WO2016029687A1 - 一种测量非金属容器中液体容量的方法和装置 - Google Patents

一种测量非金属容器中液体容量的方法和装置 Download PDF

Info

Publication number
WO2016029687A1
WO2016029687A1 PCT/CN2015/074957 CN2015074957W WO2016029687A1 WO 2016029687 A1 WO2016029687 A1 WO 2016029687A1 CN 2015074957 W CN2015074957 W CN 2015074957W WO 2016029687 A1 WO2016029687 A1 WO 2016029687A1
Authority
WO
WIPO (PCT)
Prior art keywords
liquid
container
mcu
capacitive sensing
measuring
Prior art date
Application number
PCT/CN2015/074957
Other languages
English (en)
French (fr)
Inventor
杨忠国
陈世穷
张宏伟
Original Assignee
深圳睿讴科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 深圳睿讴科技有限公司 filed Critical 深圳睿讴科技有限公司
Publication of WO2016029687A1 publication Critical patent/WO2016029687A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F22/00—Methods or apparatus for measuring volume of fluids or fluent solid material, not otherwise provided for

Definitions

  • the present invention is in the field of liquid measurement and, in particular, relates to a method and apparatus for measuring the volume of liquid in a non-metallic container.
  • the method for measuring the liquid capacity in the container mainly includes the labeling method of the outer wall of the container, the pressure change test method and the conventional capacitance induction test method.
  • the outer wall of the container needs to be marked with a scale, and the operator directly observes it by the naked eye.
  • the disadvantage of this method is that the outer wall of the container must be transparent; subject to the subjective factors of the operator, it is not easy to ensure the accuracy of the measurement results.
  • the defects of this method are: the cost of the pressure sensor is high, the assembly is difficult, especially the assembly space is small; the measurement accuracy is poor, the container needs to be placed horizontally, and the probability of misdetection is high; the pressure sensor needs to be in direct contact with the liquid, which is easy to pollute.
  • the accuracy of the liquid is also susceptible to the temperature and type of the liquid.
  • the disadvantage of this method is that the measurement accuracy is limited by the number of capacitive sensing sheets; as shown in Figure 1, due to the gap between the capacitive sensing sheets, the capacitive sensing sheet cannot be accurately measured when the liquid level is in the above gap.
  • the height of the liquid outlet surface makes the gap become a measurement dead angle, resulting in a large measurement error; the measurement circuit needs to be powered continuously, and the current liquid level cannot be judged after the power failure is restarted; it is susceptible to environmental influences and static interference.
  • the above three methods of measuring the liquid capacity cannot be accurately measured when the container is tilted.
  • the present invention provides a method and apparatus for measuring the liquid capacity in a non-metallic container, the container does not need to be transparent, does not depend on the subjective feeling of the person; the assembly is simple, the cost is low; the measurement accuracy is high, It can be measured seamlessly; it has good adaptability to the measurement environment; it can recognize the current liquid level after power-down and restart; it has good anti-interference performance; ultra-low power consumption; adapt to various usage scenarios, even if the container is tilted, accurate measurement can be realized.
  • the specific technical solutions are as follows:
  • a device for measuring the liquid capacity in a non-metallic container comprising a detection IC circuit, an MCU and at least two capacitive sensing sheets,
  • the detecting IC circuit is respectively coupled to each of the capacitive sensing sheets, and the detecting IC circuit is coupled to the MCU through a first communication interface;
  • the at least two capacitive sensing sheets each have a protruding portion and a concave portion In part, a protruding portion of one of the capacitive sensing sheets protrudes into a concave portion of the adjacent one of the capacitive sensing sheets such that adjacent capacitive sensing sheets are interlaced with each other.
  • the apparatus further includes a vector sensor coupled to the MCU via a second communication interface.
  • the device further includes a power switch and a power source, the power source supplies power to the detection IC circuit through the power switch, the power switch is coupled to the MCU through an IO communication interface, and the MCU can turn the MCU on or off switch.
  • the device further includes a reference capacitive sensing sheet, the reference capacitive sensing sheet being separately coupled to the detecting IC circuit, and the reference capacitive sensing sheet being disposed on a position on the outer wall of the container where the liquid level cannot be reached.
  • the first communication interface and the second communication interface are both IIC, SPI or UART communication interfaces.
  • the at least two capacitive sensing sheets are each formed of a copper foil uniformly distributed from top to bottom arranged on a flexible PCB.
  • the shape of the at least two capacitive sensing sheets is zigzag.
  • a copper mesh is grounded on both sides of the flexible PCB and on the back side.
  • the flexible PCB is attached to the outer wall of the container from top to bottom using glue.
  • a method of measuring the volume of liquid in a non-metallic container comprising the steps of:
  • a flexible PCB corresponding to the shape and size of the container, the flexible PCB comprising at least two copper foils having a certain area, each of the copper foils forming a capacitive sensing sheet, that is, the composition At least two capacitive sensing sheets; each of the at least two capacitive sensing sheets has a protruding portion and a concave portion, and a protruding portion of one of the capacitive sensing sheets protrudes into a concave portion of another of the capacitive sensing sheets, thereby Interleaving adjacent capacitive sensing sheets;
  • the detecting IC circuit detects the change of the plurality of capacitive sensing sheets corresponding to the change in the liquid level Capacitance value data;
  • the detection IC circuit is coupled to the MCU through the first communication interface, and transmits the detected data to the MCU; and a vector sensor is disposed on the outer wall of the container for detecting the tilt of the container Angle, the vector sensor is coupled to the MCU through the second communication interface, and transmits the detected data to the MCU;
  • V ⁇ ⁇ f(x, y, z) dxdydz
  • the shape of the at least two capacitive sensing sheets is zigzag.
  • the method further includes the step of laying a copper grid ground around the flexible PCB.
  • the method further includes the step of attaching the flexible PCB to the outer wall of the container from top to bottom using glue.
  • the first communication interface and the second communication interface are both IIC, SPI or UART communication interfaces.
  • the data detected by the detection IC circuit and transmitted to the MCU is: a capacitance value C1 of the capacitance sensing sheet A corresponding to the liquid level height in the container, and another capacitance corresponding to the liquid surface height in the container
  • the capacitance value C2 of the sensing sheet B and the number N of inductive capacitive sheets completely below the liquid level; the data detected by the vector sensor and transmitted to the MCU is: the tilt angle of the container.
  • the method further includes the steps of: setting a reference capacitance sensing sheet, the reference capacitance sensing sheet being separately coupled to the detecting IC circuit, and calculating the height of the current liquid level after the power failure restart.
  • the method further includes the step of detecting, by the detection of the vector sensor, the MCU detecting whether the container has an action of pouring or pouring liquid; in the absence of the action of pouring or pouring liquid And the MCU turns off the power switch to stop supplying power to the detecting IC circuit; when the MCU detects that the container has the action of pouring or pouring liquid, the MCU turns on the power switch to The detection IC circuit supplies power.
  • FIG. 1 is a schematic diagram of a conventional capacitive sensing test method in the prior art
  • Figure 2 is a schematic view of the apparatus for measuring the liquid capacity in a non-metallic container in the present invention
  • FIG. 3a-3c are schematic diagrams showing the shape and arrangement of a capacitance sensing sheet according to the present invention, wherein FIG. 3a is a state diagram when the container is tilted, FIG. 3b is a state diagram when the container is horizontal, and FIG. 3c is another shape of the capacitance sensing sheets A and B. schematic diagram.
  • FIG. 5 is a schematic diagram of detecting a tilt angle of a vector sensor according to the present invention.
  • Figure 6 is a schematic view showing the change of the liquid surface before and after the container is inclined according to the present invention.
  • FIG. 7 is a schematic diagram of coordinate axis transformation and liquid capacity calculation before and after tilting of a container according to the present invention, wherein a is a schematic diagram of an initial state, and b is a schematic diagram of a coordinate axis conversion of a tilted state.
  • the apparatus for measuring the liquid capacity in a non-metallic container includes a capacitive sensing sheet, a detecting IC circuit, an MCU, a vector sensor, a power switch, and a power source.
  • the power switch is connected to the MCU through the IO interface.
  • a flexible PCB ie, a printed circuit board
  • the flexible PCB including at least two (eg, three, four, five, or more) copper foil having a certain area
  • Each copper foil constitutes a capacitive sensing piece, which is represented by symbols T1, T2, ..., Tn.
  • the capacitive sensing piece on the outer wall of the container can be arranged according to the precision required for the measurement. For example, when the height of the measured container is 150 mm, the capacitive sensing piece on the flexible PCB can be evenly arranged from top to bottom 15 each of the capacitive sensing pieces. Can be directly positioned to an accuracy of 10mm.
  • Each copper foil has a protruding portion and a concave portion. There is a gap between two adjacent copper foils, and a protruding portion of one of the copper foils protrudes into a concave portion of the other copper foil.
  • all of the adjacent copper foils are interdigitated, and adjacent copper foils overlap each other when viewed from one side of the flexible PCB in a direction perpendicular to the longitudinal axis of the flexible PCB.
  • two capacitive sensing sheets A and B sense the height of the liquid surface, thereby improving the measurement accuracy. If the angle of inclination of the container is large, there are three or more capacitive sensing sheets that simultaneously sense the height of the liquid level.
  • the gap between two adjacent copper foils is the production process gap, which is generally 0.1 mm or less.
  • the shape of the copper foil is zigzag, but the shape of the copper foil is not limited to a zigzag shape as long as it has a protruding portion and a concave portion and can be mutually staggered in shape, thereby realizing at least two capacitive sensing sheets at the same time.
  • Inductive liquid level height and thus improved measurement accuracy, are in accordance with the inventive spirit of the present invention, as shown in Fig. 3c. According to the inventive spirit of the present invention, those skilled in the art can easily set the shape of the copper foil.
  • a copper grid is grounded around the flexible PCB and on the back to shield external interference, such as human contact interference and static interference.
  • the flexible PCB is attached to the outer wall of the container from top to bottom using 3M glue.
  • a vector sensor is disposed on the outer wall of the container to detect the direction and angle of tilt of the container.
  • the vector sensor is coupled to the MCU via a communication interface and transmits data to the MCU.
  • the communication interface is an IIC, SPI, UART or other communication interface.
  • the container In the initial state, the container is placed horizontally, and the vector sensor performs calibration of the three-direction coordinates of X, Y, and Z. As shown in FIG. 5, when the container is tilted, the vector sensor calculates the tilt angle of the container in three directions according to the data of the three directions X', Y', and Z' after tilting, and transmits the tilt angle data through the communication interface. To the MCU.
  • the detecting IC circuit is coupled to each of the capacitive sensing sheets one by one.
  • the capacitance values of the corresponding capacitive sensing sheets change, including a capacitive sensing sheet that is flush with the liquid surface and an inductive capacitive sheet that is completely below the liquid level.
  • the detection IC circuit is connected to the MCU through a communication interface, and transmits the detected data to the MCU. Place The communication interface is IIC, SPI, UART or other communication interface. As shown in FIG.
  • the detecting IC circuit respectively detects the capacitance value C1 of the capacitive sensing sheet A corresponding to the liquid level in the container, the capacitance value C2 of the capacitive sensing sheet B, and the capacitive sensing sheets A and B in all capacitive sensing.
  • the position in the sheet (thereby obtaining the number N of inductive capacitive sheets completely below the liquid level), and passing the capacitance value C1, the capacitance value C2, and the number N of inductive capacitive sheets completely below the liquid level through the communication interface Transfer to the MCU.
  • the MCU can obtain the M value according to the following algorithm (for the calculation method, see the following). At the same time, the number N of inductive capacitive sheets completely below the liquid level can be measured.
  • the adjacent capacitive sensing sheets A and B are such that the capacitive sensing sheets A and B are located at coordinates as shown in FIG. 4, the capacitive sensing sheet has a width of 2 d, a single height e, a sawtooth height g, and a production process gap f.
  • the angle between the capacitive sensing sheet and the plane circle is ⁇ , and the corresponding angle of the projection on the ellipse is also ⁇ .
  • ⁇ (2d/2D ⁇ )*360
  • ⁇ a and ⁇ are the data obtained by the vector sensor detection ( ⁇ a is the clamp of the Z-axis and the Z-axis) Angle, ⁇ is the angle between the X axis and the X' axis).
  • the area of the capacitive sensing sheet A under the liquid surface is S1
  • the area of the capacitive sensing sheet B under the liquid surface is S2.
  • C1 and C2 are the capacitance value C1 of the capacitance sensing sheet A and the capacitance value C2 of the capacitance sensing sheet B detected by the detection IC circuit.
  • ⁇ is related to ⁇ and ⁇ a, and can be obtained by the above-mentioned calculation method of ⁇ , and e, f is a fixed value known by design. So you can find the M value.
  • Set the container bottom plane function Z 0, mathematically model the container inner wall function f(x, y, z) for various irregular containers, and calculate the liquid capacity in the container according to the advanced mathematical multiple integral algorithm. It should be noted that when the container is not inclined, each inclination angle is zero, so it can be regarded as a special case of inclination, and the same algorithm can be used to obtain the capacity of the liquid in the container.
  • the coordinate transformation of the tilted container is shown in Figure 7.
  • the height h of the point C is the data sent by the MCU according to the received detection IC circuit (the capacitance value C1, the capacitance value C2, and the number N of the induction capacitance sheets completely below the liquid level), and the vector sensor transmits
  • the data (inclination angles ⁇ a and ⁇ , ⁇ a is the angle between the Z axis and the Z′ axis, and ⁇ is the angle between the X axis and the X′ axis) is the calculated liquid level height h.
  • the cylinder expression is f(x, y, z) and can be mathematically modeled.
  • the reference capacitance sensing piece Ta is set at a position that is not affected by the change in the liquid level (ie, regardless of the change in the liquid level or the liquid level cannot be reached). As shown in FIG. 2, the reference capacitance sensing sheet Ta is separately coupled to the detection IC circuit.
  • the detection IC circuit After each power failure and power-on, the detection IC circuit first detects the capacitance value of the reference capacitance sensing piece Ta, and then separately detects the capacitance values of the capacitance sensing pieces T1-Tn, and then respectively compares the capacitance values of the capacitance sensing pieces T1-Tn with The capacitance value of the reference capacitance sensing piece Ta is compared to obtain a capacitance sensing piece flush with the liquid surface and a capacitance change amount of the sensing capacitance piece completely below the liquid surface, so that the MCU is accurately measured according to the above-mentioned liquid level height. Calculate the liquid capacity.
  • the reference capacitance sensor Ta function is not limited to the power-down restart detection, and can be used as a calibration reference for environmental changes.
  • the capacitance sensing sheets T1-Tn can be parameter-compensated, and in order to improve the compensation accuracy, the compensation can be appropriately increased.
  • the number of reference capacitive sensing sheets Ta is not limited to the power-down restart detection, and can be used as a calibration reference for environmental changes.
  • the capacitance sensing sheets T1-Tn can be parameter-compensated, and in order to improve the compensation accuracy, the compensation can be appropriately increased.
  • the number of reference capacitive sensing sheets Ta can be appropriately increased.
  • the MCU can detect whether the container has been poured or poured into the liquid. In the absence of the above action, the MCU turns off the power switch through the IO communication interface to stop supplying power to the detection IC circuit, so that the detection IC circuit does not work, thereby reducing power consumption.
  • the MCU detects that the container has an action of pouring or pouring liquid
  • the MCU turns on the power switch through the IO communication interface to supply power to the detection IC circuit, and the MCU calculates the liquid capacity according to the data transmitted by the detection IC circuit and the vector sensor.
  • the time for detecting the IC circuit is much less than the time when it is not working (according to the estimation, the ratio of the time during which the IC circuit is operated to the time when it is not working is about 1: 50), by stopping the supply of power to the detection IC circuit, the purpose of power saving is achieved. Battery life can be extended when running on battery power.

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)

Abstract

一种测量非金属容器中液体容量的方法和装置，其中，该装置包括检测IC电路、MCU和至少两个电容感应片，所述检测IC电路与每一个所述电容感应片分别一一联接，并通过第一通讯接口与所述MCU相联接；所述至少两个电容感应片由软性PCB上布置的铜箔形成，且均具有突出部分和凹下部分，一个所述电容感应片的突出部分伸入相邻另一个所述电容感应片的凹下部分，从而使得相邻电容感应片相互交错。所述方法和装置可以实现无缝测量，测量精度较高，掉电重启后可以识别当前的液面高度。

Description

一种测量非金属容器中液体容量的方法和装置 技术领域
本发明属于液体测量领域，具体而言，涉及一种测量非金属容器中液体容量的方法和装置。
背景技术
现有技术中，测量容器中液体容量的方法主要有容器外壁标示刻度法、压力变化测试法和传统电容感应测试法。利用容器外壁标示刻度法测量液体容量时，容器的外壁需标示刻度，操作者通过肉眼直接对比观察。此方法存在的缺陷是：容器外壁必须透明；受操作者主观因素影响较大，不容易保证测量结果的精度。利用压力变化测试法测量液体容量时，当容器内液体重量变化时，必然产生压力的变化，通过设置压力传感器感知上述压力的变化，并将这种压力变化换算为液体容量。此方法存在的缺陷是：压力传感器成本较高，装配困难，尤其是装配空间狭小时；测量精度较差，容器需要水平摆放，误测几率较高；压力传感器需要与液体直接接触，容易污染液体，其测试精度也易受液体温度及种类的影响。利用传统电容感应测试法测量液体容量时，有无液体，会导致电容感应片的电容量发生变化，通过比较电容量的变化值以确定液体的高度。此方法存在的缺陷是：测量精度受电容感应片数量的限制；如图1所示，由于电容感应片之间存在生产工艺导致的间隙，当液面位于上述间隙时，电容感应片无法准确测出液面高度，从而使得上述间隙成为测量死角，导致测量误差较大；测量电路需要一直供电，掉电重启后无法判断当前的液面高度；易受环境影响和静电干扰。以上三种液体容量的测试方法，当容器倾斜时，均无法进行准确测量。
发明内容
针对现有技术中存在的缺陷，本发明提出一种测量非金属容器中液体容量的方法和装置，容器无须透明，不依赖于人的主观感觉；装配简单，成本较低；测量精度较高，可以无缝测量；对测量环境适应性好；掉电重启后可以识别当前的液面高度；抗干扰性能好；超低功耗；适应各种使用场景，即使容器倾斜，也能实现准确测量。具体技术方案如下：
一种测量非金属容器中液体容量的装置，包括检测IC电路、MCU和至少两个电容感应片， 所述检测IC电路与每一个所述电容感应片分别一一联接，所述检测IC电路通过第一通讯接口与所述MCU相联接；所述至少两个电容感应片均具有突出部分和凹下部分，一个所述电容感应片的突出部分伸入相邻另一个所述电容感应片的凹下部分，从而使得相邻电容感应片相互交错。
所述装置进一步包括矢量传感器，所述矢量传感器通过第二通讯接口与所述MCU相联接。
所述装置进一步包括电源开关和电源，所述电源通过所述电源开关向所述检测IC电路供电，所述电源开关通过IO通讯接口与所述MCU相联接，所述MCU可打开或关闭所述电源开关。
所述装置进一步包括参考电容感应片，所述参考电容感应片与所述检测IC电路单独联接，所述参考电容感应片被设置于所述容器外壁上的、液面高度无法达到的位置。
所述第一通讯接口和第二通讯接口均为IIC、SPI或UART通讯接口。
所述至少两个电容感应片均由布置于软性PCB上的、自上而下均匀分布的铜箔构成。
所述至少两个电容感应片的形状均为锯齿形。
所述软性PCB四周和背面均铺设铜网格接地。
使用胶将所述软性PCB自上而下贴装在所述容器的外壁。
一种测量非金属容器中液体容量的方法，其特征在于，包括以下步骤：
(1)制作与所述容器的形状和尺寸相对应的软性PCB，所述软性PCB包括至少两块具有一定面积的铜箔，每块所述铜箔均构成一个电容感应片，即构成至少两个电容感应片；所述至少两个电容感应片均具有突出部分和凹下部分，一个所述电容感应片的突出部分伸入相邻另一个所述电容感应片的凹下部分，从而使得相邻电容感应片相互交错；
(2)检测IC电路与每一个电容感应片分别一一联接；当所述容器中液面高度变化时，所述检测IC电路检测与液面高度变化相对应的若干电容感应片的变化后的电容值数据；所述检测IC电路通过第一通讯接口与MCU相联接，并将检测得到的数据传送给所述MCU；在所述容器的外壁上设置矢量传感器，用以检测所述容器倾斜的角度，所述矢量传感器通过第二通讯接口与MCU相联接，并将检测得到的数据传送给所述MCU；
(3)根据接收到的所述检测IC电路和所述矢量传感器发送的数据，所述MCU计算出液面的高度；
(4)根据计算得到的液面高度，如果所述容器的形状是规则的，则所述MCU结合所述容器的尺寸计算出所述容器内液体的容量；如果所述容器的形状是不规则的，则所述MCU对于所述容器进行数学建模，根据多重积分算法计算出所述容器内液体的容量，即利用公式 V＝∫∫∫Ωf(x，y，z)dxdydz计算所述容器内液体的容量，其中，Ω为积分区域即所述容器内液体表面区域，f(x，y，z)为液体密度的表达式。
所述至少两个电容感应片的形状均为锯齿形。
所述方法进一步包括以下步骤：所述软性PCB四周和背面铺设铜网格接地。
所述方法进一步包括以下步骤：使用胶将所述软性PCB自上而下贴装在所述容器的外壁。
所述第一通讯接口和第二通讯接口均为IIC、SPI或UART通讯接口。
所述检测IC电路检测并传送给所述MCU的数据是：与所述容器中液面高度相对应的电容感应片A的电容值C1、与所述容器中液面高度相对应的另一电容感应片B的电容值C2以及完全处于液面以下的感应电容片的数量N；所述矢量传感器检测并传送给所述MCU的数据是：所述容器的倾斜角度。
所述步骤(3)中液面高度的计算方法是：在接收电容值C1、电容值C2、完全处于液面以下的感应电容片的数量N和所述容器的倾斜角度数据后，所述MCU经计算得到M值，再由液面高度的计算公式h＝P*N+M可得到液面高度h，其中，P为测量的精度，N为完全处于液面以下的感应电容片的数量。
所述方法进一步包括以下步骤：设置参考电容感应片，所述参考电容感应片与所述检测IC电路单独联接，可在掉电重启后计算得到当前液面的高度。
所述方法进一步包括以下步骤：通过所述矢量传感器的检测，所述MCU可检测出所述容器是否有倒出或倒入液体的动作；在没有所述倒出或倒入液体的动作的情况下，所述MCU关闭电源开关从而停止向所述检测IC电路供电；当所述MCU检测到所述容器有所述倒出或倒入液体的动作时，所述MCU打开所述电源开关从而向所述检测IC电路供电。
附图说明
图1为现有技术中传统电容感应测试法的示意图；
图2为本发明中测量非金属容器中液体容量的装置的示意图；
图3a-3c为本发明中电容感应片的形状和布置示意图，其中图3a为容器倾斜时的状态图，图3b为容器水平时的状态图，图3c为电容感应片A、B的其它形状示意图。
图4为本发明中计算M值的示意图；
图5为本发明中矢量传感器检测倾斜角度的示意图；
图6为本发明中容器倾斜前后液面变化示意图；
图7为本发明中容器倾斜前后坐标轴变换及液体容量计算示意图，其中a为初始状态示意图，b为倾斜状态坐标轴换算示意图。
具体实施方式
如图2所示，测量非金属容器中液体容量的装置包括电容感应片、检测IC电路、MCU、矢量传感器、电源开关和电源。电源开关通过IO接口与MCU相联接。
制作与容器的形状和尺寸相对应的软性PCB(即印刷电路板)，所述软性PCB包括至少两块(如三块、四块、五块或更多块)具有一定面积的铜箔，每块铜箔均构成一个电容感应片，用符号T1、T2、…...、Tn表示。可根据测量所需的精度来布置容器外壁上的电容感应片，例如被测量的容器高度为150mm时，软性PCB上的电容感应片可以自上而下均匀布置15个，每一个电容感应片可以直接定位到10mm的精度。
每块铜箔均具有突出部分和凹下部分。相邻两块铜箔之间具有间隙，并且，其中一块铜箔的突出部分伸入另一块铜箔的凹下部分。由此，所有相邻铜箔均相互交错，当从软性PCB的一侧沿垂直于软性PCB纵向轴线的方向观察时，相邻的铜箔彼此重叠。由此，如图3a所示，同时有两个电容感应片A、B感应液面的高度，进而提高测量精度。如果容器倾斜角度较大，则有三个或更多电容感应片同时感应液面的高度。相邻两块铜箔之间的间隙为生产工艺间隙，一般为0.1mm或更小。如图1所示，铜箔的形状为锯齿形，但铜箔的形状不限于锯齿形，只要具有突出部分和凹下部分并且能够在形状上相互交错，从而实现同时有至少两个电容感应片感应液面的高度，进而提高测量精度，都符合本发明的发明精神，如图3c所示的形状。根据本发明的发明精神，本领域的技术人员可对铜箔的形状进行简单设定。
软性PCB四周和背面铺设铜网格接地，以屏蔽外界干扰，如人手接触干扰和静电干扰。使用3M胶将软性PCB自上而下贴装在容器的外壁。
在容器的外壁上设置矢量传感器，用以检测容器倾斜的方向和角度。所述矢量传感器通过通讯接口与MCU相联接，并将数据传送给MCU。所述通讯接口是IIC、SPI、UART或其它通讯接口。初始状态时，容器水平放置，矢量传感器进行X、Y、Z三方向坐标的校准。如图5所示，当容器倾斜时，所述矢量传感器根据倾斜后X`、Y`、Z`三方向的数据，计算出容器在三方向的倾斜角度，并通过通讯接口将倾斜角度数据传送给MCU。
检测IC电路与每一个电容感应片分别一一联接。当容器中液面高度变化时，对应的若干电容感应片的电容值发生变化，包括与液面齐平的电容感应片以及完全处于液面以下的感应电容片。检测IC电路通过通讯接口与MCU相联接，并将检测得到的数据传送给MCU。所 述通讯接口是IIC、SPI、UART或其它通讯接口。如图3a-3c所示，检测IC电路分别检测与容器中液面高度相对应的电容感应片A的电容值C1、电容感应片B的电容值C2以及电容感应片A、B在所有电容感应片中所处的位置(由此可得到完全处于液面以下的感应电容片的数量N)，并将电容值C1、电容值C2和完全处于液面以下的感应电容片的数量N通过通讯接口传送给MCU。MCU根据以下算法即可得到M值(计算方法见以下内容)。同时可以测得完全处于液面以下的感应电容片的数量N，MCU根据由液面高度的计算公式h＝P*N+M(其中，P为测量的精度，以上实施例中的测量的精度P为10mm，如前所述，测量的精度P取决于容器高度和电容感应片的多少；N为完全处于液面以下的感应电容片的数量)可得到液面高度h。
M值的计算方法
如图4所示，相邻电容感应片A、B，令电容感应片A、B位于如图4中所示的坐标，电容感应片宽度2d，单个高度e，锯齿高度g，生产工艺间隙f，电容感应片展开后与水平面之间的夹角α，电容感应片展开后与水平面界线的长度为L，液面与Y轴交点的坐标为(0，M)，则液面的表达式为：Y＝tan(α)*X+M，
液面与内壁切线为一椭圆，则椭圆的短半轴长为D，长半轴长为R＝D/cos(△a)，焦距2c由
Figure PCTCN2015074957-appb-000001
得c＝D*tan(△a)
电容感应片在平面圆的夹角为σ，则椭圆上投影对应的夹角也为σ
σ＝(2d/2Dπ)*360
α的计算方法
根据椭圆周长计算积分公式
Figure PCTCN2015074957-appb-000002
Figure PCTCN2015074957-appb-000003
根据数学计算得：
Cos(α)＝D/L
Figure PCTCN2015074957-appb-000004
式中，σ＝(2d/2Dπ)*360；△a和θ为矢量传感器检测所得到的数据(△a为Z轴与Z`轴的夹 角，θ为X轴与X`轴的夹角)。
所以α可计算得出。
电容感应片B下侧锯齿形状表达式为Y＝f(X)，电容感应片B上侧锯齿形状表达式为Y＝f(X)+e，电容感应片A下侧锯齿形状表达式为Y＝f(X)+e+f，电容感应片A上侧锯齿形状表达式为Y＝f(X)+2e+f，
电容感应片A位于液面下的面积为S1，电容感应片B位于液面下的面积为S2，
S1为Y＝f(X)+e+f，Y＝f(X)+2e+f，Y＝tan(α)*X+M，X＝d四条线围成的封闭平面，
S2为Y＝f(X)Y＝f(X)+e，Y＝tan(α)*X+M，X＝d四条线围成的封闭平面，
根据四线法可求得S1＝Ψ(α，M，e，f)，
Figure PCTCN2015074957-appb-000005
根据电容计算公式，
C＝εS/4πkd
得
Figure PCTCN2015074957-appb-000006
C1，C2是由检测IC电路所检测得到的电容感应片A的电容值C1、电容感应片B的电容值C2。α与θ、△a相关，可由上面提到的α的计算方法得出，e，f为设计已知的固定数值。所以可求得M值。
如图6所示，MCU根据接收到的倾斜角度数值以及根据计算得到的液面高度h，计算出C点的平面函数Z＝pX+q，p、q为常数。设容器底平面函数Z＝0，针对各种不规则的容器，对容器内壁函数进行数学建模f(x，y，z)，根据高等数学多重积分算法计算出容器内液体的容量。需要说明的是，当容器不倾斜时，各倾斜角度为零，因此可以将其视为倾斜的一种特殊情形，可用相同算法得出容器内液体的容量。
当容器倾斜时，对于容器内液体容量的计算，举例说明如下：
为使计算简化，对倾斜后的容器进行坐标变换，如图7所示。此时，C点的高度h即为MCU根据接收到的检测IC电路所发送的数据(电容值C1、电容值C2和完全处于液面以下的感应电容片的数量N)、矢量传感器所发送的数据(倾斜角度△a和θ，△a为Z轴与Z`轴的夹角，θ为X轴与X`轴的夹角)所计算得到的液面高度h。
对于C点的坐标(X，Y，Z)，其中，X＝f(z)*cosθ，Y＝f(z)*sinθ，Z＝h。本例以半径为D的圆柱体为例，因此f(z)＝D，则液面的数学表达式为Z＝mX+n＝X*tan△a+h-D*cosθ*tan△a，液面通过C点，令m＝tan△a，n＝h-D*cosθ*tan△a。
柱面表达式为f(x，y，z)，可通过数学建模得出。本例以圆柱体为例，因此D2＝X2+Y2，圆柱底平面函数表达式Z＝0。圆柱体体积V用高等数学三重积分计算： V＝∫∫∫Ωf(x，y，z)dxdydz式中，Ω为积分区域即容器内液体表面区域，f(x，y，z)为液体密度的表达式，如果容器内的液体是水，则f(x，y，z)＝1。
对于圆柱体，Ω由D2＝X2+Y2、Z＝0、Z＝X*m+n围成的区域
Figure PCTCN2015074957-appb-000007
其中，m＝tan△a，n＝h-D*cosθ*tan△a，r是公式中的代数，dr是对r的积分。
在容器外壁上，选择不受液面高度变化影响(即与液面高度变化无关，或者说液面高度无法达到)的位置，设置参考电容感应片Ta。如图2所示，参考电容感应片Ta与检测IC电路单独联接。每次掉电并重新上电后，检测IC电路首先检测参考电容感应片Ta的电容值，再分别检测电容感应片T1-Tn的电容值，然后将电容感应片T1-Tn的电容值逐一与参考电容感应片Ta的电容值进行比较，得出与液面齐平的电容感应片以及完全处于液面以下的感应电容片的电容变化量，从而根据上述的液位高度精确测量方法，由MCU计算出液体容量。
参考电容感应片Ta功能不限于掉电重启检测，同时可以作为环境变化的一个校准参考，如温度变化时，可以对电容感应片T1-Tn进行参数补偿，同时为了提高补偿准确度，可以适当增加参考电容感应片Ta的数量。
通过软件计算和矢量传感器的检测，MCU可检测出容器是否有倒出或倒入液体的动作。在没有上述动作的情况下，MCU通过IO通讯接口关闭电源开关从而停止向检测IC电路供电，使检测IC电路不工作，从而减少电量的消耗。当MCU检测到容器有倒出或倒入液体的动作时，MCU通过IO通讯接口打开电源开关从而向检测IC电路供电，根据检测IC电路以及矢量传感器传送的数据，MCU计算出液体容量。因为一般家用容器倒出或倒入液体的次数很少，所以检测IC电路工作的时间远少于不工作的时间(根据估算，检测IC电路工作的时间与不工作的时间的比例约为1：50)，通过停止向检测IC电路供电，达到了节电目的。当使用电池供电时，可延长电池工作时间。

Claims (18)

  1. 测量非金属容器中液体容量的装置，包括检测IC电路、MCU和至少两个电容感应片，其特征在于，所述检测IC电路与每一个所述电容感应片分别一一联接，所述检测IC电路通过第一通讯接口与所述MCU相联接；所述至少两个电容感应片均具有突出部分和凹下部分，一个所述电容感应片的突出部分伸入相邻另一个所述电容感应片的凹下部分，从而使得相邻电容感应片相互交错。
  2. 根据权利要求1所述的测量非金属容器中液体容量的装置，其特征在于，所述装置进一步包括矢量传感器，所述矢量传感器通过第二通讯接口与所述MCU相联接。
  3. 根据权利要求2所述的测量非金属容器中液体容量的装置，其特征在于，所述装置进一步包括电源开关和电源，所述电源通过所述电源开关向所述检测IC电路供电，所述电源开关通过IO通讯接口与所述MCU相联接，所述MCU可打开或关闭所述电源开关。
  4. 根据权利要求1所述的测量非金属容器中液体容量的装置，其特征在于，所述装置进一步包括参考电容感应片，所述参考电容感应片与所述检测IC电路单独联接，所述参考电容感应片被设置于所述容器外壁上的、液面高度无法达到的位置。
  5. 根据权利要求1-4任一项所述的测量非金属容器中液体容量的装置，其特征在于，所述第一通讯接口和第二通讯接口均为IIC、SPI或UART通讯接口。
  6. 根据权利要求1-4任一项所述的测量非金属容器中液体容量的装置，其特征在于，所述至少两个电容感应片均由布置于软性PCB上的、自上而下均匀分布的铜箔构成。
  7. 根据权利要求1-4任一项所述的测量非金属容器中液体容量的装置，其特征在于，所述至少两个电容感应片的形状均为锯齿形。
  8. 根据权利要求6所述的测量非金属容器中液体容量的装置，其特征在于，所述软性PCB四周和背面均铺设铜网格接地。
  9. 根据权利要求6所述的测量非金属容器中液体容量的装置，其特征在于，使用胶将所述软性PCB自上而下贴装在所述容器的外壁。
  10. 一种测量非金属容器中液体容量的方法，其特征在于，包括以下步骤：
    (1)制作与所述容器的形状和尺寸相对应的软性PCB，所述软性PCB包括至少两块具有一定面积的铜箔，每块所述铜箔均构成一个电容感应片，即构成至少两个电容感应片；所述至少两个电容感应片均具有突出部分和凹下部分，一个所述电容感应片的突出部分伸入相邻另一个所述电容感应片的凹下部分，从而使得相邻电容感应片相互交错；
    (2)检测IC电路与每一个电容感应片分别一一联接；当所述容器中液面高度变化时，所述检测IC电路检测与液面高度变化相对应的若干电容感应片的变化后的电容值数据；所述检测IC电路通过第一通讯接口与MCU相联接，并将检测得到的数据传送给所述MCU；在所述 容器的外壁上设置矢量传感器，用以检测所述容器倾斜的角度，所述矢量传感器通过第二通讯接口与MCU相联接，并将检测得到的数据传送给所述MCU；
    (3)根据接收到的所述检测IC电路和所述矢量传感器发送的数据，所述MCU计算出液面的高度；
    (4)根据计算得到的液面高度，如果所述容器的形状是规则的，则所述MCU结合所述容器的尺寸计算出所述容器内液体的容量；如果所述容器的形状是不规则的，则所述MCU对于所述容器进行数学建模，根据多重积分算法计算出所述容器内液体的容量，即利用公式V＝∫∫∫Ωf(x，y，z)dxdydz计算所述容器内液体的容量，其中，Ω为积分区域即所述容器内液体表面区域，f(x，y，z)为液体密度的表达式。
  11. 根据权利要求10所述的测量非金属容器中液体容量的方法，其特征在于，所述至少两个电容感应片的形状均为锯齿形。
  12. 根据权利要求10所述的测量非金属容器中液体容量的方法，其特征在于，所述方法进一步包括以下步骤：所述软性PCB四周和背面铺设铜网格接地。
  13. 根据权利要求10所述的测量非金属容器中液体容量的方法，其特征在于，所述方法进一步包括以下步骤：使用胶将所述软性PCB自上而下贴装在所述容器的外壁。
  14. 根据权利要求10所述的测量非金属容器中液体容量的方法，其特征在于，所述第一通讯接口和第二通讯接口均为IIC、SPI或UART通讯接口。
  15. 根据权利要求10所述的测量非金属容器中液体容量的方法，其特征在于，所述检测IC电路检测并传送给所述MCU的数据是：与所述容器中液面高度相对应的电容感应片A的电容值C1、与所述容器中液面高度相对应的另一电容感应片B的电容值C2以及完全处于液面以下的感应电容片的数量N；所述矢量传感器检测并传送给所述MCU的数据是：所述容器的倾斜角度。
  16. 根据权利要求10所述的测量非金属容器中液体容量的方法，其特征在于，所述步骤(3)中液面高度的计算方法是：在接收电容值C1、电容值C2、完全处于液面以下的感应电容片的数量N和所述容器的倾斜角度数据后，根据电容值算法曲线，所述MCU经计算可得到M值，再由液面高度的计算公式h＝P*N+M可得到液面高度h，其中，P为测量的精度，N为完全处于液面以下的感应电容片的数量。
  17. 根据权利要求10所述的测量非金属容器中液体容量的方法，其特征在于，所述方法进一步包括以下步骤：设置参考电容感应片，所述参考电容感应片与所述检测IC电路单独联接，可在掉电重启后计算得到当前液面的高度。
  18. 根据权利要求10所述的测量非金属容器中液体容量的方法，其特征在于，所述方法进一步包括以下步骤：通过所述矢量传感器的检测，所述MCU可检测出所述容器是否有倒出或倒入液体的动作；在没有所述倒出或倒入液体的动作的情况下，所述MCU关闭电源开关从而停止向所述检测IC电路供电；当所述MCU检测到所述容器有所述倒出或倒入液体的动作时，所述MCU打开所述电源开关从而向所述检测IC电路供电。
PCT/CN2015/074957 2014-08-29 2015-03-24 一种测量非金属容器中液体容量的方法和装置 WO2016029687A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201410446500.8 2014-08-29
CN201410446500.8A CN104215292A (zh) 2014-08-29 2014-08-29 一种测量非金属容器中液体容量的方法和装置

Publications (1)

Publication Number Publication Date
WO2016029687A1 true WO2016029687A1 (zh) 2016-03-03

Family

ID=52097023

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2015/074957 WO2016029687A1 (zh) 2014-08-29 2015-03-24 一种测量非金属容器中液体容量的方法和装置

Country Status (2)

Country Link
CN (1) CN104215292A (zh)
WO (1) WO2016029687A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220404187A1 (en) * 2021-06-16 2022-12-22 Man Yin Arthur Newton Chu Smart hydration reservoir and algorithm of calculating the liquid level thereof

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104215292A (zh) * 2014-08-29 2014-12-17 深圳感臻科技有限公司 一种测量非金属容器中液体容量的方法和装置
CN111024178B (zh) * 2019-12-16 2021-04-06 大连理工大学 一种浮式海洋平台压载监测系统的舱中液体体积计算方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6293145B1 (en) * 1998-04-14 2001-09-25 Mannesmann Vdo Sensor for accurate measurement of levels in irregularly shaped tanks
US20050076711A1 (en) * 2003-10-10 2005-04-14 Urquidi Carlos A. Resonant network fluid level sensor assembly
US20050172712A1 (en) * 2004-02-06 2005-08-11 Nyce David S. Isolated capacitive fluid level sensor
US20050280424A1 (en) * 2002-12-19 2005-12-22 Wenmin Qu Device and method for measuring capacitance and device for determing the level of a liquid using one such device
CN201772914U (zh) * 2010-08-27 2011-03-23 重庆支点仪器仪表有限公司 一种梳状电容式油位传感器
CN104215292A (zh) * 2014-08-29 2014-12-17 深圳感臻科技有限公司 一种测量非金属容器中液体容量的方法和装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6293145B1 (en) * 1998-04-14 2001-09-25 Mannesmann Vdo Sensor for accurate measurement of levels in irregularly shaped tanks
US20050280424A1 (en) * 2002-12-19 2005-12-22 Wenmin Qu Device and method for measuring capacitance and device for determing the level of a liquid using one such device
US20050076711A1 (en) * 2003-10-10 2005-04-14 Urquidi Carlos A. Resonant network fluid level sensor assembly
US20050172712A1 (en) * 2004-02-06 2005-08-11 Nyce David S. Isolated capacitive fluid level sensor
CN201772914U (zh) * 2010-08-27 2011-03-23 重庆支点仪器仪表有限公司 一种梳状电容式油位传感器
CN104215292A (zh) * 2014-08-29 2014-12-17 深圳感臻科技有限公司 一种测量非金属容器中液体容量的方法和装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220404187A1 (en) * 2021-06-16 2022-12-22 Man Yin Arthur Newton Chu Smart hydration reservoir and algorithm of calculating the liquid level thereof

Also Published As

Publication number Publication date
CN104215292A (zh) 2014-12-17

Similar Documents

Publication Publication Date Title
JP2020024706A5 (zh)
WO2016029687A1 (zh) 一种测量非金属容器中液体容量的方法和装置
US20130276533A1 (en) Device for measuring fluid level in a container
TWI601037B (zh) 應用於觸控裝置之測試系統及測試方法
TW201716963A (zh) 可偵測觸控面板是否覆蓋大面積導電液體或物件的觸控處理裝置、觸控電子系統與其觸控處理方法
CN107518851A (zh) 洗碗机及其液位检测装置和液位检测方法
CN211380877U (zh) 咖啡机
KR101329107B1 (ko) 파이프 진원도 측정장치 및 측정방법
CN102799300B (zh) 触摸点侦测装置及其侦测方法
CN207395654U (zh) 铆接检测装置
CN204241063U (zh) 一种测量非金属容器中液体容量的装置
CN205748193U (zh) 一种便携式梁宽测量工具
CN207395593U (zh) 一种螺杆检具
CN105783805B (zh) 焊接接头尺寸及筒体圆度检验仪器
KR101838935B1 (ko) 기기의 수위 센싱 시스템
CN205449051U (zh) 一种数显水平仪
TWI442050B (zh) Contact object water content sensing device, sensing method and computer program products
CN208140221U (zh) 液位检测装置和液体容器
CN203758549U (zh) 用于同时获得容器倾角和液位的电容式传感器
CN209167178U (zh) 纳米材料热性能测试装置
TWI526904B (zh) Capacitive touch device and its chord wave measurement method
CN201219531Y (zh) 一种勘测鞋
CN208766631U (zh) 一种防止漏光的电容屏
CN105953904A (zh) 测温型称重电子秤
CN204202626U (zh) 一种电容式传感器感应装置结构

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15835675

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15835675

Country of ref document: EP

Kind code of ref document: A1