CN103698059A - Sensing antenna, tension measuring device and load measuring system - Google Patents

Abstract

The invention discloses a sensing antenna, which comprises an elastic material body with a sealed channel and normal temperature liquid metal located in the sealed channel; the elastic material body is used to be arranged on a measured object, and when subjected to tension, The sealing channel in the elastic material body can produce a corresponding amount of deformation with the deformation of the measured object, and the liquid metal can flow in the sealing channel, so that the resonant frequency of the sensing antenna is the same as that of the sealing channel corresponding to the amount of deformation. In addition, the invention also discloses a tension measuring device and a load measuring system comprising the above-mentioned antenna. The technical solution disclosed by the invention can be applied to moving objects or rotating objects.

Description

Sensing Antenna, Tension Measuring Device and Load Metering System

technical field

The invention relates to the field of tension measurement, in particular to a sensor antenna, a tension measurement device and a load measurement system of a transmission system.

Background technique

A tension measuring device is a device used to measure the tension of an object, specifically for pressure measurement, load measurement, biological measurement, and structural performance monitoring. Usually, the tensiometer includes a sensing element and a measuring element, and the sensing element and the calculating element are connected by metal wires. The sensing element can be a metal foil on the insulating elastic material. When in use, the elastic material with the metal foil is pasted on the surface of the object. When the object is deformed, the metal foil is driven to deform, thereby causing the resistance of the metal foil to change. , the measuring element calculates the deformation of the object by measuring the resistance change of the metal foil.

But the above-mentioned tension measuring device cannot be applied to moving objects or rotating objects. Taking the material transmission system as an example, in order to measure the material, it is necessary to arrange multiple sensing elements at intervals on the load transmission device, such as the material conveyor belt, each sensing element is set in a set unit area, and due to the sensing The element and measuring element are connected by wires so that as the load transmission moves, the wire connections between the individual sensing elements and the measuring element become entangled. This not only affects the signal transmission, but may also damage the tension measuring device.

In order to solve this problem, the sensing element in the current tension measuring device is usually a piezoresistive film sensing element, for example, a silicon element or a ceramic element located on a plastic or stainless steel support body, and the sensing element passes through The wires are connected to an external measuring element, such as a Wheatstone bridge. Since there are wires connected between the sensing element and the measuring element, the sensing element is usually arranged outside the load transfer device and kept separate from the load transfer device. At the same time, an additional mechanical support structure needs to be provided for transmitting the load pressure on the load transmission device to the sensing element. It can be seen that this measurement method will increase the installation complexity, and because the load pressure passes through the intermediate transmission link, the measurement result is not accurate enough.

Contents of the invention

In view of this, the present invention proposes a sensing antenna on the one hand, and proposes a tension measuring device and a load measuring system applied to a transmission system on the other hand, so that the tension measuring device can not only be applied to stationary objects, but also Can be applied directly to live or rotating objects.

The sensing antenna proposed by the present invention includes: an elastic material body with a sealed channel and a normal temperature liquid metal located in the sealed channel;

The elastic material body is used to be arranged on a deformable object to be measured. When subjected to tension, the sealing channel in the elastic material body can produce a corresponding amount of deformation according to the deformation of the object to be measured. The liquid metal Flow is enabled within the sealed channel such that the resonant frequency of the sensing antenna corresponds to the amount of deformation of the sealed channel.

In one embodiment of the present invention, the tension sensing antenna is a dipole antenna, and there are two sealing passages on the elastic material body, which constitute the dipole of the antenna.

Preferably, the antenna is a passive antenna.

In one embodiment of the present invention, the room temperature liquid metal is eutectic indium gallium alloy EGaIn.

In one embodiment of the present invention, the elastic material body is made of silica gel, rubber material or plastic material.

In one embodiment of the present invention, the elastic material body is polydimethylsiloxane.

The tension measuring device proposed by the present invention includes a transceiver and any sensing antenna in any of the above-mentioned specific implementation forms,

The transceiver is used to transmit electromagnetic wave signals and receive electromagnetic wave signals reflected by the tension sensing antenna, wherein the frequency of the reflected electromagnetic wave signals with the smallest energy loss is the resonant frequency of the antenna.

A load metering system, comprising: a speedometer, a load meter and the above-mentioned tension measuring device; wherein,

The tension measurement device has a plurality of tension measurement antennas, and the antennas are arranged at intervals on each unit area of the load transmission device;

The sealing channel on the antenna can produce a corresponding amount of deformation along with the deformation of the load transmission device, and the deformation amount of the sealing channel corresponds to the deformation amount when the load transmission device carries a load;

The speedometer is used to measure the movement speed of the load transmission device;

The load meter is used to determine the load flow on the load transmission device according to the load on each unit area of the load transmission device and the moving speed; the load on each unit area of the load transmission device is measured according to the tension The magnitude of the resonant frequency of each antenna measured by the device is determined.

Wherein, the tension sensing antenna is pasted on the load transmission device, or integrated on the load transmission device.

It can be seen from the above scheme that since the tension measuring device in the embodiment of the present invention has an antenna capable of correspondingly deforming with the deformation of the object to be measured, and utilizes radio frequency identification (RFID, Radio Frequency Identification) technology in the field of wireless communication, The transceiver sends radio signals to identify the antenna and reads and writes the resonant frequency data related to the deformation of the object to be measured, without making the transceiver mechanically or optically contact the antenna. This enables a wireless connection between the sensing element (i.e. the antenna) and the measuring element (i.e. the transceiver) of the tension measuring device, making the tension measuring device not only applicable to stationary objects, but also to moving objects or rotating On the object, and avoid the mechanical support structure that needs to convert the force on the moving object or rotating object to the load measuring element in the prior art. In addition, due to the absence of intermediate force transmission links, the accuracy of measurement is improved.

In addition, since the room temperature liquid metal sealing channel formed by elastic material is used in the embodiment of the present invention, it is possible to select an elastic material with proper elasticity according to the tension range to be measured, so the tension measuring device of the present invention can measure various ranges tension. In addition, since the elasticity of the elastic material is relatively large, that is, the antenna of the present invention can be measured by using the elastic material to measure a relatively large tension. And the use of elastic material makes the antenna have deformation reversibility and durability. In addition, the sensitivity of the antenna can also be adjusted by selecting a suitable elastic elastic material.

In addition, a simple soft lithography (soft lithography) process can be used to manufacture the sensing antenna, and multiple antennas can be produced by using one replica mold, which makes the product of the present invention have low manufacturing cost.

In addition, since the eutectic InGa alloy is a low-viscosity liquid metal alloy with relatively high conductivity at room temperature, and the eutectic InGa alloy has low toxicity, the tension sensor in the embodiment of the present invention When the antenna is made of eutectic indium gallium alloy, it has high conductivity, strong mechanical stability and high safety.

In addition, since the sensing antenna and the transceiver in the embodiment of the present invention are wirelessly connected, when the tension measuring device is applied to logistics measurement, the sensing antenna for measuring tension in the tension measuring device can be integrated in the On the load transmission device, this reduces the installation steps of the independent sensing antenna, and also does not need to set the position maintaining part of the antenna.

Description of drawings

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that those of ordinary skill in the art will be more aware of the above-mentioned and other features and advantages of the present invention. In the accompanying drawings:

FIG. 1 is a schematic structural diagram of a tension sensing antenna in an embodiment of the present invention.

FIG. 2 is a partial side view of the elastic material body in a processing method of the tension sensing antenna shown in FIG. 1 .

Fig. 3 is a schematic diagram of the resonant frequency of the antenna measured by the transceiver under different tensions in the embodiment of the present invention.

Fig. 4 is a schematic structural diagram of a load metering system in an embodiment of the present invention.

Among them, the accompanying drawings are as follows:

110-elastic material body 111, 112-microfluidic sealing channel 120-normal temperature liquid metal 210-first layer of elastic material body 220-second layer of elastic material body 230-adhesive 211-microfluidic sealing channel

410-Tension Measuring Device 411-Tension Sensing Antenna 412-Transceiver 420-Speedometer 430-Load Meter 440-Load Transmission Device

Detailed ways

In the embodiment of the present invention, in order to reduce the mechanical support structure that needs to convert the force on the moving object or rotating object to the load measuring unit in the prior art, so that the tension measuring device can be directly applied to the moving object or rotating object, consider A wireless connection is used between the sensing unit and the computing unit of the tension measuring device. For this reason, the inventor of the present application overcomes inertial thinking after creative work, and considers using radio frequency identification (RFID, Radio Frequency Identification) technology in the field of wireless communication to measure the load. Radio frequency identification, also known as electronic tags and radio frequency identification, can identify specific targets through radio signals and read and write related data without establishing mechanical or optical contact between the identification system and specific targets. Commonly used radio frequency identification technologies include low frequency (125k~134.2K), high frequency (13.56Mhz), ultra high frequency, passive and other technologies.

In order to be able to measure tension, it is necessary for the tension sensing antenna to be able to achieve relatively obvious deformation. Therefore, after a lot of creative work, the inventors of the present application considered using room temperature liquid metal to make the tension sensing antenna. In order to make the size of the antenna made of room-temperature liquid metal deformable, the present application further considers making the carrier containing the room-temperature liquid metal deformable. For this reason, it is considered to use an insulating elastic material as the carrier of the room-temperature liquid metal. In this way, the tension sensing antenna in the embodiment of the present invention may include: an elastic material body with a sealed channel and a normal temperature liquid metal located in the microfluidic sealed channel. Wherein, the elastic material body is used to be arranged on the measured object, and when subjected to tension, the sealing channel in the elastic material body can produce a corresponding amount of deformation along with the deformation of the measured object, and the room temperature liquid Metal can flow in the sealing channel along with the deformation of the sealing channel, and generate a resonant frequency corresponding to the deformation amount of the sealing channel. That is, the sensing antenna is used to be arranged on a measured object capable of generating deformation, and can generate a corresponding amount of deformation along with the deformation of the measured object, and generate a resonant frequency corresponding to the amount of deformation.

In order to make the purpose, technical solution and advantages of the present invention clearer, the following examples are given to further describe the present invention in detail.

FIG. 1 is a schematic structural diagram of a tension sensing antenna in an embodiment of the present invention. As shown in Fig. 1, the tension sensing antenna in this embodiment is a dipole antenna, which includes: an elastic material body 110 with two microfluidic sealing channels 111, 112 and an elastic material body 110 located in the two sealing channels 111, 112 The room temperature liquid metal 120 inside. Preferably, the two sealing channels 111 and 112 have the same length and are arranged on the same straight line with an insulating gap in between. The normal-temperature liquid metal 120 located in the two sealed passages 111 and 112 constitutes two wireless wires and constitutes the long axis of the entire antenna. The dipole antenna resonates with wavelength λ. The wavelength λ is approximately twice the length L of the entire antenna, ie λ=2L. The wavelength λ and the antenna length L are inversely proportional to the resonance frequency.

Wherein, the elastic material body 110 is used to be arranged on the object to be measured, and the sealing passages 111, 112 in the elastic material body 110 can produce a corresponding amount of deformation with the deformation of the object to be measured, which can be calibrated through experiments The method determines the relationship between the deformation of the microfluidic sealing channels 111 and 112 and the deformation of the measured object. The room temperature liquid metal 120 can flow in the sealed channels 111, 112 along with the deformation of the sealed channels 111, 112, and generate a resonant frequency that is a function of the deformation of the microfluidic sealed channels 111, 112 , so that the resonant frequency of the tension sensing antenna corresponds to the deformation of the sealed channel.

In specific implementation, the normal-temperature liquid metal can be eutectic indium-gallium alloy EGaIn, or mercury. Among them, since EGaIn is a low-viscosity liquid metal alloy, it has relatively high conductivity at room temperature, and EGaIn has low toxicity, so the tension sensing antenna has higher conductivity and stronger Mechanical stability and high safety.

In addition, the elastic material body can be made of silica gel, rubber material or plastic material or the like. For example, the elastic material body may be polydimethylsiloxane (PDMS) or the like.

In specific processing, the tension sensing antenna shown in Fig. 1 may have various specific processing methods. Fig. 2 shows a partial side view of the body of elastic material in one of its processing methods. As shown in FIG. 2 , during processing, the upper and lower layers of the elastic material body 110 can be processed first, that is, the first layer 210 and the second layer 220 . Wherein, the microfluidic sealing channel can be located on the first layer 210 or on the second layer 220 , or a part can be located on the first layer 210 and another part can be located on the second layer 220 . In this embodiment, taking the case where the microfluidic sealing channel is located on the first layer 210 as an example, during processing, a mold with two linear protrusions can be made first, and the two linear protrusions can be located on the same axis, and the middle several millimeters apart. Then inject liquid elastic material into the mold and solidify it (for example, soft photolithography process can be used) to obtain the first layer 210 of the elastic material body 110, wherein the positions of the two straight line protrusions corresponding to the model are located at the first Two sealed channels 211 on layer 210 . The first layer 210 with the sealed channel and the second layer 220 with the platform contact surface are then glued together by adhesive 230 . Then, a normal-temperature liquid metal, such as EGaIn, is injected into the two microfluidic sealing channels 211 , and then the inlets and outlets of the two microfluidic sealing channels 211 are sealed.

The above is only one processing method of the tension sensing antenna, in addition, there may be other processing methods, which will not be repeated here.

In addition to the above-mentioned antenna, the tension measuring device in the embodiment of the present invention also includes a transceiver. The transceiver is used to transmit electromagnetic wave signals and receive electromagnetic wave signals reflected by the antenna. The transceiver can scan a wide frequency range, and the frequency of the electromagnetic wave signal with the smallest energy loss reflected by the antenna is the resonant frequency of the antenna.

Further, the transceiver can also determine the magnitude of the tension on the measured object according to the resonance frequency of the sensing antenna.

Fig. 3 shows a schematic diagram of the resonant frequency of the sensing antenna measured by the transceiver under four different tensions in the embodiment of the present invention. Wherein, the positions corresponding to the valley peaks of each curve are the values of the four resonant frequencies of the antenna under the corresponding tension.

During specific implementation, the tension measurement device in the embodiment of the present invention can be applied not only to stationary objects but also to Applied to live objects or rotating objects. When applied to a moving object or a rotating object, the sensing element, that is, the tension sensing antenna, can be directly placed on the object to be measured, thereby avoiding the need to place the force on the moving object or rotating object in the prior art It is converted to the mechanical support structure on the load measuring element, and the accuracy of the measurement is improved due to the lack of intermediate force conversion links.

Taking the logistics transmission system as an example, the tension measuring device in the embodiment of the present invention can be used to measure the load on the logistics conveyor belt. Fig. 4 is a schematic structural diagram of a load metering system in an embodiment of the present invention. As shown in FIG. 4 , the load measuring system may include: a tension measuring device 410 in the embodiment of the present invention, a speedometer 420 and a load gauge 430 .

Wherein, the tension measuring device 410 has a plurality of tension sensing antennas 411 as shown in FIG. on the unit area. The sealing passage in the elastic material body of each tension sensing antenna 411 can produce a corresponding amount of deformation with the deformation of the load transmission device 440 when the load is carried on the load transmission device; and the normal temperature liquid metal in the sealing passage It can flow in the sealing channel along with the deformation of the sealing channel, and generate a resonance frequency corresponding to the deformation amount of the sealing channel.

The transceiver 412 of the tension measuring device 410 is used to measure the resonant frequency of each tension sensing antenna 411 and output the load in each unit area of the load transmission device 440 . For example, the unit is kg/m.

The speed detector 420 can be an encoder, which is used to record the moving speed of the load conveying device. For example, the unit is m/s.

The load meter 430 is used to determine the current load flow on the load transfer device 440 according to the load amount in each unit area of the load transfer device 440 and the moving speed of the load transfer device 440 . For example, the unit is kg/s.

The load meter 430 can further calculate the accumulated load on the load transfer device 440 within a period of time.

During specific implementation, the transceiver 412 of the tension measuring device 410 may also output the magnitude of the resonance frequency or the magnitude of tension corresponding to the magnitude of the resonance frequency to the load meter after measuring the magnitude of the resonance frequency of each tension sensing antenna 411 The load meter 430 calculates the load of the load transfer device 440 on each unit area by the load meter 430 .

In practical applications, since the tension sensing antenna 411 and the transceiver 412 in the embodiment of the present invention are wirelessly connected, when the tension measurement device 410 is applied to the above-mentioned logistics measurement, the tension measurement device 410 can be The tension sensing antenna 411 is integrated on the load transmission device 440, which reduces the installation steps of the independent sensing antenna, and also eliminates the need to set the antenna position maintaining components.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (9)

1. A sensing antenna, comprising: an elastic material body with a sealed channel and a normal temperature liquid metal located in the sealed channel; The elastic material body is used to be arranged on the measured object capable of generating deformation. When subjected to tension, the sealing channel in the elastic material body can produce a corresponding amount of deformation according to the deformation of the measured object. The liquid Metal is able to flow within the sealed channel such that the resonant frequency of the antenna corresponds to the amount of deformation of the sealed channel. 2 . The antenna according to claim 1 , wherein the sensing antenna is a dipole antenna, and there are two sealed passages on the elastic material body, which constitute the dipole of the antenna. 3 . 3. An antenna according to claim 1 or 2, which is a passive antenna. 4. The antenna according to claim 1 or 2, characterized in that the room temperature liquid metal is eutectic indium gallium alloy EGaIn. 5. The antenna according to claim 1 or 2, wherein the elastic material body is made of silica gel, rubber material or plastic material. 6. The antenna according to claim 5, wherein the elastic material body is polydimethylsiloxane. 7. A tension measuring device comprising a transceiver and the antenna according to any one of claims 1 to 6, The transceiver is used to transmit electromagnetic wave signals and receive electromagnetic wave signals reflected by the antenna, wherein the frequency of the reflected electromagnetic wave signals with the least energy loss is the resonant frequency of the antenna. 8. A load metering system comprising: a velocimeter, a load meter and a tension measuring device as claimed in claim 7; wherein, The tension measurement device has a plurality of tension measurement antennas, and the antennas are arranged at intervals on each unit area of the load transmission device; The sealing channel on the antenna can produce a corresponding amount of deformation along with the deformation of the load transmission device, and the deformation amount of the sealing channel corresponds to the deformation amount when the load transmission device carries a load; The speedometer is used to measure the movement speed of the load transmission device; The load meter is used to determine the load flow on the load conveying device according to the load on each unit area of the load conveying device and the moving speed; the load on each unit area of the load conveying device is measured according to the tension The magnitude of the resonant frequency of each antenna measured by the device is determined. 9. The system according to claim 8, wherein the antenna is pasted or integrated on the load transfer device.

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