A loaded coal rock drilling experiment platform and a while-drilling mechanical parameter identification method

Abstract

A kind of loaded coal rock drilling experiment platform and method for identifying mechanical parameters while drilling, the experiment platform includes loading unit, drilling unit and while drilling controller;Loading unit is arranged with drilling unit side by side.Method is: using cement mortar to manufacture simulated coal rock test piece, different strength coal rock test piece can be prepared according to the need of experiment;By applying confining pressure to coal rock test piece in laboratory, the occurrence conditions of coal rock underground can be simulated;Using dynamic torque sensor, displacement sensor can monitor and obtain the while drilling parameters of drilling machine in operation process;Using improved particle swarm optimization algorithm to identify while drilling parameters, the efficiency and accuracy of while drilling parameter identification are improved by using while drilling parameters as particles;The present application is based on drilling and measuring integrated technology, data generated during drilling process can be collected and analyzed in real time while drilling, the mechanical properties of coal rock are inverted using these data, the measurement lag problem is eliminated, the progress of project is ensured not to be disturbed, and the identification ability of geological abnormal block is strengthened.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coal mining, and particularly relates to a loaded coal rock drilling experiment platform and a drilling mechanical parameter identification method. BACKGROUND

[0002] With the continuous increase of the depth of coal mining, the intensity and frequency of coal and gas outburst and rock burst disasters are also becoming more and more serious, and geological abnormal areas such as faults and collapse columns can also cause coal seam crushing and poor coal seam occurrence conditions, which are the root causes of coal and gas outburst and rock burst accidents.

[0003] In order to prevent accidents, the causes of the accidents must be analyzed in depth, and only by analyzing the potential causes of the accidents can the risks be better identified and evaluated.

[0004] Coal rock mechanical parameters are one of the most important basic parameters of coal rock, and due to the variability and complexity of natural rock structures, accurate determination of coal rock mechanical parameters has always been an important challenge in the field of rock mechanics.

[0005] However, the traditional coal rock mechanical parameter measurement method has a lag problem, the engineering progress is easy to be disturbed, and it is difficult to directly and efficiently detect the scene, and the drilling and measurement integrated technology research is lacking, and it is difficult to conduct experiments indoors. SUMMARY

[0006] In view of the problems existing in the prior art, the present application provides a loaded coal rock drilling experiment platform and a drilling mechanical parameter identification method, which uses cement mortar to manufacture simulated coal rock test pieces, and can prepare coal rock test pieces with different strengths according to the needs of the experiment; the occurrence conditions of coal rock underground can be simulated by applying confining pressure to the coal rock test pieces indoors; the dynamic torque sensor and the displacement sensor can be used to monitor and obtain the key indicators of the drilling machine during operation in real time, including thrust size, torque change, drilling speed, rotation speed and other drilling parameters; the improved particle swarm optimization algorithm is used to identify the drilling parameters, and the collected drilling parameters are used as particles to improve the efficiency and accuracy of the drilling parameter identification; the present application is based on the drilling and measurement integrated technology, and can collect and analyze the data generated during drilling at the same time, and use these data to invert the mechanical properties of coal rock, eliminate the measurement lag problem, ensure that the engineering progress is not disturbed, effectively strengthen the ability of real-time identification of geological abnormal blocks underground in coal mines, effectively maintain the safety and stability of coal mining, and reduce the risk of accidents.

[0007] In order to achieve the above purpose, the present application adopts the following technical scheme: a loaded coal rock drilling experiment platform, comprising a loading unit, a drilling unit and a drilling controller; the loading unit and the drilling unit are arranged side by side;

[0008] The loading unit comprises a base, a stand, a top beam, a first hydraulic cylinder, a second hydraulic cylinder, a third hydraulic cylinder, a pressure chamber, a support pad, a first pad, a second pad and a third pad; the top beam is horizontally fixed above the base through the stand; the pressure chamber is fixedly installed at the center of the upper surface of the base; the support pad is located inside the pressure chamber and is horizontally fixed at the center of the upper surface of the bottom plate of the pressure chamber, and the simulated coal rock sample is placed on the upper surface of the support pad; the first hydraulic cylinder is vertically fixed at the center of the top beam with the piston rod downward, and the piston rod of the first hydraulic cylinder extends downward into the pressure chamber; the first pad is horizontally arranged, the end of the piston rod of the first hydraulic cylinder is fixedly connected with the center of the upper surface of the first pad, and the lower surface of the first pad is in top-contacting fit with the simulated coal rock sample; the second hydraulic cylinder is horizontally fixed on one side plate of the pressure chamber, and the piston rod of the second hydraulic cylinder extends inward into the pressure chamber; the second pad is vertically arranged, the end of the piston rod of the second hydraulic cylinder is fixedly connected with the center of the outer surface of the second pad, and the inner surface of the second pad is in top-contacting fit with the simulated coal rock sample; the third hydraulic cylinder is horizontally fixed on the other side plate of the pressure chamber, and the third hydraulic cylinder is mirror-symmetrically and coaxially distributed with the second hydraulic cylinder; the third pad is vertically arranged, the end of the piston rod of the third hydraulic cylinder is fixedly connected with the center of the outer surface of the third pad, and the inner surface of the third pad is in top-contacting fit with the simulated coal rock sample; the other two side plates of the pressure chamber are open structures;

[0009] The drilling unit comprises a support table, a feeding motor, a slide rail, a screw nut sliding table, a lead screw, a drilling motor, a drill rod, a dynamic torque sensor and a laser displacement sensor; the slide rail is horizontally fixed on the upper surface of the support table; the lead screw is horizontally arranged above the slide rail, and the lead screw is parallelly distributed with the slide rail, and one end of the lead screw is connected with the upper surface of the support table through a bearing seat; the feeding motor is horizontally arranged, and the feeding motor is connected with the upper surface of the support table through a motor mounting seat; the motor shaft of the feeding motor is coaxially fixedly connected with the other end of the lead screw through a first coupling; the screw nut sliding table is arranged between the slide rail and the lead screw, and the screw nut sliding table has a linear movement degree along the slide rail; the drilling motor is horizontally fixed on the upper surface of the screw nut sliding table; the dynamic torque sensor is horizontally fixed on the upper surface of the screw nut sliding table, and the power input shaft of the dynamic torque sensor is coaxially fixedly connected with the motor shaft of the drilling motor through a second coupling; the power output shaft of the dynamic torque sensor is coaxially fixedly connected with one end of the drill rod through a third coupling, and the other end of the drill rod is opposite to the simulated coal rock sample; the laser displacement sensor is fixedly installed on the upper surface of the screw nut sliding table, and the laser emitting end of the laser displacement sensor is opposite to the motor mounting seat; the while-drilling controller is fixedly installed on the upper surface of the support table, and the control end of the feeding motor, the control end of the drilling motor, the data output end of the dynamic torque sensor and the data output end of the laser displacement sensor are electrically connected with the while-drilling controller.

[0010] A method for identifying mechanical parameters while drilling, which adopts the loaded coal rock drilling experiment platform, comprises the following steps:

[0011] Step one: prepare a simulated coal rock sample by using cement mortar;

[0012] Step two: place the prepared simulated coal rock sample into the pressure chamber and put it on the upper surface of the supporting cushion block, then simultaneously start the second hydraulic cylinder and the third hydraulic cylinder until the simulated coal rock sample is centered and clamped between the second cushion block and the third cushion block in the horizontal direction, and then start the first hydraulic cylinder to make the simulated coal rock sample centered and clamped between the first cushion block and the supporting cushion block in the vertical direction;

[0013] Step three: apply load force to the simulated coal rock sample through the first hydraulic cylinder, the second hydraulic cylinder and the third hydraulic cylinder until the confining pressure borne by the simulated coal rock sample reaches the set value;

[0014] Step four: start the feed motor to drive the screw to rotate, and the rotary motion of the screw will be converted into the linear motion of the nut slide synchronously, and the drilling motor, the drill rod, the dynamic torque sensor and the laser displacement sensor will move synchronously with the nut slide until the drill rod is in contact with the surface of the simulated coal rock sample, and then the feed motor is turned off;

[0015] Step five: start the drilling motor to drive the drill rod to rotate and reach the set rotational speed, and then restart the feed motor to drive the drill rod to move at the set feed speed so that the drill rod drills into the simulated coal rock sample;

[0016] Step six: in the process of drilling the drill rod into the simulated coal rock sample, the dynamic torque sensor and the laser displacement sensor measure data in real time and synchronously transmit the data to the while-drilling controller for storage until the drill rod penetrates the simulated coal rock sample, and then the drilling motor is turned off;

[0017] Step seven: reverse start the feed motor until the drill rod completely exits from the drill hole of the simulated coal rock sample, and the nut slide synchronously retreats to the initial position, the feed motor is turned off, and then the unloading of the first hydraulic cylinder, the second hydraulic cylinder and the third hydraulic cylinder is completed, and the first cushion block, the second cushion block and the third cushion block return to the initial position, and then the simulated coal rock sample is removed from the pressure chamber;

[0018] Step eight: import the while-drilling parameter data stored in the while-drilling controller into a computer, and the improved particle swarm optimization algorithm is loaded in the computer, and the formula is:

[0019]

[0020] χ k+1 =χ k +V k+1

[0021]

[0022] In the formula, omega is a nonlinear dynamic inertia weight coefficient, k is the number of particle swarm iterations, V is the particle swarm velocity, X is the particle swarm position, p best is the individual extreme value, g best is the group extreme value, c1 and c2 are learning factors, r1 and r2 are [0, 1] random numbers, omega max is the maximum inertia weight, omega min is the minimum inertia weight, f is the fitness of the current particle position, f avg is the average fitness of the current particle position, f min is the minimum fitness of the current particle position;

[0023] The while-drilling parameter data is taken as a particle, firstly, the particle swarm parameters are initialized, then the position and velocity of each particle are randomly initialized, and then it is judged whether the termination condition is met, if the termination condition is met, the optimal solution is directly output, if the termination condition is not met, the position and velocity of each particle are updated, the fitness value of each particle is calculated, the individual historical optimal fitness and position of each particle are updated, then the particle swarm parameters are updated, and then it is judged again whether the termination condition is met, the above judgment process is repeated until the termination condition is met, and the optimal solution is output.

[0024] In order to eliminate the adverse effects of the differences of the collected data samples on the results, 70% of the samples are extracted from the collected data samples as training samples and sample comparison charts are obtained, and the remaining 30% of the samples are used as test samples and sample comparison charts are obtained.

[0025] The beneficial effects of the present application are:

[0026] The loaded coal rock drilling experiment platform and the while-drilling mechanical parameter identification method of the present application use cement mortar to manufacture simulated coal rock test pieces, which can be prepared with different strengths according to the needs of the experiment, the confining pressure is applied to the coal rock test pieces in the laboratory to simulate the occurrence conditions of the coal rock underground, the dynamic torque sensor and the displacement sensor are used to monitor and obtain the key indicators of the drilling machine in the operation process in real time, including the thrust size, the torque change, the drilling speed, the rotation speed and other while-drilling parameters, the improved particle swarm optimization algorithm is used to identify the while-drilling parameters, the collected while-drilling parameters are taken as particles, and the efficiency and accuracy of the while-drilling parameter identification are improved, the present application is based on the drilling and measuring integrated technology, the data generated in the drilling process can be collected and analyzed in real time while the operation is being carried out, the mechanical properties of the coal rock are inverted through these data, the measurement lag problem is eliminated, the engineering progress is ensured not to be disturbed, the ability of the coal mine to identify the abnormal geological blocks in real time underground is effectively strengthened, the safety and stability of the coal mining are effectively maintained, and the accident risk is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1It is a structure schematic view of a loaded coal rock drilling experiment platform (front view angle) of the present application;

[0028] Figure 2 It is a structure schematic view of a loaded coal rock drilling experiment platform (top view angle) of the present application;

[0029] Figure 3 It is a training set prediction sample comparison graph of the present application;

[0030] Figure 4 It is a test set prediction sample comparison graph of the present application;

[0031] In the figure, 1 is a while-drilling controller, 2 is a base, 3 is a stand, 4 is a top beam, 5 is a first hydraulic cylinder, 6 is a second hydraulic cylinder, 7 is a third hydraulic cylinder, 8 is a pressure chamber, 9 is a support pad, 10 is a first pad plate, 11 is a second pad plate, 12 is a third pad plate, 13 is a simulated coal rock sample, 14 is a support table, 15 is a feeding motor, 16 is a slide rail, 17 is a screw nut sliding table, 18 is a lead screw, 19 is a drilling motor, 20 is a drill rod, 21 is a dynamic torque sensor, 22 is a laser displacement sensor, 23 is a bearing seat, 24 is a motor mounting seat, 25 is a first coupling, 26 is a second coupling, and 27 is a third coupling. DETAILED DESCRIPTION

[0032] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0033] As shown in Figure 1 , 2 , a loaded coal rock drilling experiment platform comprises a loading unit, a drilling unit and a while-drilling controller 1; the loading unit and the drilling unit are arranged side by side;

[0034] The loading unit comprises a base 2, a stand column 3, a top beam 4, a first hydraulic cylinder 5, a second hydraulic cylinder 6, a third hydraulic cylinder 7, a pressure chamber 8, a support pad 9, a first pad plate 10, a second pad plate 11 and a third pad plate 12; the top beam 4 is horizontally fixed above the base 2 through the stand column 3; the pressure chamber 8 is fixedly installed at the center of the upper surface of the base 2; the support pad 9 is located inside the pressure chamber 8 and is horizontally fixed at the center of the upper surface of the bottom plate of the pressure chamber 8, and a simulated coal rock sample 13 is placed on the upper surface of the support pad 9; the first hydraulic cylinder 5 is vertically fixed at the center of the top beam 4 with the piston rod downward, and the piston rod of the first hydraulic cylinder 5 extends downward into the pressure chamber 8; the first pad plate 10 is horizontally arranged, the end of the piston rod of the first hydraulic cylinder 5 is fixedly connected with the center of the upper surface of the first pad plate 10, and the lower surface of the first pad plate 10 is in contact with the top of the simulated coal rock sample 13; the second hydraulic cylinder 6 is horizontally fixed on one side plate of the pressure chamber 8, and the piston rod of the second hydraulic cylinder 6 extends inward into the pressure chamber 8; the second pad plate 11 is vertically arranged, the end of the piston rod of the second hydraulic cylinder 6 is fixedly connected with the center of the outer surface of the second pad plate 11, and the inner surface of the second pad plate 11 is in contact with the top of the simulated coal rock sample 13; the third hydraulic cylinder 7 is horizontally fixed on the other side plate of the pressure chamber 8, and the third hydraulic cylinder 7 is mirror-symmetrically and coaxially distributed with the second hydraulic cylinder 6; the third pad plate 12 is vertically arranged, the end of the piston rod of the third hydraulic cylinder 7 is fixedly connected with the center of the outer surface of the third pad plate 12, and the inner surface of the third pad plate 12 is in contact with the top of the simulated coal rock sample 13; the other two side plates of the pressure chamber 8 are open structures;

[0035] The drilling unit comprises a support table 14, a feeding motor 15, a sliding rail 16, a nut sliding table 17, a lead screw 18, a drilling motor 19, a drill rod 20, a dynamic torque sensor 21 and a laser displacement sensor 22; the sliding rail 16 is horizontally fixed on the upper surface of the support table 14; the lead screw 18 is horizontally arranged above the sliding rail 16, the lead screw 18 and the sliding rail 16 are parallelly distributed, one end of the lead screw 18 is connected with the upper surface of the support table 14 through a bearing seat 23; the feeding motor 15 is horizontally arranged, the feeding motor 15 is connected with the upper surface of the support table 14 through a motor mounting seat 24, the motor shaft of the feeding motor 15 is coaxially fixedly connected with the other end of the lead screw 18 through a first coupling 25; the nut sliding table 17 is arranged between the sliding rail 16 and the lead screw 18, the nut sliding table 17 has a linear movement degree of freedom along the sliding rail 16; the drilling motor 19 is horizontally fixed on the upper surface of the nut sliding table 17; the dynamic torque sensor 21 is horizontally fixed on the upper surface of the nut sliding table 17, the power input shaft of the dynamic torque sensor 21 is coaxially fixedly connected with the motor shaft of the drilling motor 19 through a second coupling 26, the power output shaft of the dynamic torque sensor 21 is coaxially fixedly connected with one end of the drill rod 20 through a third coupling 27, the other end of the drill rod 20 is opposite to the simulated coal rock sample 13; the laser displacement sensor 22 is fixedly installed on the upper surface of the nut sliding table 17, the laser emitting end of the laser displacement sensor 22 is opposite to the motor mounting seat 24; the while-drilling controller 1 is fixedly installed on the upper surface of the support table 14, the control end of the feeding motor 15, the control end of the drilling motor 19, the data output end of the dynamic torque sensor 21 and the data output end of the laser displacement sensor 22 are electrically connected with the while-drilling controller 1. In the embodiment, the feeding motor 15 is a stepping motor, and the drilling motor 19 is a three-phase asynchronous motor.

[0036] A while-drilling mechanical parameter identification method, which adopts the loaded coal rock drilling experiment platform, comprises the following steps:

[0037] Step one: the simulated coal rock sample 13 is prepared by using cement mortar;

[0038] In the embodiment, river sand, cement and water are used as raw materials, the river sand is sieved to remove large-diameter stones and impurities in the river sand before use, then the sieved river sand, cement and water are mixed uniformly according to the required strength of the experiment, and the cement mortar is prepared, the cement mortar is poured into a sample forming mold, and a layer of lubricating grease is applied on the surface of the mold before molding to facilitate subsequent demolding, a vibrator is used to vibrate and compact the cement mortar after molding to prevent pores in the cement mortar, and the cement mortar is cured until the designed strength is reached, and finally the simulated coal rock sample 13 is formed, and the simulated coal rock sample 13 is taken out of the sample forming mold;

[0039] Step two: Put the prepared simulated coal rock sample 13 into the pressure chamber 8 and place it on the upper surface of the supporting pad 9, then simultaneously start the second hydraulic cylinder 6 and the third hydraulic cylinder 7 until the simulated coal rock sample 13 is centered and clamped between the second pad 11 and the third pad 12 in the horizontal direction, and then start the first hydraulic cylinder 5 to center and clamp the simulated coal rock sample 13 between the first pad 10 and the supporting pad 9 in the vertical direction;

[0040] Step three: Load the simulated coal rock sample 13 through the first hydraulic cylinder 5, the second hydraulic cylinder 6 and the third hydraulic cylinder 7 until the confining pressure of the simulated coal rock sample 13 reaches the set value;

[0041] Step four: Start the feed motor 15 to drive the lead screw 18 to rotate, and the rotary motion of the lead screw 18 will be converted into the linear motion of the nut slide 17 at the same time, and the drilling motor 19, the drill rod 20, the dynamic torque sensor 21 and the laser displacement sensor 22 will move synchronously with the nut slide 17 until the drill rod 20 is in contact with the surface of the simulated coal rock sample 13, and the feed motor 15 is turned off;

[0042] Step five: Start the drilling motor 19 to drive the drill rod 20 to rotate and reach the set speed, then restart the feed motor 15 to drive the drill rod 20 to move at a set feed speed, so that the drill rod 20 drills into the simulated coal rock sample 13;

[0043] Step six: During the process of the drill rod 20 drilling into the simulated coal rock sample 13, the dynamic torque sensor 21 and the laser displacement sensor 22 measure data in real time and transmit the data to the MWD controller 1 for storage at the same time until the drill rod 20 penetrates the simulated coal rock sample 13, and the drilling motor 19 is turned off;

[0044] Step seven: Reverse start the feed motor 15 until the drill rod 20 completely exits from the drill hole in the simulated coal rock sample 13, and the nut slide 17 synchronously retreats to the initial position, the feed motor 15 is turned off, and then the unloading of the first hydraulic cylinder 5, the second hydraulic cylinder 6 and the third hydraulic cylinder 7 is completed, and the first pad 10, the second pad 11 and the third pad 12 return to the initial position, and then the simulated coal rock sample 13 is removed from the pressure chamber 8;

[0045] Step eight: Import the MWD parameter data stored in the MWD controller 1 into the computer, and the improved particle swarm optimization algorithm is loaded in the computer, and the formula is:

[0046]

[0047] χ k+1 =χ k +V k+1

[0048]

[0049] In the formula, ω is a nonlinear dynamic inertia weight coefficient, k is the number of iterations of the particle swarm, V is the velocity of the particle swarm, χ is the position of the particle swarm, p best is an individual extreme value, g best is a group extreme value, c1 and c2 are learning factors, r1 and r2 are [0, 1] random numbers, ω max is a maximum inertia weight (generally set to 0.9), ω min is a minimum inertia weight (generally set to 0.4), f is the fitness of the current particle position, f avg is the average fitness of the current particle position, f min is the minimum fitness of the current particle position;

[0050] The while-drilling parameter data is taken as a particle. Particle swarm parameters (particle swarm size, particle dimension, iteration number, inertia weight, learning factor, and iteration step range) are initialized first. The position and velocity of each particle are randomly initialized. It is judged whether the termination condition is met. If the termination condition is met, the optimal solution is directly output. If the termination condition is not met, the position and velocity of each particle are updated. The fitness value of each particle is calculated. The individual historical optimal fitness and position of each particle are updated. The particle swarm parameters are updated. It is then judged whether the termination condition is met. The above judgment process is repeated until the termination condition is met, and the optimal solution is output.

[0051] In order to eliminate the adverse effects of differences in collected data samples on the results, 70% of the samples are extracted from the collected data samples as training samples and sample comparison graphs are obtained, as shown in Figure 3 The remaining 30% of the samples are used as test samples and sample comparison graphs are obtained, as shown in Figure 4 It can be seen from the graphs that the improved particle swarm optimization algorithm has good prediction effect on the identification of while-drilling parameters.

[0052] The scheme in the embodiments is not used to limit the protection scope of the present application. Any equivalent implementation or change made without departing from the present application is included in the protection scope of the present application.

Claims

1. A loaded coal rock drilling experiment platform, characterized in that: The application relates to a drilling device for simulating coal rock, which comprises a loading unit, a drilling unit and a drilling controller. The loading unit comprises a base, a stand, a top beam, a first hydraulic cylinder, a second hydraulic cylinder, a third hydraulic cylinder, a pressure chamber, a supporting cushion block, a first cushion plate, a second cushion plate and a third cushion plate; the top beam is horizontally fixed on the top of the base through the stand; the pressure chamber is fixedly installed on the center of the upper surface of the base; the supporting cushion block is located in the pressure chamber and is horizontally fixed on the center of the upper surface of the bottom plate of the pressure chamber, and a simulated coal rock sample is placed on the upper surface of the supporting cushion block; the first hydraulic cylinder is vertically fixed on the center of the top beam with the piston rod downward, and the piston rod of the first hydraulic cylinder extends downward into the pressure chamber; the first cushion plate is horizontally arranged, the end of the piston rod of the first hydraulic cylinder is fixedly connected with the center of the upper surface of the first cushion plate, and the lower surface of the first cushion plate is in abutting contact with the simulated coal rock sample; the second hydraulic cylinder is horizontally fixed on one side plate of the pressure chamber, and the piston rod of the second hydraulic cylinder extends inward into the pressure chamber; the second cushion plate is vertically arranged, the end of the piston rod of the second hydraulic cylinder is fixedly connected with the center of the outer surface of the second cushion plate, and the inner surface of the second cushion plate is in abutting contact with the simulated coal rock sample; the third hydraulic cylinder is horizontally fixed on the other side plate of the pressure chamber, the third hydraulic cylinder is symmetrically distributed with the second hydraulic cylinder and coaxially arranged; the third cushion plate is vertically arranged, the end of the piston rod of the third hydraulic cylinder is fixedly connected with the center of the outer surface of the third cushion plate, and the inner surface of the third cushion plate is in abutting contact with the simulated coal rock sample; the other two side plates of the pressure chamber are in open structure; The drilling unit comprises a supporting table, a feeding motor, a slide rail, a screw nut sliding table, a lead screw, a drilling motor, a drill rod, a dynamic torque sensor and a laser displacement sensor; the slide rail is horizontally fixed on the upper surface of the supporting table; the lead screw is horizontally arranged above the slide rail and is parallelly arranged with the slide rail, one end of the lead screw is connected with the upper surface of the supporting table through a bearing seat; the feeding motor is horizontally arranged and is connected with the upper surface of the supporting table through a motor mounting seat, the motor shaft of the feeding motor is coaxially and fixedly connected with the other end of the lead screw through a first coupling; the screw nut sliding table is arranged between the slide rail and the lead screw and has a linear movement degree along the slide rail; the drilling motor is horizontally fixed on the upper surface of the screw nut sliding table; the dynamic torque sensor is horizontally fixed on the upper surface of the screw nut sliding table, the power input shaft of the dynamic torque sensor is coaxially and fixedly connected with the motor shaft of the drilling motor through a second coupling, the power output shaft of the dynamic torque sensor is coaxially and fixedly connected with one end of the drill rod through a third coupling, and the other end of the drill rod is opposite to the simulated coal rock sample; the laser displacement sensor is fixedly installed on the upper surface of the screw nut sliding table, and the laser emission end of the laser displacement sensor is opposite to the motor mounting seat; the drilling controller is fixedly installed on the upper surface of the supporting table, and the control end of the feeding motor, the control end of the drilling motor, the data output end of the dynamic torque sensor and the data output end of the laser displacement sensor are electrically connected with the drilling controller.

2. A method for identifying mechanical parameters while drilling, using the loaded coal rock drilling experiment platform of claim 1, characterized in that The application further relates to a drilling method for simulating coal rock, which comprises the following steps: Step one: preparing a simulated coal rock sample by using cement mortar; Step two: the prepared simulated coal rock sample is put into the pressure chamber and placed on the upper surface of the supporting pad, then the second hydraulic cylinder and the third hydraulic cylinder are started synchronously until the simulated coal rock sample is centered and clamped between the second pad and the third pad in the horizontal direction, and then the first hydraulic cylinder is started to center and clamp the simulated coal rock sample between the first pad and the supporting pad in the vertical direction; Step three: load is applied to the simulated coal rock sample through the first hydraulic cylinder, the second hydraulic cylinder and the third hydraulic cylinder until the confining pressure borne by the simulated coal rock sample reaches the set value; Step four: the feed motor is started to drive the screw to rotate, and the rotary motion of the screw is converted into the linear motion of the nut slide synchronously, and the drilling motor, the drill rod, the dynamic torque sensor and the laser displacement sensor move synchronously with the nut slide until the drill rod is in contact with the surface of the simulated coal rock sample, and the feed motor is turned off; Step five: the drilling motor is started to drive the drill rod to rotate and reach the set rotational speed, and then the feed motor is restarted to drive the drill rod to move at the set feed speed so that the drill rod drills into the simulated coal rock sample; Step six: in the process of drilling the drill rod into the simulated coal rock sample, the dynamic torque sensor and the laser displacement sensor measure data in real time and transmit the data to the while-drilling controller for storage synchronously until the drill rod penetrates the simulated coal rock sample, and the drilling motor is turned off; Step seven: the feed motor is started in reverse until the drill rod is completely withdrawn from the borehole in the simulated coal rock sample, and the nut slide is synchronously withdrawn to the initial position, the feed motor is turned off, and then the first hydraulic cylinder, the second hydraulic cylinder and the third hydraulic cylinder are unloaded, and the first pad, the second pad and the third pad are returned to the initial position, and then the simulated coal rock sample is removed from the pressure chamber; Step eight: the while-drilling parameter data stored in the while-drilling controller is imported into a computer, and the computer has an improved particle swarm optimization algorithm, and the formula is: χ k+1 = χ k + V k+1 where ω is a nonlinear dynamic inertia weight coefficient, k is the iteration number of the particle swarm, V is the particle swarm velocity, χ is the particle swarm position, p best is the individual extremum, g best is the group extremum, c1, c2 are learning factors, r1, r2 are [0, 1] random numbers, ω max is the inertia weight maximum value, ω min is the inertia weight minimum value, f is the fitness of the current particle position, f avg is the average fitness of the current particle position, f min is the minimum fitness of the current particle position; The while-drilling parameter data is taken as a particle, the particle swarm parameters are initialized first, then the position and velocity of each particle are randomly initialized, and then it is judged whether the termination condition is met, if the termination condition is met, the optimal solution is directly output; if the termination condition is not met, the position and velocity of each particle are updated, the fitness value of each particle is calculated, then the individual historical optimal fitness and position of each particle are updated, and then the particle swarm parameters are updated, and then it is judged again whether the termination condition is met; the above judgment process is repeated until the termination condition is met, and the optimal solution is output; In order to eliminate the adverse effects of the differences in the collected data samples on the results, 70% of the samples are extracted from the collected data samples as training samples and sample comparison charts are obtained, and the remaining 30% of the samples are used as test samples and sample comparison charts are obtained.

Images