阅读说明：本技术 一种高压激励的惠斯顿电桥测量方法 (High-voltage excited Wheatstone bridge measuring method ) 是由 秦小虎 刘亚蒙 黄畅悦 万成 于 2021-01-08 设计创作，主要内容包括：本发明涉及仪器仪表检测技术领域,为一种高压激励的惠斯顿电桥测量方法,包括以下步骤：S1,将惠斯顿电桥的桥臂固定电压变换为激励脉冲电压,取消固定电压供给,并跟随被测量设备灵敏度系数动态调节所述激励脉冲的激励电压的幅度；S2,当所述激励脉冲电压进入平稳保持区间时,开启ADC采样；S3,当数据采样完成,触发关断惠斯登电桥的激励脉冲电压,停止对惠斯顿电桥电压供应,整体进入下降区间,ADC采样停止。通过对常规电桥的修改,引入脉冲测量方式后,可大幅提升惠斯顿电桥驱动电压,提升灵敏度,同时降低测量功耗,大幅降低长期直流供电带来的发热问题。(The invention relates to the technical field of instrument and meter detection, in particular to a high-voltage excited Wheatstone bridge measuring method, which comprises the following steps: s1, converting the fixed voltage of the bridge arm of the Wheatstone bridge into excitation pulse voltage, canceling the fixed voltage supply, and dynamically adjusting the amplitude of the excitation voltage of the excitation pulse along with the sensitivity coefficient of the measured equipment; s2, when the excitation pulse voltage enters a steady holding interval, starting ADC sampling; and S3, when the data sampling is completed, triggering and turning off the excitation pulse voltage of the Wheatstone bridge, stopping supplying the voltage of the Wheatstone bridge, and stopping the ADC sampling when the whole body enters a descending interval. Through the modification to conventional electric bridge, introduce the pulse measurement mode after, can promote wheatstone electric bridge driving voltage by a wide margin, promote sensitivity, reduce simultaneously and measure the consumption, reduce the problem of generating heat that long-term DC power supply brought by a wide margin.)

1. A method of high voltage stimulated wheatstone bridge measurement, comprising the steps of:

s1, converting the fixed voltage of the bridge arm of the Wheatstone bridge into excitation pulse voltage, canceling the fixed voltage supply, and dynamically adjusting the amplitude of the excitation voltage of the excitation pulse along with the sensitivity coefficient of the measured equipment;

s2, when the excitation pulse voltage enters a steady holding interval, starting ADC sampling;

and S3, when the data sampling is completed, triggering and turning off the excitation pulse voltage of the Wheatstone bridge, stopping supplying the voltage of the Wheatstone bridge, and stopping the ADC sampling when the whole body enters a descending interval.

2. The high voltage excited wheatstone bridge measurement method according to claim 1, wherein said S1 specifically comprises: if the current signal sensitivity of the measured equipment is detected to be low, the excitation amplitude of the excitation pulse is increased, so that the bridge voltage output difference value is increased, and the purpose of improving the measurement sensitivity is achieved; if the signal sensitivity of the measured equipment is detected to be higher, the excitation voltage of the excitation pulse is reduced to reduce the sensitivity.

3. The high-voltage excited wheatstone bridge measurement method according to claim 1 or 2, wherein said S1 specifically comprises: the amplitude of the excitation voltage is dynamically adjusted, and when the amplitude of the detected signal is smaller, a higher pulse voltage is applied, so that the sensitivity is improved; when the amplitude of the detected signal is large, a small pulse voltage is applied to avoid ADC voltage saturation.

4. The high voltage excited wheatstone bridge measurement method of claim 1, wherein a pulse frequency of the excitation pulses is synchronized with the ADC sampling frequency.

5. The high voltage excited wheatstone bridge measurement method of claim 1, wherein the excitation voltage of said excitation pulse is a rising wave of a controlled slew rate.

6. The high voltage excited wheatstone bridge measurement method of claim 1, wherein between S1 and S2 further comprising: and dynamically adjusting the frequency of the excitation voltage to match the sampling period of the ADC, increasing the output frequency of the excitation pulse during high-density acquisition, and reducing the output frequency of the excitation pulse during sleep or low-density acquisition to achieve the highest efficiency ratio.

7. The high voltage excited wheatstone bridge measurement method according to claim 1, wherein said S2 specifically comprises: and in the process of the rising edge and the falling edge of the excitation pulse, the change amplitude of the slew rate is controlled within a preset range, so that the oscillation problem caused by sine wave excitation is avoided.

Technical Field

The invention relates to the technical field of instrument and meter detection, in particular to a high-voltage excited Wheatstone bridge measuring method.

Background

The wheatstone bridge is an important key technology in common stress-strain measurement, and is a bridge circuit composed of four resistors, wherein the four resistors are respectively called bridge arms of the bridge, and the wheatstone bridge measures the change of a physical quantity by using the change of the resistors. The method is commonly used for collecting weak signals of various weighing devices, medical equipment and the like.

Due to the principle of a wheatstone bridge balanced bridge. The system has very high sensitivity and can output very good signals after passing through the instrumentation amplifier. However, if the sensitivity of the tested element is not high enough, the signal passing through the instrumentation amplifier still does not meet the ideal requirement. The simplest way is to boost the voltage of the bridge. Thereby improving the sensitivity of the sense resistor. And increasing the voltage directly results in an increase in the overall wheatstone cambridge heating value. Even the influence of factors such as temperature drift and the like. If the power is too high, the bridge arm resistor is burnt, and how to control the heat productivity and the power consumption is avoided. The effective improvement of the measurement sensitivity becomes a key solution.

Disclosure of Invention

The invention provides a high-voltage excited Wheatstone bridge measuring method, which solves the technical problem of low measuring sensitivity of the Wheatstone bridge.

The invention provides a high-voltage excited Wheatstone bridge measuring method for solving the technical problems, which comprises the following steps:

s1, converting the fixed voltage of the bridge arm of the Wheatstone bridge into excitation pulse voltage, canceling the fixed voltage supply, and dynamically adjusting the amplitude of the excitation voltage of the excitation pulse along with the sensitivity coefficient of the measured equipment;

s2, when the excitation pulse voltage enters a steady holding interval, starting ADC sampling;

and S3, when the data sampling is completed, triggering and turning off the excitation pulse voltage of the Wheatstone bridge, stopping supplying the bridge voltage, and stopping ADC sampling when the whole body enters a descending interval.

Preferably, the S1 specifically includes: if the current signal sensitivity of the measured equipment is detected to be low, the excitation amplitude of the excitation pulse is increased, so that the bridge voltage output difference value is increased, and the purpose of improving the measurement sensitivity is achieved; if the signal sensitivity of the measured equipment is detected to be higher, the excitation voltage of the excitation pulse is reduced to reduce the sensitivity.

Preferably, the S1 specifically includes: the amplitude of the excitation voltage is dynamically adjusted, and when the amplitude of the detected signal is smaller, a higher voltage is applied, so that the sensitivity is improved; when the amplitude of the detected signal is larger, a smaller voltage is applied to avoid the saturation of the ADC voltage.

Preferably, the pulse frequency of the excitation pulse is synchronized with the ADC sampling frequency.

Preferably, the excitation voltage of the excitation pulse is a rising wave with a controllable slew rate.

Preferably, between S1 and S2, further comprising: and dynamically adjusting the frequency of the excitation voltage to match the sampling period of the ADC, increasing the output frequency of the excitation pulse during high-density acquisition, and reducing the output frequency of the excitation pulse during sleep or low-density acquisition to achieve the highest efficiency ratio.

Preferably, the S2 specifically includes: and in the process of the rising edge and the falling edge of the excitation pulse, the change amplitude of the slew rate is controlled within a preset range, so that the oscillation problem caused by sine wave excitation is avoided.

Has the advantages that: the invention provides a high-voltage excited Wheatstone bridge measuring method, which comprises the following steps: s1, converting the fixed voltage of the bridge arm of the Wheatstone bridge into excitation pulse voltage, canceling the fixed voltage supply, and dynamically adjusting the amplitude of the excitation voltage of the excitation pulse along with the sensitivity coefficient of the measured equipment; s2, when the excitation pulse voltage enters a steady holding interval, starting ADC sampling; and S3, when the data sampling is completed, triggering and turning off the excitation pulse voltage of the Wheatstone bridge, stopping supplying the voltage of the Wheatstone bridge, and stopping the ADC sampling when the whole body enters a descending interval. Through the modification to conventional electric bridge, introduce the pulse measurement mode after, can promote wheatstone electric bridge driving voltage by a wide margin, promote sensitivity, reduce simultaneously and measure the consumption, reduce the problem of generating heat that long-term direct current consumption brought by a wide margin.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings. The detailed description of the present invention is given in detail by the following examples and the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a schematic flow chart of a high voltage excited Wheatstone bridge measurement method according to the present invention.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention. The invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in FIG. 1, the present invention provides a high voltage excited Wheatstone bridge measurement method, comprising the following steps: s1, converting the fixed voltage of the bridge arm of the Wheatstone bridge into excitation pulse voltage, canceling the fixed voltage supply, and dynamically adjusting the amplitude of the excitation voltage of the excitation pulse along with the sensitivity coefficient of the measured equipment; s2, when the excitation pulse voltage enters a steady holding interval, starting ADC sampling; and S3, when the data sampling is completed, triggering and turning off the excitation pulse voltage of the Wheatstone bridge to forcibly pull down the voltage of the Wheatstone bridge, and the whole enters a descending interval, so that the ADC sampling is stopped.

When the measurement is started, the Wheatstone bridge is provided with an artificial programming voltage, namely an excitation pulse, along with the reason of the rising edge of the excitation pulse, the voltage rises until the voltage is stable, the ADC sampling is started at the moment, and when the excitation pulse enters the falling edge, the ADC sampling is stopped, and the measurement is turned off.

The specific implementation mode is as follows:

1. changing the fixed voltage of the bridge arm voltage of the Wheatstone bridge into a manual programming mode, and canceling the fixed voltage supply;

2. setting the voltage to be V1, the rising time to be S1 and the voltage rising speed per unit time to be V1/S1;

3. triggering the ADC to sample after entering the hold time S2;

4. when the data sampling is completed, the Wheatstone bridge voltage is triggered to be turned off, namely the S3 part of the trapezoidal wave, the Wheatstone bridge voltage is forcibly pulled down, and the whole goes into the descending interval.

The method includes sampling a (t) and sampling a (t) data of the ADC, wherein the data SPS (namely, the sampling frequency unit SPS, the number of bits obtained by sampling every second, for example, three points a (1), a (2) and a (3) are obtained in one second, each point is quantized in a 12-bit binary mode, the sampling rate is 3 x 12 to 36SPS, the baud rate is 36bps at the moment) and is synchronously changed along with the trigger frequency of an excitation pulse, when the sampling rate is increased, the frequency of a driving pulse is actively changed and is substantially synchronous with the sampling rate of the ADC, and the specific method includes that when the sampling of the ADC is triggered, a synchronous signal is increased and applied to the excitation pulse, and when the stable time is reached, the data SPS is acquired. By adjusting the trigger frequency to be synchronous with the sampling frequency of the ADC, the relationship between the sampling period and the excitation voltage of the excitation pulse is strictly matched.

Preferably, the S1 specifically includes: if the current signal sensitivity of the measured equipment is detected to be low, the excitation amplitude of the excitation pulse is increased, so that the bridge voltage output difference value is increased, and the purpose of improving the measurement sensitivity is achieved; if the signal sensitivity of the measured equipment is detected to be higher, the excitation voltage of the excitation pulse is reduced to reduce the sensitivity. The amplitude is dynamically adjusted along with the sensitivity coefficient of the measured equipment in the acquisition process of the ADC, the excitation amplitude of the excitation pulse is improved under the condition of weaker current signals, the bridge voltage output difference is increased, when the signal sensitivity is higher, the driving voltage can be actively reduced, namely the peak value of the excitation voltage of the excitation pulse is reduced, the sensitivity is reduced, and the saturation of the acquisition part of the ADC is avoided.

Preferably, the S1 specifically includes: the amplitude of the excitation voltage is dynamically adjusted, and when the amplitude of the detected signal is smaller, a higher pulse voltage is applied, so that the sensitivity is improved; when the amplitude of the detected signal is large, a small pulse voltage is applied to avoid ADC voltage saturation. The amplitude of the excitation voltage V is dynamically adjusted, and a higher voltage is applied to a detected signal with a smaller amplitude, so that the sensitivity is improved; and for the condition that the amplitude of the detected signal is large, a small voltage is applied to avoid the saturation of the ADC voltage.

Preferably, the pulse frequency of the excitation pulse is synchronized with the ADC sampling frequency. By adjusting the trigger frequency to be synchronous with the sampling frequency of the ADC, the relationship between the sampling period and the excitation voltage of the excitation pulse is strictly matched. The sampling accuracy of the ADC is ensured, and signal omission or noise sampling interference is avoided.

Preferably, the excitation voltage of the excitation pulse is a rising wave with a controllable slew rate. In order to avoid the harmonic interference problem caused by square wave driving, the SLOW RATE is strictly limited, the occurrence of interference is avoided, and peak pulse oscillation is reduced.

Preferably, the method further comprises the following steps between S1 and S2: and dynamically adjusting the frequency of the excitation voltage to match the sampling period of the ADC, increasing the output frequency of the excitation pulse during high-density acquisition, and reducing the output frequency of the excitation pulse during sleep or low-density acquisition to achieve the highest efficiency ratio. The frequency of the excitation voltage is dynamically adjusted, the sampling period of the ADC is strictly matched, the output frequency is improved during high-density acquisition, and the pulse output frequency is reduced during sleep or low-density acquisition, so that the highest efficiency ratio is achieved.

Preferably, the S2 specifically includes: and controlling the change amplitude of the slew rate within a preset range in the processes of the rising edge and the falling edge of the excitation pulse. The ascending and descending process controls the change amplitude of the slew rate and reduces pulse interference. And the signal sensitivity and the anti-interference capability are improved.

Has the advantages that: the invention provides a high-voltage excited Wheatstone bridge measuring method, which comprises the following steps: s1, converting the fixed voltage of the bridge arm of the Wheatstone bridge into excitation pulse voltage, canceling the fixed voltage supply, and dynamically adjusting the amplitude of the excitation voltage of the excitation pulse along with the sensitivity coefficient of the measured equipment; s2, when the excitation pulse voltage enters a steady holding interval, starting ADC sampling; and S3, when the data sampling is completed, triggering and turning off the excitation pulse voltage of the Wheatstone bridge, stopping supplying the voltage of the Wheatstone bridge, and stopping the ADC sampling when the whole body enters a descending interval. Through the modification to conventional electric bridge, introduce the pulse measurement mode after, can promote wheatstone electric bridge driving voltage by a wide margin, promote sensitivity, reduce simultaneously and measure the consumption, reduce the problem of generating heat that long-term direct current consumption brought by a wide margin.

The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner; the present invention may be readily implemented by those of ordinary skill in the art as illustrated in the accompanying drawings and described above; however, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the scope of the invention as defined by the appended claims; meanwhile, any changes, modifications, and evolutions of the equivalent changes of the above embodiments according to the actual techniques of the present invention are still within the protection scope of the technical solution of the present invention.