1. A shape memory alloy-based device, comprising:

the first wire and the second wire are wires made of shape memory alloy;

a power source electrically connected to the first wire and the second wire for applying currents of different magnitudes to the first wire and the second wire;

the probe is driven by the deformation of the first wire and/or the second wire to displace under the condition that the first wire and/or the second wire deform, wherein the first displacement direction of the probe driven by the first wire is opposite to the first displacement direction of the probe driven by the second wire, and the deformation of the first wire and/or the second wire is generated by the on-off of the current.

2. The apparatus of claim 1, further comprising:

the drive division, with the probe first silk with the second silk is connected, the one end of drive division is installed the probe, the drive division quilt the deformation drive of first silk and/or second silk takes place the displacement, the direction of displacement does the length direction of probe.

3. The apparatus of claim 2,

the driving part includes: a slide rail in the displacement direction; the push rod is arranged in the slide rail, wherein the push rod can slide along the direction of the slide rail, and the probe is installed at the first end of the push rod.

4. The apparatus of claim 3,

the first end of the first wire is connected to the first end of the push rod, and the second end of the first wire is connected to the slide rail;

the first end of the second wire is connected to the second end of the push rod, and the second end of the second wire is connected to the sliding rail.

5. The apparatus of claim 3,

two ends of the first wire are symmetrically connected to the first end of the sliding rail in the axial direction of the push rod, and the middle section of the first wire is fixed on the push rod on the first end side of the sliding rail;

the two ends of the second wire are symmetrically connected to the second end of the sliding rail in the axial direction of the push rod, and the middle section of the second wire is fixed to the push rod on the side of the second end of the sliding rail.

6. The apparatus according to claim 4 or 5,

the number of the first wires is at least two, and/or the number of the second wires is at least two.

7. The apparatus of any one of claims 1 to 5, wherein the probe comprises at least one of the following conditions:

the length of the probe is 0.5-5 mm, the diameter of the probe is 0.05-0.6 mm, and the test area of the probe is more than or equal to 100 mu m²The modulus of the probe is more than or equal to 200GPa, and the detection stroke of the probe is 5-2000 mu m.

8. The device according to any one of claims 1 to 5, wherein the shape memory alloy is a nickel titanium based shape memory alloy and/or the power source is pulsed electricity at a pulse frequency of 0.30 to 50 Hz.

9. The apparatus of any one of claims 1 to 5, further comprising:

and the software is used for setting a detection stroke and obtaining a current peak value, wherein the current peak value is a current value determined by an external power supply when the first wire and/or the second wire is/are electrified and heated to drive the probe to extend out to reach the detection stroke, and the current peak value and the detection stroke are used for calculating the modulus of the object to be tested.

10. The device of claim 8, wherein the software is further configured to control the power source to energize the first wire and/or the second wire to control the probe to extend or retract.

Background

The material is in a small strain range and is in an elastic deformation stage, and the stress and the strain are generally in a direct proportional relation, and the proportionality coefficient is called as an elastic modulus. The modulus of elasticity is usually used to indicate the degree of softness or the ease of deformation of a material, and is one of the very critical engineering parameters. On the one hand, the method is used as an important standard for engineering material selection, or can also be used for judging the property of the material. The conventional elastic modulus test methods mainly comprise three methods: static transmission, wave propagation and dynamic. The specific testing procedure requires precise sample preparation and follows a standardized measurement protocol.

However, in many application scenarios, a standard modulus test process cannot be achieved, and the modulus of the target material needs to be immediately distinguished and data fed back, so that the hardness of the target material is distinguished in the shortest time, and thus the working efficiency is improved. In addition, many subject materials, such as biological tissues, whether geometrically sized or limited in processability, often have difficulty providing standardized test samples. In addition, some applications require measuring the modulus of an object under a special scene, such as a micro-space or local modulus data of the object at a micro-scale, as a judgment basis in a continuous operation process. But testing of such elastic moduli is currently almost impossible to achieve, let alone to make instantaneous measurements and data feedback. There is currently no equipment available to meet such a need.

Disclosure of Invention

The embodiment of the application provides a device based on a shape memory alloy, and the device at least solves the problem that the modulus of an object is difficult to test.

According to one aspect of the present application, there is provided a shape memory alloy-based device comprising:

the first wire and the second wire are wires made of shape memory alloy;

a power source electrically connected to the first wire and the second wire for applying currents of different magnitudes to the first wire and the second wire;

the probe is driven by the deformation of the first wire and/or the second wire to displace under the condition that the first wire and/or the second wire deform, wherein the first displacement direction of the probe driven by the first wire is opposite to the first displacement direction of the probe driven by the second wire, and the deformation of the first wire and/or the second wire is generated by the on-off of the current.

Further, the apparatus of the present invention further includes:

the drive division, with the probe first silk with the second silk is connected, the one end of drive division is installed the probe, the drive division quilt the deformation drive of first silk and/or second silk takes place the displacement, the direction of displacement does the length direction of probe.

Further, in the apparatus of the present invention, the driving section includes: a slide rail in the displacement direction; the push rod is arranged in the slide rail, wherein the push rod can slide along the direction of the slide rail, and the probe is installed at the first end of the push rod.

Further, in the device of the present invention, a first end of the first wire is connected to a first end of the push rod, and a second end of the first wire is connected to the slide rail;

the first end of the second wire is connected to the second end of the push rod, and the second end of the second wire is connected to the sliding rail.

Further, in the device of the present invention, two ends of the first wire are symmetrically connected to the first end of the slide rail in the axial direction of the push rod, and the middle section of the first wire is fixed to the push rod on the first end side of the slide rail;

the two ends of the second wire are symmetrically connected to the second end of the sliding rail in the axial direction of the push rod, and the middle section of the second wire is fixed to the push rod on the side of the second end of the sliding rail.

Further, in the device of the present invention, the first wire is at least two, and/or the second wire is at least two.

Further, in the device of the present invention, the probe includes at least one of the following conditions:

length of the probeThe degree is 0.5-5 mm, the diameter of the probe is 0.05-0.6 mm, and the test area of the probe is more than or equal to 100 mu m²The modulus of the probe is more than or equal to 200GPa, and the detection stroke of the probe is 5-2000 mu m.

Further, in the device of the present invention, the shape memory alloy is a nickel titanium based shape memory alloy, and/or the power source is pulsed electricity with a pulse frequency of 0.30 to 50 hz.

Further, the apparatus of the present invention further includes:

and the software is used for setting a detection stroke and obtaining a current peak value, wherein the current peak value is a current value determined by an external power supply when the first wire and/or the second wire is/are electrified and heated to drive the probe to extend out to reach the detection stroke, and the current peak value and the detection stroke are used for calculating the modulus of the object to be tested.

Further, in the device of the present invention, the software is further configured to control the power supply to energize the first wire and/or the second wire to control the probe to extend or retract.

Advantageous effects

In the embodiment of the application, 2 groups of symmetrical SMA microwires are used as driving wires to form a double-wire counter-pulling mode, different currents are supplied to the double wires through an external power supply, different temperatures are formed on the double wires, different deformation quantities of the double wires are formed, and finally the movement of the probe under the double-wire driving is realized.

The device is used for modulus test, the elastic modulus of a tested object can be directly reflected according to the current difference value of the double wires, the current difference value and the modulus correlation parameter can be continuously accurate in a certain range through large-scale test training and data fitting, the test precision reaches more than 85%, instant detection can be achieved, and the working efficiency is high.

The device based on the shape memory alloy is widely popularized in the fields of precision measurement electronic devices, medical robots and the like, and has a very wide application prospect.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:

FIG. 1 is a schematic structural diagram according to an embodiment of the present application;

FIG. 2 is a schematic structural diagram of an antagonistic dual-wire structure driven model experimental platform;

FIG. 3 is a graph showing the comparison of the "strain-resistance" hysteresis parameters of the antagonistic structural drive model and the conventional fixed-load monofilament electric drive model and the results;

in the figures, the meaning of the reference numerals is as follows:

the device comprises a first power supply 1, a probe 2, a first wire 3, a sliding rail 4, a push rod 5, a second wire 6, a shell 7, a second power supply 8, an antagonistic type double-wire structure driving model experiment platform 9, a data acquisition device 9-1, a controller 9-2, a displacement sensor 9-3, a micrometer 9-4, a load sensor 9-5, a heating and cooling device 9-6 and a power supply 9-7.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

In the prior art, the modulus test of an object has many problems, including:

1. even discrimination and data feedback cannot be carried out on the object, and the working efficiency is low;

2. part of tested objects cannot provide standardized test samples, and the existing modulus testing device cannot work;

3. the continuous testing operation of the local modulus in a micro space or a micro scale cannot be finished by the conventional modulus testing device.

Based on the above problems, the present invention provides a shape memory alloy-based device, which comprises the following concepts:

in order to meet the requirements of real-time detection of an object to be detected and modulus test in a micro space and a micro scale, a driving device is used for driving a probe with a tiny test area so as to realize detection of an object to be detected;

in order to obtain modulus data, the balance relation among the resistance of the probe, the driving force of the probe and the binding force of the probe is utilized to deduce the correlation between the modulus and other physical parameters, and the test of the modulus is converted into the test of other easily obtained physical quantities;

since the shape memory alloy wire has a wide application in a minute space and has a good current-force linear relationship during its application, it is considered to use the shape memory alloy wire as a main component of the above-described drive probe and thereby convert the test of modulus into a test of easily obtainable electric quantity.

Based on the above inventive concept, the following embodiments of the present invention are proposed.

A shape memory alloy based device as shown in fig. 1, comprising:

a first wire, the first wire being a wire made of a shape memory alloy.

A second wire, the second wire being a wire made of a shape memory alloy.

And the probe is driven by the deformation of the first wire and/or the second wire to displace under the condition that the first wire and/or the second wire deforms, wherein the first displacement direction of the probe driven by the first wire is opposite to the first displacement direction of the probe driven by the second wire.

The motion of the probe also needs to be supported by a driving part, the driving part is connected with the probe, the first wire and the second wire, the probe is installed at one end of the driving part, the driving part is driven by the deformation of the first wire and/or the second wire to displace, and the displacement direction is the length direction of the probe.

The first wire and the second wire are symmetrically arranged in the movement direction of the probe, the first wire and the second wire jointly act on the probe, one wire is used for providing a probe driving force, the other wire is used for providing a probe binding force, and the probe realizes displacement under the combined action of the probe driving force and the probe binding force. Because the probe is required to perform reciprocating motion, the forces on the bifilar structure are different when the probe is in different states of motion.

The force on the dual-wire structure is derived from the electrified heating deformation of the shape memory alloy wire, so that the deformation of the first wire and/or the second wire is generated by the on-off of the current. Therefore, the device is also provided with a power supply which is electrically connected with the first wire and the second wire and is used for applying currents with different magnitudes to the first wire and the second wire. The memory alloy wire with large current has larger shrinkage deformation, and the memory alloy wire with small current has smaller shrinkage deformation, so the difference of the deformation drives the probe to displace.

The number of power supplies is not particularly limited by the embodiments of the present invention. The power supply can be one, but has the function of applying currents with different magnitudes to the first wire and the second wire; the number of the power supplies can be two, and currents with different magnitudes are respectively applied to the first wire and the second wire; the power source may be two or more, and apply currents of different magnitudes to the first wire and the second wire in a combined manner.

For SMA wires, strain is typically measured by resistance, i.e. there is a near linear relationship of resistance to strain. But the recoverable (driving) strain of the SMA wire comes from the first-order phase change cycle process, and the first-order phase change has hysteresis; this results in inconsistent relationship between "resistance and strain" in the process of energization (heating) and de-energization (cooling), which affects the control accuracy (in the practical application process, additional determination of whether the wire is in the heating or cooling process brings more troubles). But the difference caused by the phase change hysteresis can be eliminated to a great extent under the anti-double-wire structure. As shown in fig. 2, which is a schematic structural diagram of an experimental platform of a antagonistic dual-filament structure driven model, a shape memory alloy driven microwire with a diameter of 25 microns is taken as a research object, and the "strain-resistance" hysteresis parameters of the antagonistic structure driven model and a traditional fixed-load monofilament electrically driven model are compared, and the result is shown in fig. 3.

The nonlinear part of the impedance type double-wire structure driving model is cancelled, the linearity of the system is high, and the control precision is high. And under the double-wire counter-pulling mode, the temperature does not need to be reduced to be lower than the martensite phase transition temperature, and the driving or the recovery can be realized only through the force value difference caused by the temperature difference of the two groups of wire materials, so that the energy is saved, and meanwhile, the problem of the hysteresis of the SMA driving system is solved, thereby realizing the high-frequency linear driving and improving the working efficiency. As shown in FIG. 3, the results show that the hysteresis parameter is reduced by nearly 80%, which represents the advancement of the driving model of the antagonistic twin-wire structure.

More specifically, in an embodiment of the present invention, a housing is provided, where the housing has an internal accommodating space, and the housing has at least one opening for providing access to a probe, so as to implement detection of an object to be detected at the opening of the housing by the probe. As shown, the opening is disposed above the housing in this embodiment.

Further, the following preferred drive part forms are arranged in the inner accommodating space of the housing:

and the sliding rail is fixed in the inner cavity of the shell and provides guidance in the displacement direction of the probe.

The push rod, install the first end of push rod the probe, the push rod with the slide rail adaptation, consequently the push rod can extend the slide rail direction and slide, under the direction of slide rail, promotes the probe and passes in and out from the opening of shell.

More specifically, there are many possible arrangements between the above-mentioned twin-wire structure and the driving portion, and the specific embodiment of the present invention provides at least the following two arrangements, and the present invention does not limit the remaining arrangements, and those skilled in the art can expand more arrangements based on the above-mentioned principle.

In a first way,

The first end of the first wire is connected to the first end of the push rod, and the second end of the first wire is connected to the slide rail; the first end of the second wire is connected to the second end of the push rod, and the second end of the second wire is connected to the sliding rail.

In this way, the first and second wires are arranged in a straight line, preferably in a direction parallel to the direction of displacement of the probe.

The second way,

Two ends of the first wire are symmetrically connected to the first end of the sliding rail in the axial direction of the push rod, and the middle section of the first wire is fixed on the push rod on the first end side of the sliding rail; the two ends of the second wire are symmetrically connected to the second end of the sliding rail in the axial direction of the push rod, and the middle section of the second wire is fixed to the push rod on the side of the second end of the sliding rail. As shown in the figure, the middle section of the first wire bypasses and closely adheres to the end face of the push rod on the side where the first wire is located, and similarly, the middle section of the first wire can also be connected to the push rod on the side where the first wire is located in a winding, fixing and other manners. The connection mode of the middle section of the second wire and the push rod on the side is similar, and the description is omitted here.

Under this kind of mode, first silk and second silk all arrange with nonlinear line form, and the both ends of every silk all are located the slide rail, compare in mode one, can carry out the power connection more conveniently.

As a preferred embodiment of the present invention, in order to ensure the reliability of the system, said first wire and/or said second wire are at least two, two of said first wires are in parallel form, two of said second wires are also in parallel form.

In addition to the above requirements, in order to obtain good testing effect, the embodiment of the present invention has the following preferred modes for selecting the shape memory alloy wire, the probe and the power supply.

For shape memory alloy wire, the shape memory alloy used is preferably a nickel titanium based shape memory alloy.

For the probe, the length and the diameter of the probe can be adjusted, specifically, the length of the probe is 0.5 to 5mm, and the diameter of the probe is 0.05 to 0.6 mm. The test area of the probe is more than or equal to 100 mu m². The modulus of the probe is more than or equal to 200GPa, and the detection stroke of the probe is 5-2000 mu m. The probe travel can be used to determine the modulus of an object, with the longer the travel, the lower the modulus of the object being measured.

For the power source, the power source is pulsed electricity with a pulse frequency of 0.30 to 50 hertz.

Therefore, a specific embodiment of the present invention further provides software for setting a detection stroke (or a resistance) and obtaining a current peak value, where the current peak value is a current value determined by an external power supply when the first wire and/or the second wire is/are heated by being energized and the probe is driven to extend out to reach the detection stroke, and the current peak value and the detection stroke are used to calculate a modulus of an object to be tested.

The software is used to calculate the modulus of the object to be measured according to the following formula,

wherein:

e is the modulus of the object to be measured, and the unit is KPa, MPa or GPa; k is a relation constant of the current for driving the telescopic piece and the output force value, and the unit is N/mA; i is₁The first current value when the probe is extended is in mA; i is₂The second current value when the probe is extended is in mA; k' is the deformation constant of the object to be measured under the pressure of the probe and has the unit of mum²。

Further, the software is also used for controlling the power supply to electrify the first wire and/or the second wire so as to control the probe to extend or retract. When the first wire is energized more than the second wire, the probe moves downward in the figure, i.e., moves back toward the housing, and when the first wire is energized less than the second wire, the probe moves upward in the figure, i.e., moves outside the housing.

The probe stroke in the software can be reflected by a resistance value; the strain of the SMA wire is in direct proportion to the resistance, the strain of the SMA wire can be monitored through the resistance, and the stroke of the probe is calculated through the geometric structure.

The device of the invention uses a test probe with a very small volume, the measured area can reach 10 μm by 10 μm, the whole test probe can be within millimeter level, and the modulus test can be completed under the condition that a standardized test sample is difficult to obtain and/or in a micro space and under a micro scale.

The device of the invention uses symmetrical double-wire drive, so that the nonlinear part of the drive system is cancelled, the linearity of the system is high, and the control precision is high. And under the double-wire opposite-pulling mode, the temperature does not need to be reduced to be lower than the martensite phase transition temperature, and the driving or the recovery can be realized only through the force value difference caused by the temperature difference of the two groups of wire materials, so that on one hand, the energy is saved, on the other hand, the problem of low working frequency caused by insufficient temperature reduction speed of the SMA driving system is solved, the high-frequency linear driving is realized, the working efficiency is improved, and the modulus data of the object to be detected can be continuously provided as the judgment basis of continuous operation.

It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer-executable instructions and that, although a logical order is illustrated in the flowcharts, in some cases, the steps illustrated or described may be performed in an order different than presented herein.

In another embodiment, an electronic device is provided, comprising a memory having a computer program stored therein and a processor configured to execute the computer program to perform the software method of the above embodiments.

These computer programs may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks, and corresponding steps may be implemented by different modules.

The programs described above may be run on a processor or may also be stored in memory (or referred to as computer-readable media), which includes both non-transitory and non-transitory, removable and non-removable media, that implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

Based on the structure and the software, the embodiment of the invention provides the following dynamic modulus monitoring and feedback method, which comprises the following steps:

1) testing an object to be tested by the probe, electrifying and heating the first wire and the second wire by an external power supply, wherein the current of the first wire is less than that of the second wire, and determining the current peak value of the external power supply when the push rod drives the probe to extend out to reach a set detection stroke;

2) calculating the modulus of the object to be detected according to the current peak value and the set detection stroke in the step 1) and a formula (1), wherein the formula (1) is as follows:

in the formula, E is the modulus of the object to be measured, and the unit is GPa; k is a relation constant of the current for driving the telescopic piece and the output force value, and the unit is N/mA; i is₁The first current value is a first current value when the probe extends out to reach a set detection stroke, and the unit is mA; i is₂The second current value is a second current value when the probe stretches out and reaches a set detection stroke, and the unit is mA; k' is the deformation constant of the object to be measured under the pressure of the probe and has the unit of mum²；

And adjusting the current of the external power supply to the first wire and the second wire, so that the current on the first wire is greater than the current on the second wire, and the push rod drives the probe to extend back to restore the probe.

Preferably, in step 2), the formula (1) is derived according to formula (2),

the formula (2) is: Δ F ═ F₁-F₂，

Wherein Δ f is probe resistance, N; f₁As probe driving force, N; f₂Probe binding force, N. The formula (2) is used for expressing that the probe is subjected to two resistances of the probe binding force provided by the first wire and the elastic force of the measured object in the process of pushing outwards by the probe driving force provided by the second wire.

Δ f ═ k' E above. Δ f is related to the modulus of the detected object, and is nearly linear.

Above F₁＝kI₁. F is within a certain range of the driving current I₁In a nearly linear relationship.

Above F₂＝kI₂. F is within a certain range of the driving current I₂In a nearly linear relationship.

Note: f₁～I₁，F₂～I₂All are approximately linear relationships, but the linearity is not ideal; through the double-wire framework and the algorithm optimization, the nonlinear parts are mutually offset to a certain degree, so that the difference value of the nonlinear parts is close to linearity.

In the formula (1), the value of k' can be determined by fitting through sampling data in a simulation test. The k 'is a curved surface area, and is obtained by fitting in a certain integral mode, and specifically, some objects with known modulus can be used for calibration, such as wood, resin with various moduli, biological tissues and the like, and the obtained data can be subjected to simulation fitting to establish a relationship between the modulus and the k'.

Therefore, the device based on the shape memory alloy provided by the invention fully utilizes the intelligent driving and detecting characteristics of the SMA microwire through the shape memory alloy called as a material, namely a device, and integrates displacement sensing and driving, so that the microminiaturization, simple structure and instant measurement technology and equipment are developed on the basis of the integration of the displacement sensing and the driving. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.