CN112125082A - Elevator weighing measurement method based on strain induction - Google Patents
Elevator weighing measurement method based on strain induction Download PDFInfo
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- CN112125082A CN112125082A CN202010823921.3A CN202010823921A CN112125082A CN 112125082 A CN112125082 A CN 112125082A CN 202010823921 A CN202010823921 A CN 202010823921A CN 112125082 A CN112125082 A CN 112125082A
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- 238000005303 weighing Methods 0.000 title claims abstract description 19
- 230000006698 induction Effects 0.000 title claims abstract description 7
- 238000000691 measurement method Methods 0.000 title description 3
- 238000000034 method Methods 0.000 claims abstract description 24
- 230000008569 process Effects 0.000 claims abstract description 3
- 230000008859 change Effects 0.000 claims description 5
- 230000003321 amplification Effects 0.000 claims description 4
- 238000005259 measurement Methods 0.000 claims description 4
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 4
- 239000003822 epoxy resin Substances 0.000 claims description 3
- 229920000647 polyepoxide Polymers 0.000 claims description 3
- 229910001006 Constantan Inorganic materials 0.000 claims description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 239000010949 copper Substances 0.000 claims description 2
- 230000005484 gravity Effects 0.000 claims description 2
- 238000012545 processing Methods 0.000 claims description 2
- 238000009434 installation Methods 0.000 abstract description 7
- 238000004891 communication Methods 0.000 abstract description 3
- 238000010276 construction Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 5
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 230000005483 Hooke's law Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
- B66B5/00—Applications of checking, fault-correcting, or safety devices in elevators
- B66B5/0006—Monitoring devices or performance analysers
- B66B5/0018—Devices monitoring the operating condition of the elevator system
- B66B5/0031—Devices monitoring the operating condition of the elevator system for safety reasons
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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
- G01G3/13—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 having piezoelectric or piezoresistive properties
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Force In General (AREA)
Abstract
The invention discloses an elevator weighing and measuring method based on strain induction, which comprises the following steps: (1) a Wheatstone bridge is formed by four resistance strain gauges and is arranged at the bottom of an elevator car; (2) obtaining the relation between the strain and the length and the cross-sectional area of the resistance wire according to the characteristics of the resistance strain gauge; (3) when the bottom of the elevator car is stressed, the resistance strain gauge is strained, the resistance value is changed, and the resistance difference delta R of the resistance strain gauge when the bottom of the elevator car is stressed is measured through a Wheatstone bridge; (4) converting the resistance difference Delta R into a voltage signal UBD(ii) a (5) U is amplified by a differential amplifierBDAmplifying voltage; (6) the singlechip acquires the amplified voltage analog quantity, processes the data and sends the data to the elevator master control. The voltage analog quantity and the communication are acquired by using the independent single chip microcomputer, the stability and the accuracy of data are improved, the construction and the installation are convenient, and the weight distortion caused by installation errors is avoided compared with the traditional method.
Description
Technical Field
The invention relates to the field of elevator equipment, in particular to an elevator weighing and measuring method based on strain sensing.
Background
At present, in the elevator industry, a weighing method of a commercial elevator or a sightseeing elevator mostly adopts a method of installing a magnetic induction or light induction device at the bottom of a car to measure, and the distance from a sensor to an elevator master control is large, so that errors are easy to occur. The method has high economic cost and poor measurement accuracy, and if the magnet is not installed in place or dust blocks light induction and the like during installation, the actual weighing of the elevator is influenced, and in a serious case, the elevator can have safety failure. The elevator weighing measurement method based on the strain sensing can reduce economic cost, improve measurement accuracy, and calculate weight through intuitive change safely and conveniently.
Disclosure of Invention
The invention aims to provide an elevator weighing and measuring method based on strain sensing, which can improve the precision and stability of elevator weighing, thereby reducing the overload risk during the operation of an elevator and reducing the economic cost.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
an elevator weighing and measuring method based on strain sensing is characterized by comprising the following steps:
an elevator weighing and measuring method based on strain sensing comprises the following steps:
(1) a Wheatstone bridge is formed by four resistance strain gauges and is arranged at the bottom of an elevator car;
(2) obtaining the relation between the strain and the length and the cross-sectional area of the resistance wire according to the characteristics of the resistance strain gauge;
(3) when the bottom of the elevator car is stressed, the resistance strain gauge is stressed by pressure F to be strained, when the resistance is stressed and deformed, the resistance value is changed, and the resistance difference delta R of the resistance strain gauge when the bottom of the elevator car is stressed is measured through a Wheatstone bridge;
(4) converting the resistance difference Delta R into a voltage signal UBD；
(5) U is amplified by a differential amplifierBDAmplifying voltage;
(6) the singlechip acquires the amplified voltage analog quantity, processes the data and sends the data to the elevator master control.
Preferably, four resistance strain gauges are adopted and mounted at the bottom of the elevator car, and the resistance strain gauges are composed of
The constantan wire is wound into a grid shape, is clamped in two layers of insulating sheets, silver-plated copper wires are connected with strain gauge wire grids to be used as lead wires, CH31 epoxy resin is used for mounting the lead wires and the bottom around the elevator car, and four resistance strain gauges are mounted in the same direction to form a Wheatstone bridge.
Preferably, the single chip microcomputer is used for collecting signals to communicate with the host, the independent single chip microcomputer is used for processing and sending data, the independent single chip microcomputer is also arranged at the bottom of the lift car, an AD port of the single chip microcomputer is connected with 1OUT and 2OUT of the operational amplifier circuit, and then the single chip microcomputer is connected with the master control in a four-wire system mode, namely 5V, GND, 485 and 484.
Preferably, when the bottom of the elevator car is stressed by the resistance strain gauge and is strained by the pressure F, when the resistance is stressed and deformed, the resistance value is also changed, and the relation is obtained as follows:
wherein the original resistance value R, the strain coefficient K, the cross-sectional area S and the elastic modulus E are all constants, so that the F gravity borne by the elevator car can be solved only by measuring the resistance value variation delta R.
Preferably, post-strain by Wheatstone currentThe bridge measures the difference in resistance Δ R, where for ease of measurement, the change in resistance is converted to a voltage signal by applying a voltage U across the Wheatstone bridge A, C due to the small value of Δ Rac(ii) a B. D two ends as output voltage UBD；R1R2One set of bridge arms, R3R4The same bridge arm group, when the four resistance values are the same, R1＝R2＝R3＝R4When the bridge is at the equilibrium position Δ V of 0, the current-through resistor R is set1R2Has a current of IA,
Let the current flow through the resistor R3R4Has a current of IB,
When R is1R2R3R4Changed to obtain { Delta R1,ΔR2,ΔR3,ΔR4The following two relationships are derived by the formula:
wherein1,2,3,4The strain and strain reading of a resistance strain gage at the bottom of the elevator car are respectivelyr＝(1-2+3-4)；{ΔR1,ΔR2,ΔR3,ΔR4Is R1R2R3R4Obtained after the change.
Preferably, U is amplified by a differential amplifierBDVoltage amplification due to UBDThe value is too small, the method amplifies the voltage signal by a differential amplifier, and the amplification factor is generally 5 multiplied by 105Wherein the Wheatstone bridge, the differential amplifier and the single chip microcomputer are the same 5V power supply, thus reducing the resource occupancy of the elevator, and the output U of the bridgeBDThe passive output is connected with the passive inputs 1IN and 2IN of the differential operational amplifier circuit.
Preferably, the elevator is a passenger elevator.
The invention has at least the following technical effects:
the invention uses a method for weighing and measuring an elevator based on strain sensing, adopts the strain sensing technology to weigh, installs four pieces of sensing resistors on the periphery of the bottom of an elevator car, and adopts an independent single chip microcomputer to acquire voltage analog quantity and communication, thereby shortening the transmission distance of the voltage analog quantity and improving the stability and the accuracy of data. The construction and installation are convenient, and compared with the traditional method, the weight distortion caused by installation errors is avoided.
Drawings
FIG. 1 is a schematic block diagram of a method for measuring elevator weight based on strain sensing;
FIG. 2 is a schematic view of an installation location;
FIG. 3 is a schematic diagram of the principle of resistance wire sensitivity coefficient;
FIG. 4 is a schematic diagram of the connection of four strain gages;
FIG. 5 is a schematic diagram of a differential operational amplifier circuit;
FIG. 6 is a schematic diagram of sampling values using an analog voltage quantity according to the present invention;
Detailed Description
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. 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 invention.
The invention is described in detail below with reference to the figures and the specific examples.
Four resistance strain gauges are firstly adopted and installed at the bottom of the periphery of an elevator car by CH31 epoxy resin, and the installation directions of the four resistance strain gauges are consistent to form a Wheatstone bridge. When the bottom of the elevator car is stressed, the resistance strain gauge is strained, as shown in figure 2.
Measured according to a single resistance of
Where p is the resistivity of the metal, where L is the length and S is the cross-sectional area. Obtaining { delta p, delta L, delta S, delta R } after changing; when the resistivity, the length or the cross-sectional area at any point changes according to the formula, the resistance also changes, and the logarithm of the two sides is taken to obtain the formula
As shown in fig. 3.
Assuming that the resistance strain gauge generates strain of
Let the radius of the resistance wire be d, let the radius after strain be Deltad, obtain after differentiation
Coefficient of sensitivity
The value of k is constant in the formula. According to the formula of engineering mechanics
Will be a formula
Substitution into
To obtain
Therefore, when the original resistance R, the strain coefficient K, the cross section area S and the elastic modulus E are all known, the weight born in the elevator car can be obtained by measuring the resistance variation delta R.
Applying a voltage U across A and C by a bridge test memberac(ii) a The output voltage at both ends of B and D is UBD；R1R2One set of bridge arms, R3RXThe same bridge arm group, when the four resistance values are the same, R1＝R2＝R3＝R4When the bridge is at the equilibrium position Δ V of 0, the current-through resistor R is set1R2Has a current of IA,
Let the current flow through the resistor R3R4Has a current of IB,
When R is1R2R3R4Changed to obtain { Delta R1,ΔR2,ΔR3,ΔR4The following two relationships are derived by the formula:
wherein1,2,3,4Respectively the strain of a resistance strain gage at the bottom of the elevator car. (FIG. 6 shows a voltage UBDThe generated waveform) as shown in the figure, the voltage quantity of the resistance strain gauge changes successively when the resistance strain gauge is strained, wherein DC is direct current sampling, each grid is 1V, and therefore the amplitude of the voltage quantity is 5V. It is found that the strain voltage does not exceed the supply voltage at most.
By Hooke's law σ ═ ErWhere E is a constant which is the modulus of elasticity at the re-deformation stage of the material. The weight borne by the elevator car can be calculated from this formula.
The output ends of the bridge amplify the signals to the MCU through a differential operational amplifier circuit (as shown in figure 5), and the MCU AD acquires the voltage analog quantity,
wherein λ is magnification factor, generally 5 × 105
Through the calculation, the weight data is sent to the elevator master control through 485 communication.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made to the present invention by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (7)
1. An elevator weighing and measuring method based on strain sensing is characterized in that:
(1) a Wheatstone bridge is formed by four resistance strain gauges and is arranged at the bottom of an elevator car;
(2) obtaining the relation between the strain and the length and the cross-sectional area of the resistance wire according to the characteristics of the resistance strain gauge;
(3) when the bottom of the elevator car is stressed, the resistance strain gauge is stressed by pressure F to be strained, when the resistance is stressed and deformed, the resistance value is changed, and the resistance difference delta R of the resistance strain gauge when the bottom of the elevator car is stressed is measured through a Wheatstone bridge;
(4) converting the resistance difference Delta R into a voltage signal UBD；
(5) U is amplified by a differential amplifierBDAmplifying voltage;
(6) the singlechip acquires the amplified voltage analog quantity, processes the data and sends the data to the elevator master control.
2. The elevator weighing and measuring method based on the strain sensing is characterized in that: four resistance strain gauges are adopted and installed at the bottom of the elevator car, and the resistance strain gauges consist of
The constantan wire is wound into a grid shape, is clamped in two layers of insulating sheets, silver-plated copper wires are connected with strain gauge wire grids to be used as lead wires, CH31 epoxy resin is used for mounting the lead wires and the bottom around the elevator car, and four resistance strain gauges are mounted in the same direction to form a Wheatstone bridge.
3. The elevator weighing and measuring method based on the strain sensing is characterized in that: the single chip microcomputer is used for collecting signals to communicate with a host, the independent single chip microcomputer is used for processing and sending data, the independent single chip microcomputer is also arranged at the bottom of the lift car, an AD port of the single chip microcomputer is connected with 1OUT and 2OUT of the operational amplifier circuit, and then the single chip microcomputer is connected with a main control in a four-wire system mode and is respectively 5V, GND, 485 and 484-.
4. The elevator weighing and measuring method based on the strain sensing is characterized in that: when the bottom of the elevator car is stressed by the resistance strain gauge and the resistance strain gauge is stressed by pressure F, the resistance value is changed when the resistance is stressed and deformed, and the relation is obtained as follows:
wherein the original resistance value R, the strain coefficient K, the cross-sectional area S and the elastic modulus E are all constants, so that the F gravity borne by the elevator car can be solved only by measuring the resistance value variation delta R.
5. The elevator weighing and measuring method based on strain induction as claimed in claim 1, characterized in that: measuring the resistance difference Δ R through the Wheatstone bridge after strain, wherein for convenient measurement, the resistance change is converted into a voltage signal by applying a voltage U across the Wheatstone bridge A, Cac(ii) a B. D two ends as output voltage UBD；R1R2One set of bridge arms, R3R4The same bridge arm group, when the four resistance values are the same, R1＝R2＝R3＝R4When the bridge is at the equilibrium position Δ V of 0, the current-through resistor R is set1R2Has a current of IA,
Let the current flow through the resistor R3R4Has a current of IB, 
When R is1R2R3R4Changed to obtain { Delta R1,ΔR2,ΔR3,ΔR4The following two relationships are derived by the formula:
wherein1,2,3,4The strain and strain reading of a resistance strain gage at the bottom of the elevator car are respectivelyr＝(1-2+3-4)；{ΔR1,ΔR2,ΔR3,ΔR4Is R1R2R3R4Obtained after the change.
6. The elevator weighing and measuring method based on the strain sensing is characterized in that: u is amplified by a differential amplifierBDVoltage amplification due to UBDThe value is too small, the method amplifies the voltage signal by a differential amplifier, and the amplification factor is generally 5 multiplied by 105Wherein the Wheatstone bridge, the differential amplifier and the single chip microcomputer are the same 5V power supply, thus reducing the resource occupancy of the elevator, and the output U of the bridgeBDThe passive output is connected with the passive inputs 1IN and 2IN of the differential operational amplifier circuit.
7. The elevator weighing and measuring method based on the strain sensing is characterized in that: the elevator is a passenger elevator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202010823921.3A CN112125082A (en) | 2020-08-17 | 2020-08-17 | Elevator weighing measurement method based on strain induction |
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| CN202010823921.3A CN112125082A (en) | 2020-08-17 | 2020-08-17 | Elevator weighing measurement method based on strain induction |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101920875A (en) * | 2009-06-15 | 2010-12-22 | 东芝电梯株式会社 | The load detecting device of elevator |
| CN102153004A (en) * | 2011-04-27 | 2011-08-17 | 南通昌荣机电有限公司 | Novel elevator load detector |
| CN102358541A (en) * | 2011-08-31 | 2012-02-22 | 日立电梯（中国）有限公司 | Weighing device |
| CN103344450A (en) * | 2013-07-16 | 2013-10-09 | 中科华核电技术研究院有限公司 | Load simulator |
| CN203903705U (en) * | 2014-04-10 | 2014-10-29 | 上海江燕电梯配件研究所 | Signal sampling and transmitting circuit for weighing device in elevator compartment |
| CN106708327A (en) * | 2017-01-21 | 2017-05-24 | 宸鸿科技(厦门)有限公司 | Pressure sensor and display device |
-
2020
- 2020-08-17 CN CN202010823921.3A patent/CN112125082A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101920875A (en) * | 2009-06-15 | 2010-12-22 | 东芝电梯株式会社 | The load detecting device of elevator |
| CN102153004A (en) * | 2011-04-27 | 2011-08-17 | 南通昌荣机电有限公司 | Novel elevator load detector |
| CN102358541A (en) * | 2011-08-31 | 2012-02-22 | 日立电梯（中国）有限公司 | Weighing device |
| CN103344450A (en) * | 2013-07-16 | 2013-10-09 | 中科华核电技术研究院有限公司 | Load simulator |
| CN203903705U (en) * | 2014-04-10 | 2014-10-29 | 上海江燕电梯配件研究所 | Signal sampling and transmitting circuit for weighing device in elevator compartment |
| CN106708327A (en) * | 2017-01-21 | 2017-05-24 | 宸鸿科技(厦门)有限公司 | Pressure sensor and display device |
Non-Patent Citations (1)
| Title |
|---|
| 黄建亮等: "<材料与工程力学实验指导书>", 31 May 2016 * |
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Application publication date: 20201225 |