An intelligent vehicle pop-up engine hood device and its control method

Abstract

The present invention discloses a pop-up engine hood device for an intelligent vehicle, comprising: a base fixed in the engine compartment; a top cover fixed inside the vehicle engine hood; a compression spring fixed between the base and the top cover; one end of a push rod is fixed to the top cover, and the other end is selectively engaged in the base, and a longitudinal slot is provided at one end of the push rod; a sliding lead screw mechanism is rotatably disposed inside the push rod while being connected to the power end, and a lead screw nut is engaged in the slot; two release switches are selectively engaged at the other end of the push rod; one end of a shape memory alloy wire is connected to a super capacitor, and the other end is connected to the two release switches; when the compression spring is in a pre-compressed state, the lead screw nut is located at the other end of the lead screw and one end of the push rod at the same time. The present invention also discloses a control method for a pop-up engine hood device of an intelligent vehicle, which combines a shape memory alloy wire and a servo motor to timely adjust the engine hood and ensure the vehicle performance.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent vehicle cockpits, and more specifically, the present invention relates to an intelligent vehicle pop-up engine hood device and a control method thereof. Background Art

[0002] Pedestrians have always been the vulnerable group in traffic accidents. With the continuous development of the global automotive industry, pedestrian protection has become an aspect that has attracted much attention in safe driving of vehicles. Among the injuries caused by vehicle-pedestrian collision accidents, more than 30% of the injuries are head injuries, and the fatality rate caused by head injuries is as high as 62%. Thus, it can be seen that head injuries are the most fatal.

[0003] From the collision area between the head and the vehicle in the statistical results of traffic accidents, it can be seen that the collision between the pedestrian's head and the engine hood accounts for one-third. Therefore, it is particularly important to improve the structure of the engine hood to enhance the safety protection of vehicles for pedestrians. Currently, a better solution to this is to adopt a pop-up engine hood structure. Its working principle is that before the pedestrian's head contacts the engine hood, the rear part of the engine hood will lift a certain height as a buffer zone to absorb the kinetic energy brought by the impact of the pedestrian's head, and it can also prevent the pedestrian's head from colliding with the hard points under the engine hood, thus greatly reducing the head injuries of pedestrians. However, for the airbag pop-up engine hood, due to the disposable use characteristics of the airbag and the damage it causes to the engine hood, most airbag pop-up engine hoods are disposable products, and the maintenance cost is expensive; for the gas generator pop-up engine hood, due to the nature of ignition, these devices are not reusable in most cases, and the actions are mostly irreversible after completion, and if the lifting speed of the engine hood is too fast, the bending moment generated may be large enough to cause the engine hood to bend and deform under its own inertia; for the mechanical pop-up engine hood, although most of them can be reused, they must be manually reset, and due to the high spring stiffness, it is very difficult for the driver to restore to the initial state that can meet the pop-up requirements. Summary of the Invention

[0004] The object of the present invention is to design and develop an intelligent vehicle pop-up engine hood device, which consists of a release mechanism composed of a shape memory alloy wire and a compression spring, and a reset mechanism composed of a push rod and a lead screw nut. The structure is simple, the response is rapid, and it can be used continuously.

[0005] The present invention also designs and develops a control method for an intelligent vehicle pop-up engine hood device, which coordinates the release and reset of the device through a shape memory alloy wire, and adjusts the engine hood in a timely manner when a collision occurs to ensure the driving performance of the vehicle.

[0006] The technical solution provided by the present invention is as follows:

[0007] An intelligent vehicle pop-up engine hood device, comprising:

[0008] Comprising:

[0009] A base, which is detachably fixed in the engine compartment; and

[0010] A top cover, which is detachably fixed inside the vehicle engine hood;

[0011] A compression spring, which is fixed between the base and the top cover, and an accommodation cavity is formed between the compression spring and the base and the top cover;

[0012] A push rod, which is arranged in the accommodation cavity, one end of the push rod is fixed on the top cover, the other end is selectively engaged with the outside of the base, and a longitudinal card slot is arranged at one end of the push rod;

[0013] A servo motor, which is fixed on the base;

[0014] A lead screw, one end of which is connected to the output end of the servo motor, and the other end is rotatably arranged in the push rod;

[0015] A lead screw nut, which is rotatably arranged on the lead screw, and the lead screw nut is engaged in the card slot;

[0016] Two release switches, which are symmetrically arranged on the base, and the two release switches are selectively engaged with the other end of the push rod;

[0017] A shape memory alloy wire, one end of which is connected to a super capacitor, and the other end is connected to the two release switches;

[0018] Wherein, when the compression spring is in a pre-compressed state, the lead screw nut is simultaneously located at the other end of the lead screw and one end of the push rod.

[0019] Preferably, the base comprises:

[0020] A first base, the inside of which is a hollow structure, and two through holes are symmetrically arranged on the first base;

[0021] A second base, which is a hollow structure, and the second base has a central through hole, and the second base is coaxially arranged on the upper part of the first base;

[0022] Two reset slots, which are symmetrically arranged in the first base, and the two reset slots respectively correspond to the two through holes;

[0023] Wherein, the inside of the first base is communicated with the inside of the second base, and the diameter of the second base is smaller than that of the first base, and the other end of the push rod passes through the central through hole.

[0024] Preferably, the length of the card slot is 100 mm.

[0025] Preferably, it further includes:

[0026] A limiter, which is fixed at the other end of the push rod, and the limiter is arranged in the first base or the second base, and the limiter can be selectively engaged in the second base;

[0027] Two limiting grooves, which are symmetrically arranged on both sides of the limiter, and the two limiting grooves respectively correspond to the two through holes.

[0028] Preferably, the release switch includes:

[0029] A limiting head, which is arranged in the reset groove;

[0030] A connecting rod, one end of which is fixed on one side of the limiting head, and the other end passes through the reset groove and the through hole;

[0031] A wedge-shaped block, which is arranged on the other side of the limiting head, and the wedge-shaped block can be selectively engaged in the limiting groove;

[0032] A reset spring, which is sleeved on the outside of the connecting rod, and the reset spring is arranged between the limiting head and the reset groove.

[0033] Preferably, it further includes:

[0034] A plurality of ceramic guide wheels, which are arranged at intervals on the outside of the first base, and the plurality of ceramic guide wheels are symmetrically arranged between the two through holes;

[0035] Wherein, the other end of the shape memory alloy wire is sequentially connected to the other end of the connecting rod after passing through the plurality of ceramic guide wheels.

[0036] Preferably, it further includes:

[0037] Two guide posts, one end of which is symmetrically arranged in the top cover;

[0038] Two guide sleeves, one end of which is symmetrically arranged on the first base, and the other ends of the two guide sleeves are respectively sleeved on the outside of the other ends of the two guide posts.

[0039] A control method for an intelligent vehicle pop-up engine hood device, using the intelligent vehicle pop-up engine hood device, includes the following steps:

[0040] Step 1: When the vehicle starts, the super capacitor preheats the shape memory alloy wire, and the preheating temperature is 35 °C;

[0041] Step 2: When a pedestrian collides with a vehicle, the super capacitor performs secondary heating on the shape memory alloy wire to cause the shape memory alloy wire to contract, enabling the compression spring to be released until the limiter engages with the second base, and the vehicle engine hood pops up;

[0042] Among them, the time from when the super capacitor performs secondary heating on the shape memory alloy wire to when the shape memory alloy wire starts to contract is 5 ms, and the maximum temperature of the secondary heating of the shape memory alloy wire is 60 °C;

[0043] Step 3: After the driver issues a reset command, the servo motor rotates forward, the lead screw nut drives the push rod to reset, the super capacitor maintains the temperature of the shape memory alloy wire at the preheating temperature, the release switch engages with the push rod, and the vehicle engine hood resets;

[0044] Step 4: The servo motor rotates in reverse, and the lead screw nut resets.

[0045] Preferably, the preheating temperature of the shape memory alloy wire is 35 °C, the length of the shape memory alloy wire is 140 mm, the number of the shape memory alloy wires is 6, the diameter of each shape memory alloy wire is 0.5 mm, and the contraction length of the shape memory alloy wire is 6 mm.

[0046] Preferably, in Step 2, the time from when a pedestrian collides with a vehicle to when the vehicle engine hood pops up is 80 ms.

[0047] The beneficial effects of the present invention are as follows:

[0048] (1) An intelligent vehicle pop-up engine hood device designed and developed by the present invention uses a shape memory alloy wire and a compression spring to form a release mechanism, and a push rod, a lead screw nut, and a servo motor to form a reset mechanism. It has a simple structure, rapid response, does not require modification design of the engine hood, and is sustainable and applicable to various vehicle models.

[0049] (2) The control method of the intelligent vehicle pop-up engine hood device designed and developed by the present invention ensures the pop-up and recovery of the vehicle engine hood during a collision through the contraction or extension of the shape memory alloy wire, restoring the driving performance of the vehicle. Description of the Drawings

[0050] Figure 1 It is the front view structural schematic diagram of the intelligent vehicle pop-up engine hood device described in the present invention.

[0051] Figure 2 It is the axonometric structural schematic diagram of the intelligent vehicle pop-up engine hood device described in the present invention.

[0052] Figure 3 It is the assembly structural schematic diagram of the top cover described in the present invention.

[0053] Figure 4 Schematic diagram of the assembly structure of the base according to the present invention.

[0054] Figure 5 Schematic diagram of the internal structure of the base according to the present invention.

[0055] Figure 6 Schematic diagram of the assembly structure of the top cover and the base according to the present invention.

[0056] Figure 7 Schematic diagram of the structure of the push rod according to the present invention.

[0057] Figure 8 Schematic diagram of the structure of the release switch according to the present invention.

[0058] Figure 9 Schematic diagram of the structure of the release subsystem according to the present invention.

[0059] Figure 10 Schematic diagram of the assembly structure of the lead screw according to the present invention.

[0060] Figure 11 Schematic diagram of the sectional structure of the reset subsystem according to the present invention. Detailed implementation manners

[0061] The following further describes the present invention in detail so that those skilled in the art can implement it with reference to the text of the specification.

[0062] An intelligent vehicle pop-up engine hood device provided by the present invention realizes the ultra-high-speed release and automatic reset of the device through three different subsystems: a pop-up subsystem, a release subsystem, and a reset subsystem. The main function of the pop-up subsystem is to keep the compression spring in a pre-compressed state when the device is in a locked state, and when it is in a released state after receiving a signal, the spring can pop up to a specified height and stabilize within a specified time; the main function of the release subsystem is to keep the compression spring in a compressed state (900 N) under normal driving conditions, and when receiving an instruction, it can release the compression spring to make it pop up within a specified time (15 ms); the main function of the reset subsystem is to automatically restore the compression spring to its initial state after it pops up.

[0063] As Figure 1 、 Figure 2 shown, the pop-up subsystem specifically includes: a top cover 110, a base 120, and a compression spring 130. The top cover 110 is detachably fixed inside the vehicle engine hood, the base 120 is detachably fixed in the engine compartment, one end of the compression spring 130 is connected to the top cover 110, and the other end is connected to the base 120, so that an accommodation cavity is formed among the compression spring 130, the top cover 110, and the base 120.

[0064] As shown Figure 3 in the figure, two guide posts 211 are symmetrically fixed inside the top cover 110. As shown Figure 4 , Figure 5 in the figure, the base 120 includes a first base 201, a second base 202 and two reset grooves 204. Both the first base 201 and the second base 202 are hollow structures. Two through holes 203 are symmetrically arranged on the first base 201. And the second base 202 is coaxially arranged on the upper part of the first base 201. The inside of the second base 202 and the first base 204 are connected and communicated. The diameter of the second base 202 is smaller than that of the first base 201. The second base 202 has a central through hole. Two reset grooves 204 are symmetrically arranged inside the first base 201. And the two reset grooves 204 are arranged at the position where the first base 201 and the second base 202 are joined. At the same time, the two reset grooves 204 are respectively arranged corresponding to the two through holes 203.

[0065] Two guide sleeves 205 are symmetrically arranged on the base 120. As shown Figure 6 in the figure, the two guide sleeves 205 are respectively sleeved on the outside of the two guide posts 211, so that the two guide posts 211 can slide in the two guide sleeves 205, thereby restricting that only vertical movement is possible between the top cover 110 and the base 120.

[0066] As shown Figure 7 in the figure, the pop-up subsystem further includes: a push rod 140, which is arranged in the accommodation cavity, and the push rod 140 is a hollow structure. One end of the push rod 140 is fixed inside the top cover 110, and the other end passes through the central through hole of the second base 202. At the same time, longitudinal card slots 221 are symmetrically arranged at one end of the push rod 140. A stopper 222 is fixed at the other end of the push rod 140. Two limiting slots 223 are symmetrically arranged on the stopper 222. The two limiting slots 223 are respectively arranged corresponding to the two through holes 203. The stopper 222 is located inside the first base 201 or the second base 202 and can be selectively engaged inside the second base 202.

[0067] The stopper 222 cooperates with the second base 202 to limit the distance that the compression spring 130 pops up.

[0068] As shown Figure 11 in the figure, in this embodiment, a gasket 206 is arranged inside the upper end of the second base 202, aiming to quickly absorb the collision energy between the compression spring 130 and the base 120, make the compression spring 130 quickly stable, and avoid causing secondary injury to the head of pedestrians due to the oscillation of the compression spring 130.

[0069] In this embodiment, the length of the card slot 221 is 100 mm.

[0070] As shown in Figure 1 , Figure 8 , Figure 9 The release subsystem includes: two release switches 180, six ceramic guide wheels 191 and a shape memory alloy wire 192. The release switch 180 specifically includes: a limit head 231, a connecting rod 232, a wedge block 233, a return spring 234 and a connecting bolt 235. The limit head 231 is arranged in a return slot 204. One end of the connecting rod 232 is connected to one side of the limit head 231, and the other end passes through the return slot 204 and a through hole 203. The wedge block 233 is arranged on the other side of the limit head 231, and the wedge block 233 can be selectively engaged in a limit slot 223 to limit the position of a push rod 140. The return spring 234 is sleeved outside the connecting rod 232, and the return spring 234 is compressed between the limit head 231 and the return slot 204 to help the release switch 180 reset so that the release switch 180 can be reused automatically. The connecting bolt 235 is fixed to the other end of the connecting rod 232 for connecting with the shape memory alloy wire 192. The two release switches 180 have exactly the same structure and are respectively arranged in two return slots 204. At the same time, they respectively pass through two through holes 203. The six ceramic guide wheels 191 are arranged at intervals outside the first base 201, and the six ceramic guide wheels 191 are symmetrically arranged between the two through holes 203. One end of the shape memory alloy wire 192 is connected to a super capacitor, and the other end is connected to the two connecting bolts 235 after passing through the six ceramic guide wheels 191 respectively, for driving the two release switches to move outwards.

[0071] In this embodiment, the shape memory alloy wire 192 is composed of six SMAs with a diameter of 0.5 mm and a length of about 140 mm, so that the required displacement (6 mm) of the release switch does not exceed 5% strain.

[0072] The return spring 234 is a small spring with low stiffness and large pre-tightening force.

[0073] As shown in Figure 10 , Figure 11 The return subsystem includes: a servo motor 150, a coupling 160 and a sliding lead screw mechanism. The sliding lead screw mechanism includes a lead screw 171 and a lead screw nut 172. The servo motor 150 is fixed on a base 120. One end of the coupling 160 is connected to the output end of the servo motor 150, and the other end is connected to one end of the lead screw 171. The other end of the lead screw 171 is rotatably arranged in the push rod 140 (without interference between the two). The lead screw nut 172 is rotatably arranged on the lead screw 171 for converting the rotation of the lead screw 171 into the movement of the lead screw nut 172 and having a self-locking function. At the same time, the lead screw nut 172 is vertically movably engaged in the card slot 221, and the free movement stroke is the length of the card slot 221.

[0074] In this embodiment, the upper end of the lead screw 171 is the initial position of the lead screw nut 172.

[0075] In this embodiment, the number of the devices is 2, which are respectively arranged at the left and right rear feet at the rear end of the engine hood.

[0076] The working process of the automotive pop-up engine hood device based on shape memory alloy wire according to the present invention is as follows:

[0077] Initially, the device is in a locked state, the compression spring 130 maintains pre-compression, the two wedge blocks 233 are engaged in the two limiting grooves 223, the shape memory alloy wire 192 is not powered on, the lead screw nut 172 is located at the upper end of the lead screw 171, and the servo motor 150 is not started; when the engine hood needs to pop up, the super capacitor powers on the shape memory alloy wire 192, causing the shape memory alloy wire 192 to contract, driving the release switch 180 to move outwards, and the super-high-speed release of the compression spring 130 drives the push rod 140 to move upwards until the upper end of the stopper 222 is engaged with the second base 202, and the release stops; when the engine hood needs to return, the servo motor 150 rotates forward, driving the lead screw nut 172 to move downwards on the lead screw 171, so that the lead screw nut 172 drives the push rod 140 to move downwards until the push rod 140 returns to the initial position, the wedge block 233 is engaged in the limiting groove 223, the servo motor 150 rotates in reverse, and the lead screw nut 172 returns to the upper end of the lead screw 171, and the return is completed.

[0078] An intelligent automotive pop-up engine hood device designed and developed by the present invention enables the shape memory alloy wire (SMA) to quickly contract by energizing and heating, pulling the release switch to release the pre-compressed compression spring, causing the engine hood connected to the compression spring to quickly pop up to a specified height and be stable. By introducing a lead screw nut pair, the rotational motion of the lead screw can be converted into the axial motion of the nut structure thereon, adding an automatic reset function, thereby achieving the purpose of device reset. The structure is simple, the response is rapid, there is no need to modify the design of the engine hood, and it can be continuously used while being applicable to various vehicle models.

[0079] The present invention also provides a control method for an intelligent automotive pop-up engine hood device, using the intelligent automotive pop-up engine hood device described above, which specifically includes the following steps:

[0080] Step 1: When the vehicle starts, the super capacitor preheats the shape memory alloy wire.

[0081] Among them, the length of the shape memory alloy wire is 140 mm, the number of roots is set to 6, the diameter of each root is 0.5 mm, and the preheating temperature is 35 °C.

[0082] The temperature of the shape memory alloy wire is obtained by a temperature sensor, and the signal is transmitted to the computer control system.

[0083] Step 2: If the pedestrian collision detection system detects a collision between a pedestrian and a vehicle, the computer control system issues a heating instruction to the super capacitor. The super capacitor rapidly reheats the shape memory alloy wire, causing the shape memory alloy wire to start contracting. When the temperature of the shape memory alloy wire reaches 60 °C, the heating stops. At this time, the contraction length ΔL of the alloy wire is approximately 6 mm, generating a strain of about 5%, thereby driving the release switch to release the push rod, and finally causing the compression spring to be released until the stopper engages with the second base, and the vehicle engine hood pops up;

[0084] The time from detecting a collision between a pedestrian and a vehicle to the engine hood popping up is approximately 80 ms. Among them, the response time of the pedestrian collision detection system is 30 ms, and the time for the engine hood to pop up is 50 ms. This time can not only make the engine hood fully pop up before the pedestrian's head collides with the engine hood, but also avoid excessive bending moment caused by the engine hood lifting too fast, which may cause the engine hood to bend under its own inertia. The 50 ms of the engine hood popping-up device can be further divided into: the time from the start of the super capacitor reheating the SMA to the start of the SMA contraction is 5 ms, the time for the engine hood popping-up mechanism to respond and start releasing the popping-up device is 10 ms (i.e., the contraction time of the shape memory alloy wire), and the time for the popping-up subsystem to start popping up until completing the entire popping-up action and stabilizing is 35 ms;

[0085] During the reheating process, the super capacitor can instantaneously output a current of more than 2000 A, while the actual current flowing in the circuit is 80 A, and the shape memory alloy wire will undergo a phase change and start contracting in 5 ms. As long as it starts to contract, the release switch can be triggered, and finally the heating stops after the temperature of the shape memory alloy wire reaches 60 °C.

[0086] Step 3: After the driver issues a reset instruction, the servo motor rotates forward, the lead screw nut drives the push rod to reset, the super capacitor maintains the temperature of the shape memory alloy wire at the preheating temperature, the release switch engages with the push rod, and the vehicle engine hood resets;

[0087] Step 4: The servo motor rotates in reverse, and the lead screw nut resets.

[0088] A control method for an intelligent vehicle pop-up engine hood device designed and developed by the present invention ensures the popping up and recovery of the vehicle engine hood during a collision by controlling the contraction or extension of the shape memory alloy wire, thereby restoring the driving performance of the vehicle.

[0089] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those skilled in the art, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. An intelligent vehicle pop-up engine hood device, characterized in that Comprising: A base, which is detachably fixed in the engine compartment; And A top cover, which is detachably fixed inside the vehicle engine hood; A compression spring, which is fixed between the base and the top cover, and an accommodation cavity is formed between the compression spring and the base and the top cover; A push rod, which is arranged in the accommodation cavity, one end of the push rod is fixed on the top cover, the other end is selectively engaged on the outside of the base, and a longitudinal slot is arranged at one end of the push rod; A servo motor, which is fixed on the base; A lead screw, one end of which is connected to the output end of the servo motor, and the other end is rotatably arranged in the push rod; A lead screw nut, which is rotatably arranged on the lead screw, and the lead screw nut is engaged in the slot; Two release switches, which are symmetrically arranged on the base, and the two release switches are selectively engaged on the other end of the push rod; A shape memory alloy wire, one end of which is connected to a supercapacitor, and the other end is connected to the two release switches; Wherein, when the compression spring is in a pre-compressed state, the lead screw nut is simultaneously located at the other end of the lead screw and one end of the push rod; The base includes: A first base, the inside of which is a hollow structure, and two through holes are symmetrically arranged on the first base; A second base, which is a hollow structure, and the second base has a central through hole, and the second base is coaxially arranged on the upper part of the first base; Two reset grooves, which are symmetrically arranged in the first base, and the two reset grooves respectively correspond to the two through holes; Wherein, the inside of the first base is communicated with the inside of the second base, and the diameter of the second base is smaller than that of the first base, and the other end of the push rod passes through the central through hole; A limiter, which is fixed at the other end of the push rod, and the limiter is arranged in the first base or the second base, and the limiter is selectively engaged in the second base; Two limit grooves, which are symmetrically arranged on both sides of the limiter, and the two limit grooves respectively correspond to the two through holes; The release switch includes: A limit head, which is arranged in the reset groove; A connecting rod, one end of which is fixed on one side of the limit head, and the other end passes through the reset groove and the through hole; A wedge block, which is arranged on the other side of the limit head, and the wedge block is selectively engaged in the limit groove; A reset spring, which is sleeved on the outside of the connecting rod, and the reset spring is arranged between the limit head and the reset groove; A plurality of ceramic guide wheels, which are arranged at intervals on the outside of the first base, and the plurality of ceramic guide wheels are symmetrically arranged between the two through holes; Wherein, the other end of the shape memory alloy wire is sequentially connected to the other end of the connecting rod after passing through the plurality of ceramic guide wheels.

2. The pop-up engine hood device for an intelligent vehicle according to claim 1, characterized in that, It further includes: Two guide posts, one end of which is symmetrically arranged inside the top cover; Two guide sleeves, one end of which is symmetrically arranged on the first base, and the other ends of the two guide sleeves are respectively sleeved on the outside of the other ends of the two guide posts.

3. A control method for a pop-up engine hood device of an intelligent vehicle, using the pop-up engine hood device of an intelligent vehicle as described in any one of claims 1-2, characterized in that, Including the following steps: Step 1, when the vehicle is started, the supercapacitor preheats the shape memory alloy wire, and the preheating temperature is 35°C; Step 2: When a pedestrian collides with a vehicle, the supercapacitor performs secondary heating on the shape memory alloy wire to cause the shape memory alloy wire to contract, so that the compression spring is released until the stopper engages with the second base, and the vehicle engine hood pops up; Among them, the time from when the supercapacitor performs secondary heating on the shape memory alloy wire to when the shape memory alloy wire starts to contract is 5 ms, and the maximum temperature of the secondary heating of the shape memory alloy wire is 60 °C; Step 3: After the driver issues a reset command, the servo motor rotates forward, the lead screw nut drives the push rod to reset, the supercapacitor maintains the temperature of the shape memory alloy wire at the preheating temperature, the release switch engages with the push rod, and the vehicle engine hood resets; Step 4: The servo motor rotates in reverse, and the lead screw nut resets.

4. The control method of the intelligent vehicle pop-up engine hood device according to claim 3, characterized in that, The length of the shape memory alloy wire is 140 mm, the number of the shape memory alloy wires is 6, the diameter of each shape memory alloy wire is 0.5 mm, and the contraction length of the shape memory alloy wire is 6 mm.

5. The control method of the intelligent vehicle pop-up engine hood device according to claim 4, characterized in that In Step 2, the time from when a pedestrian collides with a vehicle to when the vehicle engine hood pops up is 80 ms.

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