Concrete expansion rate tester based on non-contact operation and use method

Abstract

The invention discloses a concrete expansion rate tester based on non-contact operation and a use method, and belongs to the technical field of civil engineering material testing, the concrete expansion rate tester comprises a device base, and a dial indicator measuring device, a mechanical arm and a data acquisition box are fixedly arranged on the top surface of the device base; the dial indicator measuring device comprises a test piece measuring box, an electronic dial indicator is installed on each side wall of the box body, a V-shaped groove is formed in the box body, and a test piece is placed on two bevel edges of the V-shaped groove. The test piece is placed on the V-shaped groove, and only two side lines of the test piece and the V-shaped groove are in contact, so that the test piece can freely expand on any surface; the five electronic dial indicators are arranged in the X direction, the Y direction and the Z direction, monitoring data of the electronic dial indicators are finally transmitted to the data processing terminal to be processed, long-time monitoring on multiple faces of the test piece can be achieved, the expansion change amount of the test piece can be accurately displayed in real time, and the test accuracy is improved. The data is accurate, and the expansion variation of the test piece and the deformation condition along with time can be shown.

Description

Technical Field

[0001] The present invention belongs to the technical field of testing of civil engineering materials, and particularly relates to a concrete expansion rate measuring instrument based on non-contact operation and a using method thereof. Background Art

[0002] The statements in this part only provide background technical information related to the present invention, and do not necessarily constitute prior art.

[0003] As a material widely used in modern engineering structures, the volume stability of concrete directly affects the safety and durability of engineering structures. During the service period of concrete, due to temperature changes, humidity changes, and chemical reactions (such as alkali-aggregate reaction, sulfate erosion, etc.), volume expansion or contraction will occur. If this tiny deformation cannot be monitored and evaluated in time, it may lead to cracks or even structural failure, thus having a significant impact on the safety and service life of the project.

[0004] In the prior art, a concrete expansion rate measuring instrument is usually used to measure the restricted expansion rate of concrete specimens. For example, a concrete shrinkage and expansion tester disclosed in Patent CN216956045U has a V-shaped groove provided on a base, with a first and a second bracket provided at both ends of the V-shaped groove. A dial indicator is inserted into the first bracket, and a limit groove is provided on the second bracket; the concrete test block is placed in the V-shaped groove, one end contacts the head of the dial indicator, and the other end abuts against the limit groove. The concrete test block is pressed tightly by hand, and the dial indicator shows the measured value.

[0005] The deficiencies of this method are as follows:

[0006] It is necessary to manually press the concrete test block to read the measured value. Each concrete test block is repeatedly measured multiple times, and its stable value is taken. The value is not accurate enough and is interfered by human errors, resulting in greater data differences; multiple surfaces of the concrete test block cannot be measured simultaneously, and the method of pressing the concrete test block to make the dial indicator show the measured value cannot accurately show the real-time expansion change amount of the concrete specimen, and it is even more impossible to realize long-term monitoring of the specimen. Summary of the Invention

[0007] In view of the above problems, the present invention provides a concrete expansion rate measuring instrument based on non-contact operation and a using method. By setting a specimen measuring box and a fixing rod, a V-shaped groove is arranged at the bottom of the specimen measuring box. The specimen is placed on the V-shaped groove in the specimen measuring box, and the specimen only contacts the V-shaped groove at two side lines. The specimen can freely expand on any surface in the specimen measuring box. By arranging five electronic dial indicators in the X, Y, and Z directions and finally transmitting the monitoring data of the electronic dial indicators to a data processing terminal for processing, long-term monitoring of multiple surfaces of the specimen can be realized, the expansion change amount of the specimen can be accurately shown in real time, the data is accurate, and the expansion change amount of the specimen and the deformation condition over time can be shown, avoiding the situation that the traditional method requires multiple measurements to obtain a stable value and the large data difference caused by human error.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] In the first aspect, a concrete expansion rate measuring instrument based on non-contact operation is provided, including a device base. A dial indicator measuring device, a robotic arm, and a data acquisition box are fixedly arranged on the top surface of the device base;

[0010] The dial indicator measuring device includes a specimen measuring box and a fixing rod fixedly arranged on the device base. The fixing rod is located on one side of the specimen measuring box. A V-shaped groove is fixedly connected to the inner bottom of the box body. Through holes are arranged on the midlines of each side wall of the box body, and electronic dial indicators are installed in the through holes; the bottom of the V-shaped groove is located at the center of the specimen measuring box. The specimen is placed on two inclined sides of the V-shaped groove, and the vertical projection of the midline of the bottom surface of the specimen coincides with the bottom of the V-shaped groove;

[0011] A PLC controller is arranged inside the device base. Electric telescopic rods are fixedly arranged at the four corners of the bottom, and an inclination sensor is also arranged on the top surface. The inclination sensor and the electric telescopic rods are both connected to the PLC controller.

[0012] Preferably, the top end of the fixing rod is movably connected to a connecting rod, and the other end of the connecting rod is fixedly connected to a Z electronic dial indicator. The measuring head of the Z electronic dial indicator is vertically downward and faces the inside of the specimen measuring box; all the electronic dial indicators including the Z electronic dial indicator are connected to the data acquisition box through cables.

[0013] Preferably, the robotic arm includes a robotic arm base. A horizontal rotation assembly is connected to the robotic arm base. The horizontal rotation assembly includes a first driving motor fixed on the robotic arm base. The output end of the first driving motor is fixedly connected to a connecting groove; a second driving motor is fixedly arranged on one side of the connecting groove. The output end of the second driving motor is rotationally connected to both sides of the connecting groove. Inside the connecting groove, the output end of the second driving motor is fixedly connected to one end of a first arm rod. The first driving motor and the second driving motor are connected to the PLC controller.

[0014] Preferably, the other end of the first arm is connected to the second arm through a rotary joint, the second arm is connected to the third arm through a rotary joint, the third arm is connected to the fourth arm through a rotary joint, the other end of the fourth arm is fixedly provided with a fourth driving motor, the output end of the fourth driving motor is connected to the grasping mechanism, and the fourth driving motor is connected to the PLC controller.

[0015] Preferably, the rotary joint includes a transfer groove connecting the end of the arm, a third driving motor is fixedly arranged in the transfer groove, a horizontal first bevel gear is fixedly arranged at the output end of the third driving motor, the transfer groove is also rotatably connected with a rotating head, a vertical second bevel gear is fixedly arranged on one side of the rotating head, and the rotating head rotates relative to the connecting groove driven by the third driving motor through the meshing of the first bevel gear and the second bevel gear. The third driving motor is connected to the PLC controller.

[0016] Preferably, the grasping mechanism is an electric gripper, which includes a gripper motor. The gripper motor drives the grippers to move relative to each other through a reducer and a transmission system. The grippers are made of flexible materials, and pressure sensors are arranged inside the opposite sides of the grippers; on the side where the grippers are located, an infrared ranging sensor is arranged in the middle of the gripper motor housing; the infrared ranging sensor, the pressure sensor, and the gripper motor are connected to the PLC controller.

[0017] Preferably, the manipulator is fixed in position with the specimen measurement box, and the manipulator has an initial position. A fixed path plan from the initial position of the manipulator to the specimen measurement box is set in the PLC controller.

[0018] Preferably, the data acquisition box includes a signal conditioning module, a signal converter, and a wireless transmission module. The data acquisition box is connected to the data processing terminal through the wireless transmission module.

[0019] In a second aspect, a method for using the above concrete expansion rate measuring instrument based on non-contact operation is provided, and the specific steps include:

[0020] Place the measuring instrument on the ground so that the grasping mechanism is above the specimen. After turning on the measuring instrument, first, the inclination sensor obtains the angle of the current device base. The PLC controller controls the telescopic strokes of the respective electric telescopic rods according to the monitoring data of the inclination sensor to ensure that the device base is horizontal and in a stable state;

[0021] When the inclination sensor obtains that the current device base is horizontal, the PLC controller controls the manipulator to grasp the specimen and place the specimen into the specimen measurement box, and the vertical projection of the bottom center line of the specimen coincides with the bottom of the V-shaped groove;

[0022] After placing the test piece, install each electronic dial indicator, and then adjust the probes of each electronic dial indicator to make them contact the side surface of the test piece, ensuring that the expansion / contraction of the test piece in each direction (X, Y, Z) can be monitored by the electronic dial indicator, and making the initial readings of the probes of all electronic dial indicators at zero (zero reset);

[0023] The data acquisition box records the measurement data of each electronic dial indicator in real time, converts the data into digital signals and transmits them to the computer terminal for analysis, calculates the overall expansion rate of the test piece, generates an expansion rate curve, and shows the deformation of the test piece at different time periods.

[0024] Preferably, when the robotic arm grabs the test piece, the PLC controller first controls the robotic arm to drive the test piece to return to the initial position, and then controls the robotic arm to send the test piece into the test piece measurement box according to the path planning.

[0025] Compared with the prior art, the advantages and positive effects of the present invention are:

[0026] In the present invention, by setting up a test piece measurement box and a fixing rod, a V-shaped groove is arranged at the bottom of the test piece measurement box, and the test piece is placed on the V-shaped groove in the test piece measurement box. The test piece only contacts two side lines of the V-shaped groove, and the test piece can freely expand on any surface in the test piece measurement box; by arranging five electronic dial indicators in the three directions of X, Y, and Z, and finally transmitting the monitoring data of the electronic dial indicators to the data processing terminal for processing, it is possible to monitor multiple surfaces of the test piece for a long time, accurately show the expansion change amount of the test piece in real time, the data is accurate and can show the expansion change amount of the test piece and the deformation situation over time, avoiding the situation that the traditional method requires multiple measurements to obtain a stable value and the data difference caused by human error is too large.

[0027] The present invention also sets an electric telescopic rod to adjust the horizontal of the device base, which is convenient for the robotic arm to grab and place the test piece into the test piece measurement box, as much as possible avoiding human interference in the test process and ensuring the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0029] Figure 1 is a schematic diagram of the measuring instrument according to Embodiment 1 or 2 of the present invention;

[0030] Figure 2 is a schematic diagram of the dial indicator measuring device according to Embodiment 1 or 2 of the present invention;

[0031] Figure 3 is a schematic diagram of a test piece placed on the V-shaped groove according to Embodiment 1 or 2 of the present invention;

[0032] Figure 4 is a schematic diagram of a mechanical arm according to Embodiment 1 or 2 of the present invention;

[0033] Figure 5 is a schematic diagram of the second, third and fourth rotation joints of Embodiment 1 or 2 of the present invention;

[0034] Figure 6 is a schematic diagram of the clamping jaws of Embodiment 1 or 2 of the present invention;

[0035] In the figure:

[0036] 1. Device base; 101. Connecting rod; 102. Tilt sensor; 103. Electric telescopic rod; 2. Micrometer measuring device; 3. Mechanical arm; 4. Data acquisition box; 5. Data processing terminal; 6. Y1 electronic micrometer; 7. Specimen measuring box; 8. X1 electronic micrometer; 9. V-shaped groove; 10. Fixed rod; 11. Y2 electronic micrometer; 12. X2 electronic micrometer; 13. Z electronic micrometer; 14. Cable; 15. Mechanical Arm base; 16, horizontal rotation component; 17, connecting slot; 171, second drive motor; 18, first arm; 19, second arm; 20, third arm; 21, fourth arm; 22, rotary joint; 23, adapter slot; 24, rotating head; 25, fourth drive motor; 26, grabbing mechanism; 261, clamping claw; 262, infrared ranging sensor; 27, third drive motor; 28, first bevel gear; 29, second bevel gear. DETAILED DESCRIPTION

[0037] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0038] The present invention is described in detail below in conjunction with the accompanying drawings.

[0039] Example 1

[0040] This embodiment discloses a concrete expansion rate measuring instrument based on non-contact operation, such as Figure 1 As shown, the device comprises a base 1, and a micrometer measuring device 2, a mechanical arm 3 and a data acquisition box 4 are arranged on the top surface of the base 1. Figure 1 As shown, electric telescopic rods 103 are provided at the four corners of the device base 1 , and the device base 1 is adjusted to be horizontal through the telescopic travel of multiple electric telescopic rods 103 .

[0041] Specifically, the electric telescopic rod 103 is perpendicular to the device base 1 and is fixedly installed at the bottom of the device base 1. The end of the output end of the electric telescopic rod 103 is hinged to the support plate. When the device base 1 is placed on the ground, the four electric telescopic rods 103 play a supporting role. When the ground is uneven, the support plate of a certain electric telescopic rod 103 cannot contact the ground, resulting in the shaking of the device base 1. At this time, the telescopic stroke of the electric telescopic rod 103 can be adjusted so that the support plates of the four electric telescopic rods 103 all contact the ground and keep the device base horizontal.

[0042] It should be noted that an inclination sensor 102 is also provided on the top surface of the device base 1, and a storage battery and a PLC controller are provided inside the device base 1. The inclination sensor and multiple electric telescopic rods are all connected to the PLC controller. The inclination sensor 102 is used to obtain whether the device base 1 is in a horizontal state at present and transmit this information to the PLC controller. The PLC controller controls each electric telescopic rod to adjust the telescopic stroke according to the information transmitted by the inclination sensor 102, so as to adjust the device base to a horizontal state and prevent the device base from shaking and affecting the subsequent placement of the test piece.

[0043] Specifically, as Figure 2 shown, the dial indicator measuring device 2 includes a square test piece measuring box 7 fixedly arranged above the device base 1 and a fixed rod 10 arranged on one side of the test piece measuring box 7; a V-shaped groove 9 is fixedly connected to the inner bottom of the box body of the test piece measuring box 7, and through holes are arranged on the midlines of each side wall of the box body, and an electronic dial indicator is installed in the through holes. When installed, the measuring heads of the electronic dial indicators pass through the through holes and are all located inside the test piece measuring box 7.

[0044] In this embodiment, the electronic dial indicators of the test piece measuring box 7 include an X1 electronic dial indicator 8, an X2 electronic dial indicator 12, a Y1 electronic dial indicator 6, and a Y2 electronic dial indicator 11, which are used to detect the expansion rates of two surfaces in the X direction and two surfaces in the Y direction of the test piece inside the test piece measuring box 7.

[0045] As Figure 1 、 Figure 2 shown, the bottom of the fixed rod 10 is fixed on the device base 1, and the top is movably connected to a connecting rod 101, and the other end of the connecting rod 101 is fixedly connected to a Z electronic dial indicator 13. Specifically, the movable connection between the fixed rod 10 and the connecting rod 101 can be: a "cross groove" is opened at the top of the rod body of the fixed rod 10, and a "cross convex block" is arranged at one end of the connecting rod 101, so that the "cross convex block" is clamped in the "cross groove" to connect the connecting rod 101 and the fixed rod 10 and limit the up and down movement of the connecting rod 101 relative to the fixed rod 10. It should be noted that after the connecting rod 101 is connected to the fixed rod 10, the measuring head of the Z electronic dial indicator 13 is vertically downward and faces the inside of the test piece measuring box 7. The reason for such a setting is to facilitate the disassembly or installation between the connecting rod 101 and the fixed rod 10.

[0046] As Figure 1 shown, the bottom of the V-groove 9 is located at the central position of the specimen measurement box 7. As Figure 3 shown, the specimen is placed on the two inclined sides of the V-groove 9, and the vertical projection of the midline of the bottom surface of the specimen coincides with the bottom of the V-groove. The V-groove 9 can ensure that the contact surface between the specimen and the V-groove 9 is as small as possible. In fact, the specimen is placed on the two inclined sides of the V-groove 9, and finally only two sides of the specimen are in line contact with the inclined sides of the V-groove 9, while the X-direction and Y-direction sides and the Z-direction bottom and top surfaces of the specimen are not restricted, so that the specimen can freely expand inside the specimen measurement box 7.

[0047] In this embodiment, except for the two sides in contact with the V-groove in the specimen measurement box 7, all the surfaces to be measured of the specimen can freely expand; considering that it is not easy to set up an electronic micrometer on the Z-direction bottom surface of the V-groove of the specimen, only the Z electronic micrometer 13 is set on the Z-direction top surface of the specimen. The electronic micrometer is connected to the data acquisition box 4 through the cable 14.

[0048] As Figure 1 、 Figure 4 shown, the robotic arm 3 includes a robotic arm base 15 fixedly arranged on the device base 1. A horizontal rotation assembly 16 is connected to the robotic arm base 15, and the horizontal rotation assembly 16 rotates horizontally relative to the robotic arm base 15; the horizontal rotation assembly 16 includes a first driving motor, the bottom of the first driving motor is fixed on the robotic arm base 15, and a connecting groove 17 is fixed to the output end of the first driving motor.

[0049] A second driving motor 171 is fixedly arranged on one side of the connecting groove 17. The output end of the second driving motor 171 is rotatably connected to both sides of the connecting groove 17. Inside the connecting groove 17, the output end of the second driving motor 171 is fixedly connected to one end of the first arm rod 18. When the second driving motor 171 rotates, it can drive the first arm rod 18 to rotate back and forth relative to the connecting groove 17.

[0050] The other end of the first arm rod 18 is connected to the second arm rod 19 through a rotating joint 22. The second arm rod 19 is connected to the third arm rod 20 through a rotating joint 22. The third arm rod 20 is connected to the fourth arm rod 21 through a rotating joint 22. The other end of the fourth arm rod 21 is fixedly provided with a fourth driving motor 25, and the output end of the fourth driving motor 25 is connected to the grasping mechanism 26.

[0051] Specifically, as Figure 5As shown, the rotary joint 22 includes a transfer groove 23 connecting the end of the connecting arm rod. A third driving motor 27 is fixedly arranged in the transfer groove 23. A horizontal first bevel gear 28 is fixedly arranged at the output end of the third driving motor 27. The transfer groove also rotatably connects a rotating head 24. A vertical second bevel gear 29 is fixedly arranged on one side of the rotating head 24. Through the meshing of the first bevel gear and the second bevel gear, the rotating head 24 can rotate relative to the transfer groove 23 driven by the third driving motor 27.

[0052] It can be understood that one end of the first arm rod far from the connecting groove is fixedly connected to the transfer groove of the rotary joint. One end of the second arm rod is connected to the rotating head of the rotary joint, and the other end is connected to the transfer groove of the rotary joint. How the third arm rod and the fourth arm rod are connected to the rotary joint will not be elaborated here.

[0053] It is not difficult to see that all the rotations at the joints of the robotic arm 3 are realized by driving motors. Each of the above driving motors is connected to the PLC controller. By controlling the rotation of each driving motor, the grasping mechanism 26 can be made to approach the test piece, and then the grasping mechanism 26 can be controlled to clamp the test piece. Then, by controlling the rotation of each driving motor, the test piece can be transferred to the V-shaped groove 9 of the test piece measuring box 7. It can be understood that before placing the test piece, the connecting rod 101 is first removed from the fixed rod 10, and after the test piece is placed, the connecting rod 101 is placed on the fixed rod 10 again.

[0054] Specifically, the grasping mechanism 26 is an electric gripper of the prior art, including a gripper motor, a reducer, a transmission system, and grippers 261. The gripper motor drives the grippers to move relatively or away from each other through the reducer and the transmission system, so as to clamp and place the test piece. The grippers 261 are made of flexible materials (such as silica gel, rubber), and have good elasticity and adaptability. Pressure sensors are arranged inside the opposite sides of the grippers. The pressure sensors are connected to the PLC controller, and the gripper motor is also connected to the PLC controller. Through the monitoring data of the pressure sensors, the PLC controller can know that the current grippers have clamped the test piece, so as to control the gripper motor to stop rotating, prevent the test piece from being damaged, and at the same time reset the robotic arm to the initial position.

[0055] In this embodiment, since the position of the robotic arm 3 and the test piece measuring box 7 is relatively fixed, and the robotic arm 3 has an initial position, a fixed path planning from the initial position of the robotic arm 3 to the test piece measuring box 7 can be set in the PLC controller. The purpose is that every time the robotic arm grasps the test piece, it first resets, and then sends the test piece into the test piece measuring box 7 along the fixed path.

[0056] Such as Figure 6As shown, on the side where the gripper is located, an infrared ranging sensor 262 is provided in the middle of the gripper motor housing. The infrared ranging sensor 262 is used to obtain the distance from the test piece to the gripper. Place the measuring instrument of this embodiment on the ground on one side of the test piece, and then make the infrared ranging sensor 262 of the grasping mechanism 26 be located above the test piece. During operation, the PLC controller controls the rotation of each driving motor according to the signal transmitted by the infrared ranging sensor 262 to make the grasping mechanism 26 approach the test piece. When the grasping mechanism 26 approaches the test piece, the PLC controller controls the gripper motor to start clamping the test piece. At the same time, the robotic arm 3 grabs the test piece and resets it to the initial position, and then the robotic arm will send the test piece into the test piece measuring box 7 according to the path planning.

[0057] The test piece uses a standard cubic test piece, and the general size is: 100mm * 100mm * 100mm. In this embodiment, when the two grippers 261 clamp the test piece, they move simultaneously to clamp the test piece, which can ensure that one of the midlines of the square surface of the test piece is located at the center of the gripper. In this way, when the grasping mechanism 26 sends the test piece into the test piece measuring box, the vertical projection of one of the midlines of the test piece coincides with the bottom of the V-shaped groove.

[0058] In this embodiment, the data acquisition box 4 includes a signal conditioning module, which can amplify and filter the signals transmitted by the electronic dial indicators to eliminate environmental interference, such as using a voltage amplifier or a current amplifier, and a filter; it also includes a signal converter, which can convert the output signal data of each electronic dial indicator into digital signals; it also includes a wireless transmission module, which transmits the digital signals to the data processing terminal 5 through the wireless transmission module, such as a LoRa module.

[0059] The storage battery can supply power to the robotic arm, data acquisition box, electric telescopic rod, each electronic dial indicator, each sensor, and PLC controller.

[0060] As Figure 1 As shown, the data acquisition box 4 is connected to the data processing terminal 5 through a wireless transmission module, and the data processing terminal 5 analyzes the data. In this embodiment, the data processing terminal 5 uses a computer. According to the real-time transmitted data, it calculates the overall expansion rate of the test piece and generates an expansion rate curve, which can not only accurately show the expansion change amount of the test piece in real time, but also show the deformation situation of the test piece over time, and can obtain the deformation situation of the test piece in different time periods according to the displacement data of the electronic dial indicators monitored at different time points.

[0061] Calculate the overall expansion rate of the test piece according to the real-time transmitted data. The specific calculation process is as follows:

[0062] Determine the measurement directions of each dial indicator (for example, X1 dial indicator 8 and X2 dial indicator 12 are used to measure the X direction, Y1 dial indicator 6 and Y2 dial indicator 11 are used to measure the Y direction, and Z dial indicator 13 is used to measure the Z direction).

[0063] Take the average of multiple readings in the same direction and calculate the strain in each direction:

[0064] In the formula:

[0065] ε x is the strain in the X direction; ε y is the strain in the Y direction; ε z is the strain in the Z direction; ΔX is the average value of the readings of the dial indicators in the X direction; ΔY is the average value of the readings of the dial indicators in the Y direction; ΔZ is the average value of the readings of the dial indicators in the Z direction; L is the side length of the specimen corresponding to the dial indicators in the X, Y, and Z directions (since the specimen is a cube, the side lengths are equal);

[0066] At this time, the volume expansion rate ε v of the concrete specimen is: ε v = ε x + ε y + ε z ;

[0067] Since two dial indicators are set in both the X direction and the Y direction, while there is only one dial indicator in the Z direction, the sum of the readings of the two dial indicators in the X direction or the Y direction is divided by twice the side length of the cube specimen, and the reading of the one dial indicator in the Z direction is only divided by the side length of the cube specimen normally. Therefore,

[0068] In the formula:

[0069] δ8 is the sum of multiple readings of X1 dial indicator 8;

[0070] δ 12 is the sum of multiple readings of X2 dial indicator 12;

[0071] δ6 is the sum of multiple readings of Y1 dial indicator 6;

[0072] δ 11 is the sum of multiple readings of Y2 dial indicator 11;

[0073] δ 13 is the sum of multiple readings of Z dial indicator 13;

[0074] Therefore

[0075] The relationship between the above data is as follows: they jointly describe the expansion of the concrete specimen in three-dimensional space. The axial strains of each axis are calculated through direction assignment and averaging, and finally added together to obtain the volumetric expansion rate.

[0076] In this embodiment, the measuring range of each electronic dial gauge is 0 - 10 mm, and the accuracy is 0.001 mm, which can accurately record the subtle changes in the expansion or contraction of the concrete.

[0077] Embodiment 2

[0078] This embodiment discloses a method for using a concrete expansion rate measuring instrument based on non-contact operation. It uses a concrete expansion rate measuring instrument based on non-contact operation disclosed in Embodiment 1. The specific steps include:

[0079] Place the measuring instrument on the ground, with the grasping mechanism 26 above the specimen. After turning on the measuring instrument, first, the inclination sensor obtains the angle of the current device base 1. The PLC controller controls the telescopic strokes of each electric telescopic rod according to the monitoring data of the inclination sensor to ensure that the device base is horizontal and in a stable state.

[0080] When the inclination sensor obtains that the current device base is horizontal, the PLC controller controls the robotic arm to grasp the specimen and place it into the specimen measurement box, with the vertical projection of a midline on the bottom surface of the specimen coinciding with the bottom of the V-shaped groove.

[0081] After placing the specimen, install each electronic dial gauge, and then adjust the probe heads of each electronic dial gauge to contact the side surface of the specimen, ensuring that the specimen can be monitored by the electronic dial gauge when expanding / contracting in each direction (X, Y, Z), and making the initial readings of the probe heads of all electronic dial gauges at zero (zeroed).

[0082] Then, each electronic dial gauge will monitor the minute changes in the surface length of the specimen during the expansion or contraction process. The data is recorded with a micron-level accuracy and transmitted to the data acquisition box 4 through the cable 14.

[0083] The data acquisition box records the measurement data of each electronic dial gauge in real time, converts the data into digital signals and transmits them to the computer terminal for analysis, calculates the overall expansion rate of the specimen, generates an expansion rate curve, and shows the deformation of the specimen at different time periods.

[0084] Although the specific implementation manners of the present invention are described above in conjunction with the drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that based on the technical solutions of the present invention, various modifications or deformations that can be made without creative efforts by those skilled in the art are still within the protection scope of the present invention.

Claims

1. A concrete expansion rate measuring instrument based on non-contact operation, characterized in that: It includes a device base, and a micrometer measuring device, a mechanical arm and a data acquisition box are fixedly arranged on the top surface of the device base; The micrometer measuring device comprises a specimen measuring box and a fixing rod fixedly arranged on the base of the device, the fixing rod is located on one side of the specimen measuring box, the bottom of the box body is fixedly connected to the V-shaped groove, and a through hole is arranged on the center line of each side wall of the box body, and the electronic micrometer is installed in the through hole; the bottom of the V-shaped groove is located at the center of the specimen measuring box, the specimen is placed on the two oblique sides of the V-shaped groove, and the vertical projection of the center line of the bottom surface of the specimen coincides with the bottom of the V-shaped groove; A PLC controller is arranged inside the base of the device, electric telescopic rods are arranged at the four corners of the bottom, and an inclination sensor is also arranged on the top surface. The inclination sensor and the electric telescopic rod are connected to the PLC controller.

2. A concrete expansion rate measuring instrument based on non-contact operation as claimed in claim 1, characterized in that: The top end of the fixed rod is movably connected to the connecting rod, and the other end of the connecting rod is fixedly connected to the Z electronic micrometer. The probe of the Z electronic micrometer is vertically downward and toward the inside of the specimen measurement box; all electronic micrometers including the Z electronic micrometer are connected to the data acquisition box through cables.

3. A concrete expansion rate measuring instrument based on non-contact operation as claimed in claim 1, characterized in that: The robotic arm includes a robotic arm base, to which a horizontal rotation component is connected, and the horizontal rotation component includes a first drive motor fixed on the robotic arm base, and an output end of the first drive motor is fixed to a connecting groove; a second drive motor is fixedly arranged on one side of the connecting groove, and an output end of the second drive motor is rotatably connected to two sides of the connecting groove, and in the connecting groove, the output end of the second drive motor is fixedly connected to one end of the first arm rod, and the first drive motor and the second drive motor are connected to a PLC controller.

4. A concrete expansion rate measuring instrument based on non-contact operation as claimed in claim 3, characterized in that: The other end of the first arm is connected to the second arm through a rotating joint, the second arm is connected to the third arm through a rotating joint, the third arm is connected to the fourth arm through a rotating joint, and the other end of the fourth arm is fixedly provided with a fourth drive motor, the output end of the fourth drive motor is connected to the grasping mechanism, and the fourth drive motor is connected to the PLC controller.

5. A concrete expansion rate measuring instrument based on non-contact operation as claimed in claim 4, characterized in that: The rotary joint includes an adapter groove connected to the end of the arm rod, a third drive motor is fixedly arranged in the adapter groove, a horizontal first bevel gear is fixedly arranged at the output end of the third drive motor, the adapter groove is also rotatably connected to a rotating head, a vertical second bevel gear is fixedly arranged on one side of the rotating head, and the first bevel gear is meshed with the second bevel gear. The rotating head rotates relative to the connecting groove under the drive of the third drive motor, and the third drive motor is connected to the PLC controller.

6. A concrete expansion rate measuring instrument based on non-contact operation as claimed in claim 4, characterized in that: The gripping mechanism is an electric gripper, including a gripper motor. The gripper motor drives the gripper to move relative to one another through a reducer and a transmission system. The gripper is made of a flexible material, and a pressure sensor is disposed inside the opposite side of the gripper. An infrared ranging sensor is disposed in the middle of the gripper motor housing on the side where the gripper is located. The infrared ranging sensor, the pressure sensor, and the gripper motor are connected to a PLC controller.

7. A concrete expansion rate measuring instrument based on non-contact operation as claimed in claim 1, characterized in that: The positions of the mechanical arm and the specimen measurement box are fixed, and the mechanical arm has an initial position. A fixed path planning from the initial position of the mechanical arm to the specimen measurement box is set in the PLC controller.

8. A concrete expansion rate measuring instrument based on non-contact operation as claimed in claim 1, characterized in that: The data acquisition box comprises a signal conditioning module, a signal converter and a wireless transmission module, and the data acquisition box is connected to a data processing terminal via the wireless transmission module.

9. A method for using a concrete expansion rate measuring instrument based on non-contact operation as claimed in any one of claims 1 to 8, characterized in that: The specific steps include: Place the measuring instrument on the ground so that the gripping mechanism is above the test piece. After turning on the measuring instrument, the inclination sensor first obtains the current angle of the device base. The PLC controller controls each electric telescopic rod to adjust the telescopic stroke according to the monitoring data of the inclination sensor to ensure that the device base is level and in a stable state. When the inclination sensor obtains that the base of the current device is horizontal, the PLC controller controls the mechanical arm to grab the test piece and place the test piece in the test piece measurement box. The vertical projection of the bottom midline of the test piece coincides with the bottom of the V-groove. After placing the test piece, install each electronic micrometer, and then adjust the probe of each electronic micrometer to make it contact the side wall surface of the test piece, to ensure that the expansion / contraction of the test piece in each direction of X, Y, and Z can be monitored by the electronic micrometer, and the initial reading of the probe of all electronic micrometers is at zero; The data acquisition box records the measurement data of each electronic micrometer in real time, converts the data into digital signals and transmits them to the computer terminal for analysis, calculates the overall expansion rate of the specimen, generates an expansion rate curve, and displays the deformation of the specimen in different time periods.

10. The method for using the concrete expansion rate measuring instrument based on non-contact operation as claimed in claim 9, characterized in that: When the mechanical arm grabs the test piece, the PLC controller first controls the mechanical arm to drive the test piece to reset to the initial position, and then controls the mechanical arm to send the test piece into the test piece measurement box according to the path planning.

Images