A method and system for determining the field of view of an electronic exterior rearview mirror system

Abstract

The present invention discloses a method and system for determining the field of view of an electronic exterior rearview mirror system, including determining the field of view of the camera of the electronic exterior rearview mirror system according to the pixel value of the camera lens of the electronic exterior rearview mirror, the size of the image displayed on the display screen of the electronic exterior rearview mirror, and the field of view of the captured image; and determining the field of view of the display screen of the electronic exterior rearview mirror system according to the gear position, speed, turn signal state, and steering angle state of the vehicle. By using the method and system of the present invention, the field of view of a suitable lens can be selected so that the display effect and adjustment area of ​​the electronic exterior rearview mirror can meet the requirements; at the same time, the field of view displayed on the display screen can be changed according to the real-time driving conditions of the vehicle, providing the driver with a wider field of view, and the field of view adjustment can be made continuous and smooth during the field of view adjustment process, thereby improving driving safety.

Description

Technical Field

[0001] The invention belongs to the technical field of FOV calculation and field of view adjustment of an electronic exterior rearview mirror, and in particular relates to a method and system for determining the field of view of an electronic exterior rearview mirror system. Background Art

[0002] At present, domestic cars all use traditional mechanical rearview mirrors. The present invention uses digital exterior rearview mirrors, and uses cameras and monitors to replace traditional mechanical exterior rearview mirrors. Since cameras are used to replace traditional rearview mirrors, the field of view that the driver can see depends not only on the size of the camera lens FOV (field of view), but also on the range of the camera field of view that we crop. If the lens is too large, the image object presented to the rearview mirror will be too small, which will affect the driver's judgment; but if the lens is too small, the adjustable range of the rearview mirror will be too small, and the advantages of the electronic exterior rearview mirror cannot be reflected. If the FOV of the appropriate lens cannot be selected, it will easily lead to the display effect and adjustment area of ​​the electronic exterior rearview mirror not meeting the requirements.

[0003] At the same time, since the electronic exterior rearview mirror provides a continuously variable field of view, the displayed field of view changes according to the real-time situation of the vehicle, providing the driver with a wider field of view. Therefore, how to find a method to select a range suitable for the size of the lens FOV and provide a method for adjusting the field of view has become an urgent problem to be solved. At the same time, it is also necessary to solve the problem of ensuring the continuity and stability of the picture when adjusting the field of view. Summary of the invention

[0004] A method for determining the field of view of an electronic exterior rearview mirror system to achieve one of the objectives of the present invention comprises the following steps:

[0005] Step 1, obtaining the pixel value of the camera lens of the electronic exterior rearview mirror, the size of the image displayed on the display screen of the electronic exterior rearview mirror, and the field of view of the captured image;

[0006] The captured image is an image captured by the display screen from a partial area of ​​the image captured by the camera and displayed on the screen;

[0007] Step 2, calculating the field of view of the camera lens of the electronic exterior rearview mirror system according to the pixel value of the camera lens obtained in the above step, the size of the image displayed on the display screen, and the field of view value of the intercepted image;

[0008] Furthermore, in the above step 2, the field of view of the camera lens of the electronic exterior rearview mirror is calculated by the following formula:

[0009]

[0010] Where:

[0011] Indicates the field of view of the camera lens of the electronic exterior rearview mirror system, in degrees;

[0012] H represents the width of the camera pixel of the electronic exterior rearview mirror system;

[0013] h represents the image width of the image captured by the display screen of the electronic exterior rearview mirror system;

[0014] α represents the field of view angle of the image captured by the display screen of the electronic exterior rearview mirror system;

[0015] Furthermore, the method further comprises:

[0016] Get the vehicle's gear position, speed, turn signal status, and vehicle steering angle status;

[0017] The field of view of the display screen of the electronic exterior rearview mirror system is determined according to the vehicle's gear position, speed, turn signal status and vehicle steering angle status.

[0018] Furthermore, the method for determining the field of view of the display screen of the electronic exterior rearview mirror system includes:

[0019] When the vehicle is traveling at a low speed or is stationary: when the turn signal is on and / or the steering angle is greater than the set angle, the field of view of the electronic exterior rearview mirror display screen on the turning side indicated by the turn signal and / or the steering angle is enlarged;

[0020] The vehicle is traveling at a low speed, i.e., the vehicle speed is less than a first set value; the vehicle is in a stationary state, i.e., the vehicle gear is in P gear or N gear, and the vehicle speed is less than a third set value;

[0021] The first setting value may be 50 km / h, but is not limited to this value; the third setting value may be 2 km / h, but is not limited to this value.

[0022] When the vehicle is in reverse gear, the lower field of view of the display screens of the left and right electronic exterior mirrors is expanded at the same time; that is, the image field of the left and right display screens changes from the original middle area of ​​the camera image to the area below the camera image;

[0023] When the vehicle speed is greater than the second set value, the fields of view displayed on the left and right display screens are expanded at the same time; that is, the image field of the left display screen changes from the original middle area of ​​the camera image to the area to the left of the camera; the image field of the right display screen changes from the original middle area of ​​the camera image to the area to the right of the camera;

[0024] When the vehicle is in the forward gear, when the turn signal is on and / or the steering angle is greater than the set angle value, the field of view of the electronic exterior rearview mirror display screen on the side indicated by the turn signal and / or the steering angle is expanded; that is, when the turn signal and / or the steering angle points to the left, the image field of the left display screen changes from the original middle area of ​​the camera image to the area to the left of the camera; when the turn signal and / or the steering angle points to the right, the image field of the right display screen changes from the original middle area of ​​the camera image to the area to the right of the camera;

[0025] When the turn signal is turned off, the field of view of the electronic exterior rearview mirror display screen is restored to the default field of view of the camera; the default field of view is: the partial area of ​​the camera displayed by the electronic exterior rearview mirror without the influence of other signals. Usually, the display screen captures the area centered on the top, bottom, left and right of the image taken by the electronic exterior rearview mirror as the default field of view. The influences of other signals include turn signals, steering angle, vehicle speed and reversing signals.

[0026] During the process of expanding the field of view, the adjusted field of view FOV value increases by 10-20° compared to the value before adjustment, and the 10-20° is selected or calibrated according to the actual situation. The expanded field of view is a temporary field of view, which is used to temporarily increase the display range of the display screen. The basis for the field of view expansion display is that if the field of view needs to be enlarged on the left, it needs to be expanded to the left field of view, and if the field of view needs to be enlarged on the right, it needs to be expanded to the right field of view.

[0027] Furthermore, during the adjustment process of expanding and reducing the field of view, the pixel step size of each adjustment is set to a first set step size value, and the first set step size value can be set or calibrated according to actual needs.

[0028] Furthermore, during the field of view adjustment process, the pixel step size of each adjustment is set to 5 pixels.

[0029] The electronic exterior rearview mirror field of view calculation and adjustment system for achieving the second object of the present invention comprises an electronic exterior rearview mirror camera field of view determination module and an electronic exterior rearview mirror display field of view determination module;

[0030] The electronic exterior rearview mirror camera field of view determination module is used to calculate the field of view angle value of the camera lens of the electronic exterior rearview mirror system according to the pixel value of the camera lens of the electronic exterior rearview mirror, the size of the image displayed on the display screen of the electronic exterior rearview mirror, and the field of view value of the intercepted image;

[0031] The electronic exterior rearview mirror display screen field of view determination module is used to determine the field of view of the display screen of the electronic exterior rearview mirror system based on the horizontal field of view value of the camera lens of the electronic exterior rearview mirror obtained by the electronic exterior rearview mirror camera field of view determination module, the vehicle's gear position, vehicle speed, turn signal status and vehicle steering angle status.

[0032] The method for calculating the horizontal field of view value of the camera lens of the electronic exterior rearview mirror system in the electronic exterior rearview mirror camera field of view determination module includes:

[0033]

[0034] Where:

[0035] Indicates the field of view value of the camera lens of the electronic exterior rearview mirror system;

[0036] H represents the width of the camera pixel of the electronic exterior rearview mirror system;

[0037] h represents the image width of the image captured by the display screen of the electronic exterior rearview mirror system;

[0038] α represents the field of view angle value of the image captured by the display screen of the electronic exterior rearview mirror system.

[0039] In the electronic exterior rearview mirror display screen field of view determination module, the method for determining the display screen field of view includes:

[0040] When the vehicle is traveling at a low speed or is stationary: when the turn signal is on and / or the steering angle is greater than the set angle, the field of view of the electronic exterior rearview mirror display screen on the turning side indicated by the turn signal and / or the steering angle is enlarged;

[0041] When the vehicle is in reverse gear, the field of view below the display screens of the left and right electronic exterior mirrors is expanded simultaneously;

[0042] When the vehicle speed is greater than a second set value, the field of view displayed on the left and right display screens is expanded simultaneously; the second set value may be 55 km / h, but is not limited to this value;

[0043] When the vehicle is in the forward gear and the turn signal is on and / or the steering angle is greater than a set angle value, the field of view of the electronic exterior rearview mirror display screen on the side indicated by the turn signal and / or the steering angle is expanded; the set angle can be set or calibrated according to actual conditions.

[0044] Beneficial effects:

[0045] By using the method and system of the present invention, the FOV of a suitable lens can be selected so that the display effect and adjustment area of ​​the electronic exterior rearview mirror can meet the requirements. At the same time, the field of view displayed on the display screen can be changed according to the real-time driving conditions of the vehicle, providing the driver with a wider field of view. At the same time, the field of view can be adjusted continuously and smoothly during the field of view adjustment process, thereby improving driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the process of the method of the present invention;

[0047] Figure 2 It is a system block diagram of a digital exterior rearview mirror;

[0048] Figure 3 This is a schematic diagram of the camera pixels and display pixels under the default field of view;

[0049] Figure 4 It is a schematic diagram of the camera pixels and display screen pixels when the vehicle's left turn signal is turned on;

[0050] Figure 5 It is a schematic diagram of the camera pixels and display screen pixels when the vehicle is in reverse gear. DETAILED DESCRIPTION

[0051] The following specific implementations are used to explain the technical solutions of the claims of the present invention so that those skilled in the art can understand the claims. The protection scope of the present invention is not limited to the following specific implementation structures. The technical solutions of the claims of the present invention made by those skilled in the art but different from the following specific implementations are also within the protection scope of the present invention.

[0052] The system block diagram of the digital exterior rearview mirror is as follows: Figure 2 As shown, it mainly includes two cameras located on both sides of the vehicle, two display screens for displaying the left and right fields of view outside the vehicle, and a controller. The present invention includes a method for determining the field of view of the camera in the digital exterior rearview mirror system and a method for determining the field of view of the display screens on both sides.

[0053] Embodiment 1

[0054] Step 1, obtaining the pixel value of the camera lens of the electronic exterior rearview mirror, the size of the image displayed on the display screen of the electronic exterior rearview mirror, and the field of view of the captured image;

[0055] The pixel of the camera selected in this embodiment is 200w, and its aspect ratio is 1920*1680. We need to select the pixel point displayed on the display screen to be 900*540, and its corresponding display horizontal FOV is 35°. The specific display effect is as follows Figure 3 As shown, it is displayed in the center in the default state, which is the default field of view of the display screen. That is, the electronic exterior rearview mirror displays a part of the image captured by the camera without the influence of other signals, and the influence of other signals includes turn signal, steering angle, vehicle speed and reversing signal.

[0056] Step 2: Calculate the field of view of the camera lens of the electronic exterior rearview mirror system according to the pixel value of the camera lens obtained in the above step, the size of the image displayed on the display screen, and the field of view value of the captured image. The calculation method is shown in the following formula:

[0057]

[0058] Where:

[0059] H represents the pixel width of the electronic exterior rearview mirror system camera, which is 1920 in this embodiment;

[0060] h represents the image width of the image captured by the display screen of the electronic exterior rearview mirror system, which is 900 in this embodiment;

[0061] α represents the field of view of the image captured by the display screen of the electronic exterior rearview mirror system, which is 35° in this embodiment.

[0062] The above formula shows that the horizontal field of view of a lens with an aspect ratio of 1920*1080 is 68°, so the camera lens field of view to be selected is 68°. This field of view is the horizontal field of view angle value. In actual application, there may not be a lens with the same field of view value as the calculated result. Therefore, as long as the horizontal field of view is greater than this calculated value, the requirements described in the above step 1 can be met.

[0063] Combine the following Figure 1 Another embodiment of the method of the present invention is described:

[0064] Embodiment 2

[0065] Step 1: Obtain the vehicle's gear position, speed, turn signal status, and vehicle steering angle status;

[0066] Step 2: Determine the field of view of the display screen of the electronic exterior rearview mirror system according to the vehicle's gear position, speed, turn signal status, and vehicle steering angle status. The specific method is as follows:

[0067] In this embodiment, the side pointed by the vehicle turn signal or the steering angle is preset as the vehicle turning side, and the field of view of the display screen of the electronic exterior rearview mirror system is determined according to the following scenarios respectively;

[0068] 1. When the vehicle is traveling at a low speed or stationary

[0069] In this embodiment, the vehicle speed is less than 3 km / h, which means the vehicle is in a low-speed state; the vehicle gear is in P gear or N gear and the vehicle speed is less than 2 km / h, which means the vehicle is in a stationary state;

[0070] The electronic exterior rearview mirror obtains the turn signal status from the vehicle. If the turn signal is on or the steering angle is greater than the set value, the field of view of the display screen on the vehicle's steering side is expanded, that is, the corresponding pixels become more, that is, the display screen of the electronic exterior rearview mirror on the vehicle's steering side captures the image of the electronic exterior rearview mirror on the steering side. In this embodiment, taking the left turn signal on or the left steering angle greater than the set value as an example, the pixels captured by the left display screen are directly to the leftmost image, and the field of view on the left display screen will be expanded from Figure 3 The default view shown changes to Figure 4 As shown, the field of view of the left display screen changes from the original 900*540 image centered vertically and horizontally to a 1410*540 image that is biased to the left and centered vertically and horizontally. Figure 4 The light background in the middle shows the total pixels of the camera, and the dark background on the left shows the pixels captured and displayed on the left display screen;

[0071] 2. When the vehicle gear is in R gear

[0072] When the system detects that the vehicle is in reverse gear, in order to reflect the advantages of the electronic rearview mirror, the vehicle tires can be displayed to improve the safety of reversing. When the vehicle is in reverse, the display field of view on the left and right screens needs to be expanded at the same time. The image area displayed on the left and right screens will be changed from Figure 3 becomes Figure 5 As shown, the field of view changes from the original 900*540 image centered vertically and horizontally to a 900*910 image that is lower and centered horizontally; when the FOV is selected and arranged, the bottom pixel needs to be able to display the tire.

[0073] 3. When the vehicle is moving forward

[0074] If the following signals are detected, adjust the image according to the following requirements; if the following signals are not detected, keep the following Figure 3 The default view shown,

[0075] 1) When the vehicle speed signal is detected to be over 55km / h, the fields of view displayed on the left and right display screens need to be expanded, that is, the field of view of the left display screen changes from the original vertically centered image to an image that is biased to the left and vertically centered image; the field of view of the right display screen changes from the original vertically centered image to an image that is biased to the right and vertically centered image;

[0076] 2) When the vehicle speed is lower than 50km / h, if the turn signal is detected or the steering angle is greater than the set value, the field of view of the display screen on the steering side will be expanded. That is, when the vehicle is turning to the left, the field of view of the left display screen changes from the original centered image to an image that is biased to the left and centered up and down; when the vehicle is turning to the right, the field of view of the right display screen changes from the original centered image to an image that is biased to the right and centered up and down.

[0077] Furthermore, since the range of field of view expansion is relatively large, directly capturing the changes in the field of view will cause fragmentation in the process of field of view adjustment. Therefore, in the process of field of view enlarging and reducing, it is necessary to set the step size of pixels for each adjustment. In this embodiment, the step size is set to 5 pixels. This ensures the continuity of the field of view during the adjustment process and does not affect the driver's judgment of the field of view.

[0078] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0079] This embodiment also provides a system embodiment, including an electronic exterior rearview mirror camera field of view determination module and an electronic exterior rearview mirror display field of view determination module;

[0080] The electronic exterior rearview mirror camera field of view determination module is used to calculate the horizontal field of view value of the camera lens of the electronic exterior rearview mirror system according to the pixel value of the camera lens of the electronic exterior rearview mirror, the size of the image displayed on the display screen of the electronic exterior rearview mirror, and the field of view value of the intercepted image; the calculation method includes:

[0081]

[0082] Where:

[0083] Indicates the horizontal field of view of the camera lens of the electronic exterior rearview mirror system;

[0084] H represents the width of the camera pixel of the electronic exterior rearview mirror system;

[0085] h represents the image width of the image captured by the display screen of the electronic exterior rearview mirror system;

[0086] α represents the field of view angle value of the image captured by the display screen of the electronic exterior rearview mirror system.

[0087] The electronic exterior rearview mirror display screen field of view determination module is used to determine the field of view of the display screen of the electronic exterior rearview mirror system according to the vehicle gear position, vehicle speed, turn signal state and vehicle steering angle state. The method for determining the display screen field of view includes:

[0088] When the vehicle speed is lower than 3 km / h or the vehicle gear is in P gear or N gear, if it is detected that the turn signal is turned on and / or the steering angle is greater than the set angle, the field of view of the electronic exterior rearview mirror display screen on the turning side indicated by the turn signal and / or the steering angle is enlarged; the set angle can be set or calibrated according to actual conditions;

[0089] When the vehicle is in reverse gear, the field of view below the display screens of the left and right electronic exterior mirrors is expanded simultaneously;

[0090] When the vehicle is in the forward gear and the turn signal is on and / or the steering angle is greater than the set angle value, the field of view of the electronic exterior rearview mirror display screen on the side indicated by the turn signal and / or the steering angle is expanded.

[0091] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A method for determining the field of view of an electronic exterior rearview mirror system, characterized in that: The steps include: Step 1, obtaining the pixel value of the camera lens of the electronic exterior rearview mirror, the size of the image displayed on the display screen of the electronic exterior rearview mirror, and the field of view of the captured image; Step 2, calculating the field of view of the camera lens of the electronic exterior rearview mirror system according to the pixel value of the camera lens obtained in the above step, the size of the image displayed on the display screen, and the field of view value of the intercepted image; The method for calculating the field of view of the camera lens of the electronic exterior rearview mirror system in step 1 includes: Where: Indicates the field of view of the camera lens of the electronic exterior rearview mirror system, in degrees; H represents the width of the camera pixel of the electronic exterior rearview mirror system; h represents the image width of the image captured by the display screen of the electronic exterior rearview mirror system; α represents the field of view angle value of the image captured by the display screen of the electronic exterior rearview mirror system.

2. The method for determining the field of view of an electronic exterior rearview mirror system according to claim 1, characterized in that: The method further comprises: Get the vehicle's gear position, speed, turn signal status, and vehicle steering angle status; The field of view of the display screen of the electronic exterior rearview mirror system is determined according to the vehicle's gear position, speed, turn signal status and vehicle steering angle status.

3. The method for determining the field of view of an electronic exterior rearview mirror system according to claim 2, characterized in that: The method for determining the field of view of a display screen of an electronic exterior rearview mirror system comprises: When the vehicle is traveling at a low speed or stationary: when the turn signal is on and / or the steering angle is greater than the set angle, the field of view of the electronic exterior rearview mirror display screen on the turning side indicated by the turn signal and / or steering angle is expanded.

4. The method for determining the field of view of an electronic exterior rearview mirror system according to claim 2, characterized in that: The method for determining the field of view of a display screen of an electronic exterior rearview mirror system comprises: When the vehicle is in reverse gear, the field of view below the display screens of the left and right electronic exterior mirrors is expanded at the same time.

5. The method for determining the field of view of an electronic exterior rearview mirror system according to claim 2, characterized in that: The method for determining the field of view of a display screen of an electronic exterior rearview mirror system comprises: When the vehicle speed is greater than a second set value, the fields of view displayed on the left and right display screens are expanded simultaneously; When the vehicle is in the forward gear and the turn signal is on and / or the steering angle is greater than the set angle value, the field of view of the electronic exterior rearview mirror display screen on the side indicated by the turn signal and / or the steering angle is expanded.

6. The method for determining the field of view of an electronic exterior rearview mirror system according to claim 2, characterized in that: The method for determining the field of view of a display screen of an electronic exterior rearview mirror system comprises: When the vehicle is traveling at a low speed or is stationary: when the turn signal is on and / or the steering angle is greater than the set angle, the field of view of the electronic exterior rearview mirror display screen on the turning side indicated by the turn signal and / or the steering angle is enlarged; When the vehicle is in reverse gear, the field of view below the display screens of the left and right electronic exterior mirrors is expanded simultaneously; When the vehicle speed is greater than a second set value, the fields of view displayed on the left and right display screens are expanded simultaneously; When the vehicle is in the forward gear and the turn signal is on and / or the steering angle is greater than the set angle value, the field of view of the electronic exterior rearview mirror display screen on the side indicated by the turn signal and / or the steering angle is expanded.

7. The method for determining the visual field of an electronic exterior rearview mirror system according to any one of claims 2 to 6, characterized in that: During the process of expanding the field of view, the pixel step length of each adjustment is set to the set step length value.

8. A system for determining the field of view of an electronic exterior rearview mirror system, characterized in that: It includes an electronic exterior rearview mirror camera field of view determination module and an electronic exterior rearview mirror display field of view determination module; The electronic exterior rearview mirror camera field of view determination module is used to calculate the field of view of the camera lens of the electronic exterior rearview mirror system according to the acquired pixel value of the camera lens of the electronic exterior rearview mirror, the size of the image displayed on the display screen of the electronic exterior rearview mirror, and the field of view of the intercepted image; The electronic exterior rearview mirror display screen field of view determination module is used to determine the field of view of the display screen of the electronic exterior rearview mirror system according to the gear position, vehicle speed, turn signal state and vehicle steering angle state of the vehicle; The method for calculating the horizontal field of view value of the camera lens of the electronic exterior rearview mirror in the electronic exterior rearview mirror camera field of view determination module includes: Where: Indicates the field of view of the camera lens of the electronic exterior rearview mirror system, in degrees; H represents the width of the camera pixel of the electronic exterior rearview mirror system; h represents the image width of the image captured by the display screen of the electronic exterior rearview mirror system; α represents the field of view angle value of the image captured by the display screen of the electronic exterior rearview mirror system.

Images