Cylindrical rock test piece size measurement and precision detection device

Abstract

The invention discloses a cylindrical rock test piece size measurement and precision detection device and a use method, belongs to the technical field of indoor tests of geotechnical engineering, and aims to solve the problems of low efficiency, large error and the like in the existing rock test piece detection technology. The device comprises a base, a test piece rotating device and a laser displacement sensor moving device. The test piece rotating device clamps and limits the test piece through gear linkage and is matched with the indexing rotating mechanism to realize accurate positioning and rotation of the test piece; the laser displacement sensor moving device carries out full-surface scanning on the test piece along a preset track, and automatic cooperation of the detection process is achieved through sequential control. According to the device, indexes such as flatness, perpendicularity and parallelism of the test piece can be rapidly and precisely measured, the detection efficiency and precision are improved, and a powerful guarantee is provided for accurate acquisition of rock mechanics parameters.

Description

Technical Field

[0001] The present invention relates to geotechnical engineering indoor testing technology, and in particular to a cylindrical rock specimen size measurement and accuracy detection device and a use method thereof. Technical Background

[0002] Laboratory rock mechanical testing is an important means of determining rock mechanical parameters. Compressive strength tests and uniaxial compression tests are used to measure rock compressive strength and deformation parameters, while triaxial compression tests are used to measure rock shear strength. These tests place specific demands on specimen dimensions and processing accuracy. Specimens can be prepared from drilled cores or blocks. Cracks must be avoided during transportation and preparation. Specimen dimensions must meet the following requirements: The diameter of cylindrical specimens should be 48mm-54mm; the diameter should be greater than 10 times the diameter of the largest rock particle; and the ratio of specimen height to diameter should be 2.0-2.5. Specimen accuracy requirements stipulate that the non-parallelism error of the specimen end faces must not exceed 0.05mm; the diameter error along the specimen height must not exceed 0.3mm; and the end faces must be perpendicular to the specimen axis, with a deviation of no more than 0.25°.

[0003] Before conducting relevant experiments, the size and processing accuracy of the specimen need to be tested, including indicators such as flatness, verticality and parallelism. Currently, each indicator needs to be measured separately, which is a time-consuming and low-precision process. Therefore, a fast and high-precision measurement method is needed. Summary of the Invention

[0004] The purpose of the present invention is to address the problems of low multi-parameter separation measurement efficiency and large manual operation errors in existing rock specimen detection technology, and to propose an integrated, automated, multifunctional cylindrical rock specimen detection device and its use method.

[0005] The technical solution adopted by the present invention is: a cylindrical rock specimen size measurement and accuracy detection device and usage method, including a base, a specimen rotation device and a laser displacement sensor moving device. The specimen rotation device realizes coaxial rotation of the specimen, and the laser displacement sensor moving device covers the entire surface scanning path of the specimen through multiple tracks. The two are fixed on the base and realize automated coordination of the detection process through timing control.

[0006] According to the above scheme, the specimen rotation device mainly includes a specimen clamping and limiting mechanism and a specimen indexing and rotating mechanism. The specimen clamping and limiting mechanism part includes a specimen base, a clamping and limiting fixture, a connecting rod, a clamping and limiting device base, a central rotating shaft, a clamping and limiting center gear, a clamping and limiting intermediate gear, a clamping and limiting rotating gear, a guide groove, a guide key, and a manual knob.

[0007] According to the above scheme, the specimen clamping and limiting mechanism of the specimen rotation device uses a gear linkage to clamp and limit the specimen. A three-stage gear system is driven by a manual knob, clamping and limiting the rotating gear, intermediate gear, and then the center gear. The center gear is equipped with three centrally symmetrical and evenly distributed arc-shaped guide grooves. The guide key is mounted on the connecting rod. By driving the radial movement of the connecting rod within the guide groove, the three 120° symmetrically distributed arc-shaped clamps (radius 50cm) are synchronously moved centripetally, ensuring that the specimen axis and the center of rotation are precisely aligned. The clamping force is self-locked by the sliding fit between the guide key and the guide groove, eliminating axial deviation during rotation.

[0008] According to the above solution, the specimen rotating device mainly includes a specimen clamping and limiting mechanism and a specimen indexing and rotating mechanism. The specimen indexing and rotating mechanism includes a rotating central gear, a rotating intermediate gear, a rotating driving gear and a rotating motor.

[0009] According to the above scheme, the specimen indexing mechanism of the specimen rotation device utilizes a three-stage transmission chain consisting of a rotating drive gear, an intermediate gear, and a central gear. The rotating member is driven by a rotary motor to achieve indexing rotation of the specimen (in steps of 360° / n), while the specimen clamping and limiting mechanism simultaneously rotates coaxially. Combined with angular displacement feedback from the indexing plate, precise positioning of the specimen's axial inspection point is achieved, with an angular deviation of ≤0.1°.

[0010] According to the above scheme, the laser displacement sensor moving device includes a laser displacement sensor placement slot, a track, a moving motor and a sliding seat. The sliding seat includes a moving device connecting plate, a lower limit roller, an upper limit roller, a moving transmission shaft, a moving drive gear and a rack, and the track has a built-in rack.

[0011] According to the above scheme, the laser displacement sensor moving device, the laser displacement sensor slot connection plate and the moving device connection plate are fixed with screws. The base is equipped with upper and lower limit roller sets (two each). The limit rollers can move horizontally in small amplitudes. The elastic preload structure achieves dynamic balance of the moving drive shaft, eliminating measurement jitter caused by track gaps and ensuring sensor displacement accuracy ≤ 0.01mm. The moving motor drives the moving drive gear through the moving drive shaft. The gear meshes with the rack, driving the base and the placement slot along the rack linear guide.

[0012] According to the above scheme, the track of the laser displacement sensor's moving device comprises three continuous sections: vertical, curved, and horizontal, with a built-in high-precision rack guide. A motor drives a gear transmission, driving the laser displacement sensor along a preset trajectory. The vertical section scans upward from the bottom of the specimen at a step distance d. The curved section provides a smooth transition to prevent interference between the sensor and the specimen. The horizontal section scans along the specimen's diameter at a step distance d.

[0013] According to the above scheme, the multifunctional cylindrical rock specimen detection device, the laser displacement sensor is placed in the laser displacement sensor placement slot, the power supply and data transmission line are connected and debugged, and after the specimen can rotate smoothly on the rotating device, the laser displacement sensor is turned on to start recording data, and then the mobile motor switch is turned on to perform relevant tests.

[0014] According to the above scheme, the multifunctional cylindrical rock specimen detection device and its use method have the following measurement steps:

[0015] Step 1: Place the laser displacement sensor in the laser displacement sensor slot, connect the power supply and data transmission lines, and debug;

[0016] Step 2: Place the specimen on the base and fix it with the specimen clamping and limiting mechanism to ensure that the specimen axis is precisely aligned with the rotation axis of the rotary indexing table;

[0017] Step 3: Turn on the rotary motor switch to start the specimen indexing rotation mechanism. Each rotation angle is 360° / n, that is, each full rotation is n times, and the rotation time is set to t seconds / step;

[0018] Step 4: After the specimen can rotate smoothly on the rotating device, turn on the laser displacement sensor to start recording data, then turn on the mobile motor switch and perform relevant tests. The initial position of the laser displacement sensor is at the bottom of the vertical track. The horizontal distance between it and the center of the base (i.e., the center of the bottom surface of the specimen) is D, and the vertical distance is d0. The sensor moves in a step-by-step manner on the vertical track, with each movement distance d and the time interval between two adjacent movements being t × n seconds.

[0019] Step 5: The laser displacement sensor works at a frequency of recording data once every t seconds, with a sampling frequency of (1 / t) times / second. The recorded data is marked as recorded data s in turn. k,i (k is the number of steps, i=1,2,...,n)

[0020] Step 6: When the laser displacement sensor moves to a position higher than the test piece, the data recorded at this time is considered invalid. Subsequently, the sensor moves along the arc track and smoothly enters the horizontal track;

[0021] Step 7: When the laser displacement sensor is on the horizontal track, the vertical distance between it and the center of the base (i.e., the center of the bottom surface of the specimen) is L. On the horizontal track, the sensor also adopts a step-by-step movement method, with each movement distance d and the time interval between two adjacent movements being t × n seconds;

[0022] Step 8: When the laser displacement sensor moves to the top of one side of the bottom surface of the specimen, it starts recording valid data until it moves to the edge of the other end of the specimen and stops recording when it moves out of the specimen range. The data recorded in sequence are marked as w m,i (m is the number of steps, i=1,2,...,n)

[0023] According to the above scheme, the parameter calculation formula of the multifunctional cylindrical rock specimen detection device and its use method is as follows:

[0024] (1) Height

[0025] The height can be calculated from the data w during the horizontal measurement phase. Assume that the height of the specimen is Δ H ,but:

[0026]

[0027] (2) Flatness

[0028] Flatness refers to the flatness of the bottom surface, which can be calculated by the data w in the horizontal measurement stage. Assume that the height of the specimen is Δ F ,but:

[0029] Δ F =w max -w min

[0030] (3) Perpendicularity

[0031] Verticality refers to the verticality of the bottom surface, that is, the angle between the bottom surface and the axis of the specimen, which can be calculated using the data w from the horizontal measurement stage. Assume that the verticality of the specimen is Δ Perp , then establish a coordinate system with the center point of the base O(0,0,0) as the origin, the Z axis passing through the origin vertically upward as the Z axis, the XY plane parallel to the base, the X axis passing through the origin along the horizontal track direction, and the Y axis determined by the right-hand rule.

[0032] ①Vertical scanning data definition

[0033] The height of the sensor's kth vertical step is z k =d0+k·d, the angle of the indexing table's i-th rotation is θ i =2πi / n, measured value s k,i The corresponding specimen surface point coordinates are (x k，i ,y k，i ,z k，i ),Right now

[0034]

[0035] ②Cylindrical axis fitting

[0036] Through all vertical scanning points (x k,i ,y k,i ,z k,i ) Fitting a cylindrical model:

[0037] (x–x c ) 2 +(y–y c ) 2 =R 2 (2)

[0038] where (x–x c ) is the projection of the cylinder axis on the XY plane, and the axis direction vector is v axis =(0,0,1) (ideal right cylinder). If the specimen is tilted, the axis direction vector must be calculated through three-dimensional fitting.

[0039] ③ Upper end surface plane fitting

[0040] Assume that the radial deviation of the upper end surface satisfies the plane equation:

[0041] w m,i =Acosθ i +Bsinθ i +C+∈ m,i (3)

[0042] w m,i The measured value of the mth step and the i-th angle in the horizontal scan corresponds to the angle (m=1,2,…,M;i=1,2,…,n),∈ m,i Measurement error, A, B, and C plane fitting parameters, reflect the radial tilt and translation of the upper end surface.

[0043] The least squares objective function is used for fitting to minimize the residual sum of squares:

[0044]

[0045] Construct a system of linear equations, find the partial derivatives of A, B, and C and set the derivatives to zero, and the normal equation is:

[0046]

[0047] Simplify and solve, the indexing table rotates uniformly (θ i Equally spaced distribution), then Then solve the equation:

[0048]

[0049] ④Verticality formula

[0050] Cylinder axis direction v axis The angle with the upper end surface normal vector n is the perpendicularity:

[0051]

[0052] (4) Parallelism

[0053] The lower base is a horizontal plane z = 0; then according to the above verticality, the upper base of the formula is deduced and the formula is:

[0054] Δ Pera =arctan(A 2 +B 2 ) BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a structural diagram of a specific embodiment of the present invention.

[0056] Figure 2 Schematic diagram of the structure of the specimen rotating device in this embodiment.

[0057] Figure 3 Schematic diagram of the structure of the specimen clamping and fixing mechanism in the specimen base in this embodiment.

[0058] Figure 4 Schematic diagram of the structure of the specimen turntable in the specimen base in this embodiment.

[0059] Figure 5 Schematic diagram of the structure of the moving device of the laser displacement sensor in this embodiment.

[0060] Figure 6 2 is a side view of the moving device and rack structure of the laser displacement sensor in this embodiment.

[0061] In the figure: 1-base; 2-specimen rotating device base; 3-specimen rotating device indexing plate; 4-specimen base; 5-specimen rotating motor; 6-clamping limit fixture; 7-clamping limit device base; 8-clamping limit center gear; 9-center rotating shaft; 101-guide groove; 102-guide key; 103-connecting rod; 111-rotating center gear; 112-rotating intermediate gear; 113-rotating drive gear; 121-clamping limit intermediate gear; 122-clamping limit rotating gear; 12-clamping limit device manual knob; 13-laser displacement sensor placement slot; 14-track; 15-laser displacement sensor moving motor; 16-slot connecting plate; 17-moving device connecting plate; 18-lower limit roller; 19-upper limit roller; 20-moving transmission shaft; 21-moving drive gear; 22-rack. DETAILED DESCRIPTION

[0062] In order to better understand the present invention, the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0063] like Figures 1 to 6 The device for measuring and detecting the size and accuracy of a cylindrical rock specimen shown in the figure mainly comprises a base (1), a specimen rotating device base (2), a specimen rotating device indexing plate (3), a specimen base (4), a specimen rotating motor (5), a clamping and limiting fixture (6), a clamping and limiting device base (7), a clamping and limiting center gear (8), a center rotating shaft (9), a guide groove (101), a guide key (102), a connecting rod (103), a rotating center gear (111), a rotating intermediate gear (112), and a rotating intermediate gear (113). 12), a rotating drive gear (113), a clamping limit intermediate gear (121), a clamping limit rotating gear (122), a clamping limit device manual knob (12), a laser displacement sensor placement slot (13), a track (14), a laser displacement sensor moving motor (15), a slot connecting plate (16), a moving device connecting plate (17), a lower limit roller (18), an upper limit roller (19), a moving transmission shaft (20), a moving drive gear (21), and a rack (22).

[0064] In the present invention, a cylindrical rock specimen size measurement and accuracy detection device comprises a base (1), a specimen rotating device and a laser displacement sensor moving device. The specimen rotating device realizes the coaxial rotation of the specimen, and the laser displacement sensor moving device covers the entire surface scanning path of the specimen through multiple tracks. The two are fixed on the base and realize the automated coordination of the detection process through timing control.

[0065] In the present invention, the specimen rotation device mainly comprises a specimen clamping and limiting mechanism, a specimen indexing and rotating mechanism and a base. The specimen clamping and limiting mechanism comprises a specimen base (4), a clamping and limiting fixture (6), a clamping and limiting device base (7), a clamping and limiting center gear (8), a center rotating shaft (9), a guide groove (101), a guide key (102), a connecting rod (103), a clamping and limiting intermediate gear (121), a clamping and limiting rotating gear (122), and a clamping and limiting device manual knob (12).

[0066] In the present invention, the specimen clamping and limiting mechanism of the specimen rotating device is arranged such that the axes of the clamping and limiting central gear (8), the clamping and limiting intermediate gear (121), the clamping and limiting rotating gear (122) and the manual knob (12) of the clamping and limiting device are arranged in parallel, the central rotating shaft (9) and the central gear (8) are located at the geometric center of the specimen clamping and limiting mechanism, the intermediate gear (121) is directly meshed with the central gear (8), and the rotating gear (122) is simultaneously linked with the intermediate gear (121) and the manual knob (12).

[0067] In the present invention, the specimen clamping and limiting mechanism of the specimen rotating device has a central gear (8) with a module m=2, a number of teeth Z1=25, a tooth top circle diameter of 54mm, a tooth width of 15mm, and a surface hardness of HRC58-62 to ensure load-bearing capacity. The intermediate gear (121) and the rotating gear (122) have a module m=2, a number of teeth Z2=5, a pitch circle diameter D2=10mm, a tooth top circle diameter of 14mm, are made of aluminum alloy, have a knurled surface, and have a built-in anti-loosening spring washer to prevent the thread from retreating during operation. The above dimensions are for reference only and can be adjusted as needed.

[0068] In the present invention, the specimen clamping and limiting mechanism of the specimen rotating device drives a three-stage gear reduction system through a manual knob, and the clamping and limiting rotation gear (122) → intermediate gear (121) → central gear (8). During reverse rotation, the reverse locking characteristic of the transmission chain is ensured by the gear side clearance (controlled within 0.05-0.08mm) to ensure that there is no backlash.

[0069] In the present invention, the specimen clamping and limiting mechanism of the specimen rotating device is provided with three centrally symmetrical and evenly distributed arc-shaped guide grooves at the center of the clamping and limiting center gear (8), with an angle between the grooves of 120° and a groove length of 2 / 3 of the gear radius. The connecting rod assembly includes three groups of connecting rods (103) arranged radially, each connecting rod having a guide key (102) fixed at the end, and the guide key (102) slidingly cooperates with the guide groove (101). The clamping and limiting fixture (6) is an arc-shaped fixture with an inner arc radius of 50 cm. A polyurethane friction plate is attached to the inner arc surface. The three groups of fixtures are respectively connected to the front end of the connecting rod (103).

[0070] In the present invention, the specimen clamping and limiting mechanism of the specimen rotating device, when the manual knob (12) is rotated, drives the rotating gear (122), the intermediate gear (121) and the central gear (8) to rotate, and the involute profile of the guide groove (101) forces the guide key (102) to move radially, driving the three groups of connecting rods (103) to synchronously contract centripetally. Through the rigid coupling of the gear-connecting rod, the three groups of clamping and limiting clamps (6) synchronously clamp the specimen at an angle of 120 degrees, ensuring that the deviation between the specimen axis and the rotation center is ≤0.02mm. That is, in the clamping stage, the central gear (8) is rotated clockwise → the guide key (102) slides along the guide groove (101) → the connecting rod (103) moves radially inward → the clamp (6) closes and clamps the specimen. In the release stage, the central gear (8) is rotated counterclockwise → the connecting rod (103) is pushed outward → the clamp (6) opens.

[0071] In the present invention, the specimen indexing rotation mechanism of the specimen rotating device comprises a specimen rotating device indexing plate (3), a specimen rotating motor (5), a rotating central gear (111), a rotating intermediate gear (112) and a rotating driving gear (113).

[0072] In the present invention, the specimen indexing rotation mechanism of the specimen rotating device is characterized in that the axes of the rotating central gear (111), the rotating intermediate gear (112) and the rotating driving gear (113) are arranged in parallel, the rotating central gear (111) is located at the geometric center of the specimen indexing rotation mechanism, the intermediate gear (112) is directly meshed with the central gear (111), and the driving gear (113) is meshed with the intermediate gear (112).

[0073] In the present invention, the specimen indexing rotation mechanism of the specimen rotating device has a rotating central gear (111) with a module m=2, a number of teeth Z1=30, a pitch circle diameter D1=60mm, and a tooth width of 12mm. After solution treatment and aging hardening, both strength and wear resistance are taken into consideration. The rotating intermediate gear (112) and the rotating driving gear (113) have a module m=2, a number of teeth Z2=5, a pitch circle diameter D2=10mm, a tooth top circle diameter of 14mm, and a tooth width of 10mm. The above dimensions are for reference only and can be adjusted as needed.

[0074] In the present invention, the specimen indexing rotation mechanism of the specimen rotating device is driven by a rotary motor to realize specimen indexing rotation (step angle 360° / n). The rotary motor (5) is started → the driving gear (113) rotates counterclockwise → the intermediate gear (112) rotates clockwise → the central gear (111) rotates counterclockwise → the main shaft drives the indexing plate (3) and the specimen clamping and limiting mechanism to rotate synchronously. In conjunction with the angular displacement feedback of the indexing plate, the precise positioning of the axial detection point of the specimen is achieved, with an angular deviation of ≤0.1°.

[0075] In the present invention, the specimen indexing rotation mechanism of the specimen rotating device and the specimen rotating motor (5) can be a stepper motor or a servo motor, such as a FESTOMTR-ST series stepper motor or an EMMS-AS series servo motor, with a built-in encoder, supporting closed-loop control, and an accuracy of up to ±0.1°.

[0076] In the present invention, the laser displacement sensor moving device comprises a laser displacement sensor placement slot (13), a track (14), a laser displacement sensor moving motor (15), a slot connecting plate (16), a moving device connecting plate (17), a lower limit roller (18), an upper limit roller (19), a moving transmission shaft (20), a moving drive gear (21), and a rack (22).

[0077] In the present invention, the laser displacement sensor moving device can be a KEYENCE LK-G5000, a UK ZLDS100, a Deep Vision Intelligent SD-C series or other brand and model sensors. The size of the laser displacement sensor placement slot (13) is adjusted according to the model of the selected laser displacement sensor. A cavity is designed behind the placement slot (13) to facilitate the connection of a power line and a data transmission line of the laser displacement sensor.

[0078] In the present invention, the laser displacement sensor moving device, the laser displacement sensor placement slot (13) card slot connecting plate (16) and the moving device connecting plate (17) are fixed with screws, and two upper limit rollers (19) and two lower limit rollers (18) are configured on the base, each roller is equipped with a butterfly spring, allowing the roller to float horizontally by ±0.5mm, compensating the track gap in real time, and achieving dynamic balance of the moving transmission shaft through the elastic pre-tightening structure, eliminating the measurement jitter caused by the track gap. The moving motor (15) drives the moving drive gear (21) to rotate through the moving transmission shaft (20), and the gear (21) is engaged with the rack (22), driving the placement slot (13) to move along the rack (22) linear guide.

[0079] In the present invention, the track (14) of the laser displacement sensor moving device comprises three continuous tracks: vertical, curved, and horizontal, with a built-in high-precision rack (22) guide rail. The laser displacement sensor is driven along a preset track by a mobile motor (15) driving a gear (21). The vertical section scans upward from the bottom of the specimen at a step distance d. The curved section has a smooth transition to avoid interference between the sensor and the specimen. The horizontal section scans along the diameter of the specimen at a step distance d.

[0080] In the present invention, the moving motor (15) of the laser displacement sensor moving device can be a combination of a brushless DC motor (such as Tengxiang 906), a Renesas RL78 / G1F control module and a 12V21700 lithium battery pack, and is matched with a laser displacement sensor to realize closed-loop control.

[0081] In the present invention, the multifunctional cylindrical rock specimen detection device is characterized in that a laser displacement sensor is placed in a laser displacement sensor placement slot (13), a power supply and a data transmission line are connected and debugged, a specimen is placed on a specimen base (4), the specimen is clamped and fixed by turning a manual knob (12), a rotary motor (5) is turned on to rotate the specimen, and after the specimen rotates smoothly, the laser displacement sensor is turned on to start recording data, and then the mobile motor (15) is turned on to perform relevant detection.

[0082] According to the above scheme, the multifunctional cylindrical rock specimen detection device and its use method have the following measurement steps:

[0083] Step 1: Place the laser displacement sensor in the laser displacement sensor slot, connect the power supply and data transmission lines, and debug;

[0084] Step 2: Place the specimen on the base and fix it with the specimen clamping and limiting mechanism to ensure that the specimen axis is precisely aligned with the rotation axis of the rotary indexing table;

[0085] Step 3: Turn on the rotary motor switch to start the specimen indexing rotation mechanism. Each rotation angle is 360° / n, that is, each full rotation is n times, and the rotation time is set to t seconds / step;

[0086] Step 4: After the specimen can rotate smoothly on the rotating device, turn on the laser displacement sensor to start recording data, then turn on the mobile motor switch and perform relevant tests. The initial position of the laser displacement sensor is at the bottom of the vertical track. The horizontal distance between it and the center of the base (i.e., the center of the bottom surface of the specimen) is D, and the vertical distance is d0. The sensor moves in a step-by-step manner on the vertical track, with each movement distance d and the time interval between two adjacent movements being t × n seconds.

[0087] Step 5: The laser displacement sensor works at a frequency of recording data once every t seconds, with a sampling frequency of (1 / t) times / second. The recorded data is marked as recorded data s in turn. k,i (k is the number of steps, i=1,2,...,n)

[0088] Step 6: When the laser displacement sensor moves to a position higher than the test piece, the data recorded at this time is considered invalid. Subsequently, the sensor moves along the arc track and smoothly enters the horizontal track;

[0089] Step 7: When the laser displacement sensor is on the horizontal track, the vertical distance between it and the center of the base (i.e., the center of the bottom surface of the specimen) is L. On the horizontal track, the sensor also adopts a step-by-step movement method, with each movement distance d and the time interval between two adjacent movements being t × n seconds;

[0090] Step 8: When the laser displacement sensor moves to the top of one side of the bottom surface of the specimen, it starts recording valid data until it moves to the edge of the other end of the specimen and stops recording when it moves out of the specimen range. The data recorded in sequence are marked as w m,i (m is the number of steps, i=1,2,...,n)

[0091] According to the above scheme, the parameter calculation formula of the multifunctional cylindrical rock specimen detection device and its use method is as follows:

[0092] (1) Height

[0093] The height can be calculated from the data w during the horizontal measurement phase. Assume that the height of the specimen is ΔH ,but:

[0094]

[0095] (2) Flatness

[0096] Flatness refers to the flatness of the bottom surface, which can be calculated by the data w in the horizontal measurement stage. Assume that the flatness of the specimen is Δ F ,but:

[0097] Δ F =w max -w min

[0098] (3) Perpendicularity

[0099] Verticality refers to the verticality of the bottom surface, that is, the angle between the bottom surface and the axis of the specimen, which can be calculated using the data w from the horizontal measurement stage. Assume that the verticality of the specimen is Δ Perp , then establish a coordinate system with the center point of the base O(0,0,0) as the origin, the Z axis passing through the origin vertically upward as the Z axis, the XY plane parallel to the base, the X axis passing through the origin along the horizontal track direction, and the Y axis determined by the right-hand rule.

[0100] ①Vertical scanning data definition

[0101] The height of the sensor's kth vertical step is z k =d0+k·d, the angle of the indexing table's i-th rotation is θ i =2πi / n, measured value s k,i The corresponding specimen surface point coordinates are (x k，i ,y k，i ,z k，i ),Right now

[0102]

[0103] ②Cylindrical axis fitting

[0104] Through all vertical scanning points (x k,i ,y k,i ,z k,i ) Fitting a cylindrical model:

[0105] (x–x c ) 2 +(y–y c ) 2 =R 2 (2)

[0106] Where (x–x c) is the projection of the cylinder axis on the XY plane, and the axis direction vector is v axis =(0,0,1) (ideal right cylinder). If the specimen is tilted, the axis direction vector must be calculated through three-dimensional fitting.

[0107] ③ Upper end surface plane fitting

[0108] Assume that the radial deviation of the upper end surface satisfies the plane equation:

[0109] w m,i =Acosθ i +Bsinθ i +C+∈ m,i (3)

[0110] Among them, w m,i The measured value of the mth step and the i-th angle in the horizontal scan corresponds to the angle (m=1,2,…,M;i=1,2,…,n),∈ m,i Measurement error, A, B, and C plane fitting parameters, reflect the radial tilt and translation of the upper end surface.

[0111] The least squares objective function is used for fitting to minimize the residual sum of squares:

[0112]

[0113] Construct a system of linear equations, find the partial derivatives of A, B, and C and set the derivatives to zero, and the normal equation is:

[0114]

[0115] Simplify and solve, the indexing table rotates uniformly (θ i Equally spaced distribution), then Then solve the equation:

[0116]

[0117] ④Verticality formula

[0118] Cylinder axis direction v axis The angle with the upper end surface normal vector n is the perpendicularity:

[0119]

[0120] (4) Parallelism

[0121] The lower base is a horizontal plane z = 0; then according to the above verticality, the upper base of the formula is deduced and the formula is:

[0122] Δ Pera =arctan(A 2 +B2 ) (8)

[0123] It should be noted that for the aforementioned method embodiments, for simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should be aware that the present invention is not limited to the order of the actions described, because according to the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0124] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0125] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A cylindrical rock specimen size measurement and accuracy detection device, characterized in that: It includes a base, a specimen rotating device and a laser displacement sensor moving device; wherein, The specimen rotating device includes: a base, a dividing plate, a specimen base, a rotating motor, a clamping and limiting fixture, a connecting rod, a clamping and limiting device base, a central rotating shaft, a clamping and limiting central gear, a clamping and limiting intermediate gear, a clamping and limiting rotating gear, a guide groove, a guide key, a connecting rod, a manual knob of the clamping and limiting device, a rotating central gear, a rotating intermediate gear, and a rotating driving gear; The laser displacement sensor moving device includes: a laser displacement sensor placement slot, a track, a moving motor, a slot connecting plate, a moving device connecting plate, a lower limit roller, an upper limit roller, a moving transmission shaft, a moving drive gear and a rack.

2. A cylindrical rock specimen size measurement and accuracy detection device according to claim 1, characterized in that: The specimen rotating device and the laser displacement sensor moving device are both fixedly mounted on the base, and their positions cannot be adjusted.

3. The cylindrical rock specimen size measurement and accuracy detection device according to claim 1, characterized in that: The specimen rotation device mainly includes: a specimen clamping and limiting mechanism and a specimen indexing and rotating mechanism; The specimen clamping and limiting mechanism includes: a specimen base, a clamping and limiting fixture, a connecting rod, a clamping and limiting device base, a central rotating shaft, a clamping and limiting central gear, a clamping and limiting intermediate gear, a clamping and limiting rotating gear, a guide groove, a guide key, and a manual knob; The central rotating shaft is located at the center of the clamping limit central gear, the clamping limit intermediate gear is meshed with the clamping limit central gear, the clamping limit rotating gear is meshed with the clamping limit intermediate gear, and the clamping limit rotating gear is also connected to the manual knob; The clamping limit center gear is provided with three centrally symmetrical and evenly distributed arc-shaped guide grooves. The guide key is installed on the connecting rod. The connecting rod is connected to the clamping limit fixture. The clamping limit fixture is arc-shaped, and the radius of the arc is a preset size.

4. The cylindrical rock specimen size measurement and accuracy detection device according to claim 1, characterized in that: The specimen rotating device includes: a specimen clamping and limiting mechanism and a specimen indexing and rotating mechanism; The specimen indexing rotation mechanism includes: a rotating central gear, a rotating intermediate gear, a rotating drive gear and a rotating motor; the rotating intermediate gear is meshed with the rotating central gear, the rotating drive gear is meshed with the rotating intermediate gear, the rotating motor is connected to the rotating drive gear, and a switch is provided on the rotating motor; When the rotary motor is started, it drives the rotary drive gear, the rotary intermediate gear and the rotary center gear to rotate together, thereby causing the specimen clamping and limiting mechanism above to rotate coaxially.

5. The cylindrical rock specimen size measurement and accuracy detection device according to claim 1, characterized in that: The specimen rotating device includes: a specimen clamping and limiting mechanism and a specimen indexing and rotating mechanism; Place the specimen on the specimen base and move the clamping limit fixture toward the center by turning the manual knob to clamp the specimen.

6. The cylindrical rock specimen size measurement and accuracy detection device according to claim 1, characterized in that: The laser displacement sensor moving device includes: a laser displacement sensor placement slot, a track, a moving motor and a sliding seat; The sliding seat includes: a moving device connecting plate, a lower limit roller, an upper limit roller, a moving transmission shaft, a moving drive gear and a rack; the track includes three sections: vertical, curved and horizontal, and has a built-in rack; The laser displacement sensor is placed in the slot connecting plate and the mobile device connecting plate by screws; The base is equipped with two lower limit rollers and two upper limit rollers, which can move horizontally in small increments. The mobile motor drives the mobile drive gear with the help of the mobile transmission shaft. The gear and rack mesh with each other, thereby driving the base and the placement slot to move along the rack linear guide.

7. The cylindrical rock specimen size measurement and accuracy detection device according to claim 6, characterized in that: The laser displacement sensor is placed in the laser displacement sensor placement slot, and the power supply and data transmission line are connected for debugging; after the test piece can rotate smoothly on the rotating device, the laser displacement sensor is turned on to record data, and then the mobile motor switch is turned on to perform related testing work.

8. A method for using the cylindrical rock specimen size measurement and accuracy detection device according to any one of claims 1 to 7, wherein the steps of the method are as follows: Step 1: Place the laser displacement sensor in the laser displacement sensor slot, connect the power supply and data transmission line, and debug; Step 2: Place the specimen on the base and fix it with the specimen clamping and limiting mechanism to ensure that the specimen axis and the rotation axis of the rotary indexing table can accurately coincide; Step 3: Turn on the rotary motor switch to start the specimen indexing rotation mechanism. Each rotation angle is 360° / n, that is, each full rotation is n times, and the rotation time is set to t seconds / step; Step 4: After the specimen rotates smoothly on the rotating device, turn on the laser displacement sensor to start recording data, then turn on the mobile motor switch to perform relevant tests. The laser displacement sensor is initially located at the bottom of the vertical track, with a horizontal distance D and a vertical distance d0 from the center of the base. The sensor moves in steps on the vertical track, each movement distance d, and the time interval between two adjacent movements is t × n seconds; Step 5: The laser displacement sensor works at a frequency of recording data once every t seconds, with a sampling frequency of (1 / t) times / second. The recorded data is marked as recorded data s in turn. k,i ; k is the number of steps, i = 1, 2, ..., n; Step 6: When the laser displacement sensor moves to a position higher than the test piece, the data recorded at this time is considered invalid. Subsequently, the sensor moves along the arc track and smoothly enters the horizontal track; Step 7: When the laser displacement sensor is on the horizontal track, the vertical distance between it and the center of the base (i.e., the center of the bottom surface of the specimen) is L. On the horizontal track, the sensor also adopts a step-by-step movement method, with each movement distance d and the time interval between two adjacent movements being t × n seconds; Step 8: When the laser displacement sensor moves to the top of one side of the bottom surface of the specimen, it starts recording valid data until it moves to the edge of the other end of the specimen. The recording stops when it moves out of the specimen range. The data recorded in sequence are marked as w m,i ; m is the number of steps, i = 1, 2, ..., n, the angle of the indexing table's i-th rotation is θ i =2πi / n, the total number of steps is M.

9. The method of use according to claim 8, wherein: The parameter calculation method is as follows: high Among them, the height of the specimen is Δ H , The average value of the data w in the horizontal measurement stage, the vertical distance between the laser displacement sensor and the center of the bottom surface of the specimen is L; Flatness Δ F =w max -w min Among them, the height of the specimen is Δ F , w max and w min are the maximum and minimum values ​​of the data w in the horizontal measurement phase; Verticality Among them, the verticality of the specimen is Δ P erp, Parallelism Δ Pera =arctan(A 2 +B 2 Among them, the verticality of the specimen is Δ P era.

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