Tail clearance measurement system for shield aircraft

Abstract

To provide a tail clearance measurement system for a shield machine, capable of easily measuring a tail clearance at a skin plate rear end of the shield machine.SOLUTION: Segment surface direction measurement means measures a distance from a measurement reference position inside a shield machine to at least three measurement positions A, B, and C in a front end surface 20a of a segment 20, determines coordinate values of the measurement positions A, B, and C from the measured distance, and calculates a segment surface orientation as an orientation of the front end surface 20a of the segment 20 with respect to a skin plate on the basis of the coordinate values of each measurement position A, B, C. Skin plate rear end tail clearance measurement means determines a distance between an inner peripheral surface rear end of the skin plate and a segment outer peripheral surface from the segment surface orientation and a front surface side tail clearance.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a tail clearance measurement system for a shield machine that has a rotating cutter and excavates while assembling segments inside a skin plate, and measures the skin plate rear end tail clearance, which is the distance between the inner peripheral surface rear end of the skin plate and the outer peripheral surface of the segment.

Background Art

[0002] An annular gap is formed between the skin plate provided in the shield machine and the segments assembled inside it. If the tail clearance, which is the distance of this gap, is not properly maintained, problems such as hitting and damaging the segments or being unable to assemble the next segment may occur when the shield machine excavates. Therefore, when excavating the shield machine, it is very important to manage the tail clearance. However, for this management, usually, a person measures the tail clearance with a scale at, for example, four locations such as the top, bottom, left, and right of the shield machine, which is very time-consuming.

[0003] An apparatus that saves this labor and automatically measures the tail clearance in real time is disclosed in Patent Document 1. The tail clearance measurement apparatus for a shield machine described in Patent Document 1 is provided with an irradiation unit that irradiates laser light parallel to the extending direction of the tail part of the shield machine, a distance detection calculation unit that is movably provided perpendicular to the inner wall of the tail part and calculates and outputs a distance output signal by detecting the distance to the inner wall of the irradiation unit, a camera that captures the laser spot on the end face of the segment and outputs an image signal, a side end recognition unit that recognizes the side end part of the end face of the segment from the image signal and outputs a side end recognition signal, and a clearance calculation unit that calculates and outputs the distance between the side end part of the segment and the inner wall of the tail part based on the side end recognition signal and the distance output signal.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-121087 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The tail clearance measuring device for a shield machine, as described in Patent Document 1, detects the tail clearance at the face-side end of the segment. However, as the segments exit the shielding machine, they come into contact with the rear end of the skin plate, and this is where cracks, chips, and damage due to excessive stress on the fastening points of the segments are most likely to occur. Therefore, in practice, it is more important to know the tail clearance at the rear end of the skin plate.

[0006] The problem that this invention aims to solve is to provide a tail clearance measurement system for a shield machine that can easily and accurately measure the tail clearance at the rear end of the skin plate of the shield machine and prevent damage to segments, etc. [Means for solving the problem]

[0007] The invention according to claim 1 is a tail clearance measuring system for a shielding machine that measures the distance between the inner surface of a skin plate and the outer surface of a segment, comprising: a laser irradiation means for irradiating the front end surface of the segment and the inner surface of the skin plate with laser line light; an imaging means for imaging the laser line light irradiated to the front end surface of the segment and the inner surface of the skin plate so that the laser line light irradiated to the front end surface of the segment and the laser line light irradiated to the inner surface of the skin plate are not in a straight line; a line detection means for detecting the laser line light irradiated to the front end surface of the segment and the inner surface of the skin plate as a radial line and an axial line, respectively, in the image captured by the imaging means; and the radial line and the axial line This is a tail clearance measurement system for a shield machine, comprising: an intersection detection means for determining the intersection of two lines; a front-side tail clearance measuring means for determining the distance between the inner circumferential surface of the skin plate and the outer circumferential surface of the segment on the front side of the segment, based on the distance of the extension portion from a predetermined position on the radial line to the intersection determined by the intersection detection means; a segment surface orientation measuring means for measuring the segment surface orientation, which is the orientation of the front end surface of the segment relative to the skin plate, and the normal vector of the front end surface of the segment; and a skin plate rear end tail clearance measuring means for determining the distance between the rear end of the inner circumferential surface of the skin plate and the outer circumferential surface of the segment, based on the front-side tail clearance, the distance from the front end surface of the segment to the rear end of the skin plate, and the normal vector. The invention according to claim 2 is a tail clearance measurement system for a shield machine according to claim 1, characterized in that the segment surface orientation measuring means measures the distance from a measurement reference position inside the shield machine to at least three measurement positions on the front end surface of the segment, obtains the coordinate values ​​of each measurement position from the measured distance, and calculates the segment surface orientation based on the coordinate values ​​of each measurement position. The invention according to claim 3 is a tail clearance measurement system for a shield machine according to claim 2, characterized in that the distance from the measurement reference position to the measurement position is measured by a laser distance meter installed at the measurement reference position. The invention according to claim 4 is a tail clearance measurement system for a shield machine according to claim 2 or 3, characterized in that the segment surface orientation measuring means calculates the normal vector of the front end surface of the segment based on the coordinate values ​​of each measurement position. The invention according to claim 5 is a tail clearance measurement system for a shield machine according to claim 3, characterized in that a measuring device incorporating the laser irradiation means, the imaging means, and the laser rangefinder is installed at the measurement reference position. The following are also acceptable alternative inventions. Means 1This is a tail clearance measuring system for a shielding machine that measures the distance between the inner surface of a skin plate and the outer surface of a segment, comprising: a laser irradiation means that irradiates a laser line beam toward the front end surface of the segment and the inner surface of the skin plate; an imaging means that images the laser line beam irradiated toward the front end surface of the segment and the inner surface of the skin plate so that the laser line beam irradiated toward the front end surface of the segment and the laser line beam irradiated toward the inner surface of the skin plate are not aligned in a straight line; and a line detection means that detects the laser line beam irradiated toward the front end surface of the segment and the inner surface of the skin plate as a radial line and an axial line, respectively, in the image captured by the imaging means. The tail clearance measurement system for a shield machine is characterized by comprising: a step; an intersection detection means for determining the intersection of the radial line and the axial line; a front-side tail clearance measuring means for determining the distance between the inner circumferential surface of the skin plate and the outer circumferential surface of the segment on the front side of the segment based on the distance of the extension portion from a predetermined position on the radial line to the intersection determined by the intersection detection means; a segment surface orientation measuring means for measuring the segment surface orientation, which is the orientation of the front end surface of the segment relative to the skin plate; and a skin plate rear end tail clearance measuring means for determining the distance between the rear end of the inner circumferential surface of the skin plate and the outer circumferential surface of the segment based on the segment surface orientation and the front-side tail clearance.

[0008] Means 2 The segment surface orientation measuring means measures the distance from a measurement reference position inside the shield machine to at least three measurement positions on the front end surface of the segment, obtains the coordinate values ​​of each measurement position from the measured distance, and calculates the segment surface orientation based on the coordinate values ​​of each measurement position. Means 1 This is the tail clearance measurement system for the shield machine described in [reference].

[0009] Means 3This method is characterized by measuring the distance from the measurement reference position to the measurement position using a laser distance meter installed at the measurement reference position. Means 2 This is the tail clearance measurement system for the shield machine described in [reference].

[0010] Means 4 The segment surface orientation measuring means calculates the normal vector of the front end surface of the segment based on the coordinate values ​​of each measurement position, and the skin plate rear end tail clearance measuring means determines the front side tail clearance, the distance from the front end surface of the segment to the rear end of the skin plate, and the distance between the inner rear end of the skin plate and the outer circumferential surface of the segment from the normal vector. Means 2 or 3 This is the tail clearance measurement system for the shield machine described in [reference].

[0011] Means 5 This is characterized in that a measuring device incorporating the laser irradiation means, the imaging means, and the laser rangefinder is installed at the measurement reference position. Means 3 This is the tail clearance measurement system for the shield machine described in [reference]. [Effects of the Invention]

[0012] According to the present invention, the tail clearance at the rear end of the skin plate, which is difficult to measure, can be easily determined from the tail clearance at the front side of the segment, which is easy to measure. By knowing the tail clearance at the rear end of the skin plate, it is possible to prevent the segment from coming into contact with the skin plate and being damaged when it exits the shielding machine. Furthermore, the tail clearance on the front side of the segment that serves as the reference for determining the tail clearance at the rear end of the skin plate can also be automatically and accurately measured at all times using a compact device.

[0013] In addition, the segment-oriented measurement means measures the distances from the measurement reference position inside the shield machine to at least three measurement positions on the front end face of the segment, obtains the coordinate values of each measurement position from the measured distances, and calculates the segment orientation based on the coordinate values of each measurement position, thereby enabling the orientation of the front end face of the segment with respect to the cross section of the shield machine to be easily known. As a result, the posture of the shield machine can be maintained by selecting the shield jack or the like.

[0014] In addition, by installing a laser distance meter at a predetermined position, the distance from the predetermined position to the measurement position can be automatically and constantly measured.

[0015] In addition, if the segment-oriented measurement means calculates the normal vector of the front end face of the segment based on the coordinate values of each measurement position, and the skin plate rear end tail clearance measurement means obtains the front side tail clearance, the distance from the front end face of the segment to the rear end of the skin plate, and the distance between the rear end portion of the inner peripheral surface of the skin plate and the outer peripheral surface of the segment from the normal vector, it is possible to easily obtain the inclination of the axial direction of the segment with respect to the axial direction of the skin plate. Furthermore, the skin plate rear end tail clearance can be easily calculated from the front side tail clearance.

[0016] In addition, if a measuring device incorporating a laser irradiation means, an imaging means, and a laser distance meter is installed at the measurement reference position, the installation space for the equipment can be reduced.

Brief Description of the Drawings

[0017] [Figure 1] It is a cross-sectional view of a shield machine according to the first embodiment of the present invention. [Figure 2] It is a block diagram of a tail clearance measurement system for a shield machine showing the first embodiment of the present invention. [Figure 3] It is a perspective view for explaining the front side tail clearance measurement process according to the first embodiment of the present invention. [Figure 4]This is a flowchart of the procedure for measuring the front tail clearance according to the first embodiment of the present invention. [Figure 5] This is a partial cross-sectional view of a segment and a skin plate illustrating a tail clearance measurement method according to a first embodiment of the present invention. [Figure 6] This is a schematic perspective view of a segment and laser rangefinder according to a first embodiment of the present invention. [Figure 7] This is a schematic diagram of the front end surface of a segment according to the first embodiment of the present invention. [Figure 8] This is a schematic diagram of the main parts of a skin plate and segment as viewed from the front, according to the first embodiment of the present invention. [Figure 9] This is a flowchart of the procedure for measuring the tail clearance at the rear end of a skin plate according to the first embodiment of the present invention. [Figure 10] This is a partial cross-sectional view of a segment and a skin plate with a tapered surface, illustrating a tail clearance measurement method according to a second embodiment of the present invention. [Figure 11] This is a partial cross-sectional view of a segment and a skin plate equipped with a seal groove, illustrating a tail clearance measurement method according to a third embodiment of the present invention. [Modes for carrying out the invention]

[0018] [First Embodiment] Embodiments of the present invention will be described below with reference to the drawings. It goes without saying that the present invention is not limited to these embodiments. Figure 1 is a cross-sectional view of the shield machine, Figure 2 is a block diagram of the tail clearance measurement system of the shield machine, Figure 3 is a perspective view illustrating the front side tail clearance measurement process, Figure 4 is a flowchart of the front side tail clearance measurement procedure, Figure 5 is a partial cross-sectional view of the segment and skin plate, Figure 6 is a schematic perspective view of the segment and laser rangefinder, Figure 7 is a schematic diagram of the front end surface of the segment, Figure 8 is a schematic diagram of the main parts of the skin plate and segment viewed from the front, and Figure 9 is a flowchart of the skin plate rear end tail clearance measurement procedure.

[0019] As shown in Figure 1, the shield machine 1 assembles segments 20 while excavating through the ground and places a lining body 2 underground. For example, it is equipped with a rotary cutter 11 and a skin plate 12 at its front end. In this embodiment, it is described as a shield machine that constructs a tunnel with a circular cross-section.

[0020] The lining body 2 is constructed by assembling boat-shaped segments 20 into a ring shape and connecting them in the front-rear direction. The front part of the lining body 2 is located inside the skin plate 12. Inside the skin plate 12, a new segment 20 is assembled and connected in a ring shape to the front end of the lining body 2. The shield jack is extended to push the front end surface 20a of the segment 20, and the reaction force moves the shield machine 1 forward. An annular gap is formed between the inner circumferential surface 12a of the skin plate 12 and the outer circumferential surface 20b of the segment 20.

[0021] The tail clearance measurement system for the shield machine is a system that measures the skin plate rear end tail clearance dc', which is the distance between the rear end of the inner circumferential surface 12a of the skin plate 12 and the outer circumferential surface 20b of the segment 20.

[0022] As shown in Figure 2, the tail clearance measurement system for the shield machine comprises a laser irradiation means 3, an imaging means 4, a line detection means 5, an intersection detection means 6, a distance measuring means 7, a segment surface orientation measuring means 13, a skin plate rear end tail clearance measuring means 14, a main control unit 8, a measurement management unit 9, and a display 15.

[0023] The laser irradiation means 3 irradiates a laser line beam toward the front end surface 20a of the segment 20 and the inner circumferential surface 12a of the skin plate 12. The laser irradiation means 3 includes a laser oscillator tube 30 and a laser control unit 31 that controls the operation of the laser oscillator tube 30.

[0024] The laser oscillator tubes 30 emit laser line light and are installed inside the skin plate 12 of the shielding machine 1 at three measurement reference positions spaced apart in the circumferential direction, facing the inner circumferential surface 12a of the skin plate 12 and the front end surface 20a of the segment 20 to be installed. Specifically, each laser oscillator tube 30 is positioned so that the emitted laser line light is on a plane along the tunnel direction axis of the skin plate 12 and along the diametrical direction line of the skin plate 12.

[0025] Based on the oscillation signal from the laser control unit 31, the laser oscillator tube 30 irradiates a planar laser line beam along the tunnel direction axis and the diametric direction axis of the skin plate 12. The laser line beam from each laser oscillator tube 30 is then irradiated toward the front end surface 20a of the segment 20 and the inner circumferential surface 12a of the skin plate 12 (Figure 3). As a result, if there is tail clearance on the front side of segment 20, the laser line light irradiated onto the front end surface 20a of the installed segment 20 will not be displayed on the tail clearance side (the part indicated by L3 in Figure 3).

[0026] The imaging means 4 images the laser line light irradiated onto the front end surface 20a of the installed segment 20 and the inner circumferential surface 12a of the skin plate 12, ensuring that the laser line light irradiated onto the front end surface 20a of the segment 20 and the laser line light irradiated onto the inner circumferential surface 12a of the skin plate 12 are not aligned in a straight line.

[0027] The imaging means 4 comprises a CCD camera 40 and a camera control unit 41 that controls the operation of the CCD camera 40. The CCD camera 40 is installed inside the skin plate 12 of the shielding machine 1, in a position close to the laser oscillator tube 30. The CCD camera 40 is positioned to capture images so that the laser line light irradiated onto the front end surface 20a of the segment 20 and the laser line light irradiated onto the inner circumferential surface 12a of the skin plate 12 do not align in a straight line. For example, it is positioned to capture images from an oblique direction with respect to the plane 3a formed by the laser line light. In this embodiment, a CCD camera is used, but a digital camera such as a CMOS sensor camera may also be used.

[0028] When the camera control unit 41 sends an activation signal, the CCD camera 40 captures images of the portions on the front end surface 20a of the segment 20 and the inner circumferential surface 12a of the skin plate 12 where the laser line light from the laser irradiation means 3 is projected. In the captured image, the laser line light irradiated onto the front end surface 20a of the segment 20 and the laser line light irradiated onto the inner circumferential surface 12a of the skin plate 12 are not in a straight line.

[0029] At the position where the front tail clearance dc of segment 20 is measured, a scale marker 20c is provided in advance on the front end surface 20a of segment 20 (Figure 3). Specifically, the scale marker 20c is positioned so that the CCD camera 40 can image it together with the laser line light irradiated onto the front end surface 20a of segment 20 and the laser line light irradiated onto the inner circumferential surface 12a of the skin plate 12. The radial dimension of the scale marker 20c on the segment 20 (for example, the radial dimension between the two ends of the scale marker 20c on the segment 20) is known, and this dimension serves as the reference dimension. The scale marker 20c may be attached to the front end surface 20a of the segment 20 or it may be directly marked.

[0030] The CCD camera 40 captures the laser line light irradiated onto the front end surface 20a of the segment 20, the laser line light irradiated onto the inner circumferential surface 12a of the skin plate 12, and the scale marker 20c provided on the front end surface 20a of the segment 20.

[0031] The line detection means 5 detects the laser line light irradiated onto the front end surface 20a of the segment 20 and the inner circumferential surface 12a of the skin plate 12 as a radial line L1 and an axial line L2, respectively, in the image captured by the imaging means 4.

[0032] The line detection means 5 receives and processes the image from the imaging means 4, and as shown in Figure 3, detects the laser line light projected onto the front end surface 20a of the segment 20 and the inner circumferential surface 12a of the skin plate 12 as the radial line L1 and the axial line L2, respectively. Specifically, in the captured image, the laser line light is detected using HSV (hue, saturation, luminance), the detected laser line light is binarized, and the binarized data is thinned to recognize it as a straight line. Furthermore, the line detection means 5 detects the scale marker 20c from the image using HSV (hue, saturation, brightness) and recognizes a straight line relating to a reference dimension.

[0033] The intersection detection means 6 finds and recognizes the intersection K1 between the radial line L1 and the axial line in the captured image. The intersection point K1 may be detected by expressing it as a function of the radial line L1 and the axial line L2. Alternatively, the radial line L1 may be extended in the captured image through image processing to detect the intersection point K1 with the axial line L2.

[0034] The distance measuring means 7 acquires the number of pixels corresponding to the reference dimension of the scale marker 20c, and the number of pixels corresponding to the distance L3 of the extension from the predetermined position P1 to the intersection K1, with the intersection point of the radial line L1 and the outer edge portion of the front end surface 20a of the segment 20 (the end of the radial line L1) being the predetermined position P1. The distance L3 of the extension of the radial line L1 from the predetermined position P1 to the intersection K1 corresponds to the distance between the inner surface 12a of the skin plate 12 and the outer surface 20b of the segment 20. The distance measuring means 7 then calculates the distance between the inner circumferential surface 12a of the skin plate 12 and the outer circumferential surface 20b of the segment 20, i.e., the front side tail clearance dc, based on the ratio of the number of pixels corresponding to the reference dimension of the scale marker 20c to the number of pixels corresponding to the distance L3 of the extended portion on the front side of the segment 20.

[0035] When installing the shield machine 1, a correction parameter may be obtained as a calibration by calculating the difference between the actual tail clearance measured manually and the tail clearance measured by the shield machine's tail clearance measurement system. The distance measuring means 7 may then adjust the front tail clearance dc, calculated using the pixel ratio, based on this correction parameter. This reduces errors caused by lens distortion and other factors in the actual machine, thereby improving accuracy.

[0036] The tail clearance measurement system for the shield machine in this embodiment measures the front side tail clearance dc using the procedure shown in Figure 4.

[0037] Once shield machine 1 starts operating and the shield machine's tail clearance measurement system is activated, a system check is performed (step S1). Next, a mode check is performed to determine whether it is in automatic mode or manual mode (step S2).

[0038] In manual mode, the operator manually operates the measurement switch, and a measurement signal is sent to the laser control unit 31 of the laser irradiation means 3 (step S3). Then, a transmission signal is sent from the laser control unit 31 to the laser oscillator tube 30, and a laser line beam is emitted (step S4).

[0039] In automatic mode, when the measurement timing is reached, the measurement management unit 9 automatically sends a measurement signal to the laser control unit 31 of the laser irradiation means 3 (step S5), and proceeds to step S4.

[0040] Next, the camera control unit 41 of the imaging means 4 sends an operation signal, and the CCD camera 40 photographs the front end surface 20a of the segment 20, the scale marker 20c, and the inner circumferential surface 12a of the skin plate 12 (step S6). After that, the irradiation of the laser line light by the laser irradiation means 3 is terminated (step S7).

[0041] Next, the image captured by the CCD camera 40 is transferred to the line detection means 5 (step S8).

[0042] The line detection means 5, upon receiving the image signal, detects the scale marker 20c (step S9), and further detects and recognizes the radial line L1 and the axial line L2 (step S10).

[0043] Next, the intersection detection means 6 determines the intersection K1 from the radial line L1 and the axial line L2 (step S11).

[0044] Next, the distance measuring means 7 sets the intersection point of the radial line L1 and the outer edge portion of the front end surface 20a of the segment 20 (the end of the radial line L1) as a predetermined position P1, and calculates the distance L3 of the extension portion from the predetermined position P1 to the intersection point K1 from the ratio with the reference length based on the scale marker 20c (step S12). Furthermore, the distance measuring means 7 adjusts the distance L3 of the extension calculated in step S12 based on a correction parameter that has been acquired in advance, and calculates the front tail clearance (step S13).

[0045] Next, the calculated front tail clearance is saved as data and output processing is performed, such as displaying it on a screen (step S14).

[0046] Next, a decision is made as to whether or not to continue measuring the front tail clearance (step S15). If the answer is YES, the process returns to step S2; otherwise, the process ends.

[0047] As shown in Figure 6, the segment surface orientation measuring means 13 comprises three laser distance meters 130 and a calculation unit 131, each installed at a predetermined position inside the skin plate 12. The laser distance meters 130 are assembled together with the laser oscillator tube 30 and the CCD camera 40 into a single box to form a measuring device 16 (two are shown in Figure 1). The measuring device 16 is installed at three known reference measurement locations, and the laser distance meter 130 measures the distance from the three reference measurement locations to the three measurement locations A, B, and C.

[0048] The laser distance meter 130 of the segment surface orientation measuring means 13 is connected to the calculation unit 131. The distances to measurement positions A, B, and C measured by the laser rangefinder 130 are sent to the calculation unit 131, which then determines the coordinate values ​​of measurement positions A, B, and C. As shown in Figure 7, if the horizontal diametrical direction of the front end surface 20a of segment 20 is the Y direction, the vertical diametrical direction is the Z direction, and the direction perpendicular to the Y and Z directions is the X direction, then the coordinate values ​​of measurement position A can be expressed as Ax·Ay·Az, the coordinate values ​​of measurement position B as Bx·By·Bz, and the coordinate values ​​of measurement position C as Cx·Cy·Cz.

[0049] The calculation unit 131 determines the orientation of the front end surface 20a with respect to the cross-section of the skin plate 12, and the normal vector of the front end surface 20a, from the coordinate values ​​of three measurement positions A, B, and C on the front end surface 20a of the segment 20. Vector AB = (Bx - Ax, By - Ay, Bz - Az) Vector AC = (Cx - Ax, Cy - Ay, Cz - Az) Therefore, the normal vector of the front end surface 20a of segment 20 is the cross product, which is vector AB × vector AC.

[0050] Furthermore, the orientation of the front surface 20a can also be determined from the normal vector. The horizontal orientation angle of the front end surface 20a is, tan -1 (Normal vector y component / Normal vector x component) ÷ π × 180 degrees The vertical orientation angle of the front end surface 20a is, tan -1 The formula is (normal vector z component / normal vector x component) ÷ π × 180 degrees. If the orientation angle of the front end surface 20a with respect to the cross-section of the skin plate 12 exceeds a certain standard, it becomes difficult to maintain the posture of the shield machine 1 as it moves forward by pressing the front end surface 20a with the shield jacks. Therefore, by understanding the orientation angle of the front end surface 20a, the posture of the shield machine 1 can be controlled by selecting the appropriate shield jacks.

[0051] The skin plate rear end tail clearance measuring means 14 determines the skin plate rear end tail clearance dc', which is the distance between the inner circumferential rear end of the skin plate 12 and the outer circumferential surface of the segment, from the front side tail clearance dc obtained by the distance measuring means 7, the distance from the front end surface 20a of the segment 20 to the rear end of the skin plate 12, and the normal vector of the front end surface 20a of the segment 20 obtained by the segment surface orientation measuring means 13.

[0052] Figure 8 is a schematic diagram of the skin plate 12 and segment 20 in the area where we are trying to determine the tail clearance dc' at the rear end of the skin plate, as viewed from the front. In the figure, P is the position where the front tail clearance dc was measured, P' is the position where the rear end tail clearance dc' of the skin plate was calculated, α is the circumference angle of the position where the front tail clearance was measured (the angle from the center of the circular cross-section in a front view, for example with 12 o'clock being 0 degrees, clockwise to the position of P), vector N is the unit normal vector of the front end surface 20a of segment 20, which was determined earlier, β is the circumference angle of the normal vector N of the front end surface 20a (the angle expressed clockwise, for example with 12 o'clock being 0 degrees, representing the slope of vector N in a front view), vector R is a radial unit vector passing through P and is calculated based on α, and Is is the distance from the front end surface 20a (dc) of segment 20 to the rear end (dc') of the skin plate 12, although it is not shown in the figure.

[0053] The distance Is from the front end surface 20a of segment 20 to the rear end of skin plate 12 is the difference between the distance from the rear end of skin plate 12 to the measurement reference position where the laser distance meter 130 is installed, and the distance to the measurement position closest to the front tail clearance dc, which is the basis for calculation from the measurement reference position. Furthermore, the dc direction and the dc' direction are considered to be parallel. Then, the tail clearance at the rear end of the skin plate is given by dc' = dc - Is × vector N · vector R (where "vector N · vector R" is the dot product of vector N and vector R). In this way, based on the eight front-side tail clearances dc calculated by the distance measuring means 7, the rear end tail clearance dc' of the skin plate is determined for each location.

[0054] The main control unit 8 is the CPU of the main computer and controls the entire tail clearance measurement system of the shield machine.

[0055] The tail clearance measurement system of the shield machine can switch between a manual mode, where measurements are taken manually when the connection of a new segment 20 is completed, and an automatic mode, where measurements are taken automatically at appropriate intervals. In automatic mode, the measurement management unit 9 manages the timing of the start of measurements.

[0056] The display 15 displays the front tail clearance calculated by the distance measuring means 7, the rear tail clearance of the skin plate calculated by the rear tail clearance measuring means 14, and the like.

[0057] The laser control unit 31, CCD camera 40, camera control unit 41, line detection means 5, intersection detection means 6, distance measuring means 7, segment surface orientation measuring means 13, skin plate rear end tail clearance measuring means 14, measurement management unit 9, and display 15 are connected to the main control unit 8 and transmit and receive signals to each other via the main control unit 8.

[0058] The tail clearance measurement system for the shield machine measures the tail clearance dc' at the rear end of the skin plate using the procedure shown in Figure 9.

[0059] Once the shield machine 1 starts operating and the shield machine's tail clearance measurement system is activated, the front tail clearance dc is obtained according to the procedure shown in Figure 4 (step S20).

[0060] Next, the segment surface orientation measuring means 13 determines the surface orientation of the front end surface 20a of the segment 20 and the normal vector of the front end surface 20a of the segment 20 (step S21).

[0061] Next, the skin plate rear end tail clearance measuring means 14 calculates the skin plate rear end tail clearance dc' (step S22).

[0062] Furthermore, the calculated skin plate rear end tail clearance dc' is saved as data, and output processing such as displaying it on a screen is performed (step S23) before the process ends.

[0063] According to the present invention, the tail clearance dc' at the rear end of the skin plate, which is difficult to measure, can be easily determined from the tail clearance dc at the front side of the segment, which is easy to measure. By knowing the tail clearance at the rear end of the skin plate, it is possible to prevent the segment 20 from coming into contact with the skin plate 12 and being damaged when it exits the shield machine 1. Furthermore, the tail clearance dc on the front side of the segment that serves as the reference for determining the tail clearance dc' at the rear end of the skin plate can also be automatically and accurately measured at all times using a compact device.

[0064] Furthermore, the segment surface orientation measuring means 13 measures the distance from a measurement reference position inside the shield machine 1 to at least three measurement positions on the front end surface of the segment, obtains the coordinate values ​​of each measurement position from the measured distance, and calculates the segment surface orientation based on the coordinate values ​​of each measurement position. This makes it easy to determine the orientation of the front end surface of the segment relative to the cross-section of the shield machine 1, thereby enabling the orientation of the shield machine 1 to be maintained by selecting shield jacks, etc.

[0065] Furthermore, by installing the laser distance meter 130 at a predetermined location, the distance from the predetermined location to the measurement location can be measured automatically and continuously.

[0066] Furthermore, if the segment surface orientation measuring means 13 calculates the normal vector of the front end surface 20a of the segment 20 based on the coordinate values ​​of each measurement position, and the skin plate rear end tail clearance measuring means 14 determines the front side tail clearance dc, the distance from the front end surface of the segment to the rear end of the skin plate, and the distance between the inner rear end of the skin plate and the outer circumferential surface of the segment from the normal vector, then it is possible to easily determine the axial inclination of the segment with respect to the axial direction of the skin plate, and furthermore, the skin plate rear end tail clearance dc' can be easily calculated from the front side tail clearance.

[0067] Furthermore, by installing the measuring device, which incorporates the laser irradiation means 3, the imaging means 4, and the laser rangefinder 130, at the measurement reference position, the installation space for the equipment can be reduced.

[0068] [Second Embodiment] A second embodiment of the present invention will be described below with reference to Figure 10. Note that the same parts as in the first embodiment will be omitted from the description, and only the differences will be explained.

[0069] In the first embodiment, as shown in Figures 3 and 5, the intersection point (end of the radial line L1) between the outer peripheral edge portion of the front end surface 20a of the segment 20 and the radial line L1 was defined as a predetermined position P1, and the distance L3 of the extension portion from the predetermined position P1 to the intersection point K1 was measured as the front tail clearance dc. In the second embodiment, in the case of a segment 20 such that a tapered surface 20d is provided at the corner between the outer peripheral surface 20b and the front end surface 20a of the segment 20, as shown in Figure 10, the intersection point (end of the radial line L1) between the outer peripheral edge portion of the front end surface 20a of the segment 20 and the radial line L1 is set as a predetermined position P1, and the length 20d1 corresponding to the radial direction of the tapered surface 20d is subtracted from the distance L3 of the extension portion from the predetermined position P1 to the intersection point K1 to measure the front side tail clearance dc.

[0070] In this way, the front tail clearance dc can be measured even for segments with tapered surfaces, such as concrete segments.

[0071] [Third Embodiment] A third embodiment of the present invention will be described below with reference to Figure 11. Note that the same parts as those in the first and second embodiments will be omitted from the description, and only the differences will be explained.

[0072] In the first embodiment, as shown in Figures 3 and 5, the intersection point (end of the radial line L1) between the outer peripheral edge portion of the front end surface 20a of the segment 20 and the radial line L1 was defined as a predetermined position P1, and the distance L3 of the extension portion from the predetermined position P1 to the intersection point K1 was measured as the front tail clearance dc. In the third embodiment, as shown in Figure 11, in the case of a segment 20 having a seal groove 20e on the front end surface 20a of the segment 20 in which a seal 20f is installed, the intersection point of the stepped portion on the outer circumferential surface side of the seal groove 20e and the radial line L1 is set as a predetermined position P1, and the front side tail clearance dc is measured by subtracting the distance 20e1 from the stepped portion on the outer circumferential surface side of the seal groove 20e to the outer circumferential surface 20b from the distance L3 of the extension portion from the predetermined position P1 to the intersection point K1.

[0073] By setting the predetermined position P1 in this way, away from the outer edge of the front end surface towards the inner edge, it is possible to measure the front tail clearance dc even if chipping occurs on the outer edge of the front end surface due to concrete segments or the like.

[0074] [Other variations] The present invention is not limited to the embodiments described above. For example, the following are also included.

[0075] In this embodiment, the predetermined position P1 of the radial line L1 is set to the outer peripheral edge portion of the front end surface 20a of the segment 20 (first embodiment, second embodiment) or the outer peripheral step portion of the seal groove 20e of the front end surface 20a of the segment 20 (third embodiment), but is not limited to these. It may also be the inner peripheral edge portion of the front end surface 20a of the segment 20 or the inner peripheral step portion of the seal groove 20e of the front end surface 20a of the segment 20. Furthermore, it is sufficient that the distance to the outer peripheral surface 20b of the segment 20 is known. For example, the center line of the segment 20 relative to the thickness of the segment 20 is marked on the front end surface 20a of the segment 20 at a position where it intersects the radial line L1, and the intersection point of the center line and the radial line L1 is set as the predetermined position P1. The front side tail clearance is then measured by subtracting half the thickness of the segment 20. Furthermore, the radial line L1 may be positioned so that it overlaps the scale marker described earlier, and this centerline marking may be used for both ends of the radial segment 20 of the scale marker.

[0076] In this embodiment, a scale marker is provided separately on the front end surface of the segment, and the front tail clearance is calculated based on the reference dimension of the scale marker. However, since the thickness of the segment is known, the edge portion of the front end surface of the segment may be detected, and the minimum distance between the inner and outer edges may be used as the thickness of the segment and the reference dimension, that is, the front end surface of the segment may be used as the scale marker for measurement. Alternatively, instead of using a known segment thickness, the distance between the stepped portions on the inner and outer circumference of a known seal groove, or the distance between the corner portions on the inner and outer circumference of the seal, may be detected and measured as a reference dimension.

[0077] In this embodiment, a scale marker is provided on the front end surface of the segment. However, the scale marker may also be provided on the spreader of the shield jack of the shielding machine, which is positioned in a location where it can be imaged by the imaging means, and the measurement may be taken when the spreader comes into contact with the front end surface of the segment. In this way, it becomes unnecessary to provide a scale marker on each individual segment, and the efficiency of the measurement system can be improved. Alternatively, scale markers may be placed on both the front end surface of the segment and the spreader of the shield jack to improve accuracy. Furthermore, when measuring the front tail clearance at a position where the spreader is not imaged, a scale marker may be provided on the front end surface of the segment, and when measuring the front tail clearance at a position where the spreader is imaged, a scale marker may be provided on the spreader. In other words, appropriate measures may be taken depending on the installation location.

[0078] In this embodiment, the length of the extended portion is calculated from the ratio of the number of pixels corresponding to it and the number of pixels corresponding to the reference dimension of the scale marker. However, if the imaging means is installed and the dimensions of any part of the image obtained by imaging are known in advance and initialized so that they can be determined, a scale marker is not necessary.

[0079] In this embodiment, the distance between three reference measurement positions and three measurement positions is measured, but the number of reference measurement positions and measurement positions can be increased further.

[0080] In this embodiment, the laser oscillator tube, CCD camera, and laser rangefinder are integrated into a single measuring device, but they may be installed separately. In this case, the laser oscillator tube and CCD camera can be installed in different locations from the laser rangefinder. Furthermore, the number of laser oscillators and CCD cameras may differ from the number of laser rangefinders.

[0081] In this embodiment, segment orientation measurement and tail clearance measurement were performed and displayed at three locations in the circumferential direction of the tunnel, but this is not limited to this. For example, measurements may be performed at three locations, and the measured values ​​for eight predetermined locations in the circumferential direction of the tunnel may be displayed by calculations such as proportional distribution. Also, for example, the laser oscillator tube 30, CCD camera 40, and laser distance meter 130 may be configured so that their orientations can be changed, allowing one unit to measure at multiple locations. More than four units may also be installed. Furthermore, segment orientation measurement and tail clearance measurement may be performed at different locations and with different numbers of units.

[0082] In this embodiment, segment orientation measurement was used in conjunction with tail clearance measurement on the front side of the segment, but it is not limited to this, and can also be used only for segment orientation measurement. In this case, segment orientation measurement, which was conventionally performed manually, can be automated.

[0083] Unlike this embodiment, the system may be configured so that one or more steps are performed by a person.

[0084] In this embodiment, the tail clearance at the rear end of the skin plate was measured from the orientation of the segment surface and the front side tail clearance in a normal segment, a so-called straight segment, where the front end surface of the segment and the outer surface of the segment are perpendicular to each other. However, the embodiment is not limited to this, and a segment in which the front end surface of the segment and the outer surface of the segment are not perpendicular to each other, a so-called tapered segment (single tapered segment, double tapered segment), may also be used. In this case, the normal vector obtained from the orientation of the front end surface of the tapered segment to be measured is corrected to the normal vector obtained in the case of a straight segment, and the tail clearance at the rear end of the skin plate is measured. Note that the difference in shape between a tapered segment and a straight segment may be entered in advance for each ring to be assembled.

[0085] In this embodiment, the tail clearance at the rear end of the skin plate was measured from the orientation of the segment surface and the front side tail clearance in a normal segment, a so-called straight segment, where the outer diameter of the front end surface of the segment is the same as the outer diameter of the rear end surface of the segment. However, the embodiment is not limited to this, and segments in which the outer diameter of the front end surface of the segment is different from the outer diameter of the rear end surface of the segment, such as reduced-diameter segments and enlarged-diameter segments, may also be used. In this case, the tail clearance of the front end surface of the measured reduced-diameter or enlarged-diameter segment is corrected to the tail clearance obtained in the case of a straight segment, and the tail clearance at the rear end of the skin plate is measured. Note that the difference in shape between a reduced-diameter or enlarged-diameter segment and a straight segment may be entered in advance for each ring to be assembled.

[0086] Each technical aspect of any embodiment may be applied to other embodiments to form examples. [Explanation of symbols]

[0087] 1 Shield Unit 11 Rotary cutter 12 Skin Plates 12a Inner surface 2 Lining body 20 segments 20a Front end surface 20b Outer surface 20c scale marker 3. Laser irradiation means 3a plane 30 Laser Oscillator Tubes 31 Laser Control Unit 4. Imaging means 40 CCD camera 41 Camera Control Unit 5 Line detection means 6. Intersection detection means 7 Distance measuring means 8 Main Control Unit 9 Measurement management department 13 Segment surface orientation measuring means 130 Laser Rangefinder 131 Arithmetic section 14. Means for measuring tail clearance at the rear end of the skin plate 15 displays 16 Measuring device L1 Radial line L2 Axial Line L3 Extension Distance K1 intersection P1 predetermined position of radial line DC front tail clearance P: Position where the front tail clearance was measured. P' Calculation position for tail clearance at the rear end of the skin plate α Circumference angle at the position where the front tail clearance was measured. Unit normal vector of the front end face of the N segment Circumference angle of the normal vector of the front end face of the β segment R radial vector Distance from the front end face of the segment to the rear end of the skin plate DC' skin plate rear end tail clearance

Claims

1. A tail clearance measuring system for a shield machine that measures the distance between the inner surface of a skin plate and the outer surface of a segment, A laser irradiation means for irradiating a laser line beam toward the front end surface of the segment and the inner circumferential surface of the skin plate, An imaging means for imaging the laser line light irradiated onto the front end surface of the segment and the inner circumferential surface of the skin plate, such that the laser line light irradiated onto the front end surface of the segment and the laser line light irradiated onto the inner circumferential surface of the skin plate do not form a straight line. A line detection means detects laser line light irradiated onto the front end surface of the segment and the inner circumferential surface of the skin plate as radial lines and axial lines, respectively, in the image captured by the imaging means. Intersection detection means for determining the intersection point of the radial line and the axial line, A front-side tail clearance measuring means determines the distance between the inner circumferential surface of the skin plate and the outer circumferential surface of the segment on the front side of the segment, based on the distance of the extension portion from a predetermined position on the radial line to the intersection determined by the intersection detection means, A segment surface orientation measuring means for measuring the orientation of the front end surface of the segment relative to the skin plate, and the normal vector of the front end surface of the segment, The system includes a skin plate rear end tail clearance measuring means that determines the distance between the inner rear end of the skin plate and the outer circumferential surface of the segment from the front side tail clearance, the distance from the front end surface of the segment to the rear end of the skin plate, and the normal vector. A tail clearance measurement system for a shield machine, characterized by the following features.

2. The tail clearance measurement system for a shield machine according to claim 1, characterized in that the segment surface orientation measuring means measures the distance from a measurement reference position inside the shield machine to at least three measurement positions on the front end surface of the segment, obtains the coordinate values ​​of each measurement position from the measured distance, and calculates the segment surface orientation based on the coordinate values ​​of each measurement position.

3. The tail clearance measurement system for a shield machine according to claim 2, characterized in that the distance from the measurement reference position to the measurement position is measured using a laser rangefinder installed at the measurement reference position.

4. The segment surface orientation measuring means calculates the normal vector of the front end surface of the segment based on the coordinate values ​​of each measurement position. A tail clearance measurement system for a shield machine according to claim 2 or 3, characterized by the features described above.

5. The tail clearance measurement system for a shield machine according to claim 3, characterized in that the laser irradiation means, the imaging means, and the measuring device incorporating the laser rangefinder are installed at the measurement reference position.

Images