Thickness calibration system for ground penetrating radar with center frequency below 400MHz

Abstract

The utility model discloses a thickness calibration system for a ground penetrating radar with the center frequency below 400MHz. The device comprises a ground penetrating radar calibration device, a water tank, a water body, a steel rail, a ground and a ground penetrating radar antenna, the water tank with the tank depth larger than 4 m and the adjustable water body depth is selected, and a test scene with water as a medium is provided for thickness calibration of the ground penetrating radar. A steel tape is selected as an etalon, the designed mechanical structure realizes accurate measurement of the depth of the water tank, and a standard value of water depth, namely thickness measurement, is provided for the ground penetrating radar. Four groups of winches, six groups of fixed pulleys and a ground penetrating radar antenna are selected to be connected, and the bottom surface of the ground penetrating radar antenna can be completely attached to the surface of a water body in the suspension process by adjusting the four groups of winches. The two sliding rails and the four rotating wheels are selected to fix the main body frame structure, so that the ground penetrating radar antenna can be placed on the ground, and the safety of operators in a test is ensured. Repeated disassembly is not needed in the test process, and the device has good application effect and popularization value.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the traffic water transport engineering measurement calibration technical field, especially in the traffic engineering detection field, a kind of thickness calibration system is aimed at center frequency 400MHz below ground penetrating radar. BACKGROUND

[0002] At present, as a new emerging, efficient detection device, ground penetrating radar has been widely used in pavement quality, underground structure, tunnel structure detection and other engineering detection fields, with the characteristics of non-damage, high efficiency, strong anti-interference ability, especially in structural layer thickness measurement and defect identification (collapse, void, crack, etc.) field is widely applied. In order to ensure that the thickness parameter value measured by ground penetrating radar is accurate and reliable, ground penetrating radar needs to be calibrated to ensure its effective traceability. Therefore, the calibration of ground penetrating radar by traceability mechanism is particularly important.

[0003] At present, in the measurement field, JJG (traffic) 124-2023 "highway section flaw detection and structural layer thickness ground penetrating radar" regulation has provided reliable calibration method and calibration device for thickness parameter calibration of 400MHz above ground penetrating radar;Considering that the electromagnetic wave wavelength of 400MHz below ground penetrating radar is longer, larger test environment needs to be occupied during calibration, therefore, the regulation does not provide calibration device for thickness parameter of 400MHz below ground penetrating radar. In addition, at present, there is no traceability mechanism to develop a kind of thickness calibration device for 400MHz below ground penetrating radar with economic and practical and convenient and fast. SUMMARY

[0004] In order to solve the above problems, the purpose of the utility model is to provide a kind of thickness calibration system for 400MHz below ground penetrating radar with center frequency.

[0005] In order to achieve the above purpose, the thickness calibration system for 400MHz below ground penetrating radar with center frequency provided by the utility model includes ground penetrating radar calibration device, water tank, water body, steel rail, ground and ground penetrating radar antenna;Two steel rails are respectively fixed on the two side edges of water tank;Water tank contains height-adjustable water body, which is used to provide required water depth standard value for thickness measurement of different ground penetrating radars;The ground outside water tank provides installation site for ground penetrating radar test personnel before test;Ground penetrating radar calibration device is arranged on two steel rails;Ground penetrating radar antenna is placed on ground penetrating radar calibration device.

[0006] The ground-penetrating radar calibration device includes an antenna flattening device, an antenna suspension adjustment device, a water depth measuring device, a rotating wheel, a rail clamp, a slide rail, and a main frame. The main frame includes a lower support frame and an upper fixed frame. The lower support frame is a rectangular frame composed of two longitudinal beams and two transverse beams, horizontally positioned, with a rotating wheel installed at each of the four corners. The upper fixed frame is a cuboid frame structure fixed to the middle of the two longitudinal beams. The antenna flattening device includes an antenna tray and antenna tray rope buckles. The antenna tray is located within the internal space of the upper fixed frame, with an antenna tray rope buckle installed at each of the four corners. The antenna suspension adjustment device includes a winch, a winch cable, and winch cable reversing pulleys. Two sets of winches are installed on both sides of one transverse beam of the lower support frame. The two sets of winch cable reversing pulleys are installed on the top surface of the side transverse beam near the winches on the upper part of the upper fixed frame, corresponding to the positions of the two sets of winches. The other four sets of winches... The steel cable reversing pulleys are installed on the inner sides of the two crossbeams at the upper end of the upper fixed frame, corresponding to the positions of the two sets of winches. One end of each winch cable is wound around a winch, and the other end passes successively over a corresponding winch cable reversing pulley on the top surface of the side crossbeam and a winch cable reversing pulley on the inner side of the side crossbeam before connecting to a nearby antenna tray rope buckle. The water depth measuring device includes a steel tape measure, a steel tape measure fixing lock, a steel tape measure reversing pulley, and a plumb bob. The steel tape measure fixing lock is installed on the crossbeam of the lower support frame between the two sets of winches. The steel tape measure reversing pulley is installed in the middle of the side crossbeam at the lower end of the fixed frame, near the steel tape measure fixing lock. The outer end of the steel tape measure is connected to the plumb bob through the steel tape measure fixing lock and the steel tape measure reversing pulley. Two slide rails are installed on the bottom surfaces of the two longitudinal beams of the lower support frame, and a rail clamp is installed on each slide rail in a sliding manner.

[0007] The lower support frame of the ground-penetrating radar calibration device has a total length of 3.8m, and the slide rail 107 has a total length of 3.2m.

[0008] The water tank is deeper than 4m, and the maximum depth of the water body is 4m.

[0009] The ground penetrating radar thickness calibration system provided by the utility model has the following beneficial effects: a water tank with a groove depth greater than 4m and adjustable water depth is selected to provide a water medium test scene for the ground penetrating radar thickness calibration; a steel tape is selected as a standard device, and the mechanical structure is designed to realize accurate measurement of the water tank depth, thereby providing a standard value for the water depth, i.e. thickness measurement of the ground penetrating radar; four winches, six fixed pulleys and the ground penetrating radar antenna are selected to be connected, and the bottom surface of the ground penetrating radar antenna can be completely attached to the water surface in the suspension process by adjusting the four winches; two slide rails and four rotating wheels are selected to fix the main frame structure, thereby placing the ground penetrating radar antenna on the ground and ensuring the safety of the operator during the test; the ground penetrating radar thickness calibration system does not need to be repeatedly disassembled during the test, and has good application effect and popularization value. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a structural schematic view of the ground penetrating radar thickness calibration system provided by the utility model;

[0011] Figure 2 is a structural view of the ground penetrating radar calibration device. DETAILED DESCRIPTION

[0012] The ground penetrating radar thickness calibration system provided by the utility model will be described in detail below in combination with the drawings and specific embodiments.

[0013] As shown in Figure 1 The ground penetrating radar thickness calibration system provided by the utility model comprises a ground penetrating radar calibration device 1, a water tank 2, a water body 3, a steel rail 4, a ground 5 and a ground penetrating radar antenna 6; the two steel rails 4 are respectively fixed on the two side edges of the water tank 2; the water tank 2 contains the height-adjustable water body 3, which is used to provide the required water depth standard value for thickness measurement of different ground penetrating radars; the ground 5 outside the water tank 2 provides an installation site for the ground penetrating radar test before the test; the ground penetrating radar calibration device 1 is arranged on the two steel rails 4; and the ground penetrating radar antenna 6 is placed on the ground penetrating radar calibration device 1.

[0014] As shown in Figure 2As shown, the ground penetrating radar calibration device 1 comprises an antenna laying device, an antenna suspension adjusting device, a water body depth measuring device, a rotating wheel 105, a steel rail clamp 106, a slide rail 107 and a main body frame 108; wherein the main body frame 108 comprises a lower support frame and an upper fixing frame; the lower support frame is a rectangular frame composed of two longitudinal beams and two transverse beams, arranged horizontally, and a rotating wheel 105 is installed at each corner; the upper fixing frame is a cuboid frame structure, fixed in the middle of the two longitudinal beams; the antenna laying device comprises an antenna tray 1011 and an antenna tray rope buckle 1012; the antenna tray 1011 is located in the internal space of the upper fixing frame, and an antenna tray rope buckle 1012 is installed at each corner; the antenna suspension adjusting device comprises a winch 1021, a winch steel rope 1022 and a winch steel rope changing direction fixed pulley 1023; two groups of winches 1021 are installed on both sides of one transverse beam of the lower support frame; two groups of winch steel rope changing direction fixed pulleys 1023 are installed on the top surface of the side transverse beam of the upper fixing frame near the winches 1021, corresponding to the positions of the two groups of winches 1021, and another four groups of winch steel rope changing direction fixed pulleys 1023 are installed on the inner side surfaces of the two side transverse beams of the upper fixing frame, also corresponding to the positions of the two groups of winches 1021; one end of each winch steel rope 1022 is wound around a winch 1021, and the other end is connected to a nearby antenna tray rope buckle 1012 after passing through a corresponding winch steel rope changing direction fixed pulley 1023 on the top surface of the side transverse beam and a winch steel rope changing direction fixed pulley 1023 on the inner side surface of the side transverse beam; the water body depth measuring device comprises a steel tape 1031, a steel tape fixing lock buckle 1032, a steel tape changing direction fixed pulley 1033 and a lead sinker 104; the steel tape fixing lock buckle 1032 is installed on the transverse beam of the lower support frame between the two groups of winches 1021; the steel tape changing direction fixed pulley 1033 is installed in the middle of the side transverse beam of the lower end of the fixing frame near the steel tape fixing lock buckle 1032; the outer end of the steel tape 1031 is connected to the lead sinker 104 after passing through the steel tape fixing lock buckle 1032 and the steel tape changing direction fixed pulley 1033; two slide rails 107 are installed on the bottom surfaces of the two longitudinal beams of the lower support frame, and a steel rail clamp 106 is slidably installed on each slide rail 107.

[0015] The total length of the lower support frame of the ground penetrating radar calibration device 1 is 3.8m, and the total length of the slide rail 107 is 3.2m, which can span the water tank 2.

[0016] The depth of the water tank 2 is greater than 4m, and the maximum depth of the water body 3 is 4m, which can meet the calibration scene requirements of the ground penetrating radar with a center frequency below 400MHz.

[0017] The measurement range of the steel tape 1031 is greater than 5m, the resolution is better than 0.5mm, and the accuracy is better than 1mm.

[0018] The ground penetrating radar calibration device 1 is applicable to calibration of a radar antenna with a center frequency below 400 MHz, and the precision is better than 1 mm.

[0019] The working process of the ground penetrating radar thickness calibration system with a center frequency below 400 MHz will be described as follows.

[0020] During work, first, the test personnel places the ground penetrating radar calibration device 1 on the ground 5 and fixes the ground penetrating radar antenna 6 in the antenna tray 1011. Then, the rotating wheel 105 drives the ground penetrating radar calibration device 1 to move on the ground 5 to one side of the water tank 2, after that, the steel rail clamp 106 is moved to the end of the slide rail 107 far away from the winch steel rope 1022, then the steel rail clamp 106 is lifted and clamped on the steel rail 4 close to one side of the ground penetrating radar calibration device 1, the end of the winch steel rope 1022 is lifted and the ground penetrating radar calibration device 1 is pushed to the other side of the water tank 2, in this process, the steel rail clamp 106 is moved to the end of the slide rail 107 close to the winch steel rope 1022, until the ground penetrating radar calibration device 1 is entirely across the water tank 2; four winches 1021 are rotated, the antenna tray 1011 is suspended to the water surface through the four winch steel ropes 1022, and the bottom surface of the ground penetrating radar antenna 6 and the surface of the water body 3 are completely attached through adjusting the four winches 1021; the steel tape fixing lock 1032 is loosened and the steel tape 1031 is adjusted, so that the lower end of the lead sinker 104 contacts the surface of the water body 2, then the steel tape fixing lock 1032 is tightened, the indication value of the steel tape 1031 corresponding to the steel tape fixing lock 1032 is recorded as an initial value; the steel tape fixing lock 1032 is loosened, the lead sinker 104 drives the steel tape 1031 to be elongated, until the lower end of the lead sinker 104 slowly touches the bottom of the water tank 2, then the indication value of the steel tape 1031 corresponding to the steel tape fixing lock 1032 is recorded again as a final value; the depth value of the current water body 3 can be obtained from the difference between the final value and the initial value of the steel tape 1031, as the thickness standard value corresponding to the ground penetrating radar calibration.

Claims

1. A ground penetrating radar thickness calibration system for center frequencies below 400 MHz, characterized by: The ground penetrating radar thickness calibration system for the center frequency below 400MHz comprises a ground penetrating radar calibration device (1), a water tank (2), a water body (3), a steel rail (4), a ground (5) and a ground penetrating radar antenna (6); wherein two steel rails (4) are respectively fixed on the two side edges of the water tank (2); the water tank (2) contains an adjustable water body (3) for providing the required water depth standard value for the thickness measurement of different ground penetrating radars; the ground (5) outside the water tank (2) provides an installation site for the tester before the ground penetrating radar test; the ground penetrating radar calibration device (1) is arranged on the two steel rails (4); and the ground penetrating radar antenna (6) is placed on the ground penetrating radar calibration device (1).

2. The ground penetrating radar thickness calibration system for center frequencies below 400 MHz of claim 1, wherein: The ground penetrating radar calibration device (1) comprises an antenna laying device, an antenna suspension adjusting device, a water body depth measuring device, a rotating wheel (105), a steel rail clamp (106), a slide rail (107) and a main body frame (108); wherein the main body frame (108) comprises a lower support frame and an upper fixing frame; the lower support frame is a rectangular frame composed of two longitudinal beams and two transverse beams, is arranged horizontally, and one rotating wheel (105) is installed at each corner; the upper fixing frame is a cuboid frame structure, is fixed in the middle of the two longitudinal beams; the antenna laying device comprises an antenna tray (1011) and an antenna tray rope buckle (1012); the antenna tray (1011) is located in the internal space of the upper fixing frame, and one antenna tray rope buckle (1012) is installed at each corner; the antenna suspension adjusting device comprises a winch (1021), a winch steel rope (1022) and a winch steel rope changing direction fixed pulley (1023); two groups of winches (1021) are respectively installed at the two sides of one transverse beam of the lower support frame; two groups of winch steel rope changing direction fixed pulleys (1023) are respectively installed on the top surfaces of the side transverse beams at the upper end of the upper fixing frame and correspond to the positions of the two groups of winches (1021), and the other four groups of winch steel rope changing direction fixed pulleys (1023) are respectively installed on the inner side surfaces of the two side transverse beams at the upper end of the upper fixing frame and also correspond to the positions of the two groups of winches (1021); one end of each winch steel rope (1022) is wound around a winch (1021), and the other end is sequentially wound around a corresponding winch steel rope changing direction fixed pulley (1023) on the top surface of the side transverse beam, a winch steel rope changing direction fixed pulley (1023) on the inner side surface of the side transverse beam and then connected to a nearby antenna tray rope buckle (1012); the water body depth measuring device comprises a steel tape (1031), a steel tape fixing lock buckle (1032), a steel tape changing direction fixed pulley (1033) and a lead sinker (104); the steel tape fixing lock buckle (1032) is installed on the transverse beam of the lower support frame between the two groups of winches (1021); the steel tape changing direction fixed pulley (1033) is installed in the middle of the side transverse beam at the lower end of the fixing frame close to the steel tape fixing lock buckle (1032); the outer end of the steel tape (1031) is connected to the lead sinker (104) through the steel tape fixing lock buckle (1032) and the steel tape changing direction fixed pulley (1033); two slide rails (107) are respectively installed on the bottom surfaces of the two longitudinal beams of the lower support frame, and one steel rail clamp (106) is respectively installed on each slide rail (107) in a sliding manner.

3. The ground penetrating radar thickness calibration system for center frequencies below 400 MHz of claim 2, wherein: The total length of the lower support frame of the ground penetrating radar calibration device (1) is 3.8 m, and the total length of the slide rail (107) is 3.2 m.

4. The ground penetrating radar thickness calibration system for center frequencies below 400 MHz of claim 1, wherein: The depth of the water tank (2) is greater than 4 m, and the maximum depth of the water body (3) is 4 m.

Images