Automatic calibration system of radar liquid level meter

Abstract

The utility model discloses an automatic calibration system for a radar liquid level meter, which relates to the technical field of radar liquid level meter production and comprises a PLC (programmable logic controller) module, an instrument fixing module, a reflecting plate lifting module, a laser ranging module, a microwave darkroom and an upper computer. The PLC module is used for controlling the whole system and collecting and transmitting data; the instrument fixing module is used for installing and fixing an instrument to be calibrated; the reflecting plate lifting module is used for controlling and realizing lifting of reflecting plates at all point positions; the laser ranging module is used for monitoring the reflecting plate closest to the instrument fixing module; the microwave anechoic chamber is used for providing a pure electromagnetic environment; and the upper computer inquires measurement information of the instrument and modifies parameters of the instrument. According to the utility model, the whole process of the calibration production link of the radar liquid level meter is automated, the measured value of an instrument is automatically read, and parameters are calculated and input in the process of realizing the sequential reciprocating lifting of each calibration point position reflecting plate, so that the dependence on manual operation control is eliminated, and the production efficiency of the calibration link and the product reliability are improved.

Description

Technical Field

[0001] The invention relates to the technical field of radar level gauge production, and in particular to an automatic calibration system for radar level gauges. Background Art

[0002] Radar level meters need to be calibrated before leaving the factory to adjust the instrument parameters, reduce measurement errors, and improve the measurement accuracy of the instrument. At present, the construction of radar level meter production lines by domestic enterprises is still in its infancy. There is a lack of mature automated calibration technology, and only traditional full-process manual calibration can be used, that is, workers turn switches on the console to achieve the lifting and lowering of multiple point reflectors, thereby changing the measurement distance of the instrument. At the same time, workers also need to observe the corresponding measurement readings of the instrument, record them in the calibration table, and finally calculate and modify the instrument parameters.

[0003] At present, the calibration process of radar level gauge production has high workload intensity, low production efficiency and high risk of manual operation. Therefore, it is necessary to design an automatic calibration device and system for radar level gauge to solve the above production problems. Utility Model Content

[0004] In view of the deficiencies of the above-mentioned technology, the purpose of the utility model is to provide an automatic calibration system for a radar level gauge.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0006] A radar level meter automatic calibration system comprises a PLC module, an instrument fixing module, a reflector lifting module, a laser ranging module, a microwave darkroom and a host computer; one end of the PLC module is connected to one end of the host computer, the other end of the PLC module is connected to the instrument fixing module, the reflector lifting module and the laser ranging module, and the other ends of the instrument fixing module, the reflector lifting module and the laser ranging module are connected to the microwave darkroom; the PLC module and the host computer are placed outside the microwave darkroom.

[0007] Furthermore, the PLC module includes a CPU and an expansion module thereof, and a communication module, and the PLC module is integrated in a control cabinet.

[0008] Furthermore, the instrument fixing module is provided with an upper and lower layer, and is placed in front of the microwave darkroom; the lower layer is an "I"-shaped horizontally movable slider, which can enter and exit the microwave darkroom; the upper layer is an "concave"-shaped horizontally movable slider, and there is an instrument fixing window, which can be moved horizontally to the instrument measurement zero point; the upper and lower sliders are connected to the cylinder; the cylinder is connected to a three-position five-way solenoid valve; the three-position five-way solenoid valve is connected to the digital output point of the PLC module.

[0009] Furthermore, the reflector lifting module has reflectors at ten points, namely 0.5m, 1m, 2m, 4m, 6m, 8m, 10m, 12m, 14m and 15m away from the instrument fixing module. The reflectors are vertically placed at different positions above the microwave darkroom and can be moved up and down; the reflectors are made of aluminum alloy; the reflectors are 1m long, 1m high and 0.1m thick; the reflectors are connected to their respective cylinders; the cylinders are respectively connected to a three-position five-way solenoid valve; the three-position five-way solenoid valves are respectively connected to the digital output points of the PLC module; photoelectric limit switches are fixed on the top and bottom of each reflector.

[0010] Furthermore, the laser distance measurement module adopts a laser distance meter, which is fixed on the left side of the lower slider of the instrument fixing module, and the voltage analog output terminal of the laser distance meter is connected to the analog input terminal of the PLC module.

[0011] Furthermore, the microwave darkroom is 15m long and is constructed of absorbing materials and a metal shielding body. An instrument fixing module window is left in the front to form a closed space after the instrument is fixed; a reflector contact port is left above the microwave darkroom.

[0012] Furthermore, the host computer is equipped with an operation interface and calibration software, and the host computer is connected to the instrument to be calibrated.

[0013] Compared with the prior art, the advantages of the utility model are:

[0014] The utility model realizes the automatic lifting and lowering operation of each reflector in the calibration operation of the radar level gauge by providing a PLC module; the utility model realizes the operation of automatically reading the instrument indication number and automatically writing the instrument parameters in the calibration operation of the radar level gauge by providing a PLC module and a host computer. According to the actual production needs of the enterprise, the utility model realizes the automation upgrade of the traditional pure manual production method, and solves the problems of high work intensity, low production efficiency and high risk of manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 It is a structural schematic diagram of the automatic calibration system of the radar level gauge described in the utility model. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0018] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0019] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0020] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0021] like Figure 1 As shown, a radar level meter automatic calibration system includes a PLC module, an instrument fixing module, a reflector lifting module, a laser ranging module, a microwave darkroom and a host computer; one end of the PLC module is connected to one end of the host computer, and the other end of the PLC module is connected to the instrument fixing module, the reflector lifting module and the laser ranging module, and the other ends of the instrument fixing module, the reflector lifting module and the laser ranging module are connected to the microwave darkroom; the PLC module and the host computer are placed outside the microwave darkroom.

[0022] The PLC module includes a CPU and an expansion module thereof, and a communication module, and the PLC module is integrated in a control cabinet.

[0023] The instrument fixing module has two layers, an upper layer and an lower layer, and is placed in front of the microwave darkroom; the lower layer is an "I"-shaped horizontally movable slider, which can enter and exit the microwave darkroom; the upper layer is an "concave"-shaped horizontally movable slider, with an instrument fixing window, which can be moved horizontally to the instrument measurement zero point; the upper and lower sliders are connected to the cylinder; the cylinder is connected to a three-position five-way solenoid valve; the three-position five-way solenoid valve is connected to the digital output point of the PLC module.

[0024] The reflector lifting module has reflectors at ten points, namely 0.5m, 1m, 2m, 4m, 6m, 8m, 10m, 12m, 14m and 15m away from the instrument fixing module. The reflectors are vertically placed at different positions above the microwave darkroom and can be moved up and down. The reflectors are made of aluminum alloy. The reflectors are 1m long, 1m high and 0.1m thick. The reflectors are connected to their respective cylinders. The cylinders are respectively connected to three-position five-way solenoid valves. The three-position five-way solenoid valves are respectively connected to the digital output points of the PLC module. Photoelectric limit switches are fixed on the top and bottom of each reflector.

[0025] The laser distance measurement module adopts a laser distance meter, which is fixed on the left side of the lower slider of the instrument fixing module. The voltage analog output end of the laser distance meter is connected to the analog input end of the PLC module.

[0026] The microwave darkroom is 15 meters long and is constructed of absorbing materials and a metal shielding body. An instrument fixing module window is left in the front to form a closed space after the instrument is fixed. A reflector contact port is left above the microwave darkroom.

[0027] The host computer is equipped with an operation interface and calibration software, and the host computer is connected to the instrument to be calibrated.

[0028] The PLC module is used to control the entire system, including controlling the instrument fixing module to enter and exit the microwave darkroom, and controlling the lifting and lowering movement of each reflector in the reflector lifting module; it is used to collect and transmit data, including reading the voltage analog quantity in the laser ranging module and converting it into measurement data, and receiving instructions from the host computer operation interface and calibration software.

[0029] The instrument fixing module is used to install and fix the instrument to be calibrated. The lower slider can move horizontally into the microwave darkroom and form a closed space after positioning. The upper slider can fix the instrument to move horizontally and reach the instrument measurement zero point after positioning.

[0030] Each three-position five-way solenoid valve in the reflector lifting module is connected to the digital output port of the PLC module via a relay, which is used to control the lifting and lowering movement of the reflector, so that the measured distance of the instrument changes and the measurement of different points is realized; each limit switch in the reflector lifting module is connected to the digital input port of the PLC module, which is used to send a limit signal. When the reflector moves to the highest point or the lowest point, the limit switch detects and outputs a signal, and the reflector stops moving at this time.

[0031] The laser ranging module is used to measure the reflector closest to the instrument fixing module and use the measured data as a reference for the radar level meter distance measurement; at the same time, it also plays the role of monitoring the frontmost descending reflector. When the measured position of the descending reflector does not match the PLC module control, the system will stop running.

[0032] The microwave darkroom is used to provide a pure electromagnetic environment. When electromagnetic waves are incident on the walls, ceiling, and ground, most of the electromagnetic waves are absorbed, with very little transmission and reflection. During calibration, the radar level meter can be protected from interference from external clutter, thereby improving calibration accuracy and efficiency.

[0033] The host computer is used for human-computer interaction, querying instrument measurement information, and modifying instrument parameters; the host computer is equipped with a front-end operation interface, where operators can perform human-computer interaction to start and stop the system, fix the radar level meter, select calibration points, and view measurement information; the host computer is equipped with calibration software, which is used to read the measurement information of the radar level meter and update the instrument parameters after calculation, and send instructions to the PLC module for the next control action.

[0034] Before each use, the radar level gauge automatic calibration system will select the instrument to be calibrated. After determining the range of the instrument, the calibration points are pre-set according to the range. The ten points can be freely selected. Generally, the five-point calibration method is adopted, that is, the distances of five points are measured as experimental data. In addition, a calibration process generally requires three round-trip measurements, that is, the distance is measured from near to far and then from far to near for a total of three times.

[0035] The specific implementation process of the radar level gauge automatic calibration system is as follows:

[0036] Step 1: Power on the system and initialize it to detect the system environment. That is, the indicator light on the operation interface is on, the calibration software and PLC module communicate normally, the instrument fixing module pops up, the reflector is located on the microwave darkroom, and the laser rangefinder displays a distance of 15m.

[0037] Step 2: Determine the model and range of the instrument to be calibrated, place the instrument to be calibrated on the upper layer of the instrument fixing module, start the calibration software on the host computer, connect the instrument to be calibrated and the host computer interface, and check whether the communication is established;

[0038] Step 3: Push the instrument to be calibrated into the microwave darkroom and fix it to the measurement zero point;

[0039] Step 4: Determine the range of the instrument to be calibrated, select the calibration point according to the range of the instrument to be calibrated, and enter the number of round trips required by the system;

[0040] Step 5: Run the system, the reflector at the point closest to the instrument fixed module is lowered, and after waiting for the instrument to respond, the instrument data is stored, and the reflector at that point rises;

[0041] Step 6: The reflector of the next selected point at a farther distance drops down, and after waiting for the instrument to respond, the calibration software reads the stored instrument data, and the reflector at that point rises;

[0042] Step 7: Repeat step 6. The radar level meter will measure the distance of the reflector at the selected point from near to far in sequence. The calibration software records the data measured by the radar level meter each time the reflector falls.

[0043] Step 8: Measure the distance of the reflector plates at the selected points from far to near, and the calibration software records the data measured by the radar level meter each time the reflector plate falls;

[0044] Step 9: Repeat steps 7 and 8 until the predetermined number of times is reached;

[0045] Step 10: The calibration software calculates the parameters and inputs them into the radar level gauge.

[0046] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0047] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A radar level gauge automatic calibration system, characterized in that: It includes a PLC module, an instrument fixing module, a reflector lifting module, a laser ranging module, a microwave darkroom and a host computer; one end of the PLC module is connected to one end of the host computer, the other end of the PLC module is connected to the instrument fixing module, the reflector lifting module and the laser ranging module, and the other ends of the instrument fixing module, the reflector lifting module and the laser ranging module are connected to the microwave darkroom.

2. The radar level meter automatic calibration system according to claim 1, characterized in that: The PLC module includes a CPU and an expansion module thereof, and a communication module, and the PLC module is integrated in a control cabinet.

3. The radar level meter automatic calibration system according to claim 1, characterized in that: The instrument fixing module has two layers, an upper layer and an lower layer, and is placed in front of the microwave darkroom; the lower layer is a "I"-shaped horizontally movable slider, which can enter and exit the microwave darkroom; the upper layer is a "concave"-shaped horizontally movable slider, with an instrument fixing window, which can be moved horizontally to the instrument measurement zero point; the upper and lower sliders are connected to the cylinder; the cylinder is connected to a three-position five-way solenoid valve; the three-position five-way solenoid valve is connected to the digital output point of the PLC module.

4. The radar level meter automatic calibration system according to claim 1, characterized in that: The reflector lifting module has reflectors at ten points, namely 0.5m, 1m, 2m, 4m, 6m, 8m, 10m, 12m, 14m and 15m away from the instrument fixing module. The reflectors are vertically placed at different positions above the microwave darkroom and can be moved up and down. The reflectors are made of aluminum alloy. The reflectors are 1m long, 1m high and 0.1m thick. The reflectors are connected to their respective cylinders. The cylinders are respectively connected to three-position five-way solenoid valves. The three-position five-way solenoid valves are respectively connected to the digital output points of the PLC module. Photoelectric limit switches are fixed on the top and bottom of each reflector.

5. The radar level meter automatic calibration system according to claim 1, characterized in that: The laser distance measurement module adopts a laser distance meter, which is fixed on the left side of the lower slider of the instrument fixing module. The voltage analog output end of the laser distance meter is connected to the analog input end of the PLC module.

6. The radar level meter automatic calibration system according to claim 1, characterized in that: The microwave darkroom is 15 meters long and is constructed of absorbing materials and a metal shielding body. An instrument fixing module window is left in the front to form a closed space after the instrument is fixed. A reflector contact port is left above the microwave darkroom.

7. The radar level meter automatic calibration system according to claim 1, characterized in that: The host computer is equipped with an operation interface and calibration software, and the host computer is connected to the instrument to be calibrated.

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