Vehicle blind area monitoring method based on electronic outside rear-view mirror

Abstract

The invention provides a vehicle blind area monitoring method based on an electronic outside rear-view mirror, which comprises the following steps of: establishing kinematics models for a tractor and a trailer, respectively and accurately calculating tracks of a tractor body and a trailer body, and monitoring blind areas of the tractor body and the trailer body through a left camera and a right camera of the electronic outside rear-view mirror and a rear camera at the rear part of a carriage of the trailer. The rear view is spliced by using the relative position relation, transparent display of the trailer compartment is achieved, and therefore monitoring of the view blind area is achieved, and the driving safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic exterior rearview mirrors, and in particular to a vehicle blind spot monitoring method based on an electronic exterior rearview mirror. Background Art

[0002] The electronic rearview mirror is a monitoring system that uses a digital camera to collect road video and then displays it on a high-definition digital display screen after video processing. It has the advantages of large visual range, good imaging in low illumination or rainy and foggy days, few blind spots, less wind resistance and wind noise, etc., and has gradually been widely used, including some large trucks. A trailer is a wheeled vehicle without power, towed by an ordinary vehicle. Even for experienced drivers, its operation is quite challenging, especially when controlling the reversing of a trailer with a long body. It is difficult for the driver to see obstacles behind the vehicle through the limited field of view of the electronic rearview mirror.

[0003] In order to increase the ability of large trucks to perceive the environment, some scholars have proposed adding perception sensors (such as lidar and millimeter-wave radar) to trailers and tractors respectively. However, the implementation cost is high. In addition, since large trucks are basically fuel vehicles, their intelligence and electrification levels are not as good as passenger cars. They cannot meet the power consumption and computing power requirements of perception sensors such as lidar, making the solution difficult to implement. Summary of the invention

[0004] The present invention provides a vehicle blind spot monitoring method based on an electronic exterior rearview mirror, aiming to solve the defects in the prior art, realize the monitoring of the visual field blind spot, and improve driving safety.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides a vehicle blind spot monitoring method based on an electronic exterior rearview mirror, comprising:

[0007] Step 1, obtaining the current state parameters of the tractor, including: the speed of the tractor, the steering wheel angle, the steering ratio between the steering wheel and the front wheels of the tractor, and the yaw angle of the tractor;

[0008] Step 2: Obtain the posture of the tractor at the previous moment, and calculate the current position coordinates of the corner points of the tractor and trailer bodies and the left camera, the right camera, and the rear camera according to the current state parameters;

[0009] Step 3: Determine the visible area and blind area of ​​the left camera and the right camera respectively according to the corner points of the trailer body and the current position coordinates of the left camera and the right camera;

[0010] Step 4: intercepting a corresponding compensation image from the rear camera image according to the vehicle turning direction and the blind area of ​​the field of vision;

[0011] Step 5: scaling the visible area image and the compensation image of the left camera and the right camera according to a preset ratio;

[0012] Step 6: The zoomed visible area images of the left camera and the right camera and the compensated images are stitched together according to preset rules to generate a perspective image, and displayed on the left and right display screens of the electronic exterior rearview mirror.

[0013] Specifically, the step 2 includes:

[0014] Step 201, obtaining body parameters of the tractor and trailer;

[0015] Step 202: Establish kinematic models of the tractor and trailer according to Ackerman kinematics;

[0016] Step 203, obtaining the posture of the tractor at the previous moment, and calculating the posture of the tractor at the current moment according to the first preset relationship;

[0017] Step 204, determining the motion state parameters of the hinge point at the current moment, including the speed of the hinge point and the heading angle in the speed direction;

[0018] Step 205: determining the motion state parameters of the trailer at the current moment according to the motion state parameters of the hinge point at the current moment, including the speed of the rear axle center of the trailer, the rotation angular velocity of the trailer, the heading angle of the trailer at the current moment, and the posture of the trailer at the current moment;

[0019] Step 206, determining the body corner coordinates of the tractor and trailer according to the body parameters of the tractor and trailer, the current position and posture of the tractor, and the current position and posture of the trailer;

[0020] Step 207: determine the current position coordinates of the left camera, the right camera, and the rear camera according to the body corner coordinates of the tractor and the trailer.

[0021] Specifically, the first preset relationship is:

[0022]

[0023] in, is the current position of the tractor, is the position of the tractor at the previous moment, v is the speed of the tractor, L1 is the wheelbase of the tractor, δ is the angle of the front wheel of the tractor, is the steering wheel angle, k is the steering ratio between the steering wheel and the front wheels of the tractor, and △t is the sampling time interval.

[0024] Specifically, step 204 includes:

[0025] Step A1: determine the heading angle of the hinge point speed direction according to a second preset relationship, wherein the second preset relationship is:

[0026]

[0027] Among them, θ is the heading angle in the direction of the articulation point, d is the distance between the articulation point and the center of the rear axle of the tractor, R1 is the turning radius of the tractor, L1 is the wheelbase of the tractor, and δ is the angle of the front wheel of the tractor;

[0028] Step A2: determining the speed of the hinge point according to a third preset relationship, wherein the third preset relationship is:

[0029]

[0030] Among them, V P is the speed of the articulation point, v is the speed of the tractor, and θ is the heading angle in the direction of the articulation point speed;

[0031] Step A3: Determine the position of the hinge point at the current moment by using a fourth preset relationship according to the current posture of the tractor, wherein the fourth preset relationship is:

[0032]

[0033] in, is the current position of the tractor, (x 1,k ,y 1,k ) is the current position of the tractor, and d is the distance between the hinge point and the center of the rear axle of the tractor.

[0034] Specifically, step 205 includes:

[0035] Step B1, determining the speed of the rear axle center of the trailer according to a fifth preset relationship, wherein the fifth preset relationship is:

[0036] v 2,k-1 =v p cos(λ k-1 -θ)

[0037] Among them, v 2,k-1 is the speed of the rear axle center of the trailer, V P is the velocity of the hinge point, θ is the heading angle in the direction of the hinge point velocity, λ k-1 is the angle between the tractor heading and the trailer heading;

[0038] Step B2: determining the rotation angular velocity of the trailer according to a sixth preset relationship, wherein the sixth preset relationship is:

[0039]

[0040] Among them, ω2 is the angular velocity of the trailer, and L2 is the wheelbase of the trailer;

[0041] Step B3, determining the heading angle of the trailer at the current moment according to the seventh preset relationship, wherein the seventh preset relationship is:

[0042]

[0043] in, is the heading angle of the trailer at the current moment, Δt is the sampling time interval of the system;

[0044] Step B4: determining the current position of the trailer according to the eighth preset relationship, wherein the eighth preset relationship is:

[0045]

[0046] Among them, L2 is the wheelbase of the trailer.

[0047] Specifically, the step 3 includes:

[0048] Step 301: determining the field of view boundary of the left camera and the right camera according to the turning direction of the vehicle;

[0049] Step 302: Determine a visual field blind spot according to the visual field boundary line.

[0050] Specifically, step 301 includes:

[0051] When the vehicle turns right, the left camera and the left front corner of the trailer compartment are connected to generate a first left field of view boundary line, and the right front camera and the right rear corner of the trailer compartment are connected to generate a first right field of view boundary line;

[0052] When the vehicle turns left, the left camera and the left rear corner point of the trailer compartment are connected to generate a second left field of view boundary line, and the right front camera and the right front rear corner point of the trailer compartment are connected to generate a second right field of view boundary line.

[0053] Specifically, step 302 includes: determining the right side of the first left visual field dividing line or the second left visual field dividing line as the first visual field blind area, and determining the left side of the first right visual field dividing line or the second right visual field dividing line as the second visual field blind area.

[0054] Specifically, step 4 includes:

[0055] When the vehicle turns right, a first auxiliary line and a second auxiliary line are drawn through the center point of the rear camera, the first auxiliary line is parallel to the first left field of view dividing line, and the second auxiliary line is parallel to the first right field of view dividing line, and the image between the first auxiliary line and the second auxiliary line in the rear camera image is determined as a right turn compensation image;

[0056] When the vehicle turns left, a third auxiliary line and a fourth auxiliary line are drawn through the center point of the rear camera, the third auxiliary line is parallel to the second left field of view dividing line, and the fourth auxiliary line is parallel to the second right field of view dividing line, and the image between the third auxiliary line and the fourth auxiliary line in the rear camera image is determined as the left turn compensation image.

[0057] Specifically, step 5 includes: displaying the visible area image of the left camera on the left display screen of the electronic exterior rearview mirror and the compensated image according to the first ratio K L The image of the visible area of ​​the field of view of the right camera and the compensation image displayed on the right display screen of the electronic exterior rearview mirror are scaled according to the second ratio K. R Scaling is performed, and the first ratio and the second ratio are:

[0058]

[0059] Among them, K L is the first ratio, K R is the second ratio, f1 is the focal length of the rear camera, f2 is the focal length of the left camera or the right camera, d is the distance of the corresponding pixel from the rear camera in the real world, l l is the vertical distance from the left camera to the rear edge of the trailer, l r It is the vertical distance from the right camera to the rear edge of the trailer.

[0060] The beneficial effects of the present invention are as follows: the present invention establishes kinematic models for the tractor and the trailer, accurately estimates the tracks of the tractor and the trailer body respectively, and then uses the left and right cameras of the electronic exterior rearview mirror and the rear camera at the rear of the trailer compartment to splice the rear field of view using the relative position relationship to achieve transparent display of the trailer compartment, thereby realizing the monitoring of the blind spot of the field of view and improving driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a flow chart of a vehicle blind spot monitoring method based on an electronic exterior rearview mirror of the present invention;

[0062] Figure 2 It is a schematic diagram of the field of view of the left and right cameras of the present invention;

[0063] Figure 3 is a schematic diagram of vehicle body parameters of the present invention;

[0064] Figure 4 It is a schematic diagram of the global coordinate system of the present invention. DETAILED DESCRIPTION

[0065] The following specifically describes the embodiments of the present invention in conjunction with the accompanying drawings, which are only for reference and illustration and do not constitute a limitation on the scope of patent protection of the present invention.

[0066] In the process described in the specification, claims or drawings of the present invention, the serial numbers of each step (such as step 10, 20, etc.) are included. The serial numbers are only used to distinguish the steps, and the serial numbers themselves do not represent any execution order. It should be noted that the descriptions such as "first" and "second" in this article are only used to distinguish the description objects, etc., and do not represent the order of precedence, nor do they mean that "first", "second", etc. are different types.

[0067] like Figure 1 As shown, this embodiment provides a vehicle blind spot monitoring method based on an electronic exterior rearview mirror, comprising:

[0068] Step 1: Get the current state parameters of the tractor, including: tractor speed v, steering wheel angle The steering ratio k between the steering wheel and the front wheels of the tractor, the yaw angle of the tractor

[0069] Step 2: Obtain the position and posture of the tractor at the previous moment, and calculate the current position coordinates of the corner points of the tractor and trailer bodies and the left camera, the right camera, and the rear camera according to the current state parameters.

[0070] In specific implementation, Figure 2 As shown, the left camera C of the electronic rearview mirror is installed at the left front corner and the right front corner of the tractor. L and right camera C R , install the rear camera C at the midpoint of the rear of the trailer B , rear camera C B It is a depth camera (RGB-D).

[0071] In this embodiment, step 2 includes:

[0072] Step 201: Obtain body parameters of the tractor and trailer.

[0073] The body parameters of the tractor and trailer can be measured first and then input into the processing unit through the human-computer interaction system. Figure 3 As shown, the vehicle body parameters that need to be measured include: the wheelbase L1 of the tractor, the distance d between the hinge point and the center of the rear axle of the tractor, the wheelbase L2 of the trailer, the steering ratio k between the steering wheel and the front wheels of the tractor, and the front overhang L of the tractor. 1f 、Rear suspension L 1r and vehicle width L 1b , front overhang of trailer L 2f 、Rear suspension L 2r and vehicle width L 2bThe above body parameters correspond to the plane diagram as follows Figure 4 shown.

[0074] It should be noted that: when the hinge point is behind the center of the rear axle of the tractor, d is a positive value; when the hinge point is in front of the center of the rear axle of the tractor, d is a negative value.

[0075] Step 202: Establish kinematic models of the tractor and trailer based on Ackerman kinematics.

[0076] In this embodiment, the position of the tractor at a certain moving moment (for example, the power-on moment) is taken as the coordinate origin, the vehicle's moving direction at the starting moment is the positive direction of the x-axis, and a right-handed coordinate system is established as the global coordinate system, such as Figure 4 shown.

[0077] Step 203: Obtain the posture of the tractor at the previous moment, and calculate the posture of the tractor at the current moment according to the first preset relationship.

[0078] In this embodiment, the first preset relationship is:

[0079]

[0080] in, is the current position of the tractor, is the position of the tractor at the previous moment, v is the speed of the tractor, L1 is the wheelbase of the tractor, δ is the angle of the front wheel of the tractor, is the steering wheel angle, k is the steering ratio between the steering wheel and the front wheels of the tractor, and △t is the sampling time interval.

[0081] Step 204: Determine the motion state parameters of the hinge point at the current moment, including the velocity V of the hinge point. P , the heading angle θ in the velocity direction.

[0082] In this embodiment, step 204 includes:

[0083] Step A1: determine the heading angle of the hinge point speed direction according to a second preset relationship, wherein the second preset relationship is:

[0084]

[0085] Among them, θ is the heading angle in the direction of the articulation point, d is the distance between the articulation point and the center of the rear axle of the tractor, R1 is the turning radius of the tractor, L1 is the wheelbase of the tractor, and δ is the angle of the front wheel of the tractor.

[0086] Step A2: determining the speed of the hinge point according to a third preset relationship, wherein the third preset relationship is:

[0087]

[0088] Among them, V P is the speed of the articulation point, v is the speed of the tractor, and θ is the heading angle in the direction of the articulation point speed.

[0089] Step A3: Determine the position of the hinge point at the current moment by using a fourth preset relationship according to the current posture of the tractor, wherein the fourth preset relationship is:

[0090]

[0091] in, is the current position of the tractor, (x 1,k ,y 1,k ) is the current position of the tractor, and d is the distance between the hinge point and the center of the rear axle of the tractor.

[0092] Since the articulation point P of the tractor and the trailer is the same point in the tractor model and the trailer model, the direction and magnitude of the velocity of the articulation point P in the tractor and the trailer are equal.

[0093] Step 205: Determine the motion state parameters of the trailer at the current moment according to the motion state parameters of the hinge point at the current moment, including the speed of the rear axle center of the trailer, the rotation angular velocity of the trailer, and the heading angle of the trailer at the current moment. The current position of the trailer.

[0094] In this embodiment, step 205 includes:

[0095] Step B1, determining the speed of the rear axle center of the trailer according to a fifth preset relationship, wherein the fifth preset relationship is:

[0096] v 2,k-1 =v p cos(λ k-1 -θ)

[0097] Among them, v 2,k-1 is the speed of the rear axle center of the trailer, V P is the velocity of the hinge point, θ is the heading angle in the direction of the hinge point velocity, λ k-1 It is the angle between the tractor heading and the trailer heading.

[0098] Easy to understand, k-1 It can be determined according to the following formula:

[0099]

[0100] Step B2: determining the rotation angular velocity of the trailer according to a sixth preset relationship, wherein the sixth preset relationship is:

[0101]

[0102] Among them, ω2 is the angular velocity of the trailer, and L2 is the wheelbase of the trailer.

[0103] Step B3, determining the heading angle of the trailer at the current moment according to the seventh preset relationship, wherein the seventh preset relationship is:

[0104]

[0105] in, is the heading angle of the trailer at the current moment, and Δt is the sampling time interval of the system.

[0106] Step B4: determining the current position of the trailer according to the eighth preset relationship, wherein the eighth preset relationship is:

[0107]

[0108] Among them, L2 is the wheelbase of the trailer.

[0109] In addition, the angle λ between the tractor and the trailer at time k is k for:

[0110]

[0111] Step 206: Determine the body corner coordinates of the tractor and trailer according to the body parameters of the tractor and trailer, the current position and posture of the tractor, and the current position and posture of the trailer.

[0112] In this embodiment, step 206 includes:

[0113] According to the ninth preset relational expression, the body corner coordinates of the tractor are:

[0114]

[0115] Among them, p Tfr (x Tfr ,y Tfr ) is the right front corner of the tractor, p Tfl (x Tfl ,y Tfl ) is the left front corner of the tractor, p Trr (x Trr ,y Trr ) is the right rear corner point of the tractor, p Trl (x Trl ,y Trl ) is the left rear corner of the towing vehicle;

[0116] According to the tenth preset relational expression, the body corner coordinates of the tractor are:

[0117]

[0118]

[0119] Among them, p Sfr (x Sfr ,y sfr ) is the right front corner of the trailer, p Sfl (x sfl ,y sfl ) is the left front corner of the trailer, p Srr (x Srr ,y Srr ) is the right rear corner of the trailer, p Srl (x Srl ,y Srl ) is the left rear corner point of the trailer.

[0120] Step 207: determine the current position coordinates of the left camera, the right camera, and the rear camera according to the body corner coordinates of the tractor and the trailer.

[0121] In this embodiment, step 207 includes: determining the current position coordinates of the left camera, the right camera, and the rear camera according to the following formula:

[0122] C L (x CL ,y CL )=p Tfl (x Tfl ,y tfl )

[0123] C R (x CR ,y CR )=p Tfr (x Tfr ,y Tfr )

[0124]

[0125] Among them, C L (x CL ,y CL ) is the current position coordinate of the left camera, C R (x CR ,y CR ) is the current position coordinate of the right camera, C B (x CB ,y CB ) is the current position coordinate of the rear camera.

[0126] Step 3: Determine the visible area and blind area of ​​the left camera and the right camera respectively according to the corner points of the trailer body and the current position coordinates of the left camera and the right camera.

[0127] In this embodiment, step 3 includes:

[0128] Step 301: Determine the field of view boundary of the left camera and the right camera according to the turning direction of the vehicle.

[0129] In this embodiment, step 301 includes:

[0130] When the vehicle turns right, the left camera and the left front corner of the trailer are connected to generate the first left field of view boundary line L L1 , connect the right front camera and the right rear corner point of the trailer compartment to generate the first right field of view boundary line L R1 ;

[0131] When the vehicle turns left, the left camera and the left rear corner of the trailer are connected to generate the second left field of view dividing line L L2 , connect the right front camera and the right front and rear corner points of the trailer compartment to generate the second right field of view dividing line L R2 .

[0132] Figure 2 When the vehicle turns right, the first left field of vision boundary line L L1 , first right visual field boundary line L R1 Schematic diagram. The situation is similar when the vehicle turns right, but it is not marked on the diagram.

[0133] Step 302: Determine a visual field blind spot according to the visual field boundary line.

[0134] In this embodiment, step 302 includes: setting the first left visual field boundary line L L1 Or the second left visual field boundary L L2 The right side of is determined as the first visual field blind area, and the first right visual field dividing line L R1 , the second right visual field boundary line L R2 The left side is determined as the second visual field blind area.

[0135] Step 4: intercepting a corresponding compensation image from the rear camera image according to the vehicle turning direction and the blind area of ​​the field of vision.

[0136] In this embodiment, step 4 includes:

[0137] When the vehicle turns right, a first auxiliary line L is drawn through the center point of the rear camera. S1 , the second auxiliary line L S2 , the first auxiliary line L S1 Parallel to the first left visual field dividing line L L1, the second auxiliary line L S2 Parallel to the first right visual field dividing line L R1 , the first auxiliary line L in the rear camera image S1 , the second auxiliary line L S2 The image between is determined as the right turn compensation image;

[0138] When the vehicle turns left, a third auxiliary line L is drawn through the center point of the rear camera. S3 , the fourth auxiliary line L S4 , the third auxiliary line L S3 Parallel to the second left visual field dividing line L L2 , the fourth auxiliary line L S4 Parallel to the second right visual field dividing line L R2 , the image of the rear camera located at the third auxiliary line L S3 , the fourth auxiliary line L S4 The image in between is determined as the left rotation compensation image.

[0139] Figure 2 When the vehicle turns right, the first auxiliary line L S1 , the second auxiliary line L S2 Schematic diagram, L S1 , L S2 The angle formed in the field of view of the rear camera This is the right turn compensation image. The situation is similar when the vehicle turns right. The third auxiliary line L S3 , the fourth auxiliary line L S4 Not marked on the diagram.

[0140] Step 5: Scale the visible area images and the compensation images of the left camera and the right camera according to a preset ratio.

[0141] In this embodiment, step 5 includes: displaying the visible area image of the left camera on the left display screen of the electronic exterior rearview mirror and the compensated image according to the first ratio K L The image of the visible area of ​​the field of view of the right camera and the compensation image displayed on the right display screen of the electronic exterior rearview mirror are scaled according to the second ratio K. R Scaling is performed, the first ratio K L , the second ratio K R for:

[0142]

[0143] Among them, K L is the first ratio, K Ris the second ratio, f1 is the focal length of the rear camera, f2 is the focal length of the left camera or the right camera, d is the distance of the corresponding pixel from the rear camera in the real world, l l is the vertical distance from the left camera to the rear edge of the trailer, l r It is the vertical distance from the right camera to the rear edge of the trailer.

[0144] Since the coordinates of the left and right cameras are known to be

[0145] C L (x CL ,y CL )=p Tfl (x Tfl ,y Tfl ), C R (x CR ,y CR )=p Tfr (x Tfr ,y Tfr ), the coordinates of the right rear corner of the trailer are p Srr (x Srr ,y Srr ), left rear corner point p Srl (x Srl ,y Srl ), it is easy to calculate the distance l from the left camera to the straight line where the rear edge of the trailer is located. l , the distance from the right camera to the straight line where the rear edge of the trailer is located l r .

[0146] Step 6: The zoomed visible area images of the left camera and the right camera and the compensated images are stitched together according to preset rules to generate a perspective image, and displayed on the left and right display screens of the electronic exterior rearview mirror.

[0147] In this embodiment, step 6 includes: stitching the scaled image of the visible area of ​​the left camera's field of view on the left side of the scaled compensation image, and stitching the scaled image of the visible area of ​​the right camera's field of view on the right side of the scaled compensation image.

[0148] The above disclosure is only a preferred embodiment of the present invention, which cannot be used to limit the scope of protection of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A vehicle blind spot monitoring method based on an electronic exterior rearview mirror, characterized in that: include: Step 1, obtaining the current state parameters of the tractor, including: the speed of the tractor, the steering wheel angle, the steering ratio between the steering wheel and the front wheels of the tractor, and the yaw angle of the tractor; Step 2: Obtain the posture of the tractor at the previous moment, and calculate the current position coordinates of the corner points of the tractor and trailer bodies and the left camera, the right camera, and the rear camera according to the current state parameters; Step 3: Determine the visible area and blind area of ​​the left camera and the right camera respectively according to the corner points of the trailer body and the current position coordinates of the left camera and the right camera; Step 4: intercepting a corresponding compensation image from the rear camera image according to the vehicle turning direction and the blind area of ​​the field of vision; Step 5: scaling the visible area image and the compensation image of the left camera and the right camera according to a preset ratio; Step 6: The zoomed visible area images of the left camera and the right camera and the compensated images are stitched together according to preset rules to generate a perspective image, and displayed on the left and right display screens of the electronic exterior rearview mirror.

2. The vehicle blind spot monitoring method based on the electronic exterior rearview mirror according to claim 1 is characterized in that: The step 2 comprises: Step 201, obtaining body parameters of the tractor and trailer; Step 202: Establish kinematic models of the tractor and trailer according to Ackerman kinematics; Step 203, obtaining the posture of the tractor at the previous moment, and calculating the posture of the tractor at the current moment according to the first preset relationship; Step 204, determining the motion state parameters of the hinge point at the current moment, including the speed of the hinge point and the heading angle in the speed direction; Step 205: determining the motion state parameters of the trailer at the current moment according to the motion state parameters of the hinge point at the current moment, including the speed of the rear axle center of the trailer, the rotation angular velocity of the trailer, the heading angle of the trailer at the current moment, and the posture of the trailer at the current moment; Step 206, determining the body corner coordinates of the tractor and trailer according to the body parameters of the tractor and trailer, the current position and posture of the tractor, and the current position and posture of the trailer; Step 207: determine the current position coordinates of the left camera, the right camera, and the rear camera according to the body corner coordinates of the tractor and the trailer.

3. The vehicle blind spot monitoring method based on electronic exterior rearview mirror according to claim 2 is characterized in that: The first preset relationship is: in, is the current position of the tractor, is the position of the tractor at the previous moment, v is the speed of the tractor, L1 is the wheelbase of the tractor, δ is the angle of the front wheel of the tractor, is the steering wheel angle, k is the steering ratio between the steering wheel and the front wheels of the tractor, and △t is the sampling time interval.

4. The vehicle blind spot monitoring method based on electronic exterior rearview mirror according to claim 3 is characterized in that: The step 204 includes: Step A1: determine the heading angle of the hinge point speed direction according to a second preset relationship, wherein the second preset relationship is: Among them, θ is the heading angle in the direction of the articulation point, d is the distance between the articulation point and the center of the rear axle of the tractor, R1 is the turning radius of the tractor, L1 is the wheelbase of the tractor, and δ is the angle of the front wheel of the tractor; Step A2: determining the speed of the hinge point according to a third preset relationship, wherein the third preset relationship is: Among them, V P is the speed of the articulation point, v is the speed of the tractor, and θ is the heading angle in the direction of the articulation point speed; Step A3: Determine the position of the hinge point at the current moment by using a fourth preset relationship according to the current posture of the tractor, wherein the fourth preset relationship is: in, is the current position of the tractor, (x 1,k ,y 1,k ) is the current position of the tractor, and d is the distance between the hinge point and the center of the rear axle of the tractor.

5. The vehicle blind spot monitoring method based on electronic exterior rearview mirror according to claim 4 is characterized in that: The step 205 comprises: Step B1, determining the speed of the rear axle center of the trailer according to a fifth preset relationship, wherein the fifth preset relationship is: v 2,k-1 =v p cos(λ k-1 -i) Among them, v 2,k-1 is the speed of the rear axle center of the trailer, V P is the velocity of the hinge point, θ is the heading angle in the direction of the hinge point velocity, λ k-1 is the angle between the tractor heading and the trailer heading; Step B2: determining the rotation angular velocity of the trailer according to a sixth preset relationship, wherein the sixth preset relationship is: Among them, ω2 is the angular velocity of the trailer, and L2 is the wheelbase of the trailer; Step B3, determining the heading angle of the trailer at the current moment according to the seventh preset relationship, wherein the seventh preset relationship is: in, is the heading angle of the trailer at the current moment, Δt is the sampling time interval of the system; Step B4: determining the current position of the trailer according to the eighth preset relationship, wherein the eighth preset relationship is: Among them, L2 is the wheelbase of the trailer.

6. The vehicle blind spot monitoring method based on electronic exterior rearview mirror according to claim 5, characterized in that: The step 3 comprises: Step 301: determining the field of view boundary of the left camera and the right camera according to the turning direction of the vehicle; Step 302: Determine a visual field blind spot according to the visual field boundary line.

7. The vehicle blind spot monitoring method based on electronic exterior rearview mirror according to claim 6, characterized in that: The step 301 includes: When the vehicle turns right, the left camera and the left front corner of the trailer compartment are connected to generate a first left field of view boundary line, and the right front camera and the right rear corner of the trailer compartment are connected to generate a first right field of view boundary line; When the vehicle turns left, the left camera and the left rear corner point of the trailer compartment are connected to generate a second left field of view boundary line, and the right front camera and the right front rear corner point of the trailer compartment are connected to generate a second right field of view boundary line.

8. The vehicle blind spot monitoring method based on electronic exterior rearview mirror according to claim 7, characterized in that: The step 302 includes: determining the right side of the first left visual field dividing line or the second left visual field dividing line as the first visual field blind area, and determining the left side of the first right visual field dividing line or the second right visual field dividing line as the second visual field blind area.

9. The vehicle blind spot monitoring method based on electronic exterior rearview mirror according to claim 8, characterized in that: The step 4 comprises: When the vehicle turns right, a first auxiliary line and a second auxiliary line are drawn through the center point of the rear camera, the first auxiliary line is parallel to the first left field of view dividing line, and the second auxiliary line is parallel to the first right field of view dividing line, and the image between the first auxiliary line and the second auxiliary line in the rear camera image is determined as a right turn compensation image; When the vehicle turns left, a third auxiliary line and a fourth auxiliary line are drawn through the center point of the rear camera, the third auxiliary line is parallel to the second left field of view dividing line, and the fourth auxiliary line is parallel to the second right field of view dividing line, and the image between the third auxiliary line and the fourth auxiliary line in the rear camera image is determined as the left turn compensation image.

10. The vehicle blind spot monitoring method based on electronic exterior rearview mirror according to claim 9, characterized in that: The step 5 comprises: displaying the visible area image of the left camera on the left display screen of the electronic exterior rearview mirror and the compensated image according to the first ratio K L The image of the visible area of ​​the field of view of the right camera and the compensation image displayed on the right display screen of the electronic exterior rearview mirror are scaled according to the second ratio K. R Scaling is performed, and the first ratio and the second ratio are: Among them, K L is the first ratio, K R is the second ratio, f1 is the focal length of the rear camera, f2 is the focal length of the left camera or the right camera, d is the distance of the corresponding pixel from the rear camera in the real world, l l is the vertical distance from the left camera to the rear edge of the trailer, l r It is the vertical distance from the right camera to the rear edge of the trailer.

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