CN111998921A - Measurement circuit, measurement method and measurement device - Google Patents

Measurement circuit, measurement method and measurement device Download PDF

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Publication number
CN111998921A
CN111998921A CN202010905012.4A CN202010905012A CN111998921A CN 111998921 A CN111998921 A CN 111998921A CN 202010905012 A CN202010905012 A CN 202010905012A CN 111998921 A CN111998921 A CN 111998921A
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load cell
weighing sensor
power switch
output
circuit
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CN202010905012.4A
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Chinese (zh)
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李晓
尤杰
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Chipsea Technologies Shenzhen Co Ltd
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Chipsea Technologies Shenzhen Co Ltd
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Priority to CN202010905012.4A priority Critical patent/CN111998921A/en
Publication of CN111998921A publication Critical patent/CN111998921A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01G—WEIGHING
    • G01G3/00—Weighing apparatus characterised by the use of elastically-deformable members, e.g. spring balances
    • G01G3/12—Weighing apparatus characterised by the use of elastically-deformable members, e.g. spring balances wherein the weighing element is in the form of a solid body stressed by pressure or tension during weighing
    • G01G3/14—Weighing apparatus characterised by the use of elastically-deformable members, e.g. spring balances wherein the weighing element is in the form of a solid body stressed by pressure or tension during weighing measuring variations of electrical resistance
    • G01G3/142—Circuits specially adapted therefor
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/40—Detecting, measuring or recording for evaluating the nervous system
    • A61B5/4005—Detecting, measuring or recording for evaluating the nervous system for evaluating the sensory system
    • A61B5/4023—Evaluating sense of balance
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/48—Other medical applications
    • A61B5/4869—Determining body composition
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01G—WEIGHING
    • G01G19/00—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups
    • G01G19/44—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups for weighing persons
    • G01G19/50—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups for weighing persons having additional measuring devices, e.g. for height

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  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Surgery (AREA)
  • General Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Biophysics (AREA)
  • Animal Behavior & Ethology (AREA)
  • Pathology (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • General Physics & Mathematics (AREA)
  • Neurology (AREA)
  • Neurosurgery (AREA)
  • Physiology (AREA)
  • Measurement Of Force In General (AREA)

Abstract

The embodiment of the application provides a measuring circuit, a measuring method and measuring equipment. The measurement circuit includes: a weight measurement circuit comprising an excitation source and a signal processing circuit; a switch switching circuit including a plurality of power switches and a plurality of selection switches; the reference circuit is connected with the signal processing circuit and is also connected with the excitation source through a power switch; the weighing system comprises a plurality of weighing sensors, a power supply switch and a power supply, wherein each weighing sensor comprises a positive end, a negative end and an output end; the output ends of at least two weighing sensors are connected with an excitation source or a signal processing circuit through a selection switch, and the output ends of the other weighing sensors are connected with the signal processing circuit. The measuring circuit that this application embodiment provided both can measure weight, also can measure the focus, can also promote weight measurement's efficiency simultaneously.

Description

Measurement circuit, measurement method and measurement device
Technical Field
The present disclosure relates to the field of measurement technologies, and more particularly, to a measurement circuit, a measurement method, and a measurement device.
Background
Along with the development of the internet of things and the intelligent health industry, more and more household weighing scales have added the function of health measurement, and consumers have the requirements of measuring body fat, human body composition analysis and heart rate in addition to the requirements of the current weighing scales, and the measurement requirement of measuring the body balance degree is also more and more large, so that a measuring device capable of measuring weight and gravity center is needed. Since the gravity center position needs to be determined according to the weight distribution, the current main measurement mode is to detect the weight distribution at the four corners of the weight scale by four pressure sensors disposed at the four corners of the weight scale, so as to calculate the gravity center position according to the weight distribution at the four corners. When the weight needs to be measured, the total weight is determined according to the sum of the weights of the four corners. Although the gravity center measurement can be realized in this way, the total weight can be measured only by switching the sensor to perform multiple measurements, and the efficiency of weight measurement is reduced.
Disclosure of Invention
The embodiment of the application provides a measuring circuit, a measuring method and measuring equipment, so as to solve the problems.
The embodiment of the application is realized by adopting the following technical scheme:
in a first aspect, an embodiment of the present application provides a measurement circuit, including: a weight measurement circuit comprising an excitation source and a signal processing circuit; a switch switching circuit including a plurality of power switches and a plurality of selection switches; the reference circuit is connected with the signal processing circuit and is also connected with the excitation source through a power switch; the weighing system comprises a plurality of weighing sensors, a power supply switch and a power supply, wherein each weighing sensor comprises a positive end, a negative end and an output end; the output ends of at least two weighing sensors are connected with an excitation source or a signal processing circuit through a selection switch, and the output ends of the other weighing sensors are connected with the signal processing circuit.
In some embodiments, the plurality of load cells includes a first load cell group connected to the excitation source or the signal processing circuit at an output of each load cell through a selection switch and a second load cell group connected to the signal processing circuit at an output of each load cell, wherein the load cells of the first load cell group and the load cells of the second load cell group are alternately connected in series.
In some embodiments, the first load cell group comprises a first load cell and a third load cell, the second load cell group comprises a second load cell and a fourth load cell, the positive terminal of the first load cell is connected to the positive terminal of the fourth load cell, the negative terminal of the first load cell is connected to the negative terminal of the second load cell, the positive terminal of the second load cell is connected to the positive terminal of the third load cell, and the negative terminal of the third load cell is connected to the negative terminal of the fourth load cell; the selection switch comprises a first selection switch and a second selection switch; the output end of the first weighing sensor is connected with the positive end of the excitation source or the signal processing circuit through the first selection switch; the output end of the third weighing sensor is connected with the negative end of the excitation source or the signal processing circuit through a second selection switch; and the output end of the second weighing sensor and the output end of the fourth weighing sensor are respectively connected with the signal processing circuit.
In some embodiments, the plurality of power switches comprises a first power switch, a second power switch, a third power switch, a fourth power switch, a fifth power switch, and a sixth power switch; the reference circuit comprises a positive terminal and a negative terminal; the connection node of the first weighing sensor and the second weighing sensor is connected with the negative end of the excitation source through a first power switch; the connection node of the second weighing sensor and the third weighing sensor is connected with the positive end of the excitation source through a second power switch; the connection node of the third weighing sensor and the fourth weighing sensor is connected with the negative end of the excitation source through a third power switch; the connection node of the fourth weighing sensor and the first weighing sensor is connected with the positive end of the excitation source through a fourth power switch; the positive end of the reference circuit is connected with the positive end of the excitation source through a fifth power switch; the negative terminal of the reference circuit is connected to the negative terminal of the excitation source through a sixth power switch.
In some embodiments, the reference circuit includes a resistor string, the resistor string includes a voltage dividing node, the voltage dividing node is connected to the signal processing circuit, one end of the resistor string is connected to the positive terminal of the excitation source through a power switch, and the other end of the resistor string is connected to the negative terminal of the excitation source through another power switch.
In some embodiments, each load cell includes an elastomer and two resistors in series, at least one of the resistors being a strain resistor and attached to the elastomer.
In a second aspect, an embodiment of the present application provides a measurement method, to which the measurement circuit described above is applied, the method including: when the weight of the measured object is measured, the power switch is controlled to be switched off, and the selection switch is controlled to be communicated with the excitation source, so that the plurality of weighing sensors form a first Wheatstone bridge; acquiring a first differential signal output by a first Wheatstone bridge, and processing the first differential signal to obtain a weight value of the measured object; when the gravity center of the measured object is measured, the power switch is controlled to be closed in a time-sharing mode, the selection switch is controlled to be communicated with the excitation source, the reference circuit and the weighing sensors are enabled to output multiple groups of second differential signals in a time-sharing mode, and the gravity center data of the measured object are obtained based on the multiple groups of second differential signals.
In a third aspect, an embodiment of the present application provides a measurement apparatus, which includes a body, a control circuit and the measurement circuit, where the control circuit is configured to perform the measurement method.
The embodiment of the application provides a measuring circuit, a measuring method and measuring equipment. The measurement circuit includes: a weight measurement circuit comprising an excitation source and a signal processing circuit; a switch switching circuit including a plurality of power switches and a plurality of selection switches; the reference circuit is connected with the signal processing circuit and is also connected with the excitation source through a power switch; the weighing system comprises a plurality of weighing sensors, a power supply switch and a power supply, wherein each weighing sensor comprises a positive end, a negative end and an output end; the output ends of at least two weighing sensors are connected with an excitation source or a signal processing circuit through a selection switch, and the output ends of the other weighing sensors are connected with the signal processing circuit. The measuring circuit that this application embodiment provided both can measure weight, also can measure the focus, can also promote weight measurement's efficiency simultaneously.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 shows a block diagram of a measuring device;
FIG. 2 shows a block diagram of a measurement circuit provided by an embodiment of the present application;
FIG. 3 shows a block diagram of a measurement circuit provided by an embodiment of the present application;
FIG. 4 shows a block diagram of another measurement circuit provided by an embodiment of the present application;
FIG. 5 shows a block diagram of another measurement circuit provided by an embodiment of the present application;
FIG. 6 shows a block diagram of another measurement circuit provided in an embodiment of the present application;
FIG. 7 shows a block diagram of a measurement circuit provided in an embodiment of the present application;
fig. 8 is a circuit diagram of a signal processing circuit according to an embodiment of the present application;
FIG. 9 is a flow chart illustrating a measurement method provided by an embodiment of the present application;
FIG. 10 is a flow chart illustrating a further measurement method provided by an embodiment of the present application;
FIG. 11 is a circuit schematic diagram illustrating a weight measurement mode provided by an embodiment of the present application;
FIG. 12 is a circuit diagram illustrating a gravity center measurement mode provided by an embodiment of the present application
Fig. 13 shows a block diagram of a measuring device according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
As shown in fig. 1, fig. 1 schematically illustrates a measurement apparatus 10 provided in an embodiment of the present application. The measuring device 10 is used for measuring weight or gravity center, and the measuring device 10 may be a body scale or a body composition analyzer, which is not limited in the embodiments of the present application. For convenience of description only, the measuring device 10 is illustrated as a personal scale.
As shown in fig. 1, the measuring device 10 comprises a weighing panel 101 for holding an object to be weighed, such as a human body. The housing of the weighing panel 101 is typically constructed of engineering plastic, tempered glass, metal brackets, and the like. The measuring device 10 further comprises load cells, which may for example comprise four sets of load cells 104 a-104 d, for measuring weight.
In some embodiments, the measuring device 10 may further include a display screen 103 for displaying the measurement information, and the display screen 103 may be an LCD display screen, an LED display screen, or the like, which is not limited herein. The measurement information may include, but is not limited to, weight, body fat rate, heart rate, and the like.
Further, the measurement device 10 may further include a control circuit 102, and the control circuit 102 may be used to control, acquire, and process measurement information obtained by measurement, and the like. In some embodiments, the control circuit 102 may be connected to the load cells, and the control circuit 102 may obtain the weight value and the center of gravity data of the human body according to the weight values measured by the load cells 104 a-104 d, respectively.
However, the current main measurement mode of weight and center of gravity is to detect the weight distribution at four corners of the human body scale through four weighing sensors arranged at four corners of the human body scale, so as to calculate the center of gravity position according to the weight distribution at four corners. When the weight needs to be measured, the total weight is determined according to the sum of the weights of the four corners. Although this method can realize weight and center of gravity measurement, the total weight can be measured by switching the sensor to perform multiple measurements, which reduces the efficiency of weight measurement.
Based on the above problems, the inventors have made long-term studies to provide a measurement circuit, a measurement method, and a measurement apparatus in the embodiments of the present application. The following provides a detailed description of the measurement circuit, the measurement method and the measurement apparatus provided in the embodiments of the present application through specific embodiments.
As shown in fig. 2, fig. 2 schematically illustrates a measurement circuit 100 provided in an embodiment of the present application. In this embodiment, the measurement circuit 100 includes a weight measurement circuit 110, a switch switching circuit 120, a reference circuit 130, and a plurality of load cells 140,
wherein weight measurement circuit 110 includes a signal processing circuit 112 and an excitation source 114. The excitation source 114 is used to provide an excitation signal for the load cell. The signal processing circuit 112 is used for processing the output signal of the weighing sensor to obtain the measurement data.
In some embodiments, the switch switching circuit 120 may include a plurality of power switches W1 and a plurality of selection switches W2. Fig. 2 is only for convenience of description, and the selection switch is taken as an example of an alternative switch for illustration, where the selection switch may be an alternative switch, a three-alternative switch, or the like, and is not limited herein. In some embodiments, the reference circuit 130 may be connected to the signal processing circuit 112, and the reference circuit 130 may also be connected to the excitation source 114 through at least one power switch W1. For example, the two terminals of the reference circuit 130 can be connected to the positive terminal and the negative terminal of the excitation source 114 through two different power switches W1, respectively. For another example, one end of the reference circuit 130 may be directly connected to the positive/negative terminal of the excitation source 114, and the other end of the reference circuit 130 is connected to the negative/positive terminal of the excitation source 114 through the power switch W1.
In some embodiments, each load cell 140 of the plurality of load cells 140 includes a positive terminal D1, a negative terminal D2, and an output terminal D3, and the positive terminal D1 and the negative terminal D2 of each load cell 140 are respectively connected to the excitation source 114 through a power switch W1. Wherein the output terminals D3 of the at least two load cells 140 are connected to the excitation source 114 or the signal processing circuit 112 through a selection switch W2, as illustrated in fig. 2, the selection switch W2 may be an alternative switch, and the selection switch W2 may include an input terminal and two output terminals, which are a first output terminal and a second output terminal, respectively. The input end of the alternative switch is connected with the weighing sensor, the first output end is connected with the signal processing circuit 112, and the second output end is connected with the excitation source 114. The input terminal may be controlled to be connected to any one of the first output terminal and the second output terminal, and when the input terminal of the one-of-two switch is selected to be connected to the first output terminal, the output terminal D3 of the load cell 140 is connected to the signal processing circuit 112 through the one-of-two switch; when the input terminal of the one-of-two switch is selected to be connected to the second output terminal, the output terminal D3 of the load cell 140 is connected to the excitation source 140 through the one-of-two switch. The outputs of the load cells other than the at least two load cells are connected to the signal processing circuit 112.
For convenience of description, fig. 2 illustrates that the measurement circuit 100 includes four load cells, the four load cells are respectively connected to the positive poles of the excitation sources through four different power switches, and are respectively connected to the negative poles of the excitation sources through another four different power switches, wherein the output terminals D3 of two load cells are connected to the excitation source 114 or the signal processing circuit 112 through different selection switches, and the output terminals D3 of the other two load cells are connected to the signal processing circuit 112. In other embodiments, the total number of load cells may also be five, six, or more; the two weighing sensors with the connection relation can also be connected with the anode/cathode of the excitation source by multiplexing the same power switch; or more power switches and more selection switches may be provided in the switch switching circuit, which is not limited herein.
In this embodiment, by turning off the power switch W1 and turning on the excitation source 114 by controlling the selection switch W2, the plurality of load cells 140 can form a first wheatstone bridge, the first wheatstone bridge outputs a first differential signal under the excitation provided by the excitation source 114, and the first differential signal output by the first wheatstone bridge can be obtained by the signal processing circuit and processed to obtain the weight value of the measured object. Then, the power switches W1 are controlled to be turned on in a time-sharing manner, and the selection switch W2 is controlled to be communicated with the signal processing circuit 112, so that the reference circuit 130 and the plurality of load cells 140 output a plurality of sets of second differential signals in a time-sharing manner, and the signal processing circuit 112 processes the plurality of sets of second differential signals to obtain the gravity center data of the measured object. Therefore, the weight of a human body can be measured through the measuring circuit 100, the gravity center of the human body can also be measured, and the weight value of the measured object can be obtained only by measuring the data of one channel when the weight is measured, namely, only one group of differential signals needs to be acquired, so that the time for measuring the weight is shortened, and the weight measuring efficiency is improved.
In some embodiments, as shown in FIG. 3, the plurality of load cells may include a first load cell group 142 and a second load cell group 144. The output D23 of each load cell 1422 in the first load cell group 142 may be connected to the excitation source 114 or the signal processing circuit 112 through a selector switch W2, and the output D43 of each load cell 1442 in the second load cell group 144 is connected to the signal processing circuit 112, respectively. In some embodiments, the load cells 1422 of the first load cell group 142 and the load cells 1444 of the second load cell group 144 are alternately connected in series, i.e., either end of any one load cell 1422 of the first load cell group 142 is directly or indirectly connected to one load cell 1444 of the second load cell group 144, and likewise either end of any one load cell 1424 of the second load cell group 144 is directly or indirectly connected to one load cell 1422 of the first load cell group 142, so that both outputs of the wheatstone bridge can be connected to the signal processing circuit when the power switch is open during weighing.
In some embodiments, as shown in FIG. 4, first load cell group 142 may include a first load cell 1424 and a third load cell 1426, and second load cell group 144 may include a second load cell 1444 and a fourth load cell 1446. In some embodiments, the positive end D241 of the first load cell 1424 may be connected to the positive end D461 of the fourth load cell 1446, the negative end D242 of the first load cell 1424 may be connected to the negative end D442 of the second load cell 1444, the positive end D441 of the second load cell 1444 may be connected to the positive end D261 of the third load cell 1426, and the negative end D262 of the third load cell 1426 may be connected to the negative end D462 of the fourth load cell 1446. At this time, the positive terminal D241 of the first load cell 1424 and the positive terminal D461 of the fourth load cell 1446 may be connected to the excitation source 114 through the same power switch, the negative terminal D242 of the first load cell 1424 and the negative terminal D442 of the second load cell 1444 may be connected to the excitation source 114 through the same power switch, the positive terminal D441 of the second load cell 1444 and the positive terminal D261 of the third load cell 1426 may be connected to the excitation source 114 through the same power switch, and the negative terminal D262 of the third load cell 1426 and the negative terminal D462 of the fourth load cell 1446 may be connected to the excitation source 114 through the same power switch, so that the measurement circuit may be simplified, and the power consumption of the circuit may be reduced.
In some embodiments, the selection switches may include a first selection switch W22 and a second selection switch W24. The output terminal D243 of the first load cell 1424 may be connected to the positive terminal 1142 of the excitation source 114 or the signal processing circuit 112 through the first selection switch W22, the output terminal D263 of the third load cell 1426 may be connected to the negative terminal 1144 of the excitation source 114 or the signal processing circuit 112, and the output terminals D443, D463 of the second load cell 1444 and the fourth load cell 1446 may be connected to the signal processing circuit 112, respectively. In this embodiment, the power switch W1 can be controlled to be turned off, and the first selection switch W22 and the second selection switch W24 are controlled to be connected to the excitation source 114, so that the first load cell 1424, the second load cell 1444, the third load cell 1426 and the fourth load cell 1446 form a first wheatstone bridge, and at this time, the output end of the second load cell and the output end of the fourth load cell are used as two output ends of the first wheatstone bridge, so as to obtain a differential signal according to a signal output by the second load cell 1444 and a signal output by the fourth load cell 1446, and obtain the weight of the object to be measured after being processed by the signal processing circuit 112. The power switches W1 are controlled to be closed in a time sharing mode, and the first selection switch W22 and the second selection switch W24 are respectively controlled to be communicated with the signal processing circuit, so that the reference circuit 130, the first weighing sensor 1424, the second weighing sensor 1444, the third weighing sensor 1426 and the fourth weighing sensor 1446 output a plurality of groups of second differential signals in a time sharing mode, and the gravity center data of the measured object are obtained through processing by the signal processing circuit 112 based on the plurality of groups of second differential signals. Therefore, the weight of a human body can be measured, the gravity center of the human body can also be measured, meanwhile, when the weight is measured, the weight value of the measured object can be obtained only by measuring a group of differential signals, the time for measuring the weight is shortened, and the weight measurement efficiency is improved.
In some embodiments, as shown in fig. 5, the plurality of power switches W1 may include a first power switch W11, a second power switch W12, a third power switch W13, a fourth power switch W14, a fifth power switch W15, and a sixth power switch W16. The reference circuit 130 may include a positive terminal 132 and a negative terminal 134. In some embodiments, the connection node of the first load cell 1424 and the second load cell 1444 may be connected to the negative terminal 1144 of the excitation source 114 through the first power switch W11, the connection node of the second load cell 1444 and the third load cell 1426 may be connected to the positive terminal 1142 of the excitation source 114 through the second power switch W12, the connection node of the third load cell 1426 and the fourth load cell 1446 may be connected to the negative terminal 1144 of the excitation source 114 through the third power switch W13, and the connection node of the fourth load cell 1446 and the first load cell 1424 may be connected to the positive terminal 1142 of the excitation source 114 through the fourth power switch W14. In some embodiments, the positive terminal 132 of the reference circuit 130 may be connected to the positive terminal 1142 of the excitation source 114 through a fifth power switch W15, and the negative terminal 134 of the reference circuit 130 may be connected to the negative terminal 1144 of the excitation source 114 through a sixth power switch W16.
In this embodiment, when measuring the weight of the object, the first power switch W11, the second power switch W12, the third power switch W13, the fourth power switch W14, the fifth power switch W15 and the sixth power switch W16 may be controlled to be turned off respectively, and the first selection switch W22 and the second selection switch W24 are controlled to be connected to the excitation source 114 respectively, so that the first load cell 1424, the second load cell 1444, the third load cell 1426 and the fourth load cell 1446 constitute a first wheatstone bridge, at this time, the output terminal of the second load cell and the output terminal of the fourth load cell serve as two output terminals of the wheatstone bridge, a differential signal may be obtained according to the signal output by the second load cell 1444 and the signal output by the fourth load cell 1446, and the weight of the object may be obtained after being processed by the signal processing circuit 112. Therefore, the weight can be calculated by only measuring the data of one channel, the time for measuring the weight is shortened, and the power consumption for measuring the weight is reduced. In this embodiment, any two load cells having a connection relationship may share one power switch to be connected to the positive/negative terminal of the excitation source, for example, the first load cell and the third load cell share the switch W14 to be connected to the positive terminal of the excitation source, and the third load cell and the fourth load cell share the switch W13 to be connected to the negative terminal of the excitation source, so that the number of power switches in the switch circuit is reduced by half, the hardware cost of the circuit is effectively reduced, and the control scheme of the switches is simplified.
When measuring the center of gravity of the object, the fifth power switch W15 and the sixth power switch W16 connected to the reference circuit 130 may be controlled to be closed, respectively, so that the reference circuit 130 outputs the first signal. The first power switch W11 and the fourth power switch W14 may be controlled to be closed, the second power switch W12 and the third power switch W13 may be controlled to be opened, and the first selection switch W22 may be controlled to connect the first load cell 1424 and the signal processing circuit 112 such that the first load cell 1424 outputs a second signal. The second load cell 1444 may output a third signal by controlling the first power switch W11 and the second power switch W12 to be closed, and the second power switch W13 and the fourth power switch W14 to be opened, respectively. The fourth load cell 1426 may output the fourth signal by controlling the second power switch W12 and the third power switch W13 to be closed, the fourth power switch W14 and the first power switch W11 to be opened, and the second selection switch W24 to be connected to the third load cell 1426 and the signal processing circuit 112, respectively. The first and second power switches W11 and W12 may be controlled to be opened by controlling the third and fourth power switches W13 and W14 to be closed, respectively, so that the fourth load cell 1446 outputs a fifth signal. And taking any two of the first signal, the second signal, the third signal, the fourth signal and the fifth signal as a group to obtain at least four groups of differential signals, wherein at least one of the at least four groups of differential signals comprises the first signal. As an embodiment, the second to fifth signals may be sequentially combined with the first signal, respectively, for example, differential signals in which the first signal and the second signal are grouped, differential signals in which the first signal and the third signal are grouped, differential signals in which the first signal and the fourth signal are grouped, and differential signals in which the first signal and the fifth signal are grouped, respectively. As another embodiment, the first signal and any other signal may be combined once, and the other signals may be combined two by two, for example, the first signal and the second signal may be combined to obtain a group of differential signals, and the second signal, the third signal, the fourth signal, and the fifth signal may be combined two by two to obtain at least three groups of differential signals. The weights respectively detected by the first weighing sensor 1424, the second weighing sensor 1444, the third weighing sensor 1426 and the fourth weighing sensor 1446 are obtained through processing by the signal processing circuit, and the gravity center data of the measured object is calculated according to the weights respectively detected by the four weighing sensors.
Further, as shown in fig. 6, in some embodiments, the reference circuit 130 may further include a resistor string 132, the resistor string 132 including a voltage dividing node 1322, wherein the voltage dividing node 1322 may be connected with the signal processing circuit 112. In some embodiments, one end of the resistor string 132 may be connected to the positive terminal 1142 of the excitation source 114 through the power switch W31, and the other end of the resistor string 132 may be connected to the negative terminal 1144 of the excitation source 114 through the power switch W32. For example, the resistor string 132 may be formed by two resistors connected in series, and a connection node of the two resistors is the voltage dividing node 1332. When the power switch W31 and the power switch W32 are both turned on, the two resistors form a wheatstone half bridge, and the voltage dividing node 1332 is the output terminal of the wheatstone half bridge.
In some embodiments, as shown in fig. 7, each load cell 140 is a half-bridge strain sensor, the half-bridge strain sensor is composed of two resistors connected in series to form a wheatstone half-bridge, at least one of the two resistors is a strain resistor, and a connection node of the two resistors is an output terminal of the half-bridge strain sensor. Optionally, each load cell 140 may further include an elastomer (not shown), wherein the strain resistors in the half-bridge strain sensors may be attached to the elastomer. In some embodiments, the two resistors in each half-bridge strain sensor include a first resistor R1 and a second resistor R2, the first resistor R1 may have a first strain polarity, the second resistor R2 may have a second strain polarity, the two ends of the resistor string formed by the connection of the first resistor R1 and the second resistor R2 are the positive and negative terminals of the load cell 140, and the connection point between the first resistor R1 and the second resistor R2 may be set as the output terminal of the load cell 140. Further, as an embodiment, the first strain polarity may be a positive strain or a negative strain, and the second strain polarity may be a zero strain (i.e., an unstrained resistance). As another embodiment, the first strain polarity may be a positive strain, and the second strain polarity may be a negative strain, which is not limited herein.
In some embodiments, as shown in fig. 8, the signal processing circuit 112 may include multiple selectors MUXP and MUXN, an instrumentation amplifier PGA, and an analog-to-digital converter ADC electrically connected to the instrumentation amplifier, wherein the output terminals of the multiple load cells and the output terminal of the reference circuit are connected to the multiple selectors, two of the output signals of the multiple load cells are selected by the multiple selectors to be combined into a differential signal and input to the differential input terminal of the instrumentation amplifier, and the signal amplified by the instrumentation amplifier is analog-to-digital converted by the analog-to-digital converter to be converted into a corresponding weight value. Fig. 8 is a circuit diagram of a signal processing circuit, which is not limited to the above.
Referring to fig. 9, fig. 9 is a schematic flowchart illustrating a measurement method according to an embodiment of the present disclosure, applied to the measurement circuit 100. The flow shown in fig. 9 will be described in detail below. The above-mentioned measuring method may specifically comprise the steps of:
step S110: when the weight of the measured object is measured, the power switch is controlled to be switched off, and the selection switch is controlled to be connected with the excitation source, so that the plurality of weighing sensors form a first Wheatstone bridge.
In the present embodiment, the measurement circuit 100 includes a plurality of power switches and a plurality of selection switches, and the measurement circuit 100 further includes a plurality of load cells, wherein the output terminals of at least two load cells are connected to the excitation source or the signal processing circuit through the selection switches, and the output terminals of the other load cells are connected to the signal processing circuit. When the weight of the measured object is measured, the plurality of power switches can be controlled to be switched off, and the selection switch is controlled to connect the weighing sensor and the excitation source, so that the plurality of weighing sensors form a first Wheatstone bridge.
Step S120: and acquiring a first differential signal output by the first Wheatstone bridge, and processing the first differential signal to obtain a weight value of the measured object.
In some embodiments, the first differential signal output by the first wheatstone bridge may be obtained, and specifically, since the output terminals of the other weighing sensors are connected to the signal processing circuit, when all the power switches are turned off and the selection switch is turned on, the plurality of weighing sensors form the first wheatstone bridge, the first wheatstone bridge outputs the first differential signal under the excitation provided by the excitation source 114, and the first differential signal output by the first wheatstone bridge may be obtained by the signal processing circuit and processed to obtain the measured weight value of the object.
Step S130: when the gravity center of the measured object is measured, the power switch is controlled to be closed in a time-sharing mode, the selection switch is controlled to be communicated with the signal processing circuit, the reference circuit and the weighing sensors are enabled to output multiple groups of second differential signals in a time-sharing mode, and the gravity center data of the measured object are obtained based on the multiple groups of second differential signals.
In this embodiment, when measuring the center of gravity of the object to be measured, the power switch may be controlled to be turned on in a time-sharing manner, and the selection switch may be controlled to be connected to the signal processing circuit. Specifically, in some embodiments, the power switch connected to each of the weighing sensors may be sequentially controlled to be turned on, and the selection switch is controlled to be connected to the signal processing circuit, so that the reference circuit and the weighing sensors may be arbitrarily combined to output a plurality of sets of second differential signals in a time-sharing manner, and the gravity center data of the object to be measured may be obtained based on the plurality of sets of second differential signals, wherein the weight information detected by each of the weighing sensors may be obtained after the plurality of sets of second differential signals are processed, and the gravity center data of the object to be measured may be calculated according to the weights detected by each of the weighing sensors.
According to the measuring method provided by the embodiment of the application, when the weight of the measured object is measured, the power switch is controlled to be switched off, and the selection switch is controlled to be connected with the excitation source, so that the plurality of weighing sensors form a first Wheatstone bridge; acquiring a first differential signal output by a first Wheatstone bridge, and processing the first differential signal to obtain a weight value of the measured object; when the gravity center of the measured object is measured, the power switch is controlled to be closed in a time-sharing mode, the selection switch is controlled to be communicated with the signal processing circuit, the reference circuit and the weighing sensors are enabled to output multiple groups of second differential signals in a time-sharing mode, and the gravity center data of the measured object are obtained based on the multiple groups of second differential signals. This application is through the state of control switch and selector switch, acquire first differential signal and obtain the weight value of measurand, can also acquire the focus data that multiunit second differential signal handled and obtain measurand, thereby realize that a measuring circuit both can measure the focus, also can measure weight, the data of a passageway need be measured simultaneously, only need acquire a set of differential signal promptly, handle the weight value that can obtain measurand to a set of differential signal, reduce weight measurement's time, promote weight measurement efficiency.
Referring to fig. 10, fig. 10 is a schematic flow chart of another measurement method provided in the present embodiment, and is applied to the measurement circuit 100. The flow shown in fig. 10 will be described in detail below. The above-mentioned measuring method may specifically comprise the steps of:
step S210: when the weight of the measured object is measured, the power switch is controlled to be switched off, and the selection switch is controlled to be connected with the excitation source, so that the plurality of weighing sensors form a first Wheatstone bridge.
Step S220: and acquiring a first differential signal output by the first Wheatstone bridge, and processing the first differential signal to obtain a weight value of the measured object.
For the detailed description of steps S210 to S220, refer to steps S110 to S120, which are not described herein again.
Step S230: when the gravity center of the measured object is measured, the power switch connected with the reference circuit is controlled to be closed.
In this embodiment, when measuring the center of gravity of the object to be measured, the power switch connected to the reference circuit may be controlled to be turned on or off. So that the reference circuit can form a differential loop with the other load cells.
Step S240: and sequentially controlling the power switch connected with the weighing sensor to be closed and controlling the selection switch connected with the weighing sensor to be communicated with the signal processing circuit for each weighing sensor, so that each weighing sensor sequentially forms a second Wheatstone bridge with the reference circuit and outputs a second differential signal.
In this embodiment, the measurement circuit 100 includes a plurality of load cells, and may control a power switch connected to the load cells to be turned on and a selection switch connected to the load cells to be connected to the signal processing circuit for each load cell in turn, so that each load cell forms a second wheatstone bridge with the reference circuit in turn and outputs a second differential signal. In some embodiments, for each weighing sensor, a power switch connected with the weighing sensor is controlled to be closed, and a selection switch connected with the weighing sensor is controlled to be communicated with a signal processing circuit, so that each weighing sensor sequentially forms a second wheatstone bridge with a reference circuit, signals output by the output end of each weighing sensor are respectively acquired, the signals output by the output end of each weighing sensor sequentially form a group of second differential signals with output signals of the output end of the reference circuit, and then a plurality of groups of second differential signals are acquired.
Step S250: and processing based on the plurality of groups of second differential signals to obtain the gravity center data of the measured object.
For detailed description of step S250, please refer to step S130, which is not described herein.
In some embodiments, when the plurality of load cells includes a first load cell, a second load cell, a third load cell, and a fourth load cell, the selection switches include a first selection switch and a second selection switch, the output terminal of the first load cell is connected to the positive terminal of the excitation source or the signal processing circuit through the first selection switch, the output terminal of the third load cell is connected to the negative terminal of the excitation source or the signal processing circuit through the second selection switch, and the output terminals of the second load cell and the fourth load cell are respectively connected to the signal processing circuit (e.g., the measurement circuit 100 shown in fig. 4). All the power switches can be controlled to be turned off, the first selection switch W22 is controlled to be communicated with the positive terminal 1142 of the excitation source 114 and the first load cell 1424, the second selection switch W24 is controlled to be communicated with the negative terminal 1144 of the excitation source 114 and the third load cell 1426, and the first load cell 1424, the second load cell 1444, the third load cell 1426 and the fourth load cell 1446 form a first wheatstone bridge. Further, the signal of the output terminal D443 of the second load cell 1444 and the signal of the output terminal D463 of the fourth load cell 1446 are acquired as the first differential signal.
In some embodiments, when measuring the center of gravity data of the measured object, a power switch connected to the reference circuit 130 may be controlled to be closed, so that the reference circuit 130 outputs the first output signal. Then, the power switch connected to the first load cell 1424 may be controlled to be turned on and the power switch not connected to the first load cell 1424 may be controlled to be turned off, and the first selection switch W22 may be controlled to connect the first load cell 1424 and the signal processing circuit 112, so that the first load cell 1424 outputs the second output signal. The power switch connected to the second load cell 1444 may be controlled to be turned on and the power switch not connected to the second load cell 1444 may be controlled to be turned off, so that the second load cell 1444 outputs a third output signal. The power switch connected to the third load cell 1426 may be controlled to be turned on and the power switch not connected to the third load cell 1426 may be controlled to be turned off, and the second selection switch W24 may be controlled to connect the third load cell 1426 to the signal processing circuit 112, so that the third load cell 1426 outputs a fourth output signal. The power switch connected to the fourth load cell 1446 may be controlled to be turned on and the power switch not connected to the fourth load cell 1446 may be controlled to be turned off, so that the fourth load cell 1446 outputs a fifth output signal. The first output signal, the second output signal, the third output signal, the fourth output signal and the fifth output signal may be grouped into any two to obtain at least four groups of second differential signals, where at least one group of second differential signals includes the first output signal. As an embodiment, the second to fifth output signals may be sequentially combined with the first output signal, respectively, for example, a second differential signal in which the first output signal and the second output signal form a group, a second differential signal in which the first output signal and the third output signal form a group, a second differential signal in which the first output signal and the fourth output signal form a group, and a second differential signal in which the first output signal and the fifth output signal form a group are obtained. As another embodiment, the first output signal and any other output signal may be combined once, and the other output signals may be combined two by two, for example, the first output signal and the second output signal may be combined to obtain a group of second differential signals, and the second output signal, the third output signal, the fourth output signal, and the fifth output signal may be combined two by two to obtain at least three groups of second differential signals.
Further, in some embodiments, the at least four sets of second differential signals are input to the signal processing circuit for processing, so as to calculate and obtain the gravity center data of the measured object. Specifically, the signal processing circuit may process any group of second differential signals including the second output signal to obtain a first weight, where the first weight is a weight detected by the first weighing sensor; the signal processing circuit can process any group of second differential signals including the third output signal to obtain a second weight, wherein the second weight is the weight detected by the second weighing sensor; the signal processing circuit can process any group of second differential signals including the fourth output signal to obtain a third weight, wherein the third weight is the weight detected by the third weighing sensor; the signal processing circuit may process any one set of second differential signals including the fifth output signal to obtain a fourth weight, where the fourth weight is the weight detected by the fourth load cell. And calculating the gravity center data of the measured object according to the first weight, the second weight, the third weight and the fourth weight.
In a specific embodiment, the measuring apparatus is described by taking a human body scale as an example, when measuring the weight of the measured object, as shown in the circuit diagram of the weight measurement mode shown in fig. 11, the first power switch W11, the second power switch W12, the third power switch W13, the fourth power switch W14, the fifth power switch W15 and the sixth power switch W16 are all controlled to be off, the first selection switch W22 is controlled to be communicated with the positive terminal of the first load cell 1424 and the excitation source, the second selection switch W24 is controlled to be communicated with the negative terminal of the third load cell 1426 and the excitation source, so that the first load cell 1424, the second load cell 1444, the third load cell 1421446 and the fourth load cell W356 form a first wheatstone bridge, wherein the output terminal of the second load cell 1444 is connected with the AIN1 terminal of the multi-selector of the signal processing circuit, and the output terminal of the fourth load cell 1446 is connected with the AIN0 terminal of the multi-selector of the signal processing circuit, the signal processing circuit measures signals of a differential pair of the AIN0 end and the AIN1 end, and the weight of the measured object is calculated according to the differential signals output by the AIN0 end and the AIN1 end, so that the weight of the measured object can be calculated by measuring only one channel, the weight measuring time is shortened, and the power consumption is reduced.
Further, when measuring the weight of the object, as shown in the schematic circuit diagram of the center of gravity measuring mode shown in fig. 12, the fifth power switch W15 and the sixth power switch W16 connected to the reference circuit may be controlled to be closed, so that the reference circuit outputs the first output signal, wherein the output terminal of the reference circuit is connected to the AIN4 terminal of the multi-selector of the signal processing circuit. Then, the first and fourth power switches W11 and W14 connected to the first load cell 1424 may be controlled to be closed, the second and third power switches W12 and W13 not connected to the first load cell 1424 may be controlled to be opened, and the first selection switch W22 may be controlled to connect the first load cell 1424 and the AIN2 terminal of the multi-selector of the signal processing circuit, so that the first load cell 1424 outputs the second output signal. The weight w1 detected by the first load cell 1424 is calculated from the first output signal and the second output signal.
Then, the first power switch W11 and the second power switch W12 connected to the second load cell 1444 may be controlled to be closed, and the third power switch W13 and the fourth power switch W14 not connected to the second load cell 1444 may be controlled to be opened, so that the second load cell 1444 outputs a third output signal, and the weight W2 detected by the second load cell 1444 is calculated according to the first output signal and the third output signal.
Secondly, the second power switch W12 and the third power switch W13 connected to the third load cell 1426 may be controlled to be closed, the first power switch W11 and the fourth power switch W14 not connected to the third load cell 1426 may be controlled to be opened, and the second selection switch W24 may be controlled to be connected to the output terminal of the third load cell 1426 and the AIN3 terminal of the multi-selector of the signal processing circuit, so that the third load cell 1426 outputs a fourth output signal. The weight w3 detected by the third load cell 1426 is calculated from the first output signal and the fourth output signal.
The third and fourth power switches W13 and W14 connected to the fourth load cell 1446 may also be controlled to be closed, and the first and second power switches W11 and W12 not connected to the fourth load cell 1446 may be controlled to be opened, so that the fourth load cell outputs a fifth output signal. The weight w4 detected by the fourth load cell 1446 is calculated from the first output signal and the fifth output signal.
Further, the abscissa x of the gravity center data is obtained according to the first gravity center calculation formulac1The ordinate y of the barycentric data may be obtained from the second barycentric calculation formulac1Wherein, in the step (A),
the first center of gravity calculation formula is:
Figure BDA0002661106360000131
the second centroid calculation formula is:
Figure BDA0002661106360000132
wherein w represents the length of the human body scale, h represents the width of the human body scale, and the gravity center data of the measured object is (x)c1，yc1)。
As shown in fig. 13, an embodiment of the present application provides a measurement apparatus 20, where the measurement apparatus 20 includes a body 210, and a measurement circuit 220 and a control circuit 230 that are disposed on the body 210, where the measurement circuit 220 may be the measurement circuit 100 shown in any of the above embodiments, and the control circuit 230 is configured to perform the measurement method described in any of the above embodiments. The measuring device 20 may be a body scale or a body composition analyzer, without limitation.
In summary, the embodiments of the present application provide a measurement circuit, a measurement method, and a measurement apparatus. The measurement circuit includes: a weight measurement circuit comprising an excitation source and a signal processing circuit; a switch switching circuit including a plurality of power switches and a plurality of selection switches; the reference circuit is connected with the signal processing circuit and is also connected with the excitation source through a power switch; the weighing system comprises a plurality of weighing sensors, a power supply switch and a power supply, wherein each weighing sensor comprises a positive end, a negative end and an output end; the output ends of at least two weighing sensors are connected with an excitation source or a signal processing circuit through a selection switch, and the output ends of the other weighing sensors are connected with the signal processing circuit. The measuring circuit that this application embodiment provided both can measure weight, also can measure the focus, can also promote weight measurement's efficiency simultaneously.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not necessarily depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims (13)

1. A measurement circuit, comprising:
a weight measurement circuit comprising an excitation source and a signal processing circuit;
a switch switching circuit including a plurality of power switches and a plurality of selection switches;
the reference circuit is connected with the signal processing circuit and is also connected with the excitation source through the power switch;
the weighing sensors comprise positive ends, negative ends and output ends, and the positive ends and the negative ends of the weighing sensors are respectively connected with the excitation source through the power switch; the output ends of at least two weighing sensors are connected with the excitation source or the signal processing circuit through the selection switch, and the output ends of the other weighing sensors are connected with the signal processing circuit.
2. The measurement circuit of claim 1, wherein the plurality of load cells comprises a first load cell group and a second load cell group, wherein an output terminal of each load cell in the first load cell group is connected to the excitation source or the signal processing circuit through the selection switch, and an output terminal of each load cell in the second load cell group is connected to the signal processing circuit, wherein the load cells in the first load cell group and the load cells in the second load cell group are alternately connected in series.
3. The measurement circuit of claim 2, wherein the first load cell group comprises a first load cell and a third load cell, the second load cell group comprises a second load cell and a fourth load cell, a positive terminal of the first load cell is connected to a positive terminal of the fourth load cell, a negative terminal of the first load cell is connected to a negative terminal of the second load cell, a positive terminal of the second load cell is connected to a positive terminal of the third load cell, and a negative terminal of the third load cell is connected to a negative terminal of the fourth load cell;
the selection switch comprises a first selection switch and a second selection switch;
the output end of the first weighing sensor is connected with the positive end of the excitation source or the signal processing circuit through the first selection switch;
the output end of the third weighing sensor is connected with the negative end of the excitation source or the signal processing circuit through the second selection switch;
and the output end of the second weighing sensor and the output end of the fourth weighing sensor are respectively connected with the signal processing circuit.
4. The measurement circuit of claim 3, wherein the plurality of power switches comprises a first power switch, a second power switch, a third power switch, a fourth power switch, a fifth power switch, and a sixth power switch;
the reference circuit comprises a positive terminal and a negative terminal;
the connection node of the first weighing sensor and the second weighing sensor is connected with the negative end of the excitation source through the first power switch;
the connection node of the second weighing sensor and the third weighing sensor is connected with the positive end of the excitation source through the second power switch;
the connection node of the third weighing sensor and the fourth weighing sensor is connected with the negative end of the excitation source through the third power switch;
the connection node of the fourth weighing sensor and the first weighing sensor is connected with the positive end of the excitation source through the fourth power switch;
the positive end of the reference circuit is connected with the positive end of the excitation source through the fifth power switch;
the negative end of the reference circuit is connected with the negative end of the excitation source through the sixth power switch.
5. The measurement circuit of claim 1, wherein the reference circuit comprises a resistor string, the resistor string comprises a voltage dividing node, the voltage dividing node is connected to the signal processing circuit, one end of the resistor string is connected to a positive terminal of the excitation source through one of the power switches, and the other end of the resistor string is connected to a negative terminal of the excitation source through the other power switch.
6. The measurement circuit of claim 1, wherein each load cell comprises an elastomer and two resistors in series, at least one of the resistors being a strain resistor and affixed to the elastomer.
7. A measurement method, applied to a measurement circuit according to any one of claims 1 to 6, the method comprising:
when the weight of the measured object is measured, the power switch is controlled to be switched off, and the selection switch is controlled to be communicated with the excitation source, so that the weighing sensors form a first Wheatstone bridge;
acquiring a first differential signal output by the first Wheatstone bridge, and processing the first differential signal to obtain a weight value of the measured object;
when the gravity center of the measured object is measured, the power switch is controlled to be closed in a time sharing mode, the selection switch is controlled to be communicated with the signal processing circuit, the reference circuit and the weighing sensors are made to output multiple groups of second differential signals in a time sharing mode, and the gravity center data of the measured object are obtained based on the multiple groups of second differential signals.
8. The method of claim 7, wherein the controlling the power switch to be closed in a time-sharing manner and the selecting switch to be connected with the signal processing circuit to enable the reference circuit and the plurality of load cells to output a plurality of sets of second differential signals in a time-sharing manner comprises:
controlling a power switch connected with the reference circuit to be switched on and off;
and sequentially controlling a power switch connected with the weighing sensor to be closed and a selection switch connected with the weighing sensor to be communicated with the signal processing circuit for each weighing sensor, so that each weighing sensor sequentially forms a second Wheatstone bridge with the reference circuit and outputs a second differential signal.
9. The method of claim 7 or 8, wherein the plurality of load cells comprises a first load cell, a second load cell, a third load cell, and a fourth load cell, the selection switches comprise a first selection switch and a second selection switch, the output of the first load cell is connected to the positive terminal of the excitation source or the signal processing circuit through the first selection switch, the output of the third load cell is connected to the negative terminal of the excitation source or the signal processing circuit through the second selection switch, and the output of the second load cell and the output of the fourth load cell are respectively connected to the signal processing circuit;
the controlling the power switch to be switched off and the selecting switch to be switched on to the excitation source so that the plurality of weighing sensors form a first Wheatstone bridge comprises the following steps:
controlling the power switch to be switched off;
controlling the first selector switch to communicate the first weighing sensor with the positive end of the excitation source;
controlling the second selection switch to communicate the third weighing sensor with the negative end of the excitation source, so that the first weighing sensor, the second weighing sensor, the third weighing sensor and the fourth weighing sensor form a first Wheatstone bridge;
the acquiring a first differential signal output by the first Wheatstone bridge comprises:
and acquiring a signal of an output end of the second weighing sensor and a signal of an output end of the fourth weighing sensor as the first differential signal.
10. The method of claim 9, wherein the controlling the power switch to be closed in a time-sharing manner and the selecting switch to be connected to the signal processing circuit, the reference circuit and the plurality of load cells to output a plurality of sets of second differential signals in a time-sharing manner, and the calculating of the gravity center data of the measured object based on the plurality of sets of second differential signals comprises:
controlling a power switch connected with the reference circuit to be closed to enable the reference circuit to output a first output signal;
controlling a power switch connected with the first weighing sensor to be closed and a power switch not connected with the first weighing sensor to be disconnected, and controlling the first selection switch to connect the first weighing sensor and the signal processing circuit, so that the first weighing sensor outputs a second output signal;
controlling a power switch connected with the second weighing sensor to be closed and a power switch not connected with the second weighing sensor to be disconnected, so that the second weighing sensor outputs a third output signal;
controlling a power switch connected with the third weighing sensor to be closed and a power switch not connected with the third weighing sensor to be disconnected, and controlling the second selection switch to connect the third weighing sensor and the signal processing circuit, so that the third weighing sensor outputs a fourth output signal;
controlling a power switch connected with the fourth weighing sensor to be closed and a power switch not connected with the fourth weighing sensor to be disconnected, so that the fourth weighing sensor outputs a fifth output signal;
and grouping any two of the first output signal, the second output signal, the third output signal, the fourth output signal and the fifth output signal to obtain at least four groups of the second differential signals, wherein at least one group of the second differential signals comprises the first output signal.
11. The method of claim 10, wherein the calculating the center of gravity data of the object under test based on the plurality of sets of second differential signals comprises:
acquiring a first weight detected by the first weighing sensor, wherein the first weight is obtained by processing any at least one group of second differential signals including the second output signal by the signal processing circuit;
acquiring a second weight detected by the second weighing sensor, wherein the second weight is obtained by processing any at least one group of second differential signals including the third output signal by the signal processing circuit;
acquiring a third weight detected by the third weighing sensor, wherein the third weight is obtained by processing any at least one group of second differential signals including the fourth output signal by the signal processing circuit;
acquiring a fourth weight detected by the fourth weighing sensor, wherein the fourth weight is obtained by processing any at least one group of second differential signals including the fifth output signal by the signal processing circuit;
and calculating to obtain the gravity center data of the measured object based on the first weight, the second weight, the third weight and the fourth weight.
12. A measuring device comprising a body, a control circuit for performing the measuring method of any of claims 7-11, and a measuring circuit of any of claims 1-6.
13. The measurement device of claim 12, wherein the measurement device is a body scale or a body composition analyzer.
CN202010905012.4A 2020-09-01 2020-09-01 Measurement circuit, measurement method and measurement device Pending CN111998921A (en)

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