CN105346489A - Automobile intelligent shape memory alloy energy absorbing structure and control method thereof - Google Patents

Abstract

The invention discloses an automobile intelligent shape memory alloy energy absorbing structure and a control method thereof. The automobile intelligent shape memory alloy energy absorbing structure comprises an anti-collision beam main body, a front buffering energy absorber, a side collision preventing energy absorber and a microcomputer control system, wherein the anti-collision beam main body is connected with a longitudinal beam through a sleeve type energy absorbing box; the front buffering energy absorber is connected with the anti-collision beam main body through a shape memory alloy wire; the side collision preventing energy absorber is spliced at the two ends of the anti-collision beam main body; the rear end plate of the side collision preventing energy absorber is connected with the end part of the anti-collision beam main body through a shape memory alloy wire; and the microcomputer control system can control the heating temperature of the shape memory alloy wire. The invention further discloses a control method for the automobile intelligent shape memory alloy energy absorbing structure. The invention is advantaged in that the automobile intelligent shape memory alloy energy absorbing structure can perform multi-stage controllable collision energy absorption under a plurality of collision environments to furthest protect passengers and vehicles.

Description

A kind of marmem automobile intelligent endergonic structure and control method thereof

Technical field

The present invention relates to technical field of vehicle safety, be specifically related to a kind of marmem automobile intelligent endergonic structure and control method thereof.

Background technology

Along with the increase of automobile pollution, traffic accident takes place frequently, and automotive safety problem becomes focal issue.Research shows, the probability of automobile generation head-on crash, side collision and rear impact collision is respectively 39%, 38%, 23%.Auto trade specifies, when a frontal collision occurs, the energy-absorbing rate of automotive front energy absorbing component is greater than 50%.Therefore, automotive front thin-wall construction plays a part very important.

Traditional automotive front energy absorbing component, as Chinese patent CN104943636A, CN100480102C, CN204197064U, structure is single, and quality is large, and energy absorption is few, greatly reduce the protected effect to occupant and vehicle, and maintenance cost is high.

Shape memory alloy material, as typical intellectual material, has the good characteristics such as high damping, super-elasticity, shock resistance.Under stress or temperature loading, martensite and austenic phase co-conversion can be there is in shape memory alloy material, thus absorption dissipates large energy, its energy absorption can reach several million Jiao to tens burnt every sq ms, its damping capacity order of magnitude at least higher than ordinary metallic material.Therefore, shape memory alloy material is a kind of desirable energy-absorbing material.

Summary of the invention

The present invention has designed and developed a kind of marmem automobile intelligent endergonic structure, and object is that the structure of energy absorbing component in solution prior art is single, and quality is large, and energy absorption is few, the contradiction between vehicle safety and lightweight, and the problems such as maintenance cost height.The present invention has carry out multistage controlled collision energy-absorbing under multiple impact environment, protects the feature of occupant and vehicle to greatest extent.

The present invention has has also designed and developed a kind of control method of marmem automobile intelligent endergonic structure, and object is that to solve control method in prior art single, to problems such as the heating and temperature control differences of marmem.The present invention have by microprocessor control system to shape-memory alloy wire pass to electric current control its low speed collision, high speed collision and high-speed crash situation under equivalent stiffness and energy absorption, make each parts realize buffering energy-absorbing by the most rational gradient deformation order, ensure the feature of occupant and vehicle safety.

Technical scheme provided by the invention is:

A kind of marmem automobile intelligent endergonic structure, comprising:

Collision prevention girders body, it is connected with longeron by sleeve-type energy-absorption box;

Anterior buffering energy-absorbing device, it is connected with described collision prevention girders body by shape-memory alloy wire;

Energy absorber is hit in anti-side, and it is overlapped in described collision prevention girders body two ends, and described anti-side is hit between energy absorber lower back panel with described collision prevention girders body end and is connected by described shape-memory alloy wire;

Controller, it can control the heating-up temperature of described shape-memory alloy wire.

Preferably, described anti-collision body body cross sectional shape is " U " type, in " U " type groove, be arranged symmetrically with brace panel; And

Defining baffle, it hits the installation site of energy absorber for limiting described anti-side.

Preferably, described anterior buffering energy-absorbing device comprises: front end-plate, connecting rod and lower back panel;

Wherein, described front end-plate is connected with described lower back panel by described connecting rod, and described lower back panel is connected with described collision prevention girders body by described shape-memory alloy wire.

Preferably, described anti-side is hit energy absorber one end and is arranged deformation inductdion groove.

Preferably, described sleeve-type energy-absorption box is mutually overlapped by inner sleeve and outer sleeve and forms, and described shape-memory alloy wire is distributed on outside described outer sleeve, and one end is connected on described inner sleeve lower back panel, and the other end is connected on described longeron.

Preferably, position transduser, car speed sensor and brake pedal force sensor is also comprised.

Preferably, described shape-memory alloy wire is NiTi shape-memory alloy wire.

A control method for marmem automobile intelligent endergonic structure, comprises the steps:

Step one: obtain spacing L by position transduser, car speed sensor obtains vehicle velocity V, brake pedal force sensor obtains brake pedal folding angle beta ₀, when meeting the following conditions simultaneously, automobile collides:

(1)L＜s；

(2) $\frac{1}{3.6}(F\frac{{\mathrm{\&beta;}}_0}{\mathrm{\&beta;}}+Mgf){\&Integral;}_0^{t}Vdt<\frac{1}{2}M{\left(\frac{V}{3.6}\right)}^2;$

Wherein, s is safety distance, f is automobile total braking force, and M is car weight, and f is automobile and ground friction coefficient, and μ is coefficient of road adhesion, and t is the security reaction time, and g is acceleration due to gravity, and β is brake pedal folding angle when not trampling brake pedal;

Step 2: judge auto against environment, is divided into low speed collision, high speed to collide and high-speed crash:

As V < 30km/h, automobile generation low speed collision; Wherein, safety distance s is corrected to s ', s '=1.15s ^0.95;

As 30km/h≤V < 60km/h, automobile generation high speed is collided; Wherein, safety distance s is corrected to s ', s '=1.28s ^0.95;

As V>=60km/h, automobile generation high-speed crash; Wherein, safety distance s is corrected to s ', s '=0.95s ^1.02;

Step 3: according to impact environment, controller controls shape-memory alloy wire and carries out electrified regulation, during low speed collision, by described shape-memory alloy wire electrified regulation to 20 DEG C ~ 35 DEG C; During high speed collision, by described shape-memory alloy wire electrified regulation to 50 DEG C ~ 70 DEG C; During high-speed crash, by described shape-memory alloy wire electrified regulation to 85 DEG C ~ 105 DEG C.

Preferably, in described step one, be corrected to security reaction time t ' according to the security reaction time t in the computing formula that impact environment judges by car weight M:

Car weight M satisfy condition M < 1400kg time, t '=0.99t ^1.003;

Car weight M satisfies condition 1400kg≤M < 1800kg, t '=1.01t ^0.98;

Car weight M satisfy condition M>=1800kg time, t '=1.02t ^0.99.

Preferably,

In described step one, the security reaction time t environmentally in the computing formula that impact environment judged of temperature T and relative humidity RH% is corrected to security reaction time t ":

When ambient temperature 15 DEG C≤T≤25 DEG C,

(1) relative humidity RH% satisfies condition 75%≤RH% < 100%, t "=1.21t ^0.91;

(2 relative humidity RH% satisfy condition RH%=100%, t "=1.30t ^0.87;

In described step 2, according to impact environment, controller controls to carry out electrified regulation to shape-memory alloy wire, during low speed collision, by described shape-memory alloy wire electrified regulation to 20 DEG C; During high speed collision, by described shape-memory alloy wire electrified regulation to 60 DEG C; During high-speed crash, by described shape-memory alloy wire electrified regulation to 90 DEG C.

The beneficial effect that the present invention is had compared with prior art:

1, this endergonic structure energy absorption is large, efficiency is high and intelligent controlled, a kind of marmem automobile intelligent endergonic structure is by collision prevention girders body, anterior buffering energy-absorbing device, energy absorber and sleeve-type energy-absorption box composition are hit in anti-side, take full advantage of the high damping of shape memory alloy material, impact property, buffering energy-absorbing is carried out to auto against, and carry out the equivalent stiffness of adjustable shape memory alloy material according to the phase-change characteristic of shape memory alloy material by microprocessor control system, energy absorption etc., make intelligent endergonic structure under multiple impact environment, the gradient deformation order of as prescribed can realize multistage energy-absorbing,

2, when there is low-speed head-on collision, the shape-memory alloy wire arranged in anterior buffering energy-absorbing device and sleeve-type energy-absorption box is stretched energy-absorbing.During maintenance, only need heated shape memory alloy silk, endergonic structure just can restore to the original state; When there is high speed head-on crash, the shape-memory alloy wire in anterior buffering energy-absorbing device and sleeve-type energy-absorption box is stretched, and realizes one-level energy absorbing, and dump energy completes Secondary energy by collision prevention girders body and the conquassation of energy-absorption box sleeve and absorbs; When there is side collision, anti-side is hit energy absorber and is realized Secondary energy absorption by shape-memory alloy wire stretching energy-absorbing and sponson collapse energy-absorption.Further, by microprocessor control system to shape-memory alloy wire pass to electric current to control its low speed collision, high speed collision and high-speed crash situation under equivalent stiffness and energy absorption, make each parts realize buffering energy-absorbing by the most rational gradient deformation order, ensure occupant and vehicle safety.

Accompanying drawing explanation

Fig. 1 is structural representation of the present invention;

Fig. 2 collision prevention girders body construction of the present invention schematic diagram;

Fig. 3 anterior buffering energy-absorbing device structural representation of the present invention;

Fig. 4 anterior buffering energy-absorbing device fundamental diagram of the present invention;

Fig. 5 hits energy absorber structural representation in anti-side of the present invention;

Fig. 6 hits energy absorber fundamental diagram in anti-side of the present invention;

Fig. 7 sleeve-type energy-absorption box of the present invention structural representation;

Fig. 8 sleeve-type energy-absorption box of the present invention fundamental diagram;

Fig. 9 microprocessor control system fundamental diagram of the present invention.

Detailed description of the invention

Below in conjunction with accompanying drawing, the present invention is described in further detail, can implement according to this with reference to specification sheets word to make those skilled in the art.

As shown in Fig. 1 ~ 8, the invention provides a kind of marmem automobile intelligent endergonic structure, it comprises collision prevention girders body 110, energy absorber 130, sleeve-type energy-absorption box 140 and microprocessor control system 200 are hit in anterior buffering energy-absorbing device 120, anti-side, collision prevention girders body 110 middle part is provided with anterior buffering energy-absorbing device 120, between anterior buffering energy-absorbing device 120 lower back panel and collision prevention girders body 100, is connected with shape-memory alloy wire 123, collision prevention girders body 110 two ends are provided with anti-side and hit energy absorber 130, and anti-side is hit energy absorber 130 sponson and is processed with deformation inductdion groove 137, and anti-side is hit between energy absorber 130 lower back panel 134 and collision prevention girders body 110 end and is connected with shape-memory alloy wire 133, collision prevention girders body 110 is connected with longeron 150 by sleeve-type energy-absorption box 140, when colliding, shape memory alloy material and endergonic structure successively complete buffering energy-absorbing, and the parameter such as equivalent stiffness and energy absorption of adjustable shape memory alloy material is carried out by vehicle microcomputer control system 200, it is made to be adapted to various impact environment, microprocessor control system 200 comprises position transduser, car speed sensor, brake pedal force sensor, automobile ECU 210, storage battery 220 and control circuit 230, microprocessor control system 200 can pass through position transduser, car speed sensor and brake pedal force sensor are respectively spacing information, speed information and braking information feed back to automobile ECU 210, automobile ECU 210 judges, storage battery 220 is controlled by control circuit 230 pairs of shape-memory alloy wire electrified regulation with this, the equivalent stiffness of shape-memory alloy wire and energy absorption are changed, to adapt to different impact environment, protection occupant and vehicle, microprocessor control system 200 is according to sensor information, impact environment is divided into low speed collision, high speed collision and high-speed crash three class, under different impact environment, by electrically heated mode, shape-memory alloy wire is heated to different temperatures, its equivalent stiffness and energy absorption and impact environment are matched, so that each energy absorbing component meets gradient deformation order, maximum absorption automobile collision energy.

In another kind of embodiment, collision prevention girders body 100 cross sectional shape is " U " type, and with flange, for connecting other energy absorbing components, brace panel 111 is provided with in collision prevention girders body 100 " U " type groove, effective reduction crash acceleration peak value and bending metaboly, be also provided with defining baffle 136 in collision prevention girders body 100, and it hits the installation site of energy absorber 130 for limiting described anti-side.

In another kind of embodiment, anterior buffering energy-absorbing device 120 comprises front end-plate 121, connecting rod 122 and lower back panel 124, front end-plate 121 is connected with lower back panel 124 by connecting rod 122, the position of lower back panel 124 is regulated by adjusting bolt 125, the lower back panel 124 of anterior buffering energy-absorbing device 120 is connected by shape-memory alloy wire 123 one end, the other end connects collision prevention girders body 110, and tensioning state is under the effect of adjusting bolt 125, when colliding, first be that shape-memory alloy wire 123 stretches energy-absorbing, dump energy is out of shape absorption by collision prevention girders body 110 again.

In another kind of embodiment, anti-side is hit energy absorber 130 and is comprised sponson 131, overlap 132, lower back panel 134 and adjusting bolt 135, distortion guide groove 137 is had in sponson 131 surface working, when there is side collision, first shape-memory alloy wire 133 stretches energy-absorbing, and when lower back panel 134 contacts with position limitation baffle plate 136, sponson 131 can collapse energy-absorption, deformation inductdion groove 137 can make sponson 131 affine deformation, reduces crash acceleration peak value.

In another kind of embodiment, sleeve-type energy-absorption box 140 is mutually overlapped by inner sleeve 142 and outer sleeve 145 and forms energy-absorption box body, sleeve-type energy-absorption box 140 comprises inner sleeve front end-plate 141, inner sleeve 142, inner sleeve lower back panel 144, outer sleeve 145, outer sleeve lower back panel 148, shape-memory alloy wire 146 and adjusting bolt 147, inner sleeve 142 and outer sleeve 145 are provided with deformation inductdion groove 143, inner sleeve lower back panel 144 is connected with shape-memory alloy wire 146, and shape-memory alloy wire 146 symmetry is distributed on outside outer sleeve 145, one end connects inner sleeve lower back panel 144, the other end is connected on longeron 150, the length fully increasing shape-memory alloy wire 146 in limited space can be ensured like this, ensure the distortion uptake of shape-memory alloy wire 146, when colliding, first shape-memory alloy wire 146 stretches, realize one-level energy absorbing, remaining energy is absorbed by inner sleeve 142, outer sleeve 145 conquassation, complete secondary energy-absorbing, deformation inductdion groove 143 on inner sleeve 142, outer sleeve 145 can make inner sleeve 142, outer sleeve 145 affine deformation, effectively reduces crash acceleration peak value, makes impact force reasonably pass to longeron 150 simultaneously.

In another kind of embodiment, shape-memory alloy wire is NiTi shape-memory alloy wire, there is high damping, super-elasticity, shape memory effect, the features such as withstanding corrosion, under any circumstance, at least as high in steel than the traditional material order of magnitude of damping capacity of NiTi marmem, during impact load, martensitic dielectric loss coefficient can reach 10%, the connection mode of shape-memory alloy wire is welding, and, this mode is a kind of explanation of preferred embodiments, but be not limited thereto, when implementing of the present invention, shape-memory alloy wire also can be copper base shape memory alloy wire or iron-base marmem silk, the connection mode of shape-memory alloy wire also can be bonding simultaneously, press or mechanical grip, in the present invention, shape-memory alloy wire is in tensioning state under the regulating action of nut.

Present invention also offers a kind of control method of marmem automobile intelligent endergonic structure, comprise the steps:

Step one: obtain spacing L by the position transduser in microprocessor control system 200, unit is m, and car speed sensor obtains vehicle velocity V, and unit is km/h, and brake pedal force sensor obtains brake pedal folding angle beta ₀, by information feed back to automobile ECU 210, when meeting the following conditions simultaneously, automobile collides,

(1)L＜s；

(2) $\frac{1}{3.6}(F\frac{{\mathrm{\&beta;}}_0}{\mathrm{\&beta;}}+Mgf){\&Integral;}_0^{t}Vdt<\frac{1}{2}M{\left(\frac{V}{3.6}\right)}^2;$

Wherein, s is safety distance, unit is m, F is automobile total braking force, and unit is N, M is car weight, and unit is kg, f is automobile and ground friction coefficient, and μ is coefficient of road adhesion, and t is the security reaction time, and unit is s, g is acceleration due to gravity, and unit is m/s ², β is brake pedal folding angle when not trampling brake pedal; In the present embodiment, μ=0.82;

Step 2: judge auto against environment, is divided into low speed collision, high speed to collide and high-speed crash:

As V < 30km/h, automobile generation low speed collision; Wherein, safety distance s is corrected to s ', s '=1.15s ^0.95;

As 30km/h≤V < 60km/h, automobile generation high speed is collided; Wherein, safety distance s is corrected to s ', s '=1.28s ^0.95;

As V>=60km/h, automobile generation high-speed crash; Wherein, safety distance s is corrected to s ', s '=0.95s ^1.02;

Step 3: according to impact environment, the judgement that microprocessor control system is made by automobile ECU 210, control storage battery 220 and carry out electrified regulation by control circuit 230 pairs of shape-memory alloy wires, NiTi shape-memory alloy wire is adopted to have the advantages such as heating is fast, controllability is good, experiment shows, during low speed collision, by NiTi shape-memory alloy wire electrified regulation to 20 DEG C ~ 35 DEG C, required time is 30ms; During high speed collision, by NiTi shape-memory alloy wire electrified regulation to 50 DEG C ~ 70 DEG C, required time is 35ms; During high-speed crash, by NiTi shape-memory alloy wire electrified regulation to 85 DEG C ~ 105 DEG C, required time is 40ms; In the present embodiment, select NiTi shape-memory alloy wire, when low speed collision, by shape-memory alloy wire electrified regulation to 20 DEG C, make the equivalent secant stiffness K of NiTi shape-memory alloy wire _sfor 3.01GPa, individual pen circulation power consumption Δ W is 7.63MJ/m ³; During high speed collision, by shape-memory alloy wire electrified regulation to 60 DEG C, make the equivalent secant stiffness K of NiTi shape-memory alloy wire _sfor 6.35GPa, individual pen circulation power consumption Δ W is 10.39MJ/m ³; During high-speed crash, by shape-memory alloy wire electrified regulation to 90 DEG C, make the equivalent secant stiffness K of NiTi shape-memory alloy wire _sfor 8.56GPa, individual pen circulation power consumption Δ W is 12.93MJ/m ³; Different by heating-up temperature, make shape-memory alloy wire realize different buffering energy-absorbings.

In another kind of embodiment, in step one, be corrected to security reaction time t ' according to the security reaction time t in the computing formula that impact environment judges by car weight M:

Car weight M satisfy condition M < 1400kg time, t '=0.99t ^1.003;

Car weight M satisfies condition 1400kg≤M < 1800kg, t '=1.01t ^0.98;

Car weight M satisfy condition M>=1800kg time, t '=1.02t ^0.99.

In another kind of embodiment, in step one, the security reaction time t environmentally in the computing formula that impact environment judged of temperature T and relative humidity RH% is corrected to security reaction time t ":

When ambient temperature 15 DEG C≤T≤25 DEG C,

(1) relative humidity RH% satisfies condition 75%≤RH% < 100%, t "=1.21t ^0.91; In the present embodiment, μ=0.53;

(2) relative humidity RH% satisfies condition RH%=100%, t "=1.30t ^0.87; In the present embodiment, μ=0.28.

Although embodiment of the present invention are open as above, but it is not restricted to listed in specification sheets and embodiment utilization, it can be applied to various applicable the field of the invention completely, for those skilled in the art, can easily realize other amendment, therefore do not deviating under the universal that claim and equivalency range limit, the present invention is not limited to specific details and illustrates here and the legend described.

Claims (10)

1. a marmem automobile intelligent endergonic structure, is characterized in that, comprising:

Collision prevention girders body, it is connected with longeron by sleeve-type energy-absorption box;

Anterior buffering energy-absorbing device, it is connected with described collision prevention girders body by shape-memory alloy wire;

Energy absorber is hit in anti-side, and it is overlapped in described collision prevention girders body two ends, and described anti-side is hit between energy absorber lower back panel with described collision prevention girders body end and is connected by described shape-memory alloy wire;

Controller, it can control the heating-up temperature of described shape-memory alloy wire.

2. marmem automobile intelligent endergonic structure as claimed in claim 1, it is characterized in that, described anti-collision body body cross sectional shape is " U " type, in " U " type groove, be arranged symmetrically with brace panel; And

Defining baffle, it hits the installation site of energy absorber for limiting described anti-side.

3. marmem automobile intelligent endergonic structure as claimed in claim 1 or 2, it is characterized in that, described anterior buffering energy-absorbing device comprises: front end-plate, connecting rod and lower back panel;

Wherein, described front end-plate is connected with described lower back panel by described connecting rod, and described lower back panel is connected with described collision prevention girders body by described shape-memory alloy wire.

4. marmem automobile intelligent endergonic structure as claimed in claim 3, it is characterized in that, described anti-side is hit energy absorber one end and is arranged deformation inductdion groove.

5. marmem automobile intelligent endergonic structure as claimed in claim 3, it is characterized in that, described sleeve-type energy-absorption box is mutually overlapped by inner sleeve and outer sleeve and forms, described shape-memory alloy wire is distributed on outside described outer sleeve, one end is connected on described inner sleeve lower back panel, and the other end is connected on described longeron.

6. marmem automobile intelligent endergonic structure as claimed in claim 5, is characterized in that, also comprise position transduser, car speed sensor and brake pedal force sensor.

7. as claim 1,2, marmem automobile intelligent endergonic structure according to any one of 4-6, it is characterized in that, described shape-memory alloy wire is NiTi shape-memory alloy wire.

8. a control method for marmem automobile intelligent endergonic structure, is characterized in that, comprises the steps:

Step one: obtain spacing L by position transduser, car speed sensor obtains vehicle velocity V, brake pedal force sensor obtains brake pedal folding angle beta ₀, when meeting the following conditions simultaneously, automobile collides:

(1)L＜s；

$\left(2\right)---\frac{1}{3.6}(F\frac{{\mathrm{\&beta;}}_0}{\mathrm{\&beta;}}+Mgf){\&Integral;}_0^{t}Vdt<\frac{1}{2}M{\left(\frac{V}{3.6}\right)}^2;$

Wherein, s is safety distance, $s=\frac{1}{2g\mathrm{\&mu;}}{\left(\frac{V}{3.6}\right)}^2+\frac{1}{3.6}{\&Integral;}_0^{t}Vdt,$ F is automobile total braking force, and M is car weight, and f is automobile and ground friction coefficient, and μ is coefficient of road adhesion, and t is the security reaction time, and g is acceleration due to gravity, and β is brake pedal folding angle when not trampling brake pedal;

Step 2: judge auto against environment, is divided into low speed collision, high speed to collide and high-speed crash:

As V < 30km/h, automobile generation low speed collision; Wherein, safety distance s is corrected to s ', s '=1.15s ^0.95;

As 30km/h≤V < 60km/h, automobile generation high speed is collided; Wherein, safety distance s is corrected to s ', s '=1.28s ^0.95;

As V>=60km/h, automobile generation high-speed crash; Wherein, safety distance s is corrected to s ', s '=0.95s ^1.02;

Step 3: according to impact environment, controller controls shape-memory alloy wire and carries out electrified regulation, during low speed collision, by described shape-memory alloy wire electrified regulation to 20 DEG C ~ 35 DEG C; During high speed collision, by described shape-memory alloy wire electrified regulation to 50 DEG C ~ 70 DEG C; During high-speed crash, by described shape-memory alloy wire electrified regulation to 85 DEG C ~ 105 DEG C.

9. the control method of marmem automobile intelligent endergonic structure as claimed in claim 8, is characterized in that, in described step one, be corrected to security reaction time t ' according to the security reaction time t in the computing formula that impact environment judges by car weight M:

Car weight M satisfy condition M < 1400kg time, t '=0.99t ^1.003;

Car weight M satisfies condition 1400kg≤M < 1800kg, t '=1.01t ^0.98;

Car weight M satisfy condition M>=1800kg time, t '=1.02t ^0.99.

10. the control method of marmem automobile intelligent endergonic structure as claimed in claim 8, is characterized in that,

In described step one, the security reaction time t environmentally in the computing formula that impact environment judged of temperature T and relative humidity RH% is corrected to security reaction time t ":

When ambient temperature 15 DEG C≤T≤25 DEG C,

(1) relative humidity RH% satisfies condition 75%≤RH% < 100%, t "=1.21t ^0.91;

(2 relative humidity RH% satisfy condition RH%=100%, t "=1.30t ^0.87;

In described step 2, according to impact environment, controller controls to carry out electrified regulation to shape-memory alloy wire, during low speed collision, by described shape-memory alloy wire electrified regulation to 20 DEG C; During high speed collision, by described shape-memory alloy wire electrified regulation to 60 DEG C; During high-speed crash, by described shape-memory alloy wire electrified regulation to 90 DEG C.