Precision and linearity automatic calibration system for prestressed bridge tension force and its calibration method

Abstract

The invention relates to a system for automatically checking the tensioning force accuracy and linearity of a prestressed bridge and a checking method thereof. The reaction frame structure is as follows: a guide column is arranged between two parallel supporting plates; a support frame and a jack placement area are arranged in a reaction frame frame; a standard sensor is fixedly connected in the support frame; the standard sensor is connected to a digital instrument through a line; the digital instrument is connected to a control conversion system through a line; a force sensor is arranged above the jack; the force sensor is connected to an automatic tensioning device through a line; the jack is connected to a hydraulic station through a hydraulic pipeline; the construction system for automatically checking and checking the tensioning force accuracy of an automatic tensioning device for prestressed tendons of a concrete bridge can quickly and accurately complete the entire inspection process during the accuracy inspection of the automatic tensioning device, realize automatic self-checking of the tensioning force of the tensioning device, and automatic correction of the linearity of the sensor, thereby achieving the purpose of improving the tensioning accuracy and inspection efficiency without manual operation.

Description

Technical Field

[0001] The invention relates to a calibration system, in particular to a prestressed bridge tensioning force accuracy and linearity automatic calibration system and a calibration method thereof, belonging to the field of bridge construction. Background Art

[0002] At present, in my country's transportation construction, bridges have occupied an absolute proportion in the line length because of their many advantages. With the application of prestressed technology in modern bridge construction, the quality and performance of bridges have been greatly improved, which has played an immeasurable role in promoting the development of bridge construction in my country. In the process of prestressed construction, careful design is required to give full play to the prestressed technology in bridge construction and improve its quality and performance. Therefore, prestressed construction of bridges is a key process to ensure the safety and durability of bridge structures.

[0003] Most of the prestressed construction of bridges in China has adopted automatic tensioning equipment, and the control of the entire process of automatic tensioning is achieved through the requirement of "tensioning force control as the main, and elongation value as the check". The accuracy of the tensioning force during the tensioning process directly affects the construction quality of the bridge. How to ensure the accuracy of the tensioning force value is particularly important. Improving the overall equipment quality stability and sensor accuracy of the automatic tensioning equipment is the goal pursued by various manufacturers. The hardware accuracy has also been broken through time and time again, but a key factor has been overlooked, which is the detection and inspection link of the automatic tensioning equipment.

[0004] The current operating method for testing tension restraint is that when corresponding data appears at each level, at least two people look at the displayed value and record it manually, and then relevant professional and technical personnel are required to calculate and modify the tension display force value to the standard force value as much as possible. During this period, there will be errors in reading the value and errors in the recording of the two people. Repeated precision calibration and linear correction are required in the morning, and the calibration rate is low, consuming a lot of time, manpower and material resources. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a system for automatically checking the accuracy and linearity of the tensioning force of a prestressed bridge and a calibration method thereof, and a construction system for automatically inspecting and verifying the accuracy of the tensioning force of automatic tensioning equipment for prestressed tendons of concrete bridges, which can quickly and accurately complete the entire inspection process during the accuracy inspection of the automatic tensioning equipment, realize automatic self-calibration of the tensioning force of the tensioning equipment, and automatic self-correction of the linearity of the sensor, thereby achieving the purpose of automatically completing the corresponding inspection and verification of the tensioning equipment during the tensioning force inspection process without the need for manual operation, especially without the need for corresponding professional technicians, thereby improving the purpose of tensioning accuracy and inspection efficiency.

[0006] To solve the above problems, the specific technical solutions of the present invention are as follows: a prestressed bridge tensioning force accuracy and linear automatic calibration system, including a reaction frame, the reaction frame structure is: a guide column is provided between two parallel support plates, the guide column and the support plate are fixedly connected by bolts, a support frame and a jack placement area are provided in the reaction frame, a standard sensor is fixedly connected in the support frame, the standard sensor is connected to a digital instrument through a line, the digital instrument is connected to a control conversion system through a line, a force sensor is provided above the jack, the force sensor is connected to an automatic tensioning device through a line, and the jack is connected to a hydraulic station through a hydraulic pipeline.

[0007] The control conversion system is composed of an A / D data acquisition module, a PLC controller and a human-machine interface. The pressure oil from the hydraulic station is output to the jack through the reversing valve group and the hydraulic pipeline. The pressure signal generated by the jack top pressure force sensor is transmitted to the PLC controller through the A / D acquisition module. The PLC controller outputs a control signal to control the reversing valve group and outputs it to the human-machine interface for display.

[0008] The beneficial effects brought by the present invention are: 1. The sensing technology and automatic control technology are adopted to realize the automatic control of the tensioning force detection process of the tensioning equipment. By automatically collecting and intelligently analyzing the data such as the tested tension force and the standard force value, the influence of adverse human factors is completely solved, and the detection quality is significantly improved; especially in the whole detection process, the real-time monitoring and dynamic discrimination technology of automatic verification of the tensioning force accuracy and linearity is used to improve the overall detection efficiency and ensure the construction quality and construction safety of the tensioning equipment.

[0009] 2. Prestress quality: The present invention can effectively avoid over-tensioning or under-tensioning, solve the problem of high discreteness of prestressing results, enable the pre-tensioning force of the bridge to be accurately applied, and effectively control the quality of prestressing.

[0010] 3. Economic benefits: The present invention effectively realizes the automatic calibration and dynamic control of the tensioning force accuracy and linearity of the tensioning equipment, which solves the problem that the existing tensioning equipment requires technicians to have a certain level of technical skills when calibrating the tensioning force, and the calibration process is repeated, which is time-consuming and labor-intensive, and even leads to huge economic losses due to construction accidents such as personal injury and death due to improper operation.

[0011] 4. It overcomes the measurement error caused by the operator's technical level or improper human recording when conducting tension force accuracy verification in the existing technology. It has a wide range of applications, does not require special professional supporting equipment and tooling, has high verification accuracy, and a simple verification method. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of the automatic calibration system for the tensioning force accuracy and linearity of prestressed bridges.

[0013] Figure 2 This is the flow chart of the automatic calibration system for the tensioning force accuracy and linearity of prestressed bridges. DETAILED DESCRIPTION

[0014] like Figure 1 and Figure 2 As shown, the automatic calibration system for the tensioning force accuracy and linearity of a prestressed bridge comprises a reaction frame 1. The reaction frame 1 has the following structure: a guide column 1-2 is arranged between two parallel support plates 1-1, the guide column 1-2 is fixedly connected to the support plate 1-1 by bolts, a support frame 1-3 and a jack placement area 1-4 are arranged in the frame of the reaction frame 1, a standard sensor 2 is fixedly connected in the support frame 1-3, the standard sensor 2 is connected to a digital instrument 3 through a line, the digital instrument 3 is connected to a control conversion system through a line, a jack 5 is placed in the jack placement area 1-4, a force sensor 4 is arranged above the jack 5, the force sensor 4 is connected to an automatic tensioning device 6 through a line, and the jack 5 is connected to a hydraulic station 11 through a hydraulic pipeline 12.

[0015] The control conversion system is composed of an A / D data acquisition module 9, a PLC controller 8 and a human-machine interface 7. The pressure oil from the hydraulic station 11 is output to the jack 5 through the reversing valve group 13 and the hydraulic pipeline 12. The pressure signal generated by the force sensor 4 above the jack 5 is transmitted to the PLC controller 8 through the A / D acquisition module 9. The PLC controller 8 outputs a control signal to control the reversing valve group 13 and outputs it to the human-machine interface 7 for display.

[0016] Embodiment: 1. Initialization

[0017] 1) Initialize the force measuring device according to the corresponding verification rules: including extending the jack to 80mm~120mm as required and locking the jack; directly return the force measuring indicator of the tensioning system to zero point; at the same time, communicate the automatic tensioning system with the standard sensor to ensure that the tensioning system can read the current value of the standard sensor at any time;

[0018] 2) Setting of initial parameters

[0019] In accordance with the requirements of standard specifications, select technical parameters such as the full scale of tensioning force detection, detection levels and corresponding points in the system; the tensioning force accuracy test method is based on 20%, 40%, 60%, 80% and 100% of the full scale of the tensioning system; load at five levels, and stop for 10 seconds after loading to the corresponding level. Then read the current force value of the tensioning system and the force value of the standard sensor for comparison or linear correction.

[0020] 2. Start real-time automatic level control loading self-check

[0021] 1) The starting system drives the jack through the hydraulic oil pump to apply pressure to the standard sensor step by step according to the preset process and level by level, and the force value data of the corresponding level of the force sensor read by the system is transferred to the accuracy and linearity automatic calibration calculation unit;

[0022] 2) Communicate with the digital display instrument of the standard force sensor through the MODBUS protocol, read the force data of the corresponding inspection level, and transfer the standard force data to the accuracy and linearity automatic calibration calculation unit;

[0023] 3) Real-time automatic linear calibration by level

[0024] 3.1) Compare and calculate in the accuracy and linearity automatic calibration calculation unit according to the preset input including the tensioning equipment force sensor calibration rate, accuracy requirements; and the current level force sensor force value, the current level standard sensor force value and other data collected in real time;

[0025] 3.2) Compare the calculated value with the minimum requirement of the current tensioning equipment’s accuracy test, and automatically correct the value if it is appropriate. After the correction is completed, proceed to the next inspection level until the entire correction process is completed;

[0026] 3.3) In the process of automatic calibration, the accuracy requirement of the inspection is added to prevent the calibration process from entering an endless loop due to the lack of accuracy requirement; the jack with unqualified calibration data is depressurized and the calculation of each level is restarted and correction is performed until the correction is completed.

[0027] The tensioning force accuracy inspection and linear automatic calibration system of the prestressed concrete bridge tensioning equipment includes at least one set of tensioning equipment, and the tensioning device includes a hydraulic station, a jack with a direct force sensor, a PLC controller, an A / D acquisition module, a human-machine interface, a calibration reaction frame, a standard force sensor, and a digital display instrument. The PLC controller in the tensioning device is electrically connected, and the pressure oil pumped out by the hydraulic station is output to the jack. The pressure signal generated by the force sensor on the jack is transmitted to the PLC controller via the A / D acquisition module. The PLC controller outputs the control signal of the jack and outputs it to the human-machine interface for display; the calibration reaction frame is used to withstand the pressure applied by the jack, and the standard sensor on the reaction frame and the pressure signal of the jack are used to directly display the electrical signal as the current force value through the external digital display instrument, and the MODBUS protocol is used to directly communicate with the PLC controller of the tensioning device to obtain the current force value of the current standard sensor.

[0028] The automatic check of the tensioning force value accuracy of the prestressed tensioning equipment first determines whether the current displayed tensioning force value accuracy meets the requirements during actual operation. If it meets the requirements, it is completed by default without modification; if the value does not meet the requirements, it is calculated according to the following formula:

[0029] ;

[0030] in:

[0031] —The current force value displayed after the tensioning equipment is automatically corrected during the actual tensioning force accuracy test, in KN;

[0032] —During the actual tension force accuracy test, the current force value displayed by the reaction frame and the standard sensor during the random verification level, in KN;

[0033] —During the actual tensioning force accuracy test, the current force value displayed by the force sensor of the jack in the tensioning equipment during the random verification level, in KN;

[0034] —The existing system standard rate of the force sensor carried by the jack in the current tensioning equipment during the actual tensioning force accuracy test;

[0035] —In the actual tensioning force accuracy test process, the internal code value corresponding to the full range of the force sensor carried by the jack in the current tensioning equipment;

[0036] —In the actual tensioning force accuracy test process, the internal code value corresponding to the 0 point of the force sensor carried by the jack in the current tensioning equipment;

[0037] —The current internal code value corresponding to the force sensor carried by the jack in the tensioning equipment during the random verification level during the actual tensioning force accuracy inspection;

[0038] In steps B1 and B2, the tensioning system collects the current tensioning force of the jack and the displayed force value of the standard calibration equipment in real time, thereby providing basic key data for automatic precision inspection and correction.

[0039] After the tension force accuracy is automatically checked, the level-by-level inspection is carried out according to the process requirements. The automatic line repair calculation method for the level-by-level inspection is as follows:

[0040] ;

[0041] in:

[0042] —During the actual tensioning force accuracy test, the current force value displayed after the tensioning equipment automatically corrects corresponding to each test level, in KN;

[0043] —During the actual tensioning force accuracy test, the current force value displayed by the tensioning equipment's own force sensor corresponding to each test level, in KN;

[0044] —During the actual tension force accuracy test, the current force value displayed by the standard sensor on the reaction frame corresponding to each test level, in KN;

[0045] —Theoretical force value at 0 point during the actual tension force accuracy test, unit KN.

[0046] Load at five levels of 20%, 40%, 60%, 80%, and 100% of the full scale of the tensioning system. After loading to the corresponding level, stop for 10 seconds, then read the current force value of the tensioning system and the force value of the standard sensor for comparison or linear correction. Taking the full scale of 5000KN as an example, the corresponding five levels of force are as follows:

[0047] Inspection level 0 20% 40% 60% 80% 100% Standard force value 0 1002 2002 3003 4001 5005 Tensioning machine displays force value 0 999 2006 3000 4001 5000

[0048] Take the 40% point level as an example for calculation:

[0049]

[0050] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the principle of the present invention, and they should also be considered to belong to the protection scope of the present invention.

Claims

1. A calibration method for a prestressed bridge tension force accuracy and linearity automatic calibration system, characterized by: The structure of the automatic calibration system for the tensioning force accuracy and linearity of a prestressed bridge includes a reaction frame, and the reaction frame structure is as follows: a guide column is arranged between two parallel support plates, the guide column is fixedly connected to the support plate by bolts, a support frame and a jack placement area are arranged in the reaction frame, a standard sensor is fixedly connected in the support frame, and the standard sensor is connected to a digital instrument through a line, and is characterized in that: the digital instrument is connected to a control conversion system through a line, a force sensor is arranged above the jack, the force sensor is connected to an automatic tensioning device through a line, and the jack is connected to a hydraulic station through a hydraulic pipeline; The control conversion system is composed of an A / D data acquisition module, a PLC controller and a human-machine interface. The pressure oil from the hydraulic station is output to the jack through the reversing valve group and the hydraulic pipeline. The pressure signal generated by the jack top pressure force sensor is transmitted to the PLC controller through the A / D acquisition module. The PLC controller outputs a control signal to control the reversing valve group and outputs it to the human-machine interface for display. The steps of the calibration method are as follows: 1) Initialization settings, initialization of the force measuring device and setting of initial parameters according to the corresponding verification rules; 2) Start real-time automatic level-by-level control loading self-calibration: 2.1) Start the system to drive the jack through the hydraulic oil pump to apply pressure to the standard sensor step by step according to the preset process, and transfer the force value data of the corresponding level of the force sensor read by the system to the accuracy and linearity automatic calibration calculation unit; 2.2) Communicate with the digital display instrument of the standard force sensor through the MODBUS protocol, read the force value data of the corresponding inspection level, and transfer the standard force value data to the accuracy and linearity automatic calibration calculation unit; 3) Real-time level-by-level linear automatic calibration : 3.1) Compare and calculate in the accuracy and linearity automatic calibration calculation unit according to the preset input including the calibration rate and accuracy requirements of the force sensor of the tensioning equipment; and the real-time collected data such as the force value of the current level force sensor and the force value of the current level standard sensor; 3.2) Compare the calculated value with the minimum requirement for the accuracy inspection of the current tensioning equipment, and automatically correct the appropriate value. After the correction is completed, enter the next inspection level until the entire correction process is completed; 4) In the automatic calibration process, add the accuracy requirements of the inspection to prevent the calibration process from entering an endless loop due to no accuracy requirements; the jack with unqualified calibration data is depressurized and the calculation of each level is restarted and corrected until the correction is completed; In the step 1), the jack is extended to 80 mm to 120 mm as required, and the jack is locked; the force measuring indicator device of the tensioning system is directly reset to zero; at the same time, the automatic tensioning system is communicated with the standard sensor to ensure that the tensioning system can read the current value of the standard sensor at any time; the tensioning force detection full range, detection level and corresponding points in the system are selected, and the tensioning force value accuracy test method is based on 20%, 40%, 60%, 80%, 100% of the full range of the tensioning system; five level points are loaded, and after loading to the corresponding level, it is stopped for 10 seconds, and then the current force value of the tensioning system and the force value of the standard sensor are read for comparison or linear correction; If the current force value of the tensioning system and the force value of the standard sensor meet the standards, they are completed by default without modification; if the values ​​do not meet the standards, they are calculated according to the following formula: ； in: —The current force value displayed after the tensioning equipment is automatically corrected during the actual tensioning force accuracy test, in KN; —During the actual tension force accuracy test, the current force value displayed by the reaction frame and the standard sensor during the random verification level, in KN; —During the actual tensioning force accuracy test, the current force value displayed by the force sensor of the jack in the tensioning equipment during the random verification level, in KN; —The existing system standard rate of the force sensor carried by the jack in the current tensioning equipment during the actual tensioning force accuracy test; —In the actual tensioning force accuracy test process, the internal code value corresponding to the full range of the force sensor carried by the jack in the current tensioning equipment; —In the actual tensioning force accuracy test process, the internal code value corresponding to the 0 point of the force sensor carried by the jack in the current tensioning equipment; —The current internal code value corresponding to the force sensor carried by the jack in the tensioning equipment during the random verification level during the actual tensioning force accuracy inspection; After the tension force accuracy is automatically checked, the level-by-level inspection is carried out according to the process requirements. The automatic line repair calculation method for the level-by-level inspection is as follows: ； in: —During the actual tensioning force accuracy test, the current force value displayed after the tensioning equipment automatically corrects corresponding to each test level, in KN; —During the actual tensioning force accuracy test, the current force value displayed by the tensioning equipment's own force sensor corresponding to each test level, in KN; —During the actual tension force accuracy test, the current force value displayed by the standard sensor on the reaction frame corresponding to each test level, in KN; —Theoretical force value at 0 point during the actual tension force accuracy test, unit KN.

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