device according to claim 1 or 2, The control unit determining two intersection points of the frame of the system ceiling from the image captured at the first position; determining the air outlet center from the two intersection points; The air flow measurement device is configured to further perform the steps of:

4. The air flow measuring device according to claim 3, The control unit adjusting at least one of brightness and contrast of the image when the two intersection points cannot be obtained from the image captured at the first position; The air flow measurement device is configured to further perform the steps of:

5. 2. An air flow measurement method for measuring an air flow rate blown out from the air outlet using the air flow measurement device according to claim 1, a step of moving the traveling carriage to the first position; and a position correction step of correcting the position of the air volume measuring unit after the traveling carriage has moved to the first position, The position correction step includes: capturing an image of the air outlet through the hood by the imaging unit at the first position; calculating, from the image captured at the first position, a first rotation angle for orienting the traveling direction of the traveling carriage toward the center of the air outlet, the first deviation amount, and a second rotation angle for aligning the traveling direction of the traveling carriage with the X-axis direction; turning the traveling carriage at the first position by the first turning angle; causing the traveling carriage that has been turned by the first turning angle to travel to the second position that is forward in the traveling direction by the first deviation amount; turning the traveling carriage by the second turning angle at the second position; capturing an image of the air outlet through the hood by the imaging unit at the second position; calculating the second deviation amount from the image captured at the second position; displacing the displacement portion in the Y-axis direction by the second displacement amount; A method for measuring air volume, including:

Images