CN-122017047-A - Model-based ultrasonic probe constant-temperature pure water calibration method

CN122017047ACN 122017047 ACN122017047 ACN 122017047ACN-122017047-A

Abstract

The ultrasonic probe constant-temperature pure water calibration method based on the model comprises the following steps of an electric appliance preparation stage, a solution preparation stage, a calibration acquisition stage, a calibration calculation stage, a calibration fitting stage, a calibration storage stage and a calibration storage stage. The method is based on integration and summarization of a large number of experimental data, and utilizes a least square method to simulate sampling data points of an ultrasonic urea concentration sensor into a urea concentration curved surface model, so that the length consistency calibration of the urea ultrasonic probe in a constant-temperature pure water environment can be realized.

Inventors

CAO QINGHE
ZHENG QIANG
TANG JIAO
LI MINGJUN

Assignees

山东艾泰克环保科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260303

Claims (8)

1. The model-based ultrasonic probe constant-temperature pure water calibration method is characterized in that a calibration data core point is a urea concentration C=f (T, V) curved surface model, the urea concentration C=f (T, V) curved surface model is integrated and summarized based on experimental data, and a least square method is utilized to fit sampling data points of an ultrasonic urea concentration sensor, and the method comprises the following steps: step one, an electrical appliance preparation stage, wherein a display control intelligent screen, a power supply and an ultrasonic urea concentration sensor are connected; Step two, in the solution preparation stage, placing an ultrasonic urea concentration sensor in a stable constant temperature tank at 40 ℃; Step three, in the calibration acquisition stage, an ultrasonic urea concentration sensor acquires solution temperature data and ultrasonic propagation speed data in the solution; A calibration calculation stage, namely calculating a urea concentration default value delta C based on a C=f (T, V) curved surface model; Step five, in the calibration fitting stage, if calibration deviation exists, calculating the length deviation of the ultrasonic probe according to the delta C and a speed time formula, and obtaining the reasonable length S1 of the ultrasonic probe; And step six, in the calibration storage stage, when the default value delta C=0, the ultrasonic probe length S=S0 is directly stored, and when the default value delta C is not equal to 0, the delta S, S =S0+delta S is calculated through a speed time formula and the ultrasonic probe length S is stored.
2. The method for calibrating the ultrasonic probe constant temperature pure water based on the model of claim 1, wherein a display control intelligent screen supporting CAN communication is used in the first step, the display control intelligent screen supporting CAN communication has a CAN bus message monitoring function and an analog message sending function, a vehicle standard SAE J1939 communication protocol is supported, macro instruction script editing and calling are supported, and a direct current power supply is used for supplying power to the display control intelligent screen and a urea quality sensor.
3. The method for calibrating the constant-temperature pure water of the ultrasonic probe based on the model of claim 1, wherein the constant-temperature pure water environment at the temperature of 40 ℃ in the second step is controlled by using a constant-temperature tank.
4. The method for calibrating the constant-temperature pure water of the ultrasonic probe based on the model of claim 1, wherein in the third step, the urea quality sensor collects solution temperature data by using an NTC thermistor mode, and ultrasonic propagation speed data in a 40 ℃ constant-temperature pure water environment is calculated by adopting a speed time formula v=s/t.
5. The method for calibrating the constant-temperature pure water of the ultrasonic probe based on the model of claim 1, wherein the curve model with the urea concentration C=f (T, V) in the fourth step is summarized as follows: C=a1+a2T+a3T2+a4V+a5V2+a6T·V。
6. The method for calibrating the constant-temperature pure water of the ultrasonic probe based on the model of claim 1, wherein the default value DeltaC=C0-0% in the fourth step reflects the deviation of the current concentration measurement.
7. The method for calibrating the constant-temperature pure water of the ultrasonic probe based on the model of claim 1, wherein the calculation method in the fifth step is characterized in that DeltaC is substituted into a C=f (T, V) curved surface model, the propagation speed deviation DeltaV is calculated, and the DeltaS is calculated according to S=V.t, so that the length S1 of the ultrasonic probe is obtained.
8. The model-based ultrasonic probe constant-temperature pure water calibration method of claim 1, wherein the ultrasonic probe length S is stored in a ROM memory of the MCU in the step six.

Description

Model-based ultrasonic probe constant-temperature pure water calibration method Technical Field The invention relates to the technical field of automobile sensors, in particular to a model-based ultrasonic probe constant-temperature pure water calibration method. Background Currently, chemical analysis, chromatography, infrared absorption spectrometry and optical refractive index method are mostly adopted for domestic measurement of liquid concentration. The chemical analysis method is mainly carried out in an important link of production, namely the chemical analysis of the sampled sample is completed through a specific chemical reaction, and the method has extremely high precision, but consumes long time, consumes large manpower and material resources, has low detection efficiency, can not realize online detection and can not meet the requirement of vehicle application; the infrared absorption spectrometry is mature at present, the method has the greatest advantages of short liquid concentration measuring time, capability of carrying out multicomponent simultaneous measurement and not damaging original components of liquid, good measuring method, large measuring instrument volume, strict testing environment requirement, complex and expensive instrument maintenance, narrow application range, and extremely high liquid concentration detecting precision due to the fact that the optical method detects the liquid concentration by utilizing the physical characteristics of different refractive indexes of light in solutions with different concentrations, and has the advantages of extremely high liquid concentration detecting precision, high requirements on detecting environment, great influence on detecting results due to small fluctuation of light intensity and poor stability. In recent years, research on the detection direction of ultrasonic urea concentration has been greatly advanced, and ultrasonic detection technology is relatively mature, so that the ultrasonic urea concentration detection method becomes a reliable detection technology means. The ultrasonic detection technology has the advantages of short detection time, no pollution and the like, and becomes a detection technology with rapid development and wide application range. When the concentration, viscosity and medium temperature of the urea solution are fixed, the maximum variation parameter is the processing precision of the appearance structural member of the ultrasonic probe, and in the mass production, the interval distance between the emitting surface and the reflecting surface of the ultrasonic probe often has certain difference, so that certain deviation exists between the concentrations measured by different ultrasonic probes under the same calibration data, and the urea concentration calculation is influenced. At present, standard urea solution with the concentration of 32.5% is mostly used for product consistency calibration in the industry of China, and the scheme has certain defects that the concentration of the urea solution possibly has poor durability in consideration of the evaporation characteristic of the urea solution, and secondly, the ultrasonic probe length calibration strategy mostly adopts PID closed loop difference fitting, so that the calibration time is long, the production efficiency is relatively slow, and the urea solution has certain corrosiveness to electronic equipment of a production line due to the alkaline and ammoniation characteristics of the urea solution. Disclosure of Invention In order to solve the problems, the invention aims to provide a model-based ultrasonic probe constant-temperature pure water calibration method. In order to achieve the purpose, the technical scheme of the invention is that the model-based ultrasonic probe constant-temperature pure water calibration method is characterized in that a calibration data core point is a urea concentration C=f (T, V) curved surface model, the curved surface model is integrated and summarized based on experimental data, and a least square method is utilized to fit sampling data points of an ultrasonic urea concentration sensor. The method specifically comprises the following steps: step one, an electrical appliance preparation stage, wherein a display control intelligent screen, a power supply and an ultrasonic urea concentration sensor are connected; Step two, in the solution preparation stage, placing an ultrasonic urea concentration sensor in a stable constant temperature tank at 40 ℃; Step three, in the calibration acquisition stage, an ultrasonic urea concentration sensor acquires solution temperature data and ultrasonic propagation speed data in the solution; A calibration calculation stage, namely calculating a urea concentration default value delta C based on a C=f (T, V) curved surface model; Step five, in the calibration fitting stage, if calibration deviation exists, calculating the length deviation of the ultrasonic probe according to the delta C