Obstacle detection device, excavation system, obstacle detection method, and obstacle detection program

Abstract

The system quickly detects contact between the cutter head and any obstructions. [Solution] The central control device 5 of the excavation system 100 acquires time-series data 61 of the rotational force (cutter torque) of the cutter head 12 of the shield excavator 1, acquires the fluctuation range ΔT of this time-series data 61, and determines that there is a possibility of contact between the cutter head 12 and the obstacle D when the fluctuation range ΔT of the time-series data 61 exceeds a predetermined threshold.

Description

Technical Field

[0001] The present invention relates to an obstacle detection device, an excavation system, an obstacle detection method, and an obstacle detection program in tunnel excavation using a shield tunneling machine.

Background Art

[0002] In tunnel excavation using a shield tunneling machine, it may encounter unexpected obstacles. For example, in the technique described in Patent Document 1, when cutting an obstacle (obstruction), the cutter head is propelled in the excavation direction by a telescopic device during abnormal times to achieve an excavation speed of the cutter head suitable for cutting the obstacle and suppress damage to the cutter bits. In addition, for such encounters with obstacles, measures such as reducing the excavation speed from before the encounter point to reduce the cutting width of the obstacle by the cutter bits to suppress damage to the cutter bits are taken.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the obstacle is a hard object or the like, it is difficult to perform the cutting itself by the cutter bits. Therefore, in order to minimize damage to the shield tunneling machine including the cutter bits, prompt detection of the obstacle is important.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to promptly detect contact between the cutter head and an obstacle.

Means for Solving the Problems

[0006] To achieve the above objective, one embodiment of the present invention is an obstacle detection device, An acquisition unit that acquires time-series data of the rotational force of the cutter head equipped with a shield drilling machine, A second acquisition unit for acquiring the range of fluctuation of the time-series data of the rotational force, A determination unit determines that there is a possibility of contact between the cutter head and an obstruction when the fluctuation range of the aforementioned time series data exceeds a predetermined threshold, If the determination unit determines that there is a possibility of contact between the cutter head and an obstacle, the calculation unit performs frequency analysis on the time-series data of the rotational force and obtains the frequency characteristics of the rotational force. A second determination unit determines whether or not there is a possibility of contact between the cutter head and an obstacle based on the frequency characteristics of the rotational force, It is equipped with. [Effects of the Invention]

[0007] According to the present invention, contact between the cutter head and an obstruction can be detected quickly. [Brief explanation of the drawing]

[0008] [Figure 1] Block diagram showing the excavation system according to the embodiment. [Figure 2] Front view of a cutter head according to an embodiment [Figure 3] Block diagram showing the schematic functional configuration of the drilling system according to the embodiment. [Figure 4] Flowchart showing the procedure for the obstacle detection process according to the embodiment. [Figure 5] A diagram illustrating the obstacle detection process according to the embodiment. [Figure 6] A diagram illustrating the obstacle detection process according to the embodiment. [Figure 7] A diagram illustrating the obstacle detection process according to the embodiment. [Figure 8] A diagram illustrating the obstacle detection process according to the embodiment. [Figure 9] A diagram illustrating the obstacle detection process according to the embodiment. [Figure 10] A flowchart showing a modified procedure of the obstacle detection process according to the embodiment. [Figure 11]Flowchart showing the procedure of a modified example of the obstacle detection process according to the embodiment [Figure 12] Diagram for explaining a modified example of the obstacle detection process according to the embodiment

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the embodiments disclosed below. Since the drawings are provided for illustrative purposes only, the scope of the present invention is not limited to the illustrations in the drawings.

[0010] [1. Excavation System] FIG. 1 is a block diagram showing an excavation system 100 according to the present embodiment. As shown in this figure, the excavation system 100 is used, for example, in a slurry shield method, and includes a shield tunneling machine 1, a slurry treatment plant 2, and a central control device 5. In FIG. 1, the central control device 5 arranged on the ground is illustrated, but the central control device 5 may be arranged in the ground G (behind the shield tunneling machine 1, etc.). Also, the type of shield method for which the excavation system 100 can be used is not particularly limited, and it may be, for example, an earth pressure balance shield method or the like.

[0011] [Shield Tunneling Machine] The shield tunneling machine 1 is arranged in the ground G. The shield tunneling machine 1 includes a tunneling machine body 11 and a cutter head 12. The tunneling machine body 11 includes a chamber (not shown) filled with slurry, a drive unit 13 such as a motor for rotationally driving the cutter head 12, and a propulsion mechanism 15 such as a propulsion jack for advancing the shield tunneling machine 1 (see FIG. 3). The cutter head 12 is rotatably provided at the front end of the excavator body 11 and is driven by the drive unit 13 to rotate. As shown in FIG. 2, among the cutter heads 12, six cutter spokes 121 are radially arranged on the front surface that abuts against the face of the tunnel face in the present embodiment. Between the cutter spokes 121 adjacent to each other in the circumferential direction, cylindrical cutter spokes 122 enabling replacement of the cutter bits 124 are provided. The cutter spokes 122 have a radial length approximately half that of the cutter spokes 121 and are arranged on the outer diameter side of the front surface of the cutter head 12. A plurality of cutter bits 124 are arranged on each of the cutter spokes 121 and 122. The cutter bits 124 are arranged at equal intervals along the extending direction of each of the cutter spokes 121 and 122, and a plurality of them are arranged in multiple rows (for example, two rows) in the circumferential direction (tangential direction).

[0012] <Slurry treatment plant> As shown in FIG. 1, the slurry treatment plant 2 is arranged on the ground. The slurry treatment plant 2 includes a primary treatment unit 21 and an adjustment tank 22. The primary treatment unit 21 is connected to the chamber of the shield tunneling machine 1 via a sludge discharge pipe 41, and the excavated slurry accumulated in the chamber of the shield tunneling machine 1 is pumped to the primary treatment unit 21 by a sludge discharge pump 42 installed on the sludge discharge pipe 41. The primary treatment unit 21 separates gravel and sand with large particle sizes from the slurry containing a large amount of earth and sand components sent from the shield tunneling machine 1, and the separated slurry is sent to the adjustment tank 22. The adjustment tank 22 temporarily stores the slurry sent from the primary treatment unit 21. The viscosity of the slurry is adjusted by an operator adding tap water or a thickening agent to the slurry stored in the adjustment tank 22. The adjustment tank 22 is connected to the chamber of the shield tunneling machine 1 via a slurry supply pipe 31, and the adjusted slurry is pumped up from the adjustment tank 22 by a slurry supply pump 32 installed on the slurry supply pipe 31 and pumped to the chamber of the shield tunneling machine 1.

[0013] <Central control device> Figure 3 is a block diagram showing the schematic functional configuration of the excavation system 100. As shown in this figure, the central control device 5 centrally controls the excavation system 100, monitoring the operating status of the shield excavator 1 and the slurry treatment plant 2 in real time, and controlling each part of the excavation system 100. For example, the central control device 5 monitors the rotational torque (cutter torque) and rotational speed of the cutter head 12, the propulsion speed (excavation speed) and propulsion pressure of the shield excavator 1, and the controlled earth pressure. The central control device 5 also controls the rotational speed of the cutter head 12, the excavation speed of the shield excavator 1, and the slurry pressure in the chamber of the shield excavator 1 (sludge amount supplied by the sludge pump 32, sludge amount discharged by the sludge pump 42). The central control device 5 corresponds to an example of an obstacle detection device according to the present invention. Specifically, the central control unit 5 comprises an operation unit 52, a display unit 53, a storage unit 56, and a control unit 57.

[0014] The operation unit 52 is an operating means that allows the operator to perform various operations to operate the central control unit 5, and includes, for example, a pointing device such as a mouse or keyboard. The display unit 53 is, for example, a liquid crystal display, an organic electroluminescent display, or other type of display. The display unit 53 displays various information based on display signals input from the control unit 57. The memory unit 56 is a memory composed of, for example, RAM (Random Access Memory) or ROM (Read Only Memory), and stores various programs and data, as well as functioning as a work area for the control unit 57. In this embodiment, the memory unit 56 pre-stores a control program 561 for executing the obstacle detection process described later. The control unit 57 is composed of, for example, a CPU (Central Processing Unit) and controls the operation of each part of the central control unit 5. Specifically, the control unit 57 deploys a program pre-stored in the memory unit 56 based on the operation content of the operation unit 52, and performs various processes in cooperation with the deployed program. The specific configuration of the central control unit 5 is not particularly limited and may consist of, for example, terminal devices and a cloud server.

[0015] <Overview of drilling system operation> In the excavation system 100, the mud supply pump 32 and the mud discharge pump 42 are operated based on the control of the central control device 5, so that mud is filled into the chamber of the shield excavator 1, and the mud pressure in the chamber is adjusted to be higher than the earth pressure received from the excavation face. Then, based on the control of the central control device 5, the shield drilling machine 1 moves forward while rotating the cutter head 12, excavating the tunnel face. The generated soil is taken into the chamber and discharged to the surface as excavation slurry through the mud discharge pipe 41. The excavation slurry discharged to the surface is separated from gravel and sand in the primary processing unit 21 and sent to the adjustment tank 22 as separated slurry. The separated slurry is adjusted for viscosity and other properties in the adjustment tank 22 and sent to the chamber of the shield drilling machine 1 through the mud supply pipe 31 as adjusted slurry. Through the repetition of these actions, a tunnel T is formed within the ground G.

[0016] [2. Obstacle detection processing] Next, we will explain the obstacle detection process that detects contact between the cutter head 12 and an obstacle when the shield excavator 1 is in operation. Figure 4 is a flowchart showing the procedure for the obstacle detection process, and Figures 5 to 9 are diagrams illustrating the obstacle detection process. In the obstacle detection process of this embodiment, the rotational torque (cutter torque) of the cutter head 12 is monitored when the shield drilling machine 1 is in operation, thereby quickly detecting obstacles D (see Figure 1) in the ground that may be encountered (contacted) by the cutter head 12. Hereinafter, "obstacle" refers to an object having a configuration (e.g., high hardness) that may hinder the sound operation of the cutter head 12. This obstacle detection process is performed, for example, by the control unit 57 of the central control unit 5 reading and deploying the control program 561 from the storage unit 56 based on user input. The control program 561 may be a part (subprogram) of a program that controls the operation of the shield drilling machine 1 (or the entire drilling system 100).

[0017] As shown in Figure 4, once the excavation system 100 is started and the shield drilling machine 1 begins its excavation (boring) operation and the boring speed becomes approximately constant, the control unit 57 of the central control device 5 measures (acquires) the rotational force (cutter torque) of the cutter head 12 (step S1). Here, the control unit 57 acquires time-series data 61 of the cutter torque from the rotational output of the drive unit 13 that drives the cutter head 12 (Figure 5). The method for measuring the cutter torque is not particularly limited; if the drive unit 13 is an electric motor, the output may be determined by measuring the current value, or if the drive unit 13 is a hydraulic motor, the output may be calculated from the pressure and flow rate of the hydraulic pump. Alternatively, a torque sensor may be installed on the drive shaft of the cutter head 12 to directly measure the rotational torque.

[0018] Next, the control unit 57 performs frequency analysis on the time-series data 61 of the cutter torque acquired in step S1 to obtain a periodic curve (periodic characteristic) that shows the relationship between the cutter torque and the period (step S2). Here, the control unit 57 converts the time-domain waveform into a frequency-domain waveform using frequency analysis (which may also utilize an FFT analyzer, etc.), and acquires data (graph) as a periodic curve 62, for example, as shown in Figure 6, with the vertical axis representing cutter torque and the horizontal axis representing period.

[0019] Next, the control unit 57 calculates the area S of a predetermined short-period region R in the periodic curve 62 (step S3). The range of the short-period region R is not particularly limited, but is set to a predetermined period (e.g., a few seconds) or less, for example, based on past contact cases. For example, in this embodiment, when the rotation speed of the cutter head 12 is 0.6 rpm, the range of less than 7 seconds is set as the short-period region R. Here, the control unit 57 calculates the amplitude area (energy component) of the cutter torque-periodic curve 62 in the short-period region R (shaded portion in Figure 6). In the example in Figure 6, it can be seen that the amplitude of the periodic curve 62 when in contact with the obstacle D (immediately after contact) is significantly larger in the short-period region R than under normal conditions (before contact). Note that the dominant component (ω component) in the example in Figure 6 is due to the excavation speed of the shield tunneling machine 1.

[0020] Next, the control unit 57 determines whether the area S of the short-period region R calculated in step S3 is greater than a predetermined threshold (step S4). By setting the threshold appropriately, it is possible to determine whether or not there is a possibility of contact between the cutter head 12 and the obstruction D.

[0021] In other words, the inventors have found that the possibility of contact with the cutter head 12 can be suitably determined by evaluating the magnitude of fluctuations in the short-period region R (high-frequency range) of the cutter torque. This point will be explained below. Figure 7 shows an example of time-series data of cutter torque when the cutter head 12 is in contact with the obstacle D. Figure 8 is an enlarged view of a part of Figure 7, and Figure 9 is an enlarged view of a part of Figure 8 (section E). In addition, Figures 8 and 9 also show torque data for construction sections (B and C) where there is no contact with the obstacle D. As shown in Figures 7 to 9, when the cutter head 12 comes into contact with an obstacle D, the amplitude of the high-frequency component (short-period component) of the cutter torque increases sharply. This is thought to be because the numerous cutter bits 124 on the cutter head 12 continuously collide with the obstacle D. Specifically, this fluctuation in cutter torque is thought to occur because the cutter bits 124 rise as they get caught on the hard obstacle D, and then sharply fall (the rise disappears abruptly) as the cutter bits 124 slip through (pass) the obstacle D. In other words, when such a phenomenon occurs, the fluctuation component of the cutter torque in the high-frequency region (short-period region) becomes sharply larger than usual. Therefore, by appropriately capturing the magnitude of such high-frequency components (for example, HF in Figure 9), it is thought that contact with the obstacle D can be detected quickly. More specifically, in order to accurately determine contact with the obstacle D and to understand the time interval at which fluctuations in cutter torque occur as the cutter bit 124 passes through the obstacle D, as well as the size of the obstacle D, it would normally be necessary to perform a high-precision frequency analysis up to the long-period region including the dominant component. For example, if only one cutter bit 124 is in contact with the obstacle D, it would take time for the cutter bit 124 to rotate at least twice to understand its period. However, frequency analysis of the dominant component, which has a relatively long period, takes time, and as a result the shield excavator 1 moves forward and contact with the obstacle D progresses, the damage to the cutter head 12 increases. Therefore, in this step, the vibration of the high-frequency component (short-period component) is evaluated more than the dominant component, so that contact (possibility) with the obstacle D can be detected quickly. Furthermore, if contact with the obstacle D could be determined based on the fluctuation range of the time-series data 61 of the cutter torque without performing frequency analysis, a quicker decision could be made. However, if frequency analysis is not performed, sufficient judgment accuracy may not be obtained. In this regard, the method of this embodiment performs frequency analysis, but determines contact with the obstacle D by evaluating only the short-period region R, thereby achieving both improved judgment accuracy and quick decision-making.

[0022] As shown in Figure 4, in step S4, if it is determined that the area S of the short-period region R is greater than a predetermined threshold (step S4; Yes), the control unit 57 determines that the cutter head 12 may have come into contact with the obstacle D and reduces the excavation speed of the shield excavator 1 (step S5). This suppresses further damage to the cutter head 12 if it has come into contact with the obstacle D. In this step, the display unit 53 may also display a message indicating that the cutter head 12 may have come into contact with the obstruction D. The notification method in this case is not particularly limited and may include, for example, the output of an alarm sound or the flashing of a warning light.

[0023] Next, the control unit 57 evaluates the fluctuations in cutter torque across the entire range of cutter torque data, including the long-period region (low-frequency region) (step S6). In other words, by evaluating the fluctuation of the cutter torque value in a region including the long-period region, the possibility of contact with the cutter head 12 can be determined with higher accuracy than the contact determination in the short-period region R in step S4. To put it another way, if the possibility of contact in the short-period region R is suspected in step S4, measures are taken in step S5 to reduce the excavation speed and suppress damage to the cutter head 12, and then in step S6, a contact determination with higher accuracy than in step S4 is made. Note that in the evaluation of torque fluctuations here, the measurement and calculation conditions may be changed from step S1 or S2, for example, by increasing the number of sampling points.

[0024] Next, the control unit 57 determines whether or not there is a possibility of contact with the cutter head 12 based on the evaluation of the cutter torque fluctuation in step S6 (step S7). If it is determined that there is no possibility of contact (step S7; No), the control unit 57 proceeds to step S9, which will be described later. At this time, the excavation speed that was reduced in step S5 may be restored to its original value. On the other hand, in step S7, if it is determined that there is a possibility of contact in the fluctuation evaluation in step S6 (step S7; Yes), the control unit 57 will emergency stop the propulsion and rotation of the shield excavator 1 (step S8). In this case, since there is a high possibility that the cutter head 12 has come into contact with a hard obstacle D, measures will be taken, including confirmation of this.

[0025] In step S4 described above, if it is determined that the area S of the short-period region R is not greater than a predetermined threshold (step S4; No), the control unit 57 determines that there is no possibility that the cutter head 12 has come into contact with the obstacle D and decides whether or not to terminate the obstacle detection process (step S9). If it is determined that the obstacle detection process should not be terminated (step S9; No), the control unit 57 proceeds to step S1 described above and continues to monitor the cutter torque. On the other hand, if it is determined that the obstacle detection process should be terminated, for example, due to the shutdown of the shield drilling machine 1 (step S9; Yes), the control unit 57 terminates the obstacle detection process.

[0026] In this embodiment, it is sufficient to perform stepwise contact detection with the obstacle D in steps S4 and S6 (S7), and the actions taken in response to the detection results are not particularly limited. Furthermore, in this embodiment, it is sufficient to perform a contact determination with the obstacle D in step S4, and if it is determined in step S4 that there is a possibility of contact with the obstacle D, the shield excavator 1 may be stopped in an emergency.

[0027] [3. Technical Effects of this Embodiment] As described above, according to this embodiment, the time-series data 61 of the cutter torque is subjected to frequency analysis to calculate a periodic curve 62 that shows the relationship between the cutter torque and the period, and based on the area S of the short-period region R in the periodic curve 62, it is determined whether or not there is a possibility of contact between the cutter head 12 and the obstacle D. In other words, by evaluating the fluctuations in cutter torque in the short-period region R, where the effects of contact are clearly evident and analysis does not require a significant amount of time, contact between the cutter head 12 and the obstruction D can be quickly detected. Consequently, if there is an obstacle D whose position is ambiguous ahead, conventionally it would be necessary to carefully control the excavation speed in preparation for encountering the obstacle D. However, according to this embodiment, since the obstacle D can be detected quickly, it is not necessary to control the excavation speed until the obstacle D is encountered.

[0028] Furthermore, according to this embodiment, if it is determined in step S4 that there is a possibility of contact between the cutter head 12 and the obstacle D, in step S6, the time-series data 61 of the cutter torque, which includes periods longer than the short-period region R, is frequency-analyzed to determine whether or not there is a possibility of contact between the cutter head 12 and the obstacle D. In other words, after quickly detecting contact in step S4, more detailed information about the contact pattern can be obtained through a more accurate contact determination in step S4. Because contact determination is performed in two stages in this way, the operating state and measurement / calculation conditions of the shield excavator 1 can be adjusted in between, allowing for safer and more accurate contact determination.

[0029] Furthermore, according to this embodiment, if it is determined in step S4 that there is a possibility of contact between the cutter head 12 and the obstacle D, the excavation speed of the shield excavator 1 is reduced. This makes it possible to suppress damage to the cutter head 12 (cutter bit 124) when the cutter head 12 is in contact with the obstruction D. Furthermore, when contact is determined again in the subsequent step S6, it is possible to evaluate data in the long-period region suitably while suppressing damage to the cutter head 12.

[0030] [4. Variant] In the above embodiment, contact with an obstacle is determined based on the frequency characteristics (periodic characteristics) obtained by frequency analysis of the time-series data of the cutter torque. However, as shown in Figure 10, contact with an obstacle may be determined based on the time-series data of the cutter torque prior to the frequency analysis of the time-series data (step T0).

[0031] Specifically, in this case, as shown in Figures 11 and 12, the control unit 57 first acquires the fluctuation range ΔT (amplitude range) of the time-series data 61 of the cutter torque (step T1). The period t of the fluctuation range ΔT is the rotation period of the cutter spoke. In step S1, which precedes step T1, it is preferable to set a sampling frequency and the like to obtain a sufficient number of data points so that the peak of the torque waveform can be suitably captured. Specifically, in typical ground excavation, time-series data of cutter torque 61 (cutter rotational force data) is acquired at a frequency of about once per second. However, because the fluctuation of cutter torque when cutting through obstacles is instantaneous, it is difficult to accurately sense the range of cutter torque fluctuations with this data acquisition frequency. With a typical cutter rotational force data acquisition frequency of once per second, the outermost rotational speed of a typical cutter is about 20 m / min = 0.33 m / second, meaning that rotational force data is acquired at intervals of 0.33 m around the outermost circumference of the cutter. Therefore, if an obstacle appears while the cutter is passing through that 0.33 m, it becomes impossible to sense the fluctuation of cutter torque in contact with the obstacle. In this modified example, time-series data of rotational force is acquired at a frequency of 100 to 500 times per second, thereby accurately sensing the instantaneous change in the range of fluctuation of cutter rotational force data when cutting through obstacles, and enabling a suitable determination of whether or not contact with an obstacle has occurred. Figure 12 illustrates the fluctuation range ΔT obtainable when the data acquisition frequency is 100 times / second, along with a comparative example when the data acquisition frequency is 1 time / second. In the comparative example, the steep peak is not captured, and a small fluctuation range ΔTa is detected. This is also the case in the above embodiment.

[0032] Next, the control unit 57 determines whether the fluctuation range ΔT of the time-series data 61 acquired in step T1 is greater than a predetermined threshold (step T2). By appropriately setting the threshold, it is possible to determine whether or not there is a possibility of contact between the cutter head 12 and the obstacle D. In this case, the threshold is set, for example, by setting the fluctuation range ΔT at the time of contact from past contact cases with the obstacle D, or by assuming a multiplier at the time of contact relative to the fluctuation range ΔT during normal ground excavation. In this modified example, for example, a value of 10 to 15% of the equipment torque of the shield drilling machine 1 is set.

[0033] In step T2, if the control unit 57 determines that the fluctuation range ΔT of the time-series data 61 is not greater than a predetermined threshold (step T2; No), it determines that there is no possibility that the cutter head 12 has come into contact with the obstruction D, and terminates the contact determination based on the time-series data 61. On the other hand, in step T2, if it is determined that the fluctuation range ΔT of the time-series data 61 is greater than a predetermined threshold (step T2; Yes), the control unit 57 determines that the cutter head 12 may have come into contact with the obstacle D and reduces the excavation speed of the shield excavator 1 (step T3). This suppresses further damage to the cutter head 12 if it has come into contact with the obstacle D. Also, in this step, similar to step S5 in the above embodiment, the display unit 53 may display that the cutter head 12 may have come into contact with the obstacle D. The notification method in this case is not particularly limited and may include, for example, the output of an alarm sound or the flashing of a warning light. After that, the control unit 57 terminates the contact determination based on the time-series data 61.

[0034] As described above, according to this modified example, if the fluctuation range ΔT of the time-series data 61 of the cutter torque exceeds a predetermined threshold, it is determined that there is a possibility of contact between the cutter head 12 and the obstruction D. This allows contact with the obstacle D to be determined using the time-series data 61 without performing frequency analysis of the time-series data 61. Consequently, contact between the cutter head 12 and the obstacle D can be detected quickly.

[0035] Furthermore, if it is determined in step T2 that there is a possibility of contact between the cutter head 12 and the obstacle D, in step S4 (or S6, S7) of the above embodiment, the presence or absence of the possibility of contact between the cutter head 12 and the obstacle D is determined based on the frequency characteristics (periodic characteristics) of the cutter torque obtained by frequency analysis of the time-series data 61 of the cutter torque. In other words, after quickly detecting contact itself in step T2, more detailed information about the contact pattern can be obtained by using frequency characteristics (periodic characteristics) to determine contact with higher accuracy. Because contact determination is performed in multiple stages in this way, the operating state of the shield excavator 1 and the measurement and calculation conditions can be adjusted in between, allowing for safer and more accurate contact determination.

[0036] In this modified example, it is sufficient that, after the contact determination with the obstacle D using the time-series data 61 in step T2, a contact determination with the obstacle D using the frequency characteristics in at least one of step S4 and step S6 (S7) can be performed, and the actions taken in response to the determination result are not particularly limited. For example, if the contact determination in step S4 determines that there is a possibility of contact, the shield excavator 1 may be stopped in an emergency, or the contact determination in step S4 may be omitted. Furthermore, in this embodiment, it is sufficient to perform a contact determination with the obstacle D based on the time-series data 61 in step T2, and if it is determined in step T2 that there is a possibility of contact with the obstacle D, the shield excavator 1 may be stopped in an emergency.

[0037] [5. Others] Although one embodiment of the present invention has been described above, the embodiments to which the present invention can be applied are not limited to the embodiments described above (including modifications). For example, in the above embodiment, contact determination is performed using the periodic curve 62 of the cutter torque, but it is also possible to use the frequency curve (frequency characteristics) corresponding to the periodic curve 62. In other words, in this case, contact determination may be performed based on the amplitude area in the high-frequency region of the frequency curve, which corresponds to the short-period region R in the periodic curve 62. Furthermore, in the above embodiment, contact between the cutter head 12 and the obstacle D is detected using cutter torque data. However, data other than cutter torque may be used as long as it is data that relatively sensitively indicates contact with the obstacle D.

[0038] Furthermore, the present invention can be broadly applied to excavation systems and shield tunneling methods that use shield drilling machines. The type of shield drilling machine or shield tunneling method is not particularly limited. Furthermore, details shown in the above embodiments can be modified as appropriate without departing from the spirit of the invention. [Explanation of Symbols]

[0039] 100 drilling systems 1. Shield drilling machine 5. Central Control System (Obstacle Detection Device) 12 cutter heads 13 Drive unit 15 Propulsion mechanism 57 Control Unit (Acquisition Unit, Second Acquisition Unit, Calculation Unit, Determination Unit, Second Determination Unit) 61 Time Series Data 62. Periodic curve (frequency response) 124 Cutter Bits 561 Control Program D Obstacles ΔT Variation range

Claims

1. An acquisition unit that acquires time-series data of the rotational force of the cutter head equipped with a shield drilling machine, A second acquisition unit acquires the range of variation of the time-series data of the rotational force, A determination unit determines that there is a possibility of contact between the cutter head and an obstruction when the fluctuation range of the aforementioned time series data exceeds a predetermined threshold, If the determination unit determines that there is a possibility of contact between the cutter head and an obstacle, the calculation unit performs frequency analysis on the time-series data of the rotational force and obtains the frequency characteristics of the rotational force. A second determination unit determines whether or not there is a possibility of contact between the cutter head and an obstacle based on the frequency characteristics of the rotational force, An obstacle detection device equipped with the following features.

2. The acquisition unit acquires the time-series data of the rotational force at a frequency of 100 to 500 times / second. Obstacle detection device according to claim 1.

3. The control unit reduces the excavation speed of the shield excavator when the determination unit determines that there is a possibility of contact between the cutter head and an obstacle. Obstacle detection device according to claim 1.

4. An obstacle detection device according to any one of claims 1 to 3, A shield drilling machine equipped with the aforementioned cutter head, A drilling system including a drilling system.

5. The control unit, The acquisition process involves obtaining time-series data of the rotational force of the cutter head equipped with a shield drilling machine, and A second acquisition step for acquiring the range of fluctuation of the time-series data of the rotational force, A determination step in which, when the fluctuation range of the aforementioned time-series data exceeds a predetermined threshold, it is determined that there is a possibility of contact between the cutter head and an obstruction, If the determination step determines that there is a possibility of contact between the cutter head and an obstacle, the calculation step involves frequency analysis of the time-series data of the rotational force and obtaining the frequency characteristics of the rotational force. A second determination step is to determine whether or not there is a possibility of contact between the cutter head and an obstacle based on the frequency characteristics of the rotational force, An obstacle detection method that performs the following actions.

6. Computers An acquisition unit that acquires time-series data of the rotational force of the cutter head of a shield drilling machine. A second acquisition unit acquires the range of variation of the time-series data of the rotational force. A determination unit determines that there is a possibility of contact between the cutter head and an obstruction when the fluctuation range of the aforementioned time series data exceeds a predetermined threshold. If the determination unit determines that there is a possibility of contact between the cutter head and an obstacle, the calculation unit performs frequency analysis on the time-series data of the rotational force and obtains the frequency characteristics of the rotational force. A second determination unit determines whether or not there is a possibility of contact between the cutter head and an obstacle based on the frequency characteristics of the rotational force. An obstacle detection program that functions as such.

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