CN107010028B - Anti-collision system and control method of electric automobile and electric automobile - Google Patents

Abstract

The invention discloses an anti-collision system and a control method of an electric automobile and the electric automobile, wherein the system comprises: a vehicle speed detection device; a vehicle distance detection device; the wheel motor braking device is arranged on the host vehicle and comprises a wheel braking motor and is used for applying braking force to the wheel when receiving an emergency braking signal so as to perform feedback braking on the host vehicle; and the vehicle control unit is used for determining collision time according to the speed of the host vehicle, the speed of the front vehicle and the first relative distance when the speed of the host vehicle is greater than the preset speed and the first relative distance is less than the preset distance, and sending an emergency braking signal to the wheel motor braking device when the collision time is less than the preset time. The anti-collision system can effectively prevent the rear-end collision of the vehicle, has the advantages of high braking response speed and short braking distance, can ensure the safety of the vehicle, and has the advantages of simple structure and low cost.

Description

Anti-collision system for electric vehicle, control method and electric vehicle

technical field

The invention relates to the technical field of automobiles, in particular to an anti-collision system for an electric vehicle, a control method and an electric vehicle.

Background technique

At present, there are some related technologies that can give an early warning to the driver when the vehicle is about to collide with the vehicle in front, so that the driver can be reminded to slow down and avoid the rear-end collision. This improves driving safety to a certain extent. However, if the driver does not slow down, a rear-end collision is usually still possible. In addition, there are some related technologies that can control the hydraulic braking system to perform automatic braking when it is judged that a rear-end collision with the preceding vehicle is about to occur, and then the structure of the hydraulic braking system itself is relatively complex, and the hydraulic braking system has a slow response and high cost. High, delayed braking is sometimes not enough to ensure driving safety.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

Therefore, an object of the present invention is to provide an anti-collision system for an electric vehicle. The anti-collision system of the electric vehicle can effectively prevent the rear-end collision of the vehicle, and has the advantages of fast braking response speed and short braking distance, thereby ensuring the safety of the vehicle. In addition, the anti-collision system has the advantages of simple structure and low cost.

Another object of the present invention is to provide a control method for an anti-collision system of an electric vehicle.

Another object of the present invention is to provide an electric vehicle.

In order to achieve the above object, an embodiment of the first aspect of the present invention discloses an anti-collision system for an electric vehicle, comprising: a vehicle speed detection device for detecting the speed of a host vehicle and a vehicle in front; a distance detection device for detecting a first relative distance between the host vehicle and the preceding vehicle; a wheel motor braking device provided on the host vehicle, the wheel motor braking device comprising a wheel braking motor, and the wheel motor braking device is used for receiving When an emergency braking signal is used, a braking force is applied to the wheels to perform regenerative braking on the host vehicle; a vehicle controller, the vehicle controller is used for when the vehicle speed of the host vehicle is greater than a predetermined vehicle speed and the first relative distance When the distance is less than the predetermined distance, the collision time is determined according to the speed of the host vehicle, the speed of the vehicle ahead and the first relative distance, and when the collision time is less than the predetermined time, an alarm signal is sent to the driver of the host vehicle and/or an alarm signal is sent to the driver of the host vehicle. The wheel motor braking device sends the emergency braking signal.

According to the anti-collision system of the electric vehicle in the embodiment of the present invention, when it is determined that the host vehicle is about to collide with the vehicle in front, it can issue an alarm to the driver, and even control the vehicle to automatically brake, so as to avoid the rear-end collision between the vehicle and the vehicle in front and ensure Driving safety. In addition, the method of applying braking force to the wheel through a wheel-side motor or an in-wheel motor, compared with the method of hydraulic braking in the related art, has the advantage of a faster braking response speed and the relative structure of the wheel-side motor or the in-wheel motor, etc. The advantages of simplicity and low cost.

An embodiment of the second aspect of the present invention discloses a control method for an anti-collision system of an electric vehicle, comprising the following steps: detecting the speed of the host vehicle and the speed of the preceding vehicle; detecting the first relative distance between the host vehicle and the preceding vehicle; When the speed of the host vehicle is greater than the predetermined speed and the first relative distance is less than the predetermined distance, the collision time is determined according to the speed of the host vehicle, the speed of the preceding vehicle and the first relative distance; when the collision time is less than the predetermined time , sending an alarm signal to the driver of the host vehicle and/or sending the emergency braking signal to the wheel motor braking device, so that the wheel motor braking device applies braking force to the wheels, so as to provide feedback control to the host vehicle verb: move.

According to the control method of the anti-collision system of the electric vehicle according to the embodiment of the present invention, when it is determined that the host vehicle is about to collide with the vehicle in front, an alarm can be issued to the driver, and even the vehicle can be controlled to automatically brake, so as to prevent the vehicle from colliding with the vehicle in front. Rear-end, to ensure driving safety. In addition, the method of applying braking force to the wheel through a wheel-side motor or an in-wheel motor, compared with the method of hydraulic braking in the related art, has the advantage of a faster braking response speed and the relative structure of the wheel-side motor or the in-wheel motor, etc. The advantages of simplicity and low cost.

The embodiment of the third aspect of the present invention discloses an electric vehicle, comprising: the anti-collision system of the electric vehicle according to the embodiment of the first aspect of the present invention. When the vehicle determines that the host vehicle is about to collide with the vehicle in front, it can issue an alarm to the driver, and even control the vehicle to automatically brake, so as to avoid the rear-end collision between the vehicle and the vehicle in front and ensure driving safety. In addition, the method of applying braking force to the wheel through a wheel-side motor or an in-wheel motor, compared with the method of hydraulic braking in the related art, has the advantage of a faster braking response speed and the relative structure of the wheel-side motor or the in-wheel motor, etc. The advantages of simplicity and low cost.

Description of drawings

1 is a structural block diagram of an anti-collision system for an electric vehicle according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a collision avoidance system for an electric vehicle according to an embodiment of the present invention; and

FIG. 3 is a flowchart of a control method of a collision avoidance system for an electric vehicle according to an embodiment of the present invention.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to explain the present invention and should not be construed as limiting the present invention.

The following describes an anti-collision system for an electric vehicle, a control method, and an electric vehicle according to embodiments of the present invention with reference to the accompanying drawings.

FIG. 1 is a structural block diagram of an anti-collision system for an electric vehicle according to an embodiment of the present invention. As shown in FIG. 1 , an anti-collision system 100 for an electric vehicle according to an embodiment of the present invention includes a vehicle speed detection device 110 , a vehicle distance detection device 120 , a wheel motor braking device 130 and a vehicle controller 140 .

Specifically, as shown in FIG. 2 , the vehicle speed detection device 110 is used to detect the vehicle speed of the host vehicle and the vehicle speed of the preceding vehicle. The vehicle distance detection device 120 is used to detect the first relative distance between the host vehicle and the preceding vehicle. The wheel motor braking device 130 is provided on the host vehicle, the wheel motor braking device 130 includes a wheel braking motor 131, and the wheel motor braking device 130 is used to apply a braking force to the wheels when an emergency braking signal is received, so as to brake the vehicle. Perform regenerative braking. The vehicle controller 140 is configured to determine the collision time according to the speed of the host vehicle, the speed of the preceding vehicle and the first relative distance when the speed of the host vehicle is greater than the predetermined speed and the first relative distance is less than the predetermined distance, and when the collision time is less than the predetermined time, A warning signal is sent to the driver of the host vehicle and/or an emergency braking signal is sent to the wheel motor braking device.

Among them, the host vehicle refers to the own vehicle, and the preceding vehicle refers to the vehicle in front of the host vehicle. The vehicle speed detection device 110 is, for example, a vehicle speed sensor provided on the host vehicle to monitor the vehicle speed V ₁ of the host vehicle and the vehicle speed V ₂ of the preceding vehicle in real time. The vehicle distance detection device 120 is, for example, a radar or laser distance measuring device provided on the host vehicle, so as to monitor the distance (ie, the first relative distance) between the host vehicle and the preceding vehicle in real time. The wheel brake motor 131 is an in-wheel motor or an in-wheel motor. That is, the wheel brake motor 131 may be a wheel-side motor or an in-wheel motor.

As a specific example, as shown in FIG. 2 , the wheel motor braking device 130 includes a wheel braking motor 131 and a motor controller 133 , and of course, a transmission 132 may also be included. The wheel brake motor 131 is connected to the wheels through the transmission 132 , and the wheel brake motor 131 is used to apply a braking force to the wheels through the transmission 132 . The motor controller 133 is respectively connected with the wheel brake motor 131 and the vehicle controller 140 to receive the emergency braking signal sent from the vehicle controller 140, and drive the wheel brake motor 131 to give feedback to the vehicle according to the emergency braking signal brake. The wheel brake motor 131 performs regenerative braking on the vehicle, instructing the wheel brake motor 131 to generate a braking force opposite to the driving direction of the vehicle, so as to achieve the purpose of braking, and the wheel brake motor 131 is in the process of performing regenerative braking. The energy of regenerative braking can be converted into electric energy to generate electricity, so that when the power battery needs to be charged, the power battery can be charged for energy recovery through the power battery, thereby reducing the energy consumption of the whole vehicle.

There are a plurality of wheel motor braking devices 130, and the plurality of wheel motor braking devices 130 correspond to a plurality of wheels of a vehicle one by one. As shown in FIG. 2, the vehicle includes four wheels, namely: left front wheel, right front wheel, left rear wheel and right rear wheel, left front wheel motor braking device 130-1 corresponding to the left front wheel, right front wheel corresponding to the right front wheel The motor braking device 130-2, the left rear wheel motor braking device 130-3 corresponding to the left rear wheel, and the right rear wheel motor braking device 130-4 corresponding to the right rear wheel. Referring to FIG. 2 again, the wheel brake motor 131 is a wheel-side motor or an in-wheel motor. That is, the wheel brake motor 131 may be a wheel-side motor or an in-wheel motor.

In an embodiment of the present invention, a risk level of an imminent collision can be determined according to the determined collision time, and then different operations are performed according to different risk levels. For example, when the risk level is relatively low, the driver can be prompted to slow down to avoid collision with the vehicle ahead; when the risk level is relatively high, the driver can be prompted to slow down and automatically brake the vehicle to avoid collision with the vehicle ahead. The vehicle ahead collided.

Specifically, the predetermined time includes a first predetermined time and a second predetermined time, the first predetermined time is greater than the second predetermined time, and the vehicle controller 140 is configured to be used when the speed of the host vehicle is greater than the predetermined speed and the first relative distance is less than the predetermined distance , determine whether the collision time is less than the first predetermined time and greater than the second predetermined time, if so, generate an alarm signal and send an alarm signal to the driver of the host vehicle, if the collision time is less than the second predetermined time, then generate an alarm signal and send it to the driver of the host vehicle. The driver of the host vehicle issues an alarm signal and an emergency braking signal to the wheel motor braking device.

For example, the collision time when the host vehicle collides with the preceding vehicle is t ₁ =L ₁ /(V ₁ -V ₂ ). Wherein, L ₁ is the first relative distance between the host vehicle and the preceding vehicle, V ₁ is the vehicle speed of the host vehicle, and V ₂ is the vehicle speed of the preceding vehicle. If t ₁ ≤ 0 seconds, it means that V ₂ is greater than V ₁ , that is, the speed of the vehicle in front is higher than that of the host vehicle, and no collision will occur; if t ₁ >0 seconds, the speed of the vehicle in front is lower than that of the host vehicle, and a collision may occur Danger.

When V ₁ is greater than 80km/h (ie: predetermined vehicle speed), and L ₁ is less than 10m (ie: predetermined distance), and t ₁ is less than 2s (ie, the first predetermined time), the vehicle controller 140 determines that the host vehicle is likely to communicate with The vehicle ahead collided. The vehicle controller 140 sends an alarm signal to the driver of the host vehicle through the CAN network, and then reminds the driver to pay attention to the driving distance and driving safety through the alarm signal.

When V ₁ is greater than 80 km/h, L ₁ is less than 10 m, and t ₁ is less than 1 s, the vehicle controller 140 determines that the host vehicle is about to collide with the preceding vehicle. The vehicle controller 140 sends an emergency braking signal to the wheel motor braking device 130, and the wheel motor braking device 130 applies braking force to the wheels to achieve the purpose of automatic braking, thereby preventing the host vehicle from colliding with the vehicle in front and improving the driving performance. Safety.

When it is determined that the host vehicle is about to collide with the vehicle ahead during high-speed driving, the vehicle controller 140 may determine the braking torque according to the host vehicle's speed, wheel speed and predetermined tire slip rate, and generate the above-mentioned braking torque according to the braking torque. The emergency braking signal specifically includes: obtaining the actual slip rate of the tire according to the speed of the host vehicle and the rotational speed of the wheel; determining the target rotational speed of the wheel according to the actual slip rate of the tire and the predetermined slip rate of the tire; And generate an emergency braking signal according to the braking torque.

Specifically, in the process of high-speed driving and a rear-end collision with the preceding vehicle is about to occur, in order to reduce the braking distance, it is necessary to determine the maximum braking torque. In the embodiment of the present invention, the maximum braking torque can be determined according to the vehicle speed of the host vehicle, the wheel speed and the predetermined tire slip rate. First, the actual slip rate of the tire is obtained by the following formula, which is:

S=(V-u)/V×100%,

Among them, S is the actual slip rate of the tire, V is the vehicle speed, and u is the wheel speed.

According to the test, when the actual slip rate S of the tire is about 20% (that is, the predetermined wheel slip rate), the wheel can obtain the maximum braking force at this time. The vehicle controller 140 calculates the actual slip rate S of the tire in real time, and then The maximum braking torque is determined according to the actual slip rate S of the tire and the predetermined wheel slip rate, etc., and then the wheel motor braking device 130 applies a braking force to the wheel according to the maximum braking torque, so that the tire is actually in the emergency braking process. The slip rate S is always maintained at about 20%, so as to achieve the effect of rapid braking, reduce the braking distance and ensure the safety of the vehicle.

According to the anti-collision system of the electric vehicle in the embodiment of the present invention, when it is determined that the host vehicle is about to collide with the vehicle in front, it can issue an alarm to the driver, and even control the vehicle to automatically brake, so as to avoid the rear-end collision between the vehicle and the vehicle in front and ensure Driving safety. In addition, the method of applying braking force to the wheel through a wheel-side motor or an in-wheel motor, compared with the method of hydraulic braking in the related art, has the advantage of a faster braking response speed and the relative structure of the wheel-side motor or the in-wheel motor, etc. The advantages of simplicity and low cost.

In an embodiment of the present invention, the vehicle speed detection device 110 is further used to detect the vehicle speed of the rear vehicle, and the vehicle distance detection device 120 is also used to detect the second relative distance between the host vehicle and the rear vehicle. The vehicle controller 140 also uses When the speed of the vehicle behind is greater than the predetermined speed and the second relative distance is less than the predetermined distance, the collision time is determined according to the speed of the host vehicle, the speed of the rear vehicle and the second relative distance, and when the collision time is less than the predetermined time, an alarm signal is sent to the vehicle behind .

Specifically, the time when the rear vehicle collides with the host vehicle is t ₂ =L ₂ /(V ₃ -V ₁ ), L ₂ is the second relative distance, and V ₃ is the speed of the rear vehicle. If t ₂ ≤ 0s, it means that V ₁ is greater than V ₃ , that is, the speed of the host vehicle is higher than that of the vehicle behind, and no collision will occur; if t ₂ >0s, it means that V ₁ is less than V ₃ , that is, the speed of the host vehicle is lower than that of the vehicle behind , a collision may occur.

Furthermore, when V ₃ is greater than 80km/h (ie: predetermined vehicle speed), L ₂ is less than 10m (ie: predetermined distance), and t ₂ is less than 2s (ie: first predetermined time), the vehicle controller 140 determines that the vehicle behind has Possible collision with host vehicle. The vehicle controller 140 sends an alarm signal to the rear vehicle.

When V ₂ is greater than 80 km/h, L ₂ is less than 10 m, and t ₂ is less than 1 s, the vehicle controller 140 determines that the rear vehicle will collide with the host vehicle. When the vehicle controller 150 sends out an alarm signal, it turns on the rear taillights and emergency warning lights of the vehicle to warn the owner behind that there is a danger of rear-end collision if the two vehicles are too close. This avoids rear-end collision with the host vehicle. Further increase driving safety.

In an embodiment of the present invention, the process of applying emergency braking to the vehicle through the wheel motor braking device 130 further includes: judging whether the power battery satisfies the charging condition, for example, when the power of the power battery is insufficient, the wheel The motor braking device 130 collects the energy generated by braking, converts it into electric energy, and then charges the power battery to realize energy recovery, thereby increasing the cruising range of the electric vehicle and avoiding waste of energy.

FIG. 3 is a flowchart of a control method of a collision avoidance system for an electric vehicle according to an embodiment of the present invention.

It should be noted that, in the control method of the anti-collision system of an electric vehicle according to the embodiment of the present invention, the anti-collision system of the electric vehicle is the anti-collision system of the electric vehicle described in the above embodiments.

As shown in FIG. 3 , a control method of an anti-collision system for an electric vehicle according to an embodiment of the present invention includes the following steps:

S301: Detect the speed of the host vehicle and the speed of the preceding vehicle.

S302: Detect a first relative distance between the host vehicle and the preceding vehicle.

S303: When the speed of the host vehicle is greater than a predetermined speed and the first relative distance is less than a predetermined distance, determine a collision time according to the speed of the host vehicle, the speed of the preceding vehicle and the first relative distance.

S304: When the collision time is less than a predetermined time, send an alarm signal to the driver of the host vehicle and/or send the emergency braking signal to the wheel motor braking device, so that the wheel motor braking device applies braking to the wheels power for regenerative braking of the host vehicle.

Further, the predetermined time includes a first predetermined time and a second predetermined time, the first predetermined time is greater than the second predetermined time, and when the collision time is less than the predetermined time, an alarm is issued to the driver of the host vehicle Signaling and/or sending the emergency braking signal to the wheel motor braking device, so that the wheel motor braking device applies braking force to the wheels to perform regenerative braking on the host vehicle, including: judging the collision time Whether it is less than the first predetermined time and greater than the second predetermined time, if so, generate the warning signal and issue the warning signal to the driver of the host vehicle; if the collision time is less than the second predetermined time time, the warning signal is generated and sent to the driver of the host vehicle, and the emergency braking signal is sent to the wheel motor braking device.

In an embodiment of the present invention, the control method for an anti-collision system of an electric vehicle further includes: obtaining an actual tire slip rate according to the vehicle speed and wheel speed of the host vehicle; according to the actual tire slip rate and the predetermined The tire slip ratio determines the target wheel speed; the braking torque is determined according to the wheel target speed, and the emergency braking signal is generated according to the braking torque.

Further, the control method further includes: detecting the speed of the rear vehicle; detecting a second relative distance between the host vehicle and the rear vehicle; when the rear vehicle speed is greater than a predetermined vehicle speed and the second relative distance is less than the predetermined distance, according to The speed of the host vehicle, the speed of the rear vehicle and the second relative distance determine the collision time, and when the collision time is less than a predetermined time, an alarm signal is sent to the rear vehicle.

According to the control method of the anti-collision system of the electric vehicle according to the embodiment of the present invention, when it is determined that the host vehicle is about to collide with the vehicle in front, an alarm can be issued to the driver, and even the vehicle can be controlled to automatically brake, so as to prevent the vehicle from colliding with the vehicle in front. Rear-end, to ensure driving safety. In addition, the method of applying a braking force to the wheel through a wheel-side motor or an in-wheel motor, compared with the hydraulic braking method in the related art, has the advantage of fast braking response speed and the relative structure of the wheel-side motor or the in-wheel motor, etc. The advantages of simplicity and low cost.

It should be noted that, for the specific implementation of the control method of the anti-collision system for electric vehicles in the embodiment of the present invention, please refer to the specific implementation of the anti-collision system for electric vehicles in the embodiment of the present invention. Repeat.

In an embodiment of the present invention, an electric vehicle is further disclosed, comprising: the anti-collision system for an electric vehicle according to any one of the above embodiments. When the vehicle determines that the host vehicle is about to collide with the vehicle in front, it can issue an alarm to the driver, and even control the vehicle to automatically brake, so as to avoid the rear-end collision between the vehicle and the vehicle in front and ensure driving safety. In addition, the method of applying braking force to the wheel through a wheel-side motor or an in-wheel motor, compared with the method of hydraulic braking in the related art, has the advantage of a faster braking response speed and the relative structure of the wheel-side motor or the in-wheel motor, etc. The advantages of simplicity and low cost. .

In addition, other structures and functions of the electric vehicle according to the embodiment of the present invention are known to those skilled in the art, and in order to reduce redundancy, details are not described here.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (8)

1. an anti-collision system of an electric vehicle, is characterized in that, comprises: A vehicle speed detection device for detecting the speed of the host vehicle and the speed of the vehicle ahead; a vehicle distance detection device for detecting a first relative distance between the host vehicle and the preceding vehicle; A wheel motor braking device provided on the host vehicle, the wheel motor braking device comprising a wheel braking motor, and the wheel motor braking device is used to apply a braking force to the wheels when an emergency braking signal is received, so as to apply a braking force to the wheels. the host vehicle performs regenerative braking; A vehicle controller, the vehicle controller is configured to, when the vehicle speed of the host vehicle is greater than the predetermined vehicle speed and the first relative distance is less than the predetermined distance, according to the vehicle speed of the host vehicle, the vehicle speed of the preceding vehicle and the first relative distance Determine the collision time, and when the collision time is less than a predetermined time, send an alarm signal to the driver of the host vehicle and/or send the emergency braking signal to the wheel motor braking device, wherein the vehicle control The device is further configured to determine a braking torque according to the host vehicle speed, wheel speed and predetermined tire slip rate, and generate the emergency braking signal according to the braking torque, which specifically includes: according to the host vehicle speed and wheel The actual tire slip rate is obtained from the rotational speed; the target wheel speed is determined according to the actual tire slip rate and the predetermined tire slip rate; the braking torque is determined according to the wheel target speed, and the braking torque is generated according to the braking torque. the emergency braking signal, Wherein, the predetermined time includes a first predetermined time and a second predetermined time, the first predetermined time is greater than the second predetermined time, and the vehicle controller is used for when the speed of the host vehicle is greater than the predetermined speed and the When the first relative distance is less than a predetermined distance, determine whether the collision time is less than the first predetermined time and greater than the second predetermined time, and if so, generate the alarm signal and send the driver of the host vehicle the a warning signal, if the collision time is less than the second predetermined time, generating the warning signal and sending the warning signal to the driver of the host vehicle, and sending the emergency braking to the wheel motor braking device Signal. 2. The anti-collision system of an electric vehicle according to claim 1, wherein the wheel motor braking device comprises: A motor controller, the motor controller is respectively connected with the wheel brake motor and the vehicle controller to receive the emergency braking signal sent from the vehicle controller, and according to the emergency braking The dynamic signal drives the wheel brake motor to perform regenerative braking on the vehicle; The wheel brake motor is connected to the wheel through a transmission, and the wheel brake motor is used to apply a braking force to the wheel through the transmission. 3 . The anti-collision system for an electric vehicle according to claim 1 or 2 , wherein there are a plurality of said wheel motor braking devices, and a plurality of said wheel motor braking devices correspond one-to-one to a plurality of vehicle wheel motor braking devices. 4 . wheel. 4 . The anti-collision system for an electric vehicle according to claim 1 , wherein the wheel brake motor is a wheel side motor or an in-wheel motor. 5 . 5 . The anti-collision system of an electric vehicle according to claim 1 , wherein the vehicle speed detection device is further used to detect the vehicle speed of the rear vehicle, and the vehicle distance detection device is also used to detect the distance between the host vehicle and the rear vehicle. 6 . the second relative distance, the vehicle controller is further configured to, when the speed of the rear vehicle is greater than the predetermined speed and the second relative distance is less than the predetermined distance, according to the speed of the host vehicle, the speed of the rear vehicle and the first The two relative distances determine the collision time, and when the collision time is less than the predetermined time, an alarm signal is sent to the rear vehicle. 6. A control method for an anti-collision system of an electric vehicle, characterized in that, comprising the following steps: Detect the speed of the host vehicle and the speed of the vehicle ahead; detecting a first relative distance between the host vehicle and the preceding vehicle; When the speed of the host vehicle is greater than the predetermined speed and the first relative distance is less than the predetermined distance, determining the collision time according to the speed of the host vehicle, the speed of the preceding vehicle and the first relative distance; When the collision time is less than a predetermined time, a warning signal is sent to the driver of the host vehicle and/or an emergency braking signal is sent to the wheel motor braking device, so that the wheel motor braking device applies braking force to the wheels to prevent the host vehicle performs regenerative braking; Also includes: Obtaining the actual slip rate of the tire according to the speed of the host vehicle and the rotational speed of the wheel; Determine the target wheel speed according to the actual slip rate of the tire and the predetermined slip rate of the tire; The braking torque is determined according to the target wheel speed, and the emergency braking signal is generated according to the braking torque, Wherein, the predetermined time includes a first predetermined time and a second predetermined time, the first predetermined time is greater than the second predetermined time, and when the collision time is less than the predetermined time, the driver of the host vehicle is issued an alarm signal and/or sending the emergency braking signal to a wheel motor braking device, so that the wheel motor braking device applies a braking force to the wheels to perform regenerative braking on the host vehicle, including: judging the collision Whether the time is less than the first predetermined time and greater than the second predetermined time, if so, generate the warning signal and issue the warning signal to the driver of the host vehicle; if the collision time is less than the second After a predetermined time, the warning signal is generated and sent to the driver of the host vehicle, and the emergency braking signal is sent to the wheel motor braking device. 7. The control method of the anti-collision system of an electric vehicle according to claim 6, characterized in that, further comprising: Detect the speed of the vehicle behind; detecting a second relative distance between the host vehicle and the rear vehicle; When the speed of the rear vehicle is greater than a predetermined speed and the second relative distance is less than a predetermined distance, a collision time is determined according to the speed of the host vehicle, the speed of the rear vehicle and the second relative distance, and when the collision time is less than a predetermined distance When the time is up, an alarm signal is sent to the vehicle behind. 8. An electric vehicle, characterized in that, comprising: the anti-collision system for an electric vehicle according to any one of claims 1-5.

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