Curve shield tunnel segment advance measurement and calibration device

Abstract

The utility model belongs to the technical field of tunnel shield construction, and solves the problems of duct piece dislocation and damage caused by duct piece posture error due to reasons such as point position typesetting or duct piece rotation of duct pieces in the tunneling process. A curve shield tunnel segment advance amount measuring and calibrating device is characterized in that a microcontroller is electrically connected with two laser distance measuring sensors, the laser distance measuring sensor I is installed at the end of a guide rail of a lead screw sliding block mechanism and used for measuring the moving distance of a sliding block of the lead screw sliding block mechanism, and the laser distance measuring sensor II is installed at the end of a guide rail of the lead screw sliding block mechanism; the laser distance measuring sensor II is installed on a sliding block of the lead screw sliding block mechanism and used for measuring the distance between the device and the segment on the other side. The bracket is fixed to the position of the inner wall of the shield tunneling machine, and a guide rail of the lead screw sliding block mechanism is connected to the bracket in a sliding mode and can be fixed through a locking buckle. The device can perform real-time measurement, can perform advance measurement after each ring of duct piece is assembled, and is beneficial to point selection of the next ring of duct piece and deviation correction of the posture of the shield tunneling machine.

Description

Technical Field

[0001] The utility model belongs to the technical field of tunnel shield construction, and in particular relates to a curved shield tunnel segment advance measurement and calibration device. Background Art

[0002] Currently, most subway tunnel construction methods use the shield method. During the shield machine excavation process, the segments play an important role in supporting and protecting the tunnel structure.

[0003] During the tunneling construction of the curved section by the shield machine, different points can be selected to assemble the segments, and the turning and uphill and downhill of the tunnel can be completed by controlling the wedge shape of the segments. On this basis, the surveying personnel will measure the deviation between the actual axis and the design axis of the tunnel center, issue instructions to the shield driver, and make adjustments to the excavation posture to ensure that the error is within the allowable range.

[0004] At present, most of the segments used in shield construction in China are universal segments, that is, they do not distinguish between straight lining rings and wedge-shaped lining rings, which can avoid cumbersome point layout and be more flexible in the selection of assembly points. However, during the construction process, there are problems such as segment posture errors caused by segment point layout or segment rotation, which may cause segment misalignment and damage.

[0005] There is a lack of a device for measuring and calibrating the advance quantity of the pipe segment that can grasp the current posture of the pipe segment in real time. Utility Model Content

[0006] In order to solve at least one of the above technical problems existing in the prior art, the utility model provides a device for measuring and calibrating the advance amount of a curved shield tunnel segment.

[0007] The utility model is implemented by the following technical scheme: a device for measuring and calibrating the advance amount of a curved shield tunnel segment, comprising a microcontroller, a laser ranging sensor, a lead screw slider mechanism and a bracket; the microcontroller is electrically connected to the laser ranging sensor, the number of the laser ranging sensors is two, wherein the laser ranging sensor I is installed at the end of the guide rail of the lead screw slider mechanism, and is used to measure the moving distance of the slider of the lead screw slider mechanism, and the laser ranging sensor II is installed on the slider of the lead screw slider mechanism, and is used to measure the distance from the device to the segment on the other side; the bracket is fixed at the position of the inner wall of the shield machine, and the guide rail of the lead screw slider mechanism is slidably connected to the bracket and can be fixed by a locking buckle.

[0008] Preferably, the bracket is a C-shaped frame and a slide rail is fixedly connected to the upper end, and the bottom end of the guide rail of the screw slider mechanism has a groove structure matching the slide rail.

[0009] Preferably, the locking buckle is a locking bolt, which is threadedly connected to the guide rail of the screw slider mechanism to achieve locking of the position between the guide rail and the slide rail.

[0010] Preferably, the microcontroller is a STM32F103C8T6 microcontroller.

[0011] Preferably, the model of the laser distance measuring sensor I installed on the guide rail is TOFSense; the model of the laser distance measuring sensor II installed on the slider is TOFSense P.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] This device can perform real-time measurement. After each ring of segments is assembled, advance measurement can be performed, which is beneficial for the point selection of the next ring of segments and the correction of the shield machine's posture. It can solve the problem of segment posture errors caused by segment point layout or segment rotation during the excavation of curved shield tunnels, thereby causing segment misalignment, damage, etc., and grasp the current segment posture in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 Schematic diagram of the structure of the connection between the bracket and the guide rail in this embodiment;

[0016] Figure 2 is a schematic diagram of the connection between the guide rail and the locking buckle in this embodiment;

[0017] Figure 3 is the pin diagram of the microcontroller in this embodiment;

[0018] Figure 4 Schematic diagram of the lead screw slider mechanism in this embodiment.

[0019] In the figure: 1-microcontroller; 2.1-laser distance sensor I; 2.2-laser sensor II; 3.1-guide rail; 3.2-slider; 3.3-servo motor; 3.4-screw; 4-bracket; 4.1-slide rail; 5-locking buckle. DETAILED DESCRIPTION

[0020] Combined with the drawings in the embodiments of the utility model, the technical solutions in the embodiments of the utility model are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented, so they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention. It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from other entities, and do not necessarily require or imply any actual relationship or order between these entities.

[0022] The utility model provides an embodiment:

[0023] like Figures 1 to 4 As shown, a device for measuring and calibrating the advance amount of a curved shield tunnel segment comprises a microcontroller 1, a laser ranging sensor 2, a lead screw slider mechanism and a bracket 4; there are two laser ranging sensors, wherein the laser ranging sensor I2.1 is mounted on the end of a guide rail 3.1 of the lead screw slider mechanism for measuring the moving distance of a slider 3.2 of the lead screw slider mechanism, and the laser ranging sensor II2.2 is mounted on the slider 3.2 of the lead screw slider mechanism for measuring the distance from the device to the segment on the other side; the slider 3.2 changes its position on the guide rail 3.1 through the transmission of the servo motor 3.3 and the lead screw 3.4 of the lead screw slider mechanism; the microcontroller 1 is electrically connected to the laser ranging sensor and the servo motor 3.3; the bracket 4 is fixed to the position of the inner wall of the shield machine, and the guide rail 3.1 of the lead screw slider mechanism is slidably connected to the bracket 4 and can be fixed by a locking buckle 5.

[0024] In this embodiment, the microcontroller 1 is a STM32F103C8T6 microcontroller, which is one of the mid-range microcontroller units based on the RISC architecture, with 64KB 64Kx8 flash memory, ARM Cortex-M3 32-bit microcontroller, STM32F1 series STM32F103, 48 pins, 72MHz 3.3V48-LQFP. It integrates a high-performance ARM Cortex-M3 32-bit RISC core with an operating frequency of 72MHz, a high-speed embedded memory (up to 128 bytes of flash memory and up to 20k bytes of SRAM), and a large number of enhanced I / Os and peripherals connected to two APB buses. The operating voltage is 2-3.6V and the operating temperature is -40℃-85℃, which fully meets the working environment in the tunnel. The advantage of this microcontroller is that it has 9 communication interfaces; up to 80 fast I / O interfaces, almost all of which can map 16 external interrupt vectors; it has a JTAG interface that is convenient for direct connection to a PC for serial communication and debugging, so it is selected as the control end of the correction system.

[0025] The model of the laser distance sensor installed on the guide rail 3.1 is TOFSense; the model of the laser distance sensor II (2.2) installed on the slider 3.2 is TOFSense P. The TOFsense series sensors have the advantages of high accuracy, support for multiple serial port communications (CAN, UART and I / O), support for output mode configuration, cascade distance measurement, etc. At the same time, it is equipped with a host computer assistant to realize data analysis and waveform monitoring. TOFsense P is installed on the slider 3.2 and is used to measure the distance between the two sides of the segment. The range of TOFsenseP long-distance mode is 0.03-8.00m, which fully meets the distance measurement requirements in ordinary shield machines; TOFsense uses short-distance mode, with a specific accurate range of 0.015-2.10m, which is used to measure the moving distance of the slider 3.2, that is, the initial measurement data of the segment advance. Considering that the wedge amount of the segment is between 37-40mm (1.2m and 1.5m segments), TOFSense meets the distance measurement requirements.

[0026] Selection of servo motor 3.3. This device obtains advance data by measuring the moving distance of the sensor. It has high requirements for position and requires the slider to stop accurately, so the position mode is used. This mode generally controls the servo system by sending pulses to the driver. The pulse frequency determines the rotation speed, and the number of pulses determines the rotation angle. Therefore, the duty cycle needs to be set in accordance with the actual situation to prevent errors in the data due to the slider moving too fast. You can also try to use the microcontroller to directly assign values ​​to the speed and limit the displacement. Microcontroller 1 is connected to the servo motor driver, and then connected to the servo motor 3.3 using the power line and encoding line. The power supply can be the 220V low-voltage AC in the shield machine, and the AC / DC transformer is used to complete the power supply.

[0027] The bracket 4 is a C-shaped frame and has a slide rail 4.1 fixedly connected to the upper end. The guide rail 3.1 of the screw slider mechanism has a groove structure matching the slide rail 4.1 at the bottom end. The locking buckle 5 is a locking bolt, which is threadedly connected to the guide rail 3.1 of the screw slider mechanism to achieve the locking of the position between the guide rail 3.1 and the slide rail 4.1. The slide rail 4.1 and the locking buckle 5 facilitate the adjustment of the position of the entire measuring device to accurately obtain the lead data. The cross section of the slide rail 4.1 is a convex structure matching the groove structure.

[0028] Specific working principle:

[0029] The device mainly obtains original measurement data through information interaction between two laser distance measuring sensors, and transmits the data to the microcontroller 1 for data calculation and integration, thereby completing the monitoring of the advance amount of the pipe segment.

[0030] First, it is necessary to find the corresponding characteristic points on the inner wall of the shield machine, that is, the placement point of the device. The traditional hanging hammer method for measuring the advance amount is to determine the hanging point on the upper segment, and roughly measure the advance amount of the segment according to the position of the hanging hammer. The limitations of this method lie in accuracy and measurement position, and it can only obtain the advance amount of the upper and lower segments, but its advantage lies in the selection of reference objects.

[0031] If laser distance measurement is used, a suitable reference point needs to be selected. This device selects the inner wall of the shield machine as the reference point. Ideal shield tunneling is "three-line coincidence", that is, the axis of the shield machine, the center line of the tunnel, and the axis of the assembled segment completely coincide. However, in the actual tunneling process, the three lines will have a certain angle deviation. Therefore, the inner wall of the shield machine is selected as the reference point for distance measurement, and the data obtained needs to be corrected for certain deviations.

[0032] After each ring of segments is assembled, mark the position of the segments aligned with the inner wall in a "M" shape. After about 100 rings, check the position range of the marking points, and reserve a length of about 5 cm in front and back. Select this length and weld the bracket 4 with the sliding rail 4.1 at eight positions. The purpose of this is to allow the entire device to move forward and backward. The locking buckle can also fix the device to avoid the situation where the advancement distance is too long or too short, resulting in the initial position of the sensor 1 not being aligned with the segment, affecting the data accuracy of the lead amount.

[0033] Compared with the hanging hammer method, it solves the limitation of only measuring the advance of the upper and lower segments, and can measure the advance of the eight characteristic points of the "M" shape, and the data has higher accuracy. In addition, the device can perform real-time measurement, and the advance can be measured after each ring of segments is assembled, which is conducive to the selection of the point of the next ring of segments and the correction of the shield machine posture.

[0034] After completing the installation and position calibration of the device, data measurement is performed. Here, the case is to measure the advance amount of the lower part of the pipe segment ahead of the upper part. After the device is started, the microcontroller performs the initial position detection of the two sensors. If the distance fed back by the laser ranging sensor I2.1 is greater than 0, the slider is moved backward. After completing the initial position detection, the slider is driven forward, and the microcontroller begins to monitor the data of the laser ranging sensor II2.2. When the data of the laser ranging sensor II2.2 is distorted for the first time, the slider is stopped, and the data a1 of the laser ranging sensor I2.1 and the data b1 of the laser ranging sensor II2.2 are output at this time.

[0035] Considering the wedge shape of the segment, when the segment is ahead, the front segment has a certain inclination angle relative to the shield machine. Therefore, the data distortion here is because the irradiation point of the laser ranging sensor II2.2 moves from the inner wall of the segment to the side of the segment. After 2 seconds, continue to drive the slider forward. When the second data distortion occurs, stop the slider again and output the data a2 of the laser ranging sensor I2.1 and the data b2 of the laser ranging sensor II2.2. The distortion here is because the irradiation point of the laser ranging sensor II2.2 moves from the side of the segment to the inner wall of the shield machine. After 2 seconds, continue to move the slider to the end of the track, record the data of the laser ranging sensor I2.1, and compare it with the slide rail length value assigned in advance. If the deviation is too large, an error will be reported and the device needs to be readjusted. If there is no deviation, stop for 3 seconds and drive the slider backward. Similarly, record the values ​​of each sensor at the two data distortion nodes and compare them during the forward movement. If the deviation is large, an error will be reported. The purpose of this is to eliminate the displacement of the entire device caused by the movement of the slider. At this time, the position of the device should be readjusted and locking buckles should be added to fix it.

[0036] After obtaining the corresponding data, we can calculate the data. Before that, we need to get the reference value. The most intuitive reference value is to calculate the overall advance amount according to the point layout through the wedge amount of each ring segment. The second way to get the reference value is to calculate the difference between the inner and outer arc lengths in a macroscopic way through the current turning radius and the up and down slopes, so as to obtain the theoretical advance amount. In general, the former method is more practical, while the advance amount calculated by the latter method is a more ideal theoretical value. If the two are approximately fitted, it means that the point layout during the excavation process is more reasonable. What we get here is the most intuitive segment advance amount, but the data feedback correction is also required. a1 is the distance from the laser ranging sensor II2.2 from the initial position (aligned with the upper segment) to the first distortion point, that is, the distance from the inner wall of the lower segment to the side edge, which can be regarded as the internal advance amount here, and a2 is the displacement distance from the first distortion point to the second distortion point of the laser ranging sensor II2.2, that is, the distance from the side edge of the inner wall to the side edge of the outer wall. Here, the data of a2 can map out the inclination angle of the segment, arctan(b2-b1) / (a2-a1) can simply calculate the elevation angle of the current formed segment, and in turn, the elevation angle combined with the size of the segment can be used to obtain the calculated value of the advance amount. However, it should be noted that the reference position of the device is the inner wall of the shield machine. There is a certain deviation between the tunneling axis of the shield machine and the center line of the tunnel, and the original data obtained by the device are based on the tunneling axis of the shield machine. To obtain accurate data, data correction must be performed based on the deviation between the tunneling axis and the center line. After completing the deviation correction, the four sets of data, namely the measured data, the two theoretical data, and the theoretical advance amount calculated by the elevation angle, are compared and fitted. If they are within the allowable error range, the measurement results are accurate.

[0037] The microcontroller 1 supports the input of current excavation line parameters, such as the excavation axis deviation angle, shield machine posture, segment point layout, etc. Such parameters can be used to correct the deviation value and calculate the reference value of the segment advance amount, which is used to compare and fit the measured value. While performing direct distance measurement, the device can also measure the pitch angle of the segment attitude, and perform feedback calculation in combination with the pre-input segment size parameters to make the obtained data more accurate. The function of the microcontroller 1 is to receive the real-time measurement data sent by the sensor, issue different instructions to the servo motor according to the data changes, and calculate the pitch angle of the sensor data to verify the accuracy of the measurement data. At the same time, the current curve parameters can be entered to calculate the fit between the current advance amount and the theoretical value. The built-in program and calculation process in the above-mentioned microcontroller 1 are all prior art and will not be repeated here.

[0038] The above is only a preferred specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.

Claims

1. A curved shield tunnel segment advance measurement and calibration device, characterized in that: It comprises a microcontroller (1), a laser distance measuring sensor (2), a lead screw slider mechanism and a bracket (4); There are two laser distance measuring sensors, wherein the laser distance measuring sensor I (2.1) is installed at the end of the guide rail (3.1) of the screw slider mechanism and is used to measure the moving distance of the slider (3.2) of the screw slider mechanism, and the laser distance measuring sensor II (2.2) is installed on the slider (3.2) of the screw slider mechanism and is used to measure the distance from the device to the pipe segment on the other side; the slider (3.2) changes its position on the guide rail (3.1) through the transmission of the servo motor (3.3) and the lead screw (3.4) of the screw slider mechanism; the microcontroller (1) is electrically connected to the laser distance measuring sensor and the servo motor (3.3); The bracket (4) is fixed at a position on the inner wall of the shield machine, and the guide rail (3.1) of the screw slider mechanism is slidably connected to the bracket (4) and can be fixed by a locking buckle (5).

2. The device for measuring and calibrating the advance amount of a curved shield tunnel segment according to claim 1, characterized in that: The bracket (4) is a C-shaped frame and has a slide rail (4.1) fixedly connected to its upper end. The bottom end of the guide rail (3.1) of the lead screw slider mechanism has a groove structure matching the slide rail (4.1). The cross section of the slide rail (4.1) is a convex-shaped structure matching the groove structure.

3. The device for measuring and calibrating the advance amount of a curved shield tunnel segment according to claim 2, characterized in that: The locking buckle (5) is a locking bolt, which is threadedly connected to the guide rail (3.1) of the screw slider mechanism to achieve locking of the position between the guide rail (3.1) and the slide rail (4.1).

4. The device for measuring and calibrating the advance amount of a curved shield tunnel segment according to claim 1, characterized in that: The microcontroller (1) is a STM32F103C8T6 microcontroller.

5. The device for measuring and calibrating the advance amount of a curved shield tunnel segment according to claim 1, characterized in that: The model of the laser distance sensor I (2.1) installed on the guide rail (3.1) is TOFSense; the model of the laser distance sensor II (2.2) installed on the slider (3.2) is TOFSense P.

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