阅读说明：本技术 一种电磁水表的自动零点修正方法 (Automatic zero correction method for electromagnetic water meter ) 是由 熊远明 杨东梅 于 2021-06-25 设计创作，主要内容包括：一种电磁水表的自动零点修正方法,依据电磁水表的测量原理,采用如下步骤实现电磁水表的零点自动修正：首先,依据励磁波形自动判别电磁水表的励磁模式,在非连续励磁测量模式下：运用现场的测量信号和无励磁时信号的偏差和产品出厂时无流量信号和无励磁时信号的偏差比对来判断是否处在无流量下静止状态；在连续励磁测量模式下：运用现场测量信号和出厂无流量信号的比对来判断是否处在无流量下静止状态；当判断现场为无流量状态下：计算无流量和无励磁的信号及二者的差值并和出厂值进行比较,对满足修正要求的现场零点信号进行自动修正,确保无流量状态下输出为零；对不满足修正要求的现场信号超过一定范围的进行系统提示。(An automatic zero point correction method of an electromagnetic water meter is characterized in that according to the measurement principle of the electromagnetic water meter, the automatic zero point correction of the electromagnetic water meter is realized by adopting the following steps: firstly, automatically judging the excitation mode of the electromagnetic water meter according to the excitation waveform, and under the discontinuous excitation measurement mode: comparing the deviation between the on-site measurement signal and the non-excitation signal with the deviation between the non-flow signal and the non-excitation signal when the product leaves the factory to judge whether the product is in a static state under no flow; in the continuous excitation measurement mode: comparing the field measurement signal with the factory no-flow signal to judge whether the device is in a static state under no-flow condition; when the field is judged to be in a no-flow state: calculating the signal without flow and the signal without excitation and the difference value of the two signals and comparing the difference value with a factory value, automatically correcting the on-site zero point signal meeting the correction requirement, and ensuring that the output is zero in the state without flow; and prompting the field signal which does not meet the correction requirement to exceed a certain range by a system.)

1. An automatic zero point correction method of an electromagnetic water meter is characterized in that according to the measurement principle of the electromagnetic water meter, a zero-flow and non-excitation signal and a difference value of the zero-flow and non-excitation signal when the electromagnetic water meter leaves a factory are used as a correction reference, and the zero point automatic correction of the electromagnetic water meter is realized by adopting the following steps: the method is characterized in that:

step S1, firstly, the system automatically judges the excitation mode of the electromagnetic water meter according to the excitation waveform, and then step S2 is carried out; the excitation mode comprises a continuous mode and a discontinuous mode;

step S2, determining whether the mode is a continuous mode or a discontinuous mode; the discontinuous mode performs step S3; the continuous mode performs step S4;

step S3, in the discontinuous mode:

comparing the deviation between the on-site measurement signal and the non-excitation signal with the deviation between the non-flow signal and the non-excitation signal when the product leaves the factory to judge whether the product is in a static state under no flow;

step S4, in continuous mode:

comparing the field measurement signal with the factory no-flow signal to judge whether the device is in a static state under no-flow condition;

step S5, when the field is judged to be in a no-flow state:

calculating the signal without flow and the signal without excitation and the difference value of the two signals and comparing the difference value with a factory value, automatically correcting the on-site zero point signal meeting the correction requirement, and ensuring that the output is zero in the state without flow;

and prompting the field signal which does not meet the correction requirement to exceed a certain range by a system.

2. The automatic zero point correction method of an electromagnetic water meter according to claim 1, characterized in that:

in step S3, reading signals with excitation and without excitation in the discontinuous mode, reading the output value of the instrument, and then executing step S3.1; in step S3.1, the system determines whether there is a static no flow, if it is determined that there is a flow, the reading continues, and if there is no flow, step S5 is executed.

3. The automatic zero point correction method of an electromagnetic water meter according to claim 1, characterized in that:

in step S4, the measurement signal in the continuous mode is read, the output value of the meter is read, and then step S4.1 is executed;

in step S4.1, the system determines whether there is a static no flow, if it is determined that there is a flow, the reading continues, and if there is no flow, step S5 is executed.

4. The automatic zero point correction method of an electromagnetic water meter according to claim 1, 2 or 3, characterized in that: in step S5, the value acquired in step S3 or step S4 is operated upon request and then step S6 is executed; in step S6, it is determined that the result of the operation in step S5 is compared with a factory-saved standard; when the signal value exceeds the required range, the control system proceeds to step S8, and in step S8, the system presents the signal values under excitation and non-excitation; when the correction request is satisfied, the process proceeds to step S7, and the system automatically performs zero point correction in step S7.

5. The automatic zero point correction method of an electromagnetic water meter according to claim 4, characterized in that: in order to ensure that zero point correction is not influenced by the instrument coefficient, correcting the initial AD value of the instrument signal; reading non-excitation signals at measurement intervals in a discontinuous mode; analyzing a correction value according to a constraint relation between field signals without excitation and with excitation but without flow and parameters when leaving a factory in a discontinuous mode; and analyzing the correction value according to the constraint relation between the field signal under no flow and the parameters when leaving the factory in the continuous excitation mode.

Technical Field

The invention relates to a zero point correction method of a water meter, in particular to an automatic zero point correction method of an electromagnetic water meter.

Background

When an electromagnetic water meter based on the electromagnetic induction principle in the market is verified by a third party and installed and used on site, the zero point of the electromagnetic water meter is influenced by factors such as different site installation stress, water quality, water temperature, electric conductivity, environment and the like to generate deviation, and the deviation has larger influence on a Q2 decomposition flow point and a Q1 minimum flow point of the water meter, particularly under the condition of high R value. For example, a Q3 flow rate of 5.6m/s with an accuracy of 2 levels is shown, with Q2 being 56mm/s for an R value of 160, and Q2 being 22.4mm/s for an R value of 400. At this time, the zero point offset of 0.5mm/s, the influence of Q2 at R value 160 is 0.89%, but the influence of Q2 at R value 400 is 2.2% (out of tolerance), and at this time, Q2 is above 25mm/s, which can be solved only by increasing the value of Q3, and at this time, the flow rate of Q3 is increased to 6.25m/s, which can meet the requirement. At present, most enterprises solve the problem by increasing the decomposition flow point (i.e. increasing Q3), and the defects are as follows: although Q2 is improved, it is worse if the zero point variation exceeds 0.5mm/s and also violates the water meter small flow metering requirement.

Disclosure of Invention

The invention provides an automatic zero point correction method of an electromagnetic water meter, aiming at the defects of the prior art. The influence of the zero point problem of the electromagnetic water meter on the small flow is solved by adopting an automatic zero setting mode, and the small flow measurement precision is ensured.

The technical scheme adopted by the invention is as follows:

a zero point correction method of an electromagnetic water meter is characterized in that according to the measurement principle of the electromagnetic water meter on the current market, an excitation mode continuous mode (positive excitation and negative excitation) and a discontinuous mode (positive excitation, negative excitation and no excitation) are firstly distinguished; in the continuous excitation measurement mode: comparing the field measurement signal with the factory no-flow signal to judge whether the device is in a static state under no-flow condition; in the discontinuous excitation measurement mode: comparing the deviation between the measuring signal and the non-excitation signal with the deviation of the product when leaving the factory to judge whether the product is in a static state under no flow;

reading the output value of the instrument, and when the field is judged to be in a no-flow state: and the on-site zero point signal meeting the correction requirement is automatically corrected, so that the output is zero in a no-flow state. Carrying out system prompt on the field signal exceeding a certain range;

through the steps, the influence of the zero point problem of the electromagnetic water meter on the small flow is solved, and the measurement precision of the small flow is ensured. To ensure that the zero point correction is not affected by the meter coefficients, the method corrects the initial AD value. And the signals of no flow and no excitation and the difference value of the signals are used as the correction reference in the program when the product leaves the factory.

The invention has the beneficial effects that:

the automatic zero correction method of the electromagnetic water meter is directly realized in control software without changing hardware of the water meter. The automatic adjustment of the influence of factors such as installation stress, water quality, water temperature, conductivity and environment on the zero point is realized, and no manual interference is needed, so that the qualification rate of third-party verification is ensured, and the measurement precision in small flow on site is also ensured.

Compared with the prior art, the invention has the following advantages:

1. under a discontinuous measurement mode, reading a non-excitation signal at a measurement interval time;

2. the instrument automatically sets the influence of different environments on the zero point;

3. the problem of low flow speed measurement accuracy of the electromagnetic water meter is solved;

4. hardware is not required to be changed, and the development cost is reduced by directly realizing the software;

5. signals in an excitation state and signals in a non-excitation state are compared with factory data, so that misjudgment is avoided, and correction reliability is improved;

6. the system adds the alarm prompt of the zero signal, and can judge whether the pipeline has leakage under no flow;

7. the method provides a guarantee for the development of the electromagnetic water meter without the R value requirement;

8. in the method, the signal without excitation is used as a comparison value in a discontinuous mode, so that the correction is more correct.

Drawings

Fig. 1 is a flow chart of an electromagnetic water meter automatic zero correction method of the invention;

fig. 2 is a block diagram of the hardware system of the automatic zero correction method for an electromagnetic water meter according to the present invention.

Detailed Description

In order to make the technical idea and advantages of the invention for realizing the purpose of the invention more clear, the technical solution of the invention is further described in detail with reference to the accompanying drawings. It should be understood that the following examples are only for illustrating and explaining preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention as claimed in the claims.

Example 1

Referring to fig. 1 and fig. 2, fig. 1 shows a specific flow of the automatic zero point correction method of the present invention, and fig. 2 shows a hardware system (including a sensor/measurement portion, a converter/sampling portion, and a calculation and correction portion) of the automatic zero point correction method of an electromagnetic water meter according to the present invention.

The invention relates to an automatic zero point correction method of an electromagnetic water meter, which takes the signal without flow and excitation and the difference value of the signal without flow and excitation as the correction reference when the electromagnetic water meter leaves the factory according to the measurement principle of the electromagnetic water meter, and adopts the following steps to realize the zero point automatic correction of the electromagnetic water meter:

step S1, firstly, the system automatically judges the excitation mode of the electromagnetic water meter according to the excitation waveform, and then the step S2 is entered;

the excitation modes comprise continuous excitation (positive excitation and negative excitation) and discontinuous modes (positive excitation, negative excitation and no excitation);

step S2, judging whether the mode is continuous or discontinuous mode; the discontinuous mode performs step S3; the continuous mode performs step S4;

step S3, in the discontinuous excitation measurement mode:

comparing the deviation between the on-site measurement signal and the non-excitation signal with the deviation between the non-flow signal and the non-excitation signal when the product leaves the factory to judge whether the product is in a static state under no flow;

step S4, in the continuous excitation measurement mode:

comparing the field measurement signal with the factory no-flow signal to judge whether the device is in a static state under no-flow condition;

step S5, when the field is judged to be in a no-flow state:

calculating the signal without flow and the signal without excitation and the difference value of the two signals and comparing the difference value with a factory value, automatically correcting the on-site zero point signal meeting the correction requirement, and ensuring that the output is zero in the state without flow;

and prompting the field signal which does not meet the correction requirement to exceed a certain range by a system.

In order to ensure that zero point correction is not influenced by the instrument coefficient, correcting the initial AD value of the instrument signal; reading non-excitation signals at measurement intervals in a discontinuous mode; analyzing a correction value according to a constraint relation between field signals without excitation and with excitation but without flow and parameters when leaving a factory in a discontinuous mode; and analyzing the correction value according to the constraint relation between the field signal under no flow and the parameters when leaving the factory in the continuous excitation mode.

Example 2

Referring to fig. 1, the automatic zero point correction method for the electromagnetic water meter of the present invention includes:

step 1, a system judges an excitation mode and then enters step 2; in step 2, it is determined whether the mode is the continuous mode or the discontinuous mode. The discontinuous mode performs step 3. The continuous mode performs step 4.

And 3, reading signals with excitation and without excitation in the discontinuous mode, and then executing the step 3.1. In step 3.1, the system determines whether the system is static and has no flow, if yes, the system continues reading, and if no, step 5 is executed.

And 4, reading the measurement signal in the continuous mode. Then step 4.1 is executed; in step 4.1, the system determines whether the system is static and has no flow, if yes, the system continues reading, and if no, step 5 is executed.

In step 5, the value obtained in step 3 or step 4 is calculated according to the requirement and then step 6 is executed. In step 6, the calculation result in step 5 is judged and compared with the factory-saved standard. When the required range is exceeded, entering a step 8 for prompting by a system; entering step 7 according with the correction requirement;

and 7, automatically executing zero point correction by the system.

And 8, prompting the system for a signal value system with excitation and without excitation.

According to the automatic zero point correction method for the electromagnetic water meter, the meter can automatically identify the influence of different environments on the zero point. And in the discontinuous mode, signals under no excitation are used as comparison values, so that the correction is more correct. The problem of the low measurement accuracy of velocity of flow of electromagnetic water gauge is solved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be construed as limiting the invention. Other modifications of the invention will occur to those skilled in the art without the benefit of this disclosure and it is intended to cover within the scope of the invention any modifications that fall within the spirit and scope of the invention or the equivalents thereof which may be substituted by one of ordinary skill in the art without departing from the scope of the invention.