Automatic loading control system and method for testing initial strength of cement water glass

Abstract

The invention relates to the technical field of automatic loading control, and particularly discloses an automatic loading control system and method for testing the initial strength of cement water glass, and the system comprises a loading frame, a clamp module, a base, a force sensor, a displacement sensor, a data processing module, a fixed switch, a display screen, a controller, a sliding rod, a loading head and a bracket, according to the scheme, an automatic clamp based on a PLC is adopted for design, and a pressure sample is pressed through vertical movement of the loading head on the sliding rod; according to the method, a fuzzy rule PID control algorithm is adopted, the loading speed and pressure are adjusted according to real-time conditions, and it is guaranteed that the loading process is stable and continuous; pID parameters are optimized to reduce overshoot and oscillation, and the test accuracy is improved; a force sensor and a displacement sensor are used for monitoring, and through linear and nonlinear regression analysis, the initial strength characteristics and statistical data of a cement water glass sample are accurately measured, so that the reliability and precision of a test result are improved.

Description

Technical Field

[0001] The invention relates to the technical field of automatic loading control, and in particular to an automatic loading control system and method for testing the initial strength of cement water glass. Background Art

[0002] In the field of building materials science, evaluating the early strength properties of cement-water glass mixtures is crucial for optimizing formulations and construction methods. Early strength refers to the compressive or flexural strength that the mixture can achieve within a few minutes to a few hours, which plays a significant role in applications such as rapid support and mold removal during construction.

[0003] There are many problems with the traditional strength test method of cement-water glass mixed materials. First, the manual clamping of samples is not only time-consuming, but also prone to human errors, resulting in inaccurate test results. In addition, manual loading is inefficient and difficult to achieve rapid measurement. Second, the pressure application speed control during loading is not precise enough, which makes it difficult to maintain consistency in test conditions and avoid sample damage caused by improper system response. Summary of the invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides an automatic loading control system and method for cement water glass initial strength testing. The manual clamping of samples is not only time-consuming, but also easily introduces human errors, resulting in low accuracy of test results, low efficiency of manual loading, and difficulty in achieving rapid measurement. This solution proposes to design an automatic fixture based on PLC, and through PLC program control, the clamping force of cement water glass samples can be accurately adjusted, the time for manual clamping of samples can be reduced, the efficiency of the test process can be improved, the errors of human operation can be reduced, and the accuracy of test results can be improved. The speed control applied during the loading process is not precise enough, resulting in difficulty in maintaining consistency in test conditions and avoiding sample damage caused by improper system response. This solution uses a PID control algorithm based on fuzzy rules to accurately control the speed and amplitude of pressure application during loading, avoiding sample damage caused by improper system response, and reasonably adjusting the parameters of the PID control algorithm to help reduce overshoot and oscillation when the system reaches a steady state, thereby improving the reliability of test results.

[0005] The present invention provides an automatic loading control system for cement water glass initial strength test, comprising a loading frame, a fixture module, a base, a force sensor, a displacement sensor, a data processing module, a fixed switch, a display screen, a controller, a slide bar, a loading head, and a bracket; The loading frame is the main part of the automatic loading control system, the base is the bottom structure of the automatic loading control system, and is vertically connected to the bracket, and the sliding rod is vertically connected to the bracket and installed above the base; The clamp module is used to automatically clamp the cement water glass sample and place it on a fixed position on the base, and the clamp module is installed on the slide bar; The loading head is connected to the slide bar and moves in the vertical direction to apply pressure to the cement water glass sample. The controller is used to control the speed and amplitude of the pressure application so that the pressure is stable and gradually increased. A force sensor is used to measure the pressure applied to the cement water glass sample. A displacement sensor is used to measure the insertion depth of the slide bar in the cement water glass sample during the test. The pressure and the insertion depth are transmitted to the data processing module. The data processing module performs linear regression fitting on the pressure and the insertion depth. For complex stress-strain relationships, nonlinear regression fitting is used to determine the initial strength characteristics of the material. Finally, the strength of the cement water glass sample is obtained and displayed on a display screen to generate a test report. The display screen is installed on the loading frame, the display screen is connected to the data processing module by wire, and the target penetration speed is set through the display screen; The displacement sensor and the force sensor are mounted on the loading head; The controller is mounted on the loading head; The fixed switch is installed on the loading head and is used to start and stop the automatic loading control system.

[0006] Furthermore, the fixture module includes a fixture, a touch screen, a limit switch, a cylinder, a pressure sensor, a PLC program controller, an amplifier, and a high-speed air switch. The PLC program controller is equipped with a PID control module. The fixture module is used to automatically clamp the cement water glass sample and place it in a fixed position on the base. The steps are as follows: Step N1: Setting the target clamping force on the touch screen; Step N2: Detect the position of the cement water glass sample through the limit switch, move the clamp to the position of the cement water glass sample, clamp the cement water glass sample with the clamp, and detect the actual clamping force through the pressure sensor; Step N3: Use the PLC program controller to control the movement of the cylinder. The PID control module calculates the PWM signal according to the target clamping force and the actual clamping force. The PWM signal is amplified by the amplifier to control the high-speed air switch to achieve high-frequency control of the cylinder's air intake and exhaust, thereby adjusting the actual clamping force, clamping the cement water glass sample, and placing it in a fixed position on the base.

[0007] The present invention provides an automatic loading control method for cement water glass initial strength test, the method comprising the following steps: Step M1: Set input and output, use the deviation change rate and deviation between the target penetration rate and the actual penetration rate of the cement water glass sample as input values, and output the parameter increment of the PID control algorithm; Step M2: construct fuzzy sets, each fuzzy set has a membership function, and the input value is converted into a fuzzy value through the membership function; Step M3: Establish fuzzy rules. For different deviations and deviation change rates, set different rules to adjust the parameters of the PID control algorithm. Use fuzzy sets for reasoning to determine the output fuzzy value. Step M4: Defuzzification: Use the weighted average method to defuzzify the output fuzzy value to obtain the precise control value. The formula used is as follows: ; In the formula, Represents the precise control amount, Indicates possible output values, Representation and The corresponding membership degree is Represents the total number of possible output values; According to the parameter increment of the PID control algorithm obtained by defuzzification, the final parameters of the PID control algorithm are obtained. The formula used is as follows: ; ; ; In the formula, represents the final proportional gain, represents the final integral gain, represents the final differential gain, and is the initial value of the parameters of the PID control algorithm, It indicates the adjustment amount of proportional gain obtained according to the fuzzy inference result. It indicates the adjustment amount of the integral gain obtained according to the fuzzy inference result. Indicates the adjustment amount of the differential gain obtained according to the fuzzy reasoning result; Step M5: executing control, using the parameters of the final PID control algorithm to control the automatic loading control system to adjust the actual penetration speed of the cement water glass sample; Step M6: closed-loop feedback, feeding back the actual penetration speed to the controller, the controller compares the deviation between the target penetration speed and the actual penetration speed, and makes adjustments based on the deviation; Step M7: During the penetration process, the penetration pressure and penetration depth are recorded, and the strength of the cement water glass sample is obtained by fitting the stress-strain curve through the penetration pressure and penetration depth.

[0008] The beneficial effects of the present invention are as follows: (1) The manual clamping method is not only time-consuming, but also prone to human errors, resulting in low accuracy of test results. In addition, the manual loading efficiency is low, making it difficult to achieve rapid measurement. This scheme proposes a PLC-based automated fixture design. Through PLC program control, the clamping force of cement water glass samples can be precisely adjusted, reducing the time for manual clamping of samples, improving the efficiency of the test process, reducing human operation errors, and improving the accuracy of test results. (2) In order to solve the problem that the speed control applied during the loading process is not precise enough, which makes it difficult to maintain consistency in the test conditions and avoid sample damage caused by improper system response, this scheme uses a PID control algorithm based on fuzzy rules to accurately control the speed and amplitude of pressure application during the loading process, thereby avoiding sample damage caused by improper system response. By reasonably adjusting the parameters of the PID control algorithm, it helps to reduce overshoot and oscillation when the system reaches a steady state, thereby improving the reliability of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a structural schematic diagram of an automatic loading control system for cement water glass initial strength test proposed by the present invention; Among them, 1. loading frame, 2. display screen, 3. data processing module, 4. fixture module, 5. loading head, 6. controller, 7. slide bar, 8. bracket, 9. fixed switch, 10. force sensor, 11. displacement sensor, 12. cement water glass sample, 13. base.

[0010] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0011] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the examples given are only used to explain the present invention, and are not used to limit the scope of the present invention.

[0012] Example 1, see Figure 1 The automatic loading control system for cement water glass initial strength test provided by the present invention comprises a loading frame 1, a fixture module 4, a base 13, a force sensor 10, a displacement sensor 11, a data processing module 3, a fixed switch 9, a display screen 2, a controller 6, a slide bar 7, a loading head 5, and a bracket 8; The loading frame 1 is the main part of the automatic loading control system, the base 13 is the bottom structure of the automatic loading control system, and is vertically connected to the bracket 8. The slide bar 7 is vertically connected to the bracket 8 and is installed above the base 13. The clamp module 4 is used to automatically clamp the cement water glass sample 12 and place it on a fixed position on the base 13. The clamp module 4 is installed on the slide bar 7; The loading head 5 is connected to the slide bar 7, moves in the vertical direction, applies pressure to the cement water glass sample 12, and uses the controller 6 to control the speed and amplitude of the pressure application, so that the pressure is stable and gradually increases. The force sensor 10 is used to measure the pressure applied to the cement water glass sample 12, and the displacement sensor 11 is used to measure the insertion depth of the cement water glass sample 12 during the loading process. The pressure and the insertion depth are transmitted to the data processing module 3. The data processing module 3 performs linear regression fitting on the pressure and the insertion depth to determine the initial strength characteristics of the material, obtain the strength of the cement water glass sample 12, and display it on the display screen 2. For complex stress-strain relationships, nonlinear regression fitting is used to statistically analyze the mean and standard deviation of the strength of the cement water glass sample 12, and generate a test report; The display screen 2 is installed on the loading frame 1, and the display screen 2 is connected to the data processing module 3 by wire, and the target penetration speed is set through the display screen 2; The displacement sensor 11 and the force sensor 10 are installed on the loading head 5; The controller 6 is installed on the loading head 5; The fixed switch 9 is installed on the loading head 5 and is used to start and stop the automatic loading control system.

[0013] Embodiment 2, based on the above embodiment, the fixture module includes a fixture, a touch screen, a limit switch, a cylinder, a pressure sensor, a PLC program controller, an amplifier, a high-speed air switch, and a PID control module is built in the PLC program controller. The fixture module is used to automatically clamp the cement water glass sample and place it in a fixed position on the base. The steps are as follows: Step N1: Setting the target clamping force on the touch screen; Step N2: Detect the position of the cement water glass sample through the limit switch, move the clamp to the position of the cement water glass sample, clamp the cement water glass sample with the clamp, and detect the actual clamping force through the pressure sensor; Step N3: Use the PLC program controller to control the movement of the cylinder. The PID control module calculates the PWM signal according to the target clamping force and the actual clamping force. The PWM signal is amplified by the amplifier to control the high-speed air switch to achieve high-frequency control of the cylinder's air intake and exhaust, thereby adjusting the actual clamping force, clamping the cement water glass sample, and placing it in a fixed position on the base.

[0014] By performing the above operations, the manual clamping of samples is not only time-consuming, but also prone to human errors, resulting in low accuracy of test results, low efficiency of manual loading, and difficulty in achieving rapid measurement. This scheme proposes a PLC-based automated fixture design. Through PLC program control, precise adjustment of the clamping force of cement water glass samples can be achieved, reducing the time for manual clamping of samples, improving the efficiency of the test process, reducing errors in human operation, and improving the accuracy of test results.

[0015] Embodiment 3, based on the above embodiment, the present invention provides an automatic loading control method for cement water glass initial strength test, the method comprising the following steps: Step M1: Set input and output, use the deviation change rate and deviation between the target penetration rate and the actual penetration rate of the cement water glass sample as input values, and output the parameter increment of the PID control algorithm; Step M2: construct fuzzy sets, each fuzzy set has a membership function, and the input value is converted into a fuzzy value through the membership function; Step M3: Establish fuzzy rules. For different deviations and deviation change rates, set different rules to adjust the parameters of the PID control algorithm. Use fuzzy sets for reasoning to determine the output fuzzy value. Step M4: Defuzzification: Use the weighted average method to defuzzify the output fuzzy value to obtain the precise control value. The formula used is as follows: ; In the formula, Represents the precise control amount, Indicates possible output values, Representation and The corresponding membership degree is Represents the total number of possible output values; According to the parameter increment of the PID control algorithm obtained by defuzzification, the final parameters of the PID control algorithm are obtained. The formula used is as follows: ; ; ; In the formula, represents the final proportional gain, represents the final integral gain, represents the final differential gain, , and is the initial value of the parameters of the PID control algorithm, It indicates the adjustment amount of proportional gain obtained according to the fuzzy inference result. It indicates the adjustment amount of the integral gain obtained according to the fuzzy inference result. Indicates the adjustment amount of the differential gain obtained according to the fuzzy reasoning result; Step M5: executing control, using the parameters of the final PID control algorithm to control the automatic loading control system to adjust the actual penetration speed of the cement water glass sample; Step M6: closed-loop feedback, feeding back the actual penetration speed to the controller, the controller compares the deviation between the target penetration speed and the actual penetration speed, and makes adjustments based on the deviation; Step M7: During the penetration process, the penetration pressure and penetration depth are recorded, and the strength of the cement water glass sample is obtained by fitting the stress-strain curve through the penetration pressure and penetration depth.

[0016] At a fixed time, such as 1s, 2s, etc., the penetration pressure and penetration depth are recorded, and the stress-strain curve is fitted by the penetration pressure and penetration depth to obtain the strength of the cement water glass sample.

[0017] By performing the above operations, the speed control applied during the loading process is not precise enough, which makes it difficult to maintain consistency in the test conditions and avoid sample damage caused by improper system response. This solution uses a fuzzy rule-based PID control algorithm to accurately control the speed and amplitude of pressure application during the loading process, avoiding sample damage caused by improper system response. By reasonably adjusting the parameters of the PID control algorithm, it helps to reduce overshoot and oscillation when the system reaches a steady state, thereby improving the reliability of the test results.

[0018] Embodiment 4, based on the above embodiment, in step M2, a fuzzy set is constructed, specifically: in fuzzy control, the basic domain needs to be discretized first, and then converted into a fuzzy domain before fuzzy reasoning can be performed. The input basic domain needs to be converted into a fuzzy domain with the help of a quantity factor, and the output fuzzy domain needs to be converted into a basic domain with the help of a scale factor. For the fuzzy domain, the finer the quantization level of the domain, the higher the control accuracy. However, too fine a quantization level will complicate the algorithm. The basic domain of the deviation is set to , the basic domain of the deviation change rate is , the parameter increments in the PID control algorithm include: , and , their basic domains are set as: , and .

[0019] Embodiment 5: Based on the above embodiment, in step M3, fuzzy rules are established. Different rules are set to adjust the parameters of the PID control algorithm for different deviations and deviation change rates, including: proportional gain , integral gain , differential gain : 1) When the deviation is large, reduce and increase , so that the system has better tracking performance and shortens the deviation elimination time. At the same time, choose a smaller To prevent a sudden increase in deviation, excessive differential saturation can lead to overshoot; 2) When the deviation is centered, , , Should not be too large, smaller The value is beneficial to optimize the overshoot phenomenon, while , A moderate value of is used to prevent the system from responding too slowly; 3) When the deviation is small, increase and It can improve the steady-state performance and avoid the system oscillating around the set value. The choice is determined by the rate of change of the deviation. If the rate of change of the deviation is large, a smaller one should be selected. ; When the deviation change rate is small, a larger , which helps to improve the system's ability to resist interference from external factors and effectively reduce oscillation phenomena.

[0020] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0021] The present invention and its implementation are described above, and such description is not restrictive. The drawings show only one implementation of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by the present invention, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should fall within the protection scope of the present invention.

Claims

1. Automatic loading control system for cement water glass initial strength test, characterized by: It includes a loading frame, a fixture module, a base, a force sensor, a displacement sensor, a data processing module, a fixed switch, a display screen, a controller, a slide bar, a loading head, and a bracket; The loading frame is the main part of the automatic loading control system, the base is the bottom structure of the automatic loading control system, and is vertically connected to the bracket, and the sliding rod is vertically connected to the bracket and installed above the base; The clamp module is used to automatically clamp the cement water glass sample and place it on a fixed position on the base, and the clamp module is installed on the slide bar; The loading head is connected to the slide bar and moves in the vertical direction to apply pressure to the cement water glass sample. The controller is used to control the speed and amplitude of the pressure application so that the pressure is stable and gradually increased. A force sensor is used to measure the pressure applied to the cement water glass sample. A displacement sensor is used to measure the insertion depth of the slide bar in the cement water glass sample during the test. The pressure and the insertion depth are transmitted to the data processing module. The data processing module performs linear regression fitting on the pressure and the insertion depth. For complex stress-strain relationships, nonlinear regression fitting is used to determine the initial strength characteristics of the material. Finally, the strength of the cement water glass sample is obtained and displayed on a display screen to generate a test report. The display screen is installed on the loading frame, the display screen is connected to the data processing module by wire, and the target penetration speed is set through the display screen; The displacement sensor and the force sensor are mounted on the loading head; The controller is mounted on the loading head; The fixed switch is installed on the loading head and is used to start and stop the automatic loading control system.

2. The automatic loading control system for cement water glass initial strength test according to claim 1 is characterized in that: The fixture module includes a fixture, a touch screen, a limit switch, a cylinder, a pressure sensor, a PLC program controller, an amplifier, and a high-speed air switch. The PLC program controller is equipped with a PID control module. The fixture module is used to automatically clamp the cement water glass sample and place it in a fixed position on the base. The steps are as follows: Step N1: Setting the target clamping force on the touch screen; Step N2: Detect the position of the cement water glass sample through the limit switch, move the clamp to the position of the cement water glass sample, clamp the cement water glass sample with the clamp, and detect the actual clamping force through the pressure sensor; Step N3: Use the PLC program controller to control the movement of the cylinder. The PID control module calculates the PWM signal according to the target clamping force and the actual clamping force. The PWM signal is amplified by the amplifier to control the high-speed air switch to achieve high-frequency control of the cylinder's air intake and exhaust, thereby adjusting the actual clamping force, clamping the cement water glass sample, and placing it in a fixed position on the base.

3. An automatic loading control method for cement water glass initial strength test, applied to the automatic loading control system for cement water glass initial strength test according to any one of claims 1-2, characterized in that: The method comprises the following steps: Step M1: Set input and output, use the deviation change rate and deviation between the target penetration rate and the actual penetration rate of the cement water glass sample as input values, and output the parameter increment of the PID control algorithm; Step M2: construct fuzzy sets, each fuzzy set has a membership function, and the input value is converted into a fuzzy value through the membership function; Step M3: Establish fuzzy rules. For different deviations and deviation change rates, set different rules to adjust the parameters of the PID control algorithm. Use fuzzy sets for reasoning to determine the output fuzzy value. Step M4: Defuzzification: Use the weighted average method to defuzzify the output fuzzy value to obtain the precise control value. The formula used is as follows: ； In the formula, Represents the precise control amount, Indicates possible output values, Representation and The corresponding membership degree is Represents the total number of possible output values; According to the parameter increment of the PID control algorithm obtained by defuzzification, the final parameters of the PID control algorithm are obtained. The formula used is as follows: ； ； ； In the formula, represents the final proportional gain, represents the final integral gain, represents the final differential gain, and is the initial value of the parameters of the PID control algorithm, It indicates the adjustment amount of proportional gain obtained according to the fuzzy inference result. It indicates the adjustment amount of the integral gain obtained according to the fuzzy inference result. Indicates the adjustment amount of the differential gain obtained according to the fuzzy reasoning result; Step M5: executing control, using the parameters of the final PID control algorithm to control the automatic loading control system to adjust the actual penetration speed of the cement water glass sample; Step M6: closed-loop feedback, feeding back the actual penetration speed to the controller, the controller compares the deviation between the target penetration speed and the actual penetration speed, and makes adjustments based on the deviation; Step M7: During the penetration process, the penetration pressure and penetration depth are recorded, and the strength of the cement water glass sample is obtained by fitting the stress-strain curve through the penetration pressure and penetration depth.

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