Method for adjusting the field of view of an electronic outside mirror

Abstract

This invention provides a method for adjusting the field of view display of an electronic exterior rearview mirror. The method includes: step 1, obtaining the current front wheel steering angle of the trailer tractor; step 2, adjusting the display field of view range of the electronic exterior rearview mirror according to the current front wheel steering angle. This invention enables the field of view display of the electronic exterior rearview mirror to automatically adjust with the steering of the tractor, thereby improving driving safety.

Description

Technical Field

[0001] This invention relates to the field of electronic exterior rearview mirror technology, and more particularly to a method for adjusting the field of view display of an electronic exterior rearview mirror. Background Technology

[0002] Currently, vehicle exterior rearview mirrors are generally traditional physical rearview mirrors, which cannot adjust the mirror surface when the vehicle turns. Therefore, when turning, the driver cannot see the rear area of ​​the vehicle through the exterior rearview mirror, creating a blind spot and affecting driving safety, especially for trucks or buses with a long overall length.

[0003] With the development of electronic technology, Category II electronic rearview mirrors are allowed to be used as external rearview mirrors for observing the rear view outside the vehicle. They are mainly used to observe the situation of vehicles behind when changing lanes, while turning on the turn signal, and to change lanes only after confirming that it is safe to do so.

[0004] However, current Category II electronic rearview mirrors still pose significant safety hazards and limited visibility when turning because the vehicle body or cargo box is too large and obstructs the rear view. Summary of the Invention

[0005] This invention provides a method for adjusting the field of view display of an electronic exterior rearview mirror, aiming to overcome the deficiencies in the prior art and realize that the field of view display of the electronic exterior rearview mirror automatically adjusts with the steering of the tractor, thereby improving driving safety.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for adjusting the field of view display of an electronic exterior rearview mirror, comprising:

[0008] Step 1: Obtain the current front wheel steering angle of the trailer tractor;

[0009] Step 2: Adjust the display field of view of the electronic exterior rearview mirror according to the current front wheel steering angle.

[0010] Specifically, step 1 includes:

[0011] Step 101: Obtain the current steering wheel rotation angle;

[0012] Step 102: Determine the current front wheel steering angle based on the ratio of the steering wheel angle to the front wheel steering angle.

[0013] Specifically, the current front wheel steering angle is determined according to a first preset formula:

[0014] β = round(α / γ)

[0015] Where β represents the current front wheel steering angle, α represents the current steering wheel rotation angle, and round() represents rounding operation.

[0016] Specifically, step 2 includes:

[0017] Step 201: Obtain the corresponding preset field of view adjustment parameters based on the current carriage length. The preset field of view adjustment parameters include: angle field of view relationship, number of large areas, and unit angle pixel cropping amount in each large area.

[0018] Step 202: Determine the target total pixels for cropping based on the current front wheel steering angle and preset field of view adjustment parameters;

[0019] Step 203: Read the field of view image, and crop the field of view image successively according to the number of pixels determined by the fourth preset formula until the total number of cropped pixels is the target total number of pixels, and refresh the field of view image after each cropping to the display device of the electronic rearview mirror.

[0020] Specifically, the calibration steps for the angle-view relationship include:

[0021] Step 201a: Calibrate and save the angular relationship between the front wheel steering angle of the tractor and the visible horizontal field of vision of the trailer for different lengths;

[0022] Step 201b: Divide the maximum front wheel steering angle of the tractor into unit angles according to the angle-view relationship, and divide the first number of unit angles into a large region to obtain a second number of large regions;

[0023] Step 201c: Set the unit angle pixel cropping amount for each of the large regions.

[0024] Specifically, the amount of pixel cropping per unit angle within each of the aforementioned large regions increases sequentially.

[0025] Specifically, step 202 includes:

[0026] Step 202a: Determine the target area to which the current front wheel steering angle belongs based on the angle and field of vision relationship;

[0027] Step 202b: Determine the total number of target pixels to be cropped based on the target large area and the unit angle pixel cropping amount.

[0028] Specifically, the target large area is determined according to a second preset formula:

[0029]

[0030] Where β represents the current front wheel steering angle, ω represents the maximum front wheel steering angle, and m represents the number of large regions. This indicates the rounding up operation.

[0031] Specifically, the total number of target pixels is determined according to a third preset formula:

[0032]

[0033] Where P represents the total number of target pixels, X k (k = i, j) represents the unit angle pixel cropping amount for the large region k. Specifically, the fourth preset formula is:

[0034] p(i,s)=p(i-1,n)+s*X i

[0035] Where p(i,s) represents the number of cropped pixels in the s-th small region within the large region i, i = 1, 2, 3…j-1, s ≤ n, p(0,s) = 0.

[0036] The beneficial effects of the present invention are as follows: by obtaining the current front wheel steering angle of the trailer tractor and then adjusting the display field of view of the electronic exterior rearview mirror according to the current front wheel steering angle, the present invention realizes that the field of view of the electronic exterior rearview mirror is automatically adjusted as the tractor turns, thereby improving driving safety. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating the electronic exterior rearview mirror field of view adjustment method of the present invention;

[0038] Figure 2 This is a schematic diagram of the visible horizontal field of view angle of the trailer according to the present invention;

[0039] Figure 3 This is a schematic diagram illustrating the maximum front wheel steering angle division of the present invention. Detailed Implementation

[0040] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The drawings are for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention.

[0041] In the process described in the specification, claims, or drawings of this invention, each step is numbered (e.g., step 10, 20, etc.). These numbers are used only to distinguish the steps and do not represent any execution order. It should be noted that the terms "first," "second," etc., used herein are only for distinguishing the objects being described and do not represent a chronological order, nor do they indicate that "first," "second," etc., are different types.

[0042] like Figure 1 As shown, this embodiment provides a method for adjusting the field of view display of an electronic exterior rearview mirror, including:

[0043] Step 1: Obtain the current front wheel steering angle β of the trailer tractor.

[0044] In this embodiment, step 1 includes:

[0045] Step 101: Obtain the current steering wheel rotation angle α;

[0046] Step 102: Determine the current front wheel steering angle β based on the ratio γ of the steering wheel to the front wheel steering angle.

[0047] In this embodiment, the current front wheel steering angle β is determined according to a first preset formula:

[0048] β = round(α / γ)

[0049] Where β represents the current front wheel steering angle, α represents the current steering wheel rotation angle, and round() represents rounding operation.

[0050] For example, when γ = 12, if the steering wheel angle α = 350°, then the corresponding front wheel steering angle β = round(350 / 12) = 29°; if the steering wheel angle α = 356°, then the corresponding front wheel steering angle β =

[0051] round(356 / 12) = 30°.

[0052] Step 2: Adjust the display field of view of the electronic exterior rearview mirror according to the current front wheel steering angle β.

[0053] In this embodiment, step 2 includes:

[0054] Step 201: Obtain the corresponding preset field of view adjustment parameters based on the current carriage length. The preset field of view adjustment parameters include: angle field of view relationship, number of large areas, and unit angle pixel cropping amount in each large area.

[0055] In this embodiment, the calibration steps for the angular field of view relationship include:

[0056] Step 201a: Calibrate and save the angular relationship between the front wheel steering angle of the tractor and the visible horizontal field of vision of the trailer for different lengths.

[0057] In this embodiment, the visible horizontal field of view angle of the trailer refers to the angle between the line connecting the far end of the trailer body and the center of the camera on the same side of the electronic rearview mirror, and the maximum boundary line of the camera's field of view (FOV) on the same side. For example... Figure 2 As shown, point A is the end of the trailer, point O is the center of the camera on the same side, and OB is the maximum boundary line of the FOV on the same side of the camera. Then ∠AOB is the horizontal field of view angle visible to the trailer.

[0058] For example, if the trailer bed is 13 meters long and the camera's field of view (FOV) is 118°, then:

[0059] When the steering angle of the front wheels of the tractor is 0 degrees, the horizontal field of vision of the trailer is 81.03°.

[0060] When the front wheel steering angle of the tractor is 15 degrees, the horizontal field of vision of the trailer is 57.68 degrees.

[0061] When the front wheel steering angle of the tractor is 30 degrees, the horizontal field of vision of the trailer is 32.56 degrees.

[0062] When the front wheel steering angle of the tractor is 45 degrees, the horizontal field of vision of the trailer is 4.04.

[0063] Step 201b: Divide the maximum front wheel steering angle of the tractor into unit angles according to the angle-view relationship, and divide the first number of unit angles into a large region to obtain a second number of large regions.

[0064] In practice, the value of the first quantity can be adjusted based on the camera resolution and the default field of view. For example, if the maximum front wheel steering angle ω is 45°, it can be divided into 45 unit angles (i.e., each 1° is one unit angle); if the first quantity n equals 5, it means that each 5 unit angles is divided into a large area, resulting in 9 large areas (i.e., the second quantity m = 9), which are sequentially denoted as large areas 1 to 9, such as... Figure 3 As shown.

[0065] Step 201c: Set the unit angle pixel cropping amount X within each of the large regions. q (q = 1, 2, 3…m).

[0066] In this embodiment, the unit angle pixel cropping amount in each of the large regions increases sequentially, that is: the unit angle pixel cropping amount of the large region number q+1 is greater than the unit angle pixel cropping amount of the large region number q.

[0067] For example, in large region 1, the cropping amount per unit angle pixel x1 is 17 pixels; in large region 2, the cropping amount per unit angle pixel x2 is 18 pixels, and so on, with large region 9 having a cropping amount per unit angle pixel x9 of 25 pixels. Of course, other values ​​can be set for the cropping amount per unit angle pixel in each region according to actual requirements.

[0068] Step 202: Determine the target total pixels P for cropping based on the current front wheel steering angle β and the preset field of view adjustment parameters.

[0069] In this embodiment, step 202 includes:

[0070] Step 202a: Determine the target area j to which the current front wheel steering angle β belongs based on the angle and field of vision relationship.

[0071] In this embodiment, the target large region j is determined according to a second preset formula:

[0072]

[0073] Where β represents the current front wheel steering angle, ω represents the maximum front wheel steering angle, and m represents the number of large regions. This indicates the rounding up operation.

[0074] For example, such as Figure 3 As shown, if the current wheel steering angle β = 29°, then the sequence number of the target area to which this angle belongs...

[0075] Step 202b: Based on the target large area j and the unit angle pixel cropping amount X i Determine the target total number of pixels P for cropping.

[0076] In this embodiment, the target total pixels P is determined according to a third preset formula:

[0077]

[0078] Where P represents the total number of target pixels, X k (k = i, j) represents the unit angle pixel cropping amount for a large region k.

[0079] Step 203: Read the field of view image, and crop the field of view image successively according to the number of pixels determined by the fourth preset formula until the total number of cropped pixels is the target total number of pixels P, and refresh the field of view image after each cropping to the display device of the electronic rearview mirror.

[0080] In this embodiment, the fourth preset formula is:

[0081] p(i,s)=p(i-1,n)+s*X i

[0082] Where p(i,s) represents the number of cropped pixels in the s-th small region within the large region i, i = 1, 2, 3…j-1, s ≤ n, p(0,s) = 0.

[0083] For example, if n = 5 and the current wheel steering angle β = 29°, then:

[0084] When i=1 and s=1: p(1,1)=p(0,5)+1*X1=0+1*17;

[0085] When i=1 and s=2: p(1,2)=p(0,5)+2*X1=0+2*17;

[0086] ...

[0087] When i=1 and s=5: p(1,5)=p(0,5)+5*X1=0+5*17;

[0088] When i=2 and s=1: p(2,1)=p(1,5)+1*X2=85+1*18;

[0089] When i=2 and s=2: p(2,2)=p(1,5)+2*X2=85+2*18;

[0090] ...

[0091] When i=2 and s=5: p(2,5)=p(1,5)+5*X2=85+5*18;

[0092] ...

[0093] p(6,4)=p(5,5)+4*X2=p(5,5)+4*22.

[0094] In this way, the field of vision image is cropped in real time as the steering wheel is turned, and the display image of the electronic rearview mirror is refreshed after each cropping, thus achieving smooth movement of the field of vision.

[0095] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for adjusting the field of view display of an electronic exterior rearview mirror, characterized in that, include: Step 1: Obtain the current front wheel steering angle of the trailer tractor; Step 2: Adjust the display field of view of the electronic exterior rearview mirror according to the current front wheel steering angle; Step 2 includes: Step 201: Obtain the corresponding preset field of view adjustment parameters based on the current carriage length. The preset field of view adjustment parameters include: angle field of view relationship, number of large areas, and unit angle pixel cropping amount in each large area. The calibration steps for the angle-view relationship include: Step 201a: Calibrate and save the angular relationship between the front wheel steering angle of the tractor and the visible horizontal field of vision of the trailer for different lengths; Step 201b: Divide the maximum front wheel steering angle of the tractor into unit angles according to the angle-view relationship, and divide the first number of unit angles into a large region to obtain a second number of large regions; Step 201c: Set the unit angle pixel cropping amount within each of the large regions; Step 202: Determine the target total pixels for cropping based on the current front wheel steering angle and preset field of view adjustment parameters, including: Step 202a: Determine the target area to which the current front wheel steering angle belongs based on the angle and field of vision relationship; Step 202b: Determine the total number of target pixels to be cropped based on the target large area and the cropping amount per unit angle pixel; The target large area is determined according to the second preset formula: Where j represents the index of the target large region, β represents the current front wheel steering angle, ω represents the maximum front wheel steering angle, and m represents the number of large regions. This indicates the rounding up operation; The total target pixels are determined according to a third preset formula: Where P represents the total number of pixels in the target, n is the number of units per angle in each large region, and X... k (k=i,j) represents the number of pixels to be clipped per unit angle in a large region k; Step 203: Read the field of view image, and crop the field of view image successively according to the number of pixels determined by the fourth preset formula until the total number of pixels cropped is the target total number of pixels, and refresh the field of view image after each cropping to the display device of the electronic rearview mirror. The fourth preset formula is: Where p(i,s) represents the number of cropped pixels in the s-th sub-region within the large region i, i=1,2,3…j-1, s≤n, p(0,s)=0.

2. The electronic exterior rearview mirror field of view adjustment method according to claim 1, characterized in that, Step 1 includes: Step 101: Obtain the current steering wheel rotation angle; Step 102: Determine the current front wheel steering angle based on the ratio of the steering wheel angle to the front wheel steering angle.

3. The electronic exterior rearview mirror field of view adjustment method according to claim 2, characterized in that, The current front wheel steering angle is determined according to a first preset formula: β = round(α / γ) Where β represents the current front wheel steering angle, α represents the current steering wheel rotation angle, and round() represents rounding operation.

4. The electronic exterior rearview mirror field of view adjustment method according to claim 1, characterized in that, The amount of pixel cropping per unit angle within each of the aforementioned large regions increases sequentially.

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