Hinge angle determination method, visual field adjustment method, control unit, electronic outside rear-view mirror device and trailer

Abstract

The invention provides a hinged angle determining method, a view adjusting method, a control unit, an electronic outside rear-view mirror device and a trailer. The hinged angle determining method comprises the steps that the first size of a first trailer under the full view of a camera at the minimum hinged angle and the second size of the first trailer under the full view of the camera at the maximum hinged angle are obtained; acquiring a third size of the first trailer under the full view of the camera at the current calculation moment; obtaining a first hinge angle based on the first size, the second size, the third size and the maximum hinge angle; acquiring vehicle body data and motion data of the trailer at the current calculation moment; a second hinge angle of the trailer at the last calculation moment is obtained; obtaining a third hinge angle based on the vehicle body data, the motion data and the second hinge angle; and determining a fourth hinge angle at the current calculation moment based on the first hinge angle and the third hinge angle. An angle sensor is not needed to measure the hinge angle, and hardware cost is reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of measurement and display technology, and specifically to a method for determining an articulation angle, a method for adjusting a field of view, a control unit, an electronic exterior rearview mirror device, and a trailer. Background Art

[0002] As an innovative product in the field of indirect vision devices that replace traditional physical mirrors, the Camera-Monitor System (CMS) collects road condition information on both sides of the vehicle through cameras and displays it in real time on the in-vehicle monitor. This system can not only effectively expand the driver's field of vision, improve the rear view effect in bad weather conditions, and make up for the blind spots of traditional physical mirrors, but also reduce the vehicle's air resistance, providing important auxiliary support for future smart cockpits and autonomous driving.

[0003] However, in the application scenario of semi-trailers, since the position of the camera of the tractor is fixed during the turning process, if the field of view cut-off position is not dynamically adjusted and displayed, the CMS display screen will often display the trailer body information, while the driver is more concerned about the status changes of the rear position. Therefore, in order to ensure that the driver can accurately judge the rear position of the vehicle, it is necessary to dynamically adjust the field of view cut-off position according to the changes in the body during the turning process, so that the rear of the trailer is always in the picture of the display screen.

[0004] In order to keep the rear of the trailer in the display screen during the turn, the key is to accurately track the position of the rear of the trailer and make corresponding field of view follow-up adjustments. This requires accurate acquisition of the articulation angle of the tractor and trailer at the saddle during the turn. At present, the main method of obtaining the articulation angle is to directly measure it by installing special sensor hardware. Such sensors are usually arranged at the connection between the tractor and the trailer (such as the saddle position). They can monitor the relative angle changes between the two in real time and feed the data back to the control system, thereby realizing the adjustment of the dynamic field of view cutting position. Although this method can provide higher measurement accuracy, it relies on additional hardware equipment, which not only increases the complexity of the system, but also significantly increases the hardware cost. Summary of the invention

[0005] The embodiments of the present invention provide a method for determining an articulation angle, a method for adjusting a field of view, a control unit, an electronic exterior rearview mirror device, and a trailer, which can reduce the cost of determining an articulation angle.

[0006] In a first aspect, an embodiment of the present application provides a method for determining an articulation angle, which is applied to a semi-trailer truck. The semi-trailer truck includes a tractor, a first trailer, and an electronic outside rearview mirror device. The electronic outside rearview mirror device includes a camera. The determination method includes: obtaining a first dimension of the first trailer in the full field of view of the camera at a minimum articulation angle, and a second dimension of the first trailer in the full field of view of the camera at a maximum articulation angle; obtaining a third dimension of the first trailer in the full field of view of the camera at the current calculation moment; obtaining a first articulation angle based on the first dimension, the second dimension, the third dimension, and the maximum articulation angle; obtaining the body data and motion data of the semi-trailer truck at the current calculation moment; obtaining a second articulation angle of the semi-trailer truck at the previous calculation moment; obtaining a third articulation angle based on the body data, the motion data, and the second articulation angle; and determining a fourth articulation angle at the current calculation moment based on the first articulation angle and the third articulation angle.

[0007] In one or more embodiments, the obtaining a first dimension of the first trailer in the full field of view of the camera at a minimum articulation angle, and a second dimension of the first trailer in the full field of view of the camera at a maximum articulation angle includes: after the electronic outside rearview mirror device is powered on, obtaining a first pixel coordinate value of the rear of the first trailer in the full field of view of the camera; obtaining a calibration data set, where the calibration data set includes first pixel coordinate information of a first area in the full field of view of the camera, and second pixel coordinate values of the rears of second trailers with different lengths in the full field of view of the camera at a minimum articulation angle and a maximum articulation angle, where the first area is the area obtained for all second trailers with different lengths in the full field of view of the camera; obtaining a third pixel coordinate value of the rear of the first trailer in the full field of view of the camera at a minimum articulation angle and a fourth pixel coordinate value of the rear of the first trailer in the full field of view of the camera at a maximum articulation angle based on the first pixel coordinate value and the calibration data set; obtaining the first dimension based on the third pixel coordinate value and the first pixel coordinate information; and obtaining the second dimension based on the fourth pixel coordinate value and the first pixel coordinate information.

[0008] In one or more embodiments, the electronic outside rearview mirror device further includes a display screen. The obtaining a first pixel coordinate value of the rear of the first trailer in the full field of view of the camera includes: obtaining a first screen coordinate value of the rear of the first trailer on the display screen; and performing coordinate conversion on the first screen coordinate value based on a preset coordinate conversion relationship between the imaging plane coordinate system of the camera and the display screen coordinate system of the display screen to obtain the first pixel coordinate value.

[0009] In one or more embodiments, the method for obtaining the coordinate conversion relationship includes: obtaining the second pixel coordinate information of the secondary field of view map under the full field of view map of the camera; obtaining the second screen coordinate value of the secondary field of view map on the display screen; and obtaining the coordinate conversion relationship based on the second pixel coordinate information and the second screen coordinate value.

[0010] In one or more embodiments, the vehicle body data includes a first distance between the front axle center and the rear axle center of the tractor, a second distance between the rear axle center of the tractor and the articulation point, and a third distance between the articulation point and the rear axle center of the first trailer. The motion data includes the time interval between the current calculation moment and the previous calculation moment, the front wheel angle of the semi-trailer truck, the vehicle speed of the semi-trailer truck, and the gear position of the semi-trailer truck. Obtaining the vehicle body data and the motion data of the semi-trailer truck at the current calculation moment includes: obtaining the steering wheel angle of the semi-trailer truck; obtaining the corresponding relationship between the steering wheel angle of the semi-trailer truck and the front wheel angle of the semi-trailer truck; and obtaining the front wheel angle of the semi-trailer truck based on the steering wheel angle of the semi-trailer truck and the corresponding relationship.

[0011] In one or more embodiments, obtaining the third articulation angle based on the vehicle body data, the motion data, and the second articulation angle includes: calculating the vehicle body data, the motion data, and the second articulation angle according to a preset calculation rule to obtain a fifth articulation angle; if the fifth articulation angle is less than 0, using 0 as the third articulation angle; if the fifth articulation angle is greater than the maximum articulation angle, using the maximum articulation angle as the third articulation angle; and if the fifth articulation angle is greater than or equal to 0 and less than or equal to the maximum articulation angle, using the fifth articulation angle as the third articulation angle.

[0012] In one or more embodiments, determining the fourth articulation angle at the current calculation moment based on the first articulation angle and the third articulation angle includes: obtaining the absolute value of the difference between the first articulation angle and the third articulation angle based on the first articulation angle and the third articulation angle; if the absolute value is less than or equal to a first threshold, using the third articulation angle as the fourth articulation angle; and if the absolute value is greater than the first threshold, using the minimum value of the first articulation angle and the third articulation angle as the fourth articulation angle.

[0013] Second aspect, an embodiment of the present application provides a field of view adjustment method, which is applied to a semi-trailer truck. The semi-trailer truck includes a tractor, a first trailer, and an electronic outside rearview mirror device. The electronic outside rearview mirror device includes a camera and a display screen. The adjustment method includes: determining a fourth articulation angle at the current calculation moment by using the determination method described in any embodiment of the first aspect; obtaining third pixel coordinate information of a second type of field of view map in the full field of view map of the camera at the previous calculation moment; determining fourth pixel coordinate information of the second type of field of view map in the full field of view map of the camera at the current calculation moment according to the fourth articulation angle, the third pixel coordinate information, and a preset display rule; cropping the full field of view map of the camera according to the fourth pixel coordinate information to obtain the second type of field of view map, and displaying the second type of field of view map on the display screen.

[0014] In one or more embodiments, the determining the fourth pixel coordinate information of the second type of field of view map in the full field of view map of the camera at the current calculation moment according to the fourth articulation angle, the third pixel coordinate information, and a preset display rule includes: if the fourth articulation angle is less than or equal to a second threshold, using the third pixel coordinate information as the fourth pixel coordinate information; if the fourth articulation angle is greater than the second threshold, obtaining a first size of the first trailer in the full field of view map of the camera at a minimum articulation angle, and a second size of the first trailer in the full field of view map of the camera at a maximum articulation angle, and obtaining the fourth pixel coordinate information according to the fourth articulation angle, the third pixel coordinate information, the first size, and the second size.

[0015] In one or more embodiments, if the fourth articulation angle is greater than the second threshold, the cropping the full field of view map of the camera according to the fourth pixel coordinate information to obtain the second type of field of view map, and displaying the second type of field of view map on the display screen includes: obtaining the number of display times; obtaining fifth pixel coordinate information of the second type of field of view map in the full field of view map of the camera each time based on the fourth pixel coordinate information and the number of display times; cropping the full field of view map of the camera in sequence based on each of the fifth pixel coordinate information to obtain the second type of field of view map each time, and sequentially displaying the second type of field of view map on the display screen.

[0016] In one or more embodiments, the display method further includes: displaying an icon for starting the field of view follow-up state on the display screen.

[0017] In a third aspect, an embodiment of the present application further provides a control unit, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and when the instructions are executed by the at least one processor, the at least one processor is enabled to execute the method according to any one of the first aspects.

[0018] In a fourth aspect, an embodiment of the present application further provides an electronic outside rearview mirror device, which includes a camera, a display screen, and the control unit according to the third aspect; the control unit is electrically connected to the camera and the display screen.

[0019] In a fifth aspect, an embodiment of the present application further provides a trailer, which includes a tractor, a first trailer, and the electronic outside rearview mirror device according to the fourth aspect; the electronic outside rearview mirror device is disposed on the tractor, and the tractor is connected to the first trailer.

[0020] In a sixth aspect, an embodiment of the present application further provides a computer-readable storage medium, which stores computer-executable instructions for causing a computer to execute the method according to the first aspect above.

[0021] In a seventh aspect, an embodiment of the present application further provides a computer program product, which includes a computer program stored on a computer-readable storage medium, and the computer program includes program instructions that, when executed by a computer, cause the computer to execute the method according to the first aspect above.

[0022] The beneficial effects of the present application are as follows: An embodiment of the present application provides a method for determining an articulation angle, a method for adjusting a field of view, a control unit, an electronic outside rearview mirror device, and a trailer. The method for determining the articulation angle includes: obtaining a first size of the first trailer in the full field of view of the camera at the minimum articulation angle, and a second size of the first trailer in the full field of view of the camera at the maximum articulation angle; obtaining a third size of the first trailer in the full field of view of the camera at the current calculation moment; obtaining a first articulation angle based on the first size, the second size, the third size, and the maximum articulation angle; obtaining the body data and motion data of the trailer at the current calculation moment; obtaining a second articulation angle of the trailer at the previous calculation moment; obtaining a third articulation angle based on the body data, the motion data, and the second articulation angle; and determining a fourth articulation angle at the current calculation moment based on the first articulation angle and the third articulation angle. The fourth articulation angle at the current calculation moment is comprehensively determined by the first articulation angle obtained through visual image measurement and the third articulation angle obtained by using a model, without using an angle sensor to measure the articulation angle, thereby reducing the hardware cost. Description of the Drawings

[0023] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated. The drawings in the figures do not constitute a scale limitation.

[0024] Figure 1 The structural block diagram of a semi-trailer provided by an embodiment of the present application;

[0025] Figure 2 The structural block diagram of an electronic outside rearview mirror device provided by an embodiment of the present application;

[0026] Figure 3 The flowchart of a method for determining an articulation angle provided by an embodiment of the present application;

[0027] Figure 4 A geometric model provided by an embodiment of the present application;

[0028] Figure 5 A full-view diagram provided by an embodiment of the present application;

[0029] Figure 6 A secondary field of view diagram provided by an embodiment of the present application;

[0030] Figure 7 The flowchart of a method for adjusting the field of view provided by an embodiment of the present application;

[0031] Figure 8 The structural block diagram of a control unit provided by an embodiment of the present application. Detailed implementation manners

[0032] For ease of understanding the present application, the following further describes the present application in detail with reference to the drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or there can be one or more intermediate elements therebetween. When an element is described as "electrically connected to" another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween. The terms "upper", "lower", "inner", "outer", "bottom", etc. used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for facilitating the description of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0033] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items. In addition, the technical features involved in different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0034] Refer to Figure 1 , Figure 1 is a structural block diagram of a semi-trailer provided by an embodiment of this application. As Figure 1 shown, the semi-trailer 100 includes: a tractor 10, a first trailer 20, and an electronic outside rearview mirror device 30. The electronic outside rearview mirror device 30 is provided on the tractor 10, and the tractor 10 is connected to the first trailer 20.

[0035] The tractor 10 refers to the front vehicle that provides power in the semi-trailer 100, usually a truck head or a power head. The first trailer 20 refers to a non-powered vehicle towed by the tractor 10, such as a cargo box, a tank, etc., for carrying goods.

[0036] The connection between the tractor 10 and the first trailer 20 means that the tractor 10 and the first trailer 20 are mechanically connected through a hinge mechanism such as a saddle.

[0037] The electronic outside rearview mirror device 30 is an electronic system that replaces a traditional optical rearview mirror. Refer to Figure 2 , the electronic outside rearview mirror device 30 includes a camera 31, a display screen 32, and a control unit 33. The control unit 33 is electrically connected to the camera 31 and the display screen 32.

[0038] The camera 31 is an image acquisition component, usually installed outside the tractor 10, such as on both sides of the tractor 10. It includes devices such as a CCD sensor and a CMOS sensor, and is used to capture images of the rear of the trailer and the side view of the semi-trailer.

[0039] The display screen 32 is an image display component, usually installed in the driving area of the tractor 10. By receiving the image signal processed by the control unit 33, it provides images of the side and / or rear road conditions for the driver. The display screen 32 can be a suitable screen such as an LED display screen, an LCD display screen, or an OLED display screen.

[0040] In the trailer 100, the control unit 33 acquires an image signal through the camera 31, processes the image signal, and then sends the image signal to the display screen 32 for display, so that the driver can observe the rear side view through the display screen 32. For example, the control unit 33 crops the full-field view acquired by the camera 31 to obtain an image signal of a second-class field of view, and sends it to the display screen 32, and the display screen 32 will display the second-class field of view. Since the position of the camera 31 is fixed on the trailer 100, during the turning process of the tractor 10, if the cropping position of the second-class field of view in the full-field view is not adjusted, the display screen 32 will display the body information of the trailer. However, what the driver generally pays attention to is the change of the position of the trailer tail during the turning process. Therefore, during the turning process of the tractor 10, it is necessary to dynamically adjust the cropping position of the second-class field of view in the full-field view so that the position of the trailer is always within the screen of the display screen 32, which is convenient for the subsequent driver to observe and judge.

[0041] To accurately track the position of the trailer tail and achieve accurate vision follow-up control, the key lies in obtaining the articulation angle at the saddle during the turning process of the tractor and the trailer in real time. There are currently two main implementation schemes: one is to directly measure the articulation angle by installing a dedicated angle sensor, but this method will increase the additional hardware cost; the other is to establish a specific calculation model for angle calculation. However, the existing models generally have the problem of cumulative errors, and in specific scenarios, there may be a large deviation between the calculated angle and the actual articulation angle, resulting in incorrect vision adjustment positions, and further causing poor user experiences such as stuttering or flashing during the adjustment process.

[0042] For the above reasons, the embodiments of the present application provide a method for determining an articulation angle, a vision adjustment method, a control unit, an electronic outside rearview mirror device, and a trailer. The fourth articulation angle at the current calculation moment is comprehensively determined by the first articulation angle measured by visual images and the third articulation angle calculated by using a model, reducing the calculation error of the model, and there is no need to use an angle sensor to measure the articulation angle, reducing the hardware cost.

[0043] In a first aspect, the embodiments of the present application provide a method for determining an articulation angle. The execution subject of the determination method is the control unit described in the present application. Refer to Figure 3 The determination method includes the following steps: Step S10: Obtain the first size of the first trailer in the full-field view of the camera at the minimum articulation angle, and the second size of the first trailer in the full-field view of the camera at the maximum articulation angle.

[0044] The articulation angle refers to the angle formed at the saddle connection between the tractor and the first trailer, that is, the angle between the geometric centerlines of the tractor and the first trailer. The geometric centerline of the tractor extends from the center of the front axle of the tractor to the center of the rear axle of the tractor, and the geometric centerline of the first trailer extends from the center of the front axle of the first trailer to the center of the rear axle of the first trailer. The articulation angle changes dynamically during vehicle driving. The minimum articulation angle of the tractor-trailer refers to the minimum value of the articulation angle, usually 0° or close to 0°, and the geometric centerlines of the tractor and the first trailer are basically coincident; the maximum articulation angle of the tractor-trailer refers to the maximum value of the articulation angle, which is limited by the vehicle mechanical structure, and the specific value depends on the physical design of the tractor-trailer and is not limited here. Among them, the center of the front axle of the tractor refers to the midpoint of the connection line of the wheel centers of the left and right front steering wheels of the tractor, the center of the rear axle of the tractor refers to the midpoint of the connection line of the wheel centers of the left and right rear drive wheels of the tractor, and the center of the rear axle of the first trailer refers to the midpoint of the connection line of the wheel centers of the left and right rear wheels of the first trailer.

[0045] The full-view image refers to the original captured image of the camera in the electronic outside rearview mirror device without any other image processing operations such as field-of-view cropping or digital zooming, that is, the original complete image within the maximum viewing angle directly captured by the sensor of the camera.

[0046] The first dimension refers to the horizontal pixel width of the first trailer in the full-view image of the camera when the tractor-trailer is at the minimum articulation angle, that is, the pixel value in the horizontal direction occupied in the full-view image of the camera. Specifically, the control unit can detect the image of the tractor-trailer at the minimum articulation angle to obtain the pixel distance between the leftmost and rightmost sides of the first trailer in the full-view image of the camera, that is, obtain the first dimension.

[0047] The second dimension refers to the horizontal pixel width of the first trailer in the full-view image of the camera when the tractor-trailer is at the maximum articulation angle, that is, the pixel value in the horizontal direction occupied in the full-view image of the camera. Specifically, the control unit can detect the image of the tractor-trailer at the maximum articulation angle to obtain the pixel distance between the leftmost and rightmost sides of the first trailer in the full-view image of the camera, that is, obtain the second dimension.

[0048] Step S20: Obtain the third dimension of the first trailer in the full-view image of the camera at the current calculation moment.

[0049] The third dimension refers to the horizontal pixel width of the first trailer in the full-view image of the camera when the tractor-trailer is at the articulation angle at the current calculation moment, that is, the pixel value in the horizontal direction occupied in the full-view image of the camera. Specifically, the control unit detects the image of the tractor-trailer at the articulation angle at the current calculation moment to obtain the pixel distance between the leftmost and rightmost sides of the first trailer in the full-view image of the camera, that is, obtain the third dimension.

[0050] Step S30: Obtain a first hinge angle based on a first dimension, a second dimension, a third dimension, and a maximum hinge angle.

[0051] Specifically, the first hinge angle can be calculated through the following formula:

[0052]

[0053] where θ1 is the first hinge angle at the current calculation moment, and W box (θ = 0) is the first dimension, and W box (θ = max) is the second dimension, and W box (t) is the third dimension, and θ max is the maximum hinge angle.

[0054] Step S40: Obtain the body data and motion data of the trailer at the current calculation moment.

[0055] The body data refers to the static information related to the physical structure, geometric state, and mechanical parameters of the trailer. Specifically, as Figure 4 shown, the body data includes a first distance m1 between the front axle center and the rear axle center of the tractor, a second distance m2 between the rear axle center of the tractor and the hinge point, and a third distance m3 between the hinge point and the rear axle center of the first trailer. Among them, the hinge point refers to the physical connection point between the tractor and the first trailer, and the rear axle center of the first trailer refers to the midpoint of the wheel center connection line of the left and right rear wheels of the first trailer.

[0056] The motion data refers to the dynamic information related to the real-time motion state of the trailer. Specifically, the motion data includes the time interval between the current calculation moment and the previous calculation moment, the front wheel angle of the trailer, the vehicle speed of the trailer, and the gear position of the trailer. Among them, the front wheel angle of the trailer refers to the deflection angle of the front steering wheel of the tractor relative to the geometric center line of the tractor, the vehicle speed of the trailer refers to the driving speed of the trailer, and the gear position of the trailer refers to the state of the gearbox, such as the forward gear or the reverse gear.

[0057] Specifically, the body data is pre-stored in the control unit when the vehicle leaves the factory, so that the control unit can obtain the body data, or the control unit obtains the body data from the server. In addition, the control unit can obtain the motion data through the vehicle bus, such as obtaining the motion data through the CAN bus.

[0058] Step S50: Obtain the second hinge angle of the trailer at the previous calculation moment.

[0059] Specifically, the fourth hinge angle at the previous calculation moment can be stored for the control unit to obtain at the current calculation moment.

[0060] Step S60: Obtain a third articulation angle based on the vehicle body data, motion data, and the second articulation angle.

[0061] Specifically, a calculation model for calculating the articulation angle can be pre-constructed, such as constructing an Ackermann motion model. After obtaining the vehicle body data, motion data, and the second articulation angle, input them into the model to obtain the third articulation angle.

[0062] Step S70: Determine a fourth articulation angle at the current calculation moment based on the first articulation angle and the third articulation angle.

[0063] It can be understood that the first articulation angle is calculated from the visual image, and the third articulation angle is predicted by the model. In this way, after obtaining the first articulation angle and the third articulation angle, the two can be compared to determine the final articulation angle, that is, the fourth articulation angle.

[0064] In the embodiment of the present application, the trailer image is collected in real time by the camera. Based on the trailer pixel width (the first dimension) at the minimum articulation angle, the trailer pixel width (the second dimension) at the maximum articulation angle, and the trailer pixel width (the third dimension) at the current calculation moment, the first articulation angle is calculated proportionally. At the same time, using the model, vehicle body data, motion data, and the second articulation angle (historical articulation angle), the third articulation angle at the current calculation moment is predicted. Then, the first articulation angle obtained by visual measurement and the third articulation angle predicted by the model are compared to determine the articulation angle at the current calculation moment (i.e., the fourth articulation angle), and the visual measurement data is used to adjust the data predicted by the model, reducing the cumulative error of the model calculation and improving the accuracy of the articulation angle calculation. Moreover, this method reuses the existing hardware resources of the electronic outside rearview mirror device, without the need to additionally install an angle sensor (such as a potentiometer or an encoder), reducing the hardware cost. In addition, this method has a low computing power requirement for the control unit, and can reuse the computing power of the neural network processor (Neural Processing Unit, NPU) of the existing electronic outside rearview mirror device to implement visual computing, with low requirements for the hardware platform, and can be applied to most of the current system-on-chip solutions that support NPU.

[0065] In one of the embodiments, obtaining the first dimension of the first trailer in the full field of view of the camera at the minimum articulation angle, and the second dimension of the first trailer in the full field of view of the camera at the maximum articulation angle includes the following steps:

[0066] Step S11: After the electronic outside rearview mirror device is powered on, obtain the first pixel coordinate value of the rear end of the first trailer in the full field of view of the camera.

[0067] The first pixel coordinate value refers to the horizontal pixel coordinate and vertical pixel coordinate of the feature point at the rear end of the first trailer in the full-field view of the camera. In this application, the feature point at the rear end is the rightmost point of the rear end. In practical applications, the feature point at the rear end can be the leftmost point or the center point of the rear end.

[0068] After the tractor starts, the electronic outside rearview mirror device is powered on. In some embodiments, the control unit can obtain the first pixel coordinate value by performing image processing on the full-field view.

[0069] Step S12: Obtain a calibration data set, which includes the first pixel coordinate information of the first area in the full-field view of the camera, and the second pixel coordinate values of the rear ends of second trailers with different lengths in the full-field view of the camera at the minimum articulation angle and the maximum articulation angle, where the first area is the area obtained for all second trailers with different lengths in the full-field view of the camera.

[0070] The second trailer refers to a trailer with different cargo box lengths used for calibration. When obtaining the calibration data set, second trailers with different lengths are successively articulated with the same tractor, and the full-field views of the camera at the minimum articulation angle and the maximum articulation angle are respectively obtained. Then, image processing is respectively performed on the full-field views of all second trailers at the minimum articulation angle and the maximum articulation angle to obtain the first area, the first pixel sub-coordinate values of the rear end of the second trailer in the full-field view of the camera at the minimum articulation angle, and the second pixel sub-coordinate values of the rear end of the second trailer in the full-field view of the camera at the maximum articulation angle.

[0071] Among them, the second pixel coordinate value includes the above-mentioned first pixel sub-coordinate value and second pixel sub-coordinate value. The first pixel sub-coordinate value is the horizontal pixel coordinate and vertical pixel coordinate of the feature point at the rear end of the second trailer in the full-field view of the camera when the second trailer is at the minimum articulation angle; the second pixel sub-coordinate value is the horizontal pixel coordinate and vertical pixel coordinate of the feature point at the rear end of the second trailer in the full-field view of the camera when the second trailer is at the maximum articulation angle.

[0072] The first area is the area in the full-field view of the camera that covers all the areas where the second trailers appear during the calibration process, such as Figure 5As shown by P3 in []. That is, the first area can cover the areas where all trailers in the calibration dataset appear at different articulation angles. The first pixel coordinate information includes the horizontal pixel coordinate of the characteristic pixel point of the first area in the full field of view of the camera, the vertical pixel coordinate of the characteristic pixel point of the first area in the full field of view of the camera, the horizontal pixel width of the first area in the full field of view of the camera, and the vertical pixel width of the first area in the full field of view of the camera. In this application, the characteristic pixel point of the first area is the pixel point at the upper left corner of the first area. In actual applications, the characteristic pixel point of the first area can also be a suitable pixel point such as the pixel point at the upper right corner, the lower left corner, or the lower right corner of the first area.

[0073] Step S13: Based on the first pixel coordinate value and the calibration dataset, obtain the third pixel coordinate value of the rear of the first trailer in the full field of view of the camera at the minimum articulation angle, and the fourth pixel coordinate value of the rear of the first trailer in the full field of view of the camera at the maximum articulation angle.

[0074] Generally, when the electronic outside rearview mirror device is powered on, the first trailer is at the minimum articulation angle. Therefore, after obtaining the first pixel coordinate value, it can be compared with the calibration dataset to find the first pixel sub-coordinate value closest to the first pixel coordinate value in the calibration dataset. Specifically, the first pixel coordinate value is (X sensor , Y sensor ). The longitudinal pixel coordinate in the first pixel sub-coordinate value with the smallest difference from Y sensor in the calibration dataset can be found, and the first pixel sub-coordinate value of the second trailer at the minimum articulation angle corresponding to this longitudinal pixel coordinate is used as the third pixel coordinate value, and the second pixel sub-coordinate value of the second trailer at the maximum articulation angle corresponding to this longitudinal pixel coordinate is used as the fourth pixel coordinate value.

[0075] Step S14: Based on the third pixel coordinate value and the first pixel coordinate information, obtain the first dimension.

[0076] Specifically, the first dimension can be calculated by the following formula:

[0077] W box (θ = 0) = X(θ = 0) - X roi ;

[0078] where W box (θ = 0) is the first dimension, X(θ = 0) is the horizontal pixel coordinate of the third pixel coordinate value, and X roi is the horizontal pixel coordinate of the characteristic pixel point of the first area in the full field of view of the camera.

[0079] Step S15: Based on the fourth pixel coordinate value and the first pixel coordinate information, obtain the second dimension.

[0080] Specifically, the second dimension can be calculated through the following formula:

[0081] W box (θ = max) = X(θ = max) - X roi ;

[0082] where W box (θ = max) is the second dimension, and X(θ = max) is the horizontal pixel coordinate of the fourth pixel coordinate value.

[0083] In the real vehicle environment, the tractor is articulated with various types of trailers, and the actual reference positions of the rear ends of various trailers are obtained to construct a calibration database. The calibration database is used as a reference for the position range of image recognition to reduce the influence of hardware differences such as camera distortion and installation angle, and improve the accuracy of subsequent calculation of the articulation angle.

[0084] In one embodiment, the electronic outside rearview mirror device further includes a display screen. Obtaining the first pixel coordinate value of the rear end of the first trailer in the full view of the camera includes the following steps:

[0085] Step S111: Obtain the first screen coordinate value of the rear end of the first trailer on the display screen.

[0086] The first screen coordinate value is the horizontal pixel coordinate and vertical pixel coordinate of the feature point of the rear end of the first trailer in the display screen.

[0087] After the electronic outside rearview mirror is powered on, the system enters the calibration mode. As Figure 6 shown, the display screen will display an image including the rear end marking line L and the rear end of the first trailer. The user can move the position of the rear end marking line L in the display screen by touching or pressing a button to make the rear end marking line L coincide with the rear end of the first trailer in the display screen to complete the marking. Then, based on the position of the rear end marking line L marked by the user in the display screen, the first screen coordinate value is obtained.

[0088] Step S112: Perform coordinate transformation on the first screen coordinate value based on the preset coordinate transformation relationship between the imaging plane coordinate system of the camera and the display screen coordinate system of the display screen to obtain the first pixel coordinate value.

[0089] The imaging plane coordinate system is the image coordinate system of the original image (full view) captured by the camera, and its origin is usually the upper left corner of the full view. The display plane coordinate system is the image coordinate system in the display screen, and its origin is usually the upper left corner of the display screen. The coordinate transformation relationship between the two can be pre-stored in the control unit. In this way, the control unit performs coordinate transformation on the first screen coordinate value through this coordinate transformation relationship to obtain the first pixel coordinate value.

[0090] In the embodiments of the present application, the first pixel coordinate value can be obtained by performing coordinate transformation on the first screen coordinate value.

[0091] In one of the embodiments, the method for obtaining the coordinate transformation relationship includes the following steps:

[0092] Step S1121: Obtain the second pixel coordinate information of the secondary field of view map under the full field of view map of the camera.

[0093] The second pixel coordinate information includes the horizontal pixel coordinates of the feature points of the cropping area of the secondary field of view map under the full field of view map of the camera, the vertical pixel coordinates of the feature points of the cropping area, the horizontal pixel width of the cropping area, and the vertical pixel width of the cropping area. The feature point of the cropping area is the pixel point at the upper left corner of the cropping area. In practical applications, the feature pixel point of the cropping area can also be a suitable pixel point such as the pixel point at the upper right corner, the lower left corner, or the lower right corner of the cropping area.

[0094] Step S1122: Obtain the second screen coordinate value of the secondary field of view map on the display screen.

[0095] The second screen coordinate value includes the horizontal pixel coordinates of the feature points of the display area of the secondary field of view map on the display screen, the vertical pixel coordinates of the feature points of the display area, the horizontal pixel width of the display area, and the vertical pixel width of the display area.

[0096] Step S1123: Obtain the coordinate transformation relationship based on the second pixel coordinate information and the second screen coordinate value.

[0097] Specifically, the coordinate transformation relationship is as follows:

[0098]

[0099] Wherein, X sensor is the horizontal pixel coordinate of the feature point at the rear of the first trailer in the full field of view map of the camera, Y sensor is the vertical pixel coordinate of the feature point at the rear of the first trailer in the full field of view map of the camera, X screen is the horizontal pixel coordinate of the feature point at the rear of the first trailer on the display screen, Y screenLet \(Tail_X\) be the vertical pixel coordinate of the feature point at the rear of the first trailer in the display screen, \(Crop_X\) be the horizontal pixel coordinate of the feature point of the cropping area of the secondary field of view image in the full field of view image of the camera, \(Crop_Y\) be the vertical pixel coordinate of the feature point of the cropping area, \(Crop_W\) be the horizontal pixel width of the cropping area, \(Crop_H\) be the vertical pixel width of the cropping area, \(Disp_X\) be the horizontal pixel coordinate of the feature point of the display area of the secondary field of view image in the display screen, \(Disp_Y\) be the vertical pixel coordinate of the feature point of the display area, \(Disp_W\) be the horizontal pixel width of the display area, and \(Disp_H\) be the vertical pixel width of the display area. In practical applications, the coordinate conversion relationship can also be embodied in the form of corresponding curves or corresponding tables.

[0100] In this embodiment, if the coordinate conversion relationship is not stored in advance, the coordinate conversion relationship can be determined by using the coordinate values of the secondary field of view image in the full field of view image and the display screen, so as to improve the applicable scenarios of the determination method.

[0101] In one of the embodiments, obtaining the body data and motion data of the semi-trailer at the current calculation moment includes the following steps: Step S41: Obtain the steering wheel angle of the semi-trailer.

[0102] The steering wheel angle of the semi-trailer refers to the rotation angle of the steering wheel relative to the central zero position (straight-ahead position) of the steering wheel when the driver operates the steering wheel at the current calculation moment. The steering wheel angle is usually in degrees, and clockwise or counterclockwise rotation will generate positive or negative values respectively (or vice versa, depending on the system design). For example: when the steering wheel is turned 30° to the right, the steering wheel angle is +30°, and when it is turned 45° to the left, the steering wheel angle is -45°.

[0103] Step S42: Obtain the corresponding relationship between the steering wheel angle of the semi-trailer and the front wheel angle of the semi-trailer.

[0104] The corresponding relationship is established and stored in advance. The corresponding relationship refers to the mapping relationship between the rotation angle of the steering wheel and the actual steering angle of the front wheels of the semi-trailer.

[0105] Step S43: Based on the steering wheel angle of the semi-trailer and the corresponding relationship, obtain the front wheel angle of the semi-trailer.

[0106] After obtaining the steering wheel angle of the semi-trailer, the front wheel angle of the semi-trailer is obtained by calculation or table lookup through the corresponding relationship.

[0107] In this embodiment, the front wheel angle of the semi-trailer is obtained through the steering wheel angle of the semi-trailer and the corresponding relationship, without the need to use complex sensors to measure the front wheel angle in real time, reducing the hardware cost.

[0108] In one embodiment, obtaining a third articulation angle based on vehicle body data, motion data, and a second articulation angle includes the following steps:

[0109] Step S61: Calculate the vehicle body data, motion data, and the second articulation angle according to a pre-designed calculation rule to obtain a fifth articulation angle.

[0110] The pre-designed calculation rule is the calculation rule of a pre-established Ackerman kinematic model. Specifically, refer to Figure 4 , and use the principle that the centers of the paths of the four wheels will converge to the same point, i.e., the instantaneous steering center, when the vehicle turns to establish a simplified geometric mathematical model of the tractor and the trailer. After that, through the conversion of the relationship between angles, the fifth articulation angle can be calculated by the following formula:

[0111]

[0112] Among them, θ5 is the fifth articulation angle, θ2 is the second articulation angle. If the previous calculation moment is the initial calculation moment (such as the power-on moment of the electronic outside rearview mirror), the second articulation angle is calculated by the following formula:

[0113]

[0114] W box (t = 0) is the third dimension of the first trailer in the full field of view of the camera at the initial calculation moment, m1 is the first distance between the front axle center and the rear axle center of the tractor, m2 is the second distance between the rear axle center of the tractor and the articulation point, m3 is the third distance between the articulation point and the rear axle center of the first trailer, Δt is the time interval between the current calculation moment and the previous calculation moment, α is the front wheel angle of the tractor-trailer, v is the vehicle speed of the tractor-trailer, and s is the gear of the tractor-trailer. When the gear of the tractor-trailer is in the forward gear, s is 1; when the gear of the tractor-trailer is in the reverse gear, s is -1.

[0115] Step S62: If the fifth articulation angle is less than 0, then use 0 as the third articulation angle.

[0116] In the kinematic model, the fifth articulation angle may theoretically be negative due to errors, but in the actual physical system, the articulation angle is usually non-negative. Therefore, when the calculated fifth articulation angle is less than 0, the third articulation angle is corrected to 0 to avoid the subsequent control logic from failing due to illegal values.

[0117] Step S63: If the fifth articulation angle is greater than the maximum articulation angle, then use the maximum articulation angle as the third articulation angle.

[0118] In the kinematic model, the above situation may theoretically occur for the fifth hinge angle due to errors. However, in practical applications, there are physical design limits for the hinge mechanisms of the semi-trailer (such as the saddle and turntable), that is, there is a maximum hinge angle. Therefore, when the calculated fifth hinge angle is greater than the maximum hinge angle, the third hinge angle is corrected to the maximum hinge angle.

[0119] Step S64: If the fifth hinge angle is greater than or equal to 0 and less than or equal to the maximum hinge angle, then use the fifth hinge angle as the third hinge angle.

[0120] In the kinematic model, if the calculated fifth hinge angle is within the actual physical range of the hinge angle, then use the fifth hinge angle as the third hinge angle.

[0121] In this embodiment, the Ackerman principle is used to establish a geometric mathematical model to make the angle calculation conform to the real physical scenario through the kinematic model. Moreover, after calculating the fifth hinge angle, it is judged to ensure that the output value always conforms to the real constraints of the physical system, improving the robustness of the determination method.

[0122] In one of the embodiments, based on the first hinge angle and the third hinge angle, determining the fourth hinge angle at the current calculation moment includes the following steps:

[0123] Step S71: Based on the first hinge angle and the third hinge angle, obtain the absolute value of the difference between the first hinge angle and the third hinge angle.

[0124] Step S72: If the absolute value is less than or equal to the first threshold, then use the third hinge angle as the fourth hinge angle.

[0125] Step S73: If the absolute value is greater than the first threshold, then use the minimum value of the first hinge angle and the third hinge angle as the fourth hinge angle.

[0126] After calculating the first hinge angle and the third hinge angle, it is necessary to compare the two to determine whether the calculated hinge angle needs to be corrected. Specifically, first use the following formula to calculate the absolute value of the difference between the first hinge angle and the third hinge angle:

[0127] θ 13 =|θ1 - θ3|;

[0128] where θ1 is the first hinge angle, θ3 is the third hinge angle, and θ 13 is the absolute value.

[0129] The first threshold is preset according to actual experience values. By comparing the size relationship between the absolute value and the first threshold, a suitable hinge angle is selected as the fourth hinge angle.

[0130] In this embodiment, by comparing the first articulated angle obtained through visual measurement with the third articulated angle predicted by the model, it is determined whether it is necessary to correct the articulated angle predicted by the model to improve the accuracy of the finally obtained articulated angle.

[0131] As another aspect of the embodiments of the present application, the embodiments of the present application further provide a field of view adjustment method, and the adjustment method includes the following steps: Step S100: Determine the fourth articulated angle at the current calculation moment by using the determination method described in any one of the embodiments of the first aspect.

[0132] The determination method of this step has the same process and function as the determination method described in any one of the embodiments of the first aspect, and will not be elaborated here.

[0133] Step S200: Obtain the third pixel coordinate information of the secondary field of view map in the full field of view map of the camera at the previous calculation moment.

[0134] The secondary field of view map refers to an image of the secondary field of view that conforms to the GB15084 standard and is generated after dynamically cropping the full field of view map (complete image) collected by the camera.

[0135] The third pixel coordinate information refers to the horizontal pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map, the vertical pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map, the horizontal pixel width of the secondary field of view map in the full field of view map, and the vertical pixel width of the secondary field of view map in the full field of view map. In the present application, the characteristic pixel point of the secondary field of view map is the pixel point at the upper left corner of the secondary field of view map. In practical applications, the characteristic pixel point can also be a suitable pixel point such as the pixel point at the upper right corner, the lower left corner, or the lower right corner of the secondary field of view map.

[0136] Step S300: Determine the fourth pixel coordinate information of the secondary field of view map in the full field of view map of the camera at the current calculation moment according to the fourth articulated angle, the third pixel coordinate information, and the preset display rule.

[0137] The fourth pixel coordinate information refers to the horizontal pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map, the vertical pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map, the horizontal pixel width of the secondary field of view map in the full field of view map, and the vertical pixel width of the secondary field of view map in the full field of view map.

[0138] The preset display rule is a rule for determining whether the vehicle is turning or whether the articulation angle has changed based on the fourth articulation angle, so as to decide whether to adjust the third pixel coordinate information. If the third pixel coordinate information is not adjusted, the third pixel coordinate information is directly used as the fourth pixel coordinate information. If the third pixel coordinate information needs to be adjusted, the adjusted third pixel coordinate information is used as the fourth pixel coordinate information.

[0139] Step S400: Crop the full view of the camera according to the fourth pixel coordinate information to obtain a second type of view, and display the second type of view on the display screen.

[0140] After obtaining the fourth pixel coordinate information, that is, obtaining the position of the second type of view in the full view at the current calculation moment, cropping the full view based on this position can obtain the second type of view at the current calculation moment, and obtain the image signal of the second type of view. After sending it to the display screen, the display screen can display the second type of view at the current calculation moment based on this image signal.

[0141] In this embodiment, by adjusting and displaying the position of the second type of view according to the calculated articulation angle, the second type of view can be updated in real time so that the rear of the trailer is in the picture.

[0142] In one of the embodiments, according to the fourth articulation angle, the third pixel coordinate information, and the preset display rule, determining the fourth pixel coordinate information of the second type of view under the full view of the camera at the current calculation moment includes the following steps:

[0143] Step S310: If the fourth articulation angle is less than or equal to the second threshold, use the third pixel coordinate information as the fourth pixel coordinate information.

[0144] Step S320: If the fourth articulation angle is greater than the second threshold, obtain the first size of the first trailer under the full view of the camera at the minimum articulation angle, and the second size of the first trailer under the full view of the camera at the maximum articulation angle, and obtain the fourth pixel coordinate information according to the fourth articulation angle, the third pixel coordinate information, the first size, and the second size.

[0145] The second threshold is preset according to actual experience values. By comparing the magnitude relationship between the fourth articulation angle and the second threshold, it is determined whether it is necessary to adjust the pixel coordinate value of the second type of view under the full view.

[0146] Specifically, if the fourth articulation angle is less than or equal to the second threshold, calculate the fourth pixel coordinate information according to the following formula:

[0147] Crop XΔt =Crop X ;

[0148] Crop YΔt = Crop Y ;

[0149] Crop WΔt = Crop W ;

[0150] Crop HΔt = Crop H ;

[0151] If the fourth hinge angle is greater than the second threshold, then calculate the fourth pixel coordinate information according to the following formula:

[0152]

[0153] Crop YΔt = Crop Y ;

[0154] Crop WΔt = Crop W ;

[0155] Crop HΔt = Crop H ;

[0156] where Crop X is the horizontal pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map at the previous calculation moment, Crop Y is the vertical pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map at the previous calculation moment, Crop W is the horizontal pixel width of the characteristic pixel point of the secondary field of view map in the full field of view map at the previous calculation moment, Crop H is the vertical pixel width of the characteristic pixel point of the secondary field of view map in the full field of view map at the previous calculation moment, Crop XΔt is the horizontal pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map at the current calculation moment, Crop YΔt is the vertical pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map at the current calculation moment, Crop WΔt is the horizontal pixel width of the characteristic pixel point of the secondary field of view map in the full field of view map at the current calculation moment, Crop HΔt is the vertical pixel width of the characteristic pixel point of the secondary field of view map in the full field of view map at the current calculation moment.

[0157] In this embodiment, the cutting position of the secondary field of view map in the full field of view map at the current calculation moment can be determined in the above manner. When the hinge angle is small (less than or equal to the second threshold), the position of the secondary field of view map in the full field of view map at the previous calculation moment is directly used, reducing unnecessary calculations and improving the system efficiency; while when the hinge angle is large (greater than the second threshold), the horizontal pixel coordinate value of the secondary field of view map in the full field of view map is adjusted proportionally to make the position of the secondary field of view map more in line with the actual trailer state and improve the display accuracy.

[0158] In one embodiment, if the fourth hinge angle is greater than the second threshold, the full field of view map of the camera is cut according to the fourth pixel coordinate information to obtain a secondary field of view map, and the secondary field of view map is displayed on the display screen, including the following steps:

[0159] Step S410: Obtain the number of displays.

[0160] The number of displays refers to the total number of adjustments required when adjusting the position of the secondary field of view map. If the number of displays is 5 times, the control unit will gradually adjust the position of the secondary field of view map to the fourth pixel coordinate information in 5 times and display the image after each adjustment on the display screen. In practical applications, the number of displays can also be input or changed by the user during the adjustment process.

[0161] Step S420: Based on the fourth pixel coordinate information and the number of displays, obtain the fifth pixel coordinate information of the secondary field of view map under the full field of view map of the camera at each display.

[0162] The fifth pixel coordinate information includes the horizontal pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map, the vertical pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map, the horizontal pixel width of the secondary field of view map in the full field of view map, and the vertical pixel width of the secondary field of view map in the full field of view map. It can be understood that only the horizontal pixel coordinate of the characteristic pixel point of the secondary field of view map in the full field of view map will change with the increase of the number of displays. If the horizontal pixel coordinate of the characteristic pixel point of the secondary field of view map changes by a certain coordinate step each time, the coordinate step is calculated by the following formula:

[0163]

[0164] where Δx is the coordinate step and n is the number of displays.

[0165] Step S430: Cut the full field of view map of the camera in sequence based on each fifth pixel coordinate information to obtain the secondary field of view map at each display, and display the secondary field of view map on the display screen in sequence.

[0166] After obtaining the fifth pixel coordinate information at each display, perform cropping according to the corresponding fifth pixel coordinate information at each display to obtain the secondary field of view maps at each display, and sequentially display these secondary field of view maps on the display screen.

[0167] In this embodiment, by presetting the number of displays, the positions of the secondary field of view maps are adjusted step by step to the fourth pixel coordinate information. Compared with the method of directly adjusting to the fourth pixel coordinate information, the method provided in this embodiment can reduce the discomfort caused by screen jumps, make the screen change smoother, the displayed screen has no sense of lag, and bring a better experience of dynamic blind area coverage to the user.

[0168] In one of the embodiments, the display method further includes step S500: Display an icon for starting the vision follow-up state on the display screen.

[0169] Specifically, an icon for starting the vision follow-up state can be displayed on the display screen through an On-Screen Display Module (OSD). The shape, color, and display method (such as continuous display or flashing) of the icon can be set according to actual needs and are not limited here.

[0170] In this embodiment, by displaying the icon for starting the vision follow-up state, the driver can understand the working state of the current CMS system.

[0171] In a third aspect, the present application provides a control unit. Figure 8 Shows a hardware structure of the control unit 33. Please refer to Figure 8 , the control unit 33 includes a processor 331, a memory 332, and a communication interface 333. The processor 331, the memory 332, and the communication interface 333 are connected by lines. In Figure 8 the shown embodiment, the processor 331, the memory 332, and the communication interface 333 are communicatively connected to each other through a bus. The memory 332 stores instructions executable by the processor 331, and the instructions are executed by the processor 331 so that the processor 331 can execute the method described in any embodiment of the present application.

[0172] The memory 332 is used to store software programs, computer-executable program instructions, etc. The memory 332 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the control unit 33, etc.

[0173] The memory 332 can be a Read-Only Memory (ROM), or other types of static storage devices that can store static information and instructions, or a random access memory (RAM), or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM). Specifically, it is not limited here.

[0174] Exemplarily, the aforementioned memory 332 can be a double data rate synchronous dynamic random access memory. This memory 332 can exist independently, but is connected to the processor 331. Optionally, this memory 332 can also be integrated with the processor 331. For example, integrated within one or more chips.

[0175] In some embodiments, the memory 332 optionally includes memories remotely set relative to the processor 331, and these remote memories can be connected to the control unit 33 through a network. Examples of the above network include but are not limited to the Internet, intranet, local area network, mobile communication network, and combinations thereof.

[0176] The processor 331 connects various parts of the entire control unit 33 using various interfaces and lines. By running or executing software programs stored in the memory 332, and by invoking data stored in the memory 332, it executes various functions of the control unit 33 and processes data, such as implementing the method described in any embodiment of the present application.

[0177] The processor 331 can be a field programmable gate array (FPGA), a digital signal processor (DSP), a central processing unit (CPU), etc.

[0178] The processor 331 can be a single-core processor or a multi-core processor. For example, the processor 331 can be composed of multiple FPGAs or multiple DSPs. In addition, the processor 331 can refer to one or more devices, circuits, and / or processing cores for processing data (such as computer program instructions). The processor 331 can be a separate semiconductor chip or integrated with other circuits into a semiconductor chip. For example, it can form a system-on-a-chip (SoC) with other circuits (such as codec circuits, hardware acceleration circuits, or various bus and interface circuits), or can be integrated as an embedded processor of an application specific integrated circuit (ASIC) in the ASIC. The ASIC integrated with the processor can be packaged separately or packaged together with other circuits.

[0179] The communication interface 333 can use a transceiver device such as a transceiver to achieve communication between the control unit 33 and other devices or communication networks.

[0180] The above-mentioned control unit 33 can execute the method provided in the embodiments of the present application, and has corresponding function modules and beneficial effects for executing the method. For technical details not described in detail in this embodiment, reference can be made to the method provided in the embodiments of the present application.

[0181] As another aspect of the embodiments of the present application, the embodiments of the present application also provide an electronic outside rearview mirror device, including a camera, a display screen, and the control unit as described in the third aspect; the control unit is electrically connected to the camera and the display screen.

[0182] The control unit described in the embodiments of the present application has the same structure and function as the control unit described in any one of the embodiments in the third aspect, and will not be described in detail here.

[0183] As another aspect of the embodiments of the present application, the embodiments of the present application also provide a trailer, including: a tractor, a first trailer, and the electronic outside rearview mirror device as described in the fourth aspect. The electronic outside rearview mirror device is provided on the tractor, and the tractor is connected to the first trailer.

[0184] The electronic outside rearview mirror device described in the embodiments of the present application has the same structure and function as the electronic outside rearview mirror device described in any one of the embodiments in the fourth aspect, and will not be described in detail here.

[0185] As another aspect of the embodiments of the present application, the embodiments of the present application also provide a computer-readable storage medium, which stores computer-executable instructions for causing an electronic device to execute the method provided in the embodiments of the present application.

[0186] In some embodiments, the storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disc, or CD-ROM; or may be various devices including one or any combination of the above memories.

[0187] In some embodiments, the executable instructions may be in the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including being deployed as an independent program or being deployed as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0188] As an example, the executable instructions may or may not correspond to a file in the file system, may be stored as part of a file that holds other programs or data, for example, in one or more scripts in a Hyper Text Markup Language (HTML) document, stored in a single file dedicated to the program being discussed, or, stored in multiple cooperating files (such as files that store one or more modules, subroutines, or portions of code).

[0189] As an example, the executable instructions may be deployed to execute on one computing device (including devices such as smart terminals and servers), or on multiple computing devices located at one location, or, on multiple computing devices distributed at multiple locations interconnected by a communication network.

[0190] As another aspect of the embodiments of the present application, the embodiments of the present application further provide a computer program product, the computer program product includes a computer program stored on a computer-readable storage medium, the computer program includes program instructions, when the program instructions are executed by a computer, the computer is caused to execute the method in the foregoing embodiments.

[0191] It should be noted that the device embodiments described above are merely illustrative, where the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0192] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to execute the methods described in each embodiment or some parts of the embodiments by at least one computer device (which can be a personal computer, a server, or a network device, etc.).

[0193] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; under the idea of the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other changes in different aspects of the present application as described above. For the sake of brevity, they are not provided in detail; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining an articulated angle, characterized in that, Applied to a semi-trailer truck, the semi-trailer truck includes a tractor, a first trailer, and an electronic outside rearview mirror device. The electronic outside rearview mirror device includes a camera. The determination method includes: Obtaining a first dimension of the first trailer in the full field of view of the camera at the minimum articulation angle, and a second dimension of the first trailer in the full field of view of the camera at the maximum articulation angle; Obtaining a third dimension of the first trailer in the full field of view of the camera at the current calculation moment; Based on the first dimension, the second dimension, the third dimension, and the maximum articulation angle, obtaining a first articulation angle; Obtaining the body data and motion data of the semi-trailer truck at the current calculation moment; Obtaining a second articulation angle of the semi-trailer truck at the previous calculation moment; Based on the body data, the motion data, and the second articulation angle, obtaining a third articulation angle; Based on the first articulation angle and the third articulation angle, determining a fourth articulation angle at the current calculation moment.

2. The determination method according to claim 1, wherein The obtaining of the first dimension of the first trailer in the full field of view of the camera at the minimum articulation angle, and the second dimension of the first trailer in the full field of view of the camera at the maximum articulation angle includes: After the electronic outside rearview mirror device is powered on, obtaining a first pixel coordinate value of the rear of the first trailer in the full field of view of the camera; Obtaining a calibration data set, which includes first pixel coordinate information of a first area in the full field of view of the camera, and second pixel coordinate values of the rear of second trailers with different lengths in the full field of view of the camera at the minimum articulation angle and the maximum articulation angle. Among them, the first area is the area obtained by all the second trailers with different lengths in the full field of view of the camera; Based on the first pixel coordinate value and the calibration data set, obtaining a third pixel coordinate value of the rear of the first trailer in the full field of view of the camera at the minimum articulation angle, and a fourth pixel coordinate value of the rear of the first trailer in the full field of view of the camera at the maximum articulation angle; Based on the third pixel coordinate value and the first pixel coordinate information, obtaining the first dimension; Based on the fourth pixel coordinate value and the first pixel coordinate information, obtaining the second dimension.

3. The determination method according to claim 2, wherein The electronic outside rearview mirror device further includes a display screen. The obtaining of the first pixel coordinate value of the rear of the first trailer in the full field of view of the camera includes: Obtaining a first screen coordinate value of the rear of the first trailer on the display screen; Based on a preset coordinate conversion relationship between the imaging plane coordinate system of the camera and the display screen coordinate system of the display screen, performing coordinate conversion on the first screen coordinate value to obtain the first pixel coordinate value.

4. The determination method according to claim 3, wherein The method for obtaining the coordinate conversion relationship includes: Obtaining second pixel coordinate information of a second type of field of view in the full field of view of the camera; Obtaining a second screen coordinate value of the second type of field of view on the display screen; Based on the second pixel coordinate information and the second screen coordinate value, obtaining the coordinate conversion relationship.

5. The determination method according to claim 1, characterized in that The vehicle body data includes a first distance between the center of the front axle and the center of the rear axle of the tractor, a second distance between the center of the rear axle of the tractor and the articulation point, and a third distance between the articulation point and the center of the rear axle of the first trailer. The motion data includes the time interval between the current calculation moment and the previous calculation moment, the front wheel angle of the semi-trailer truck, the vehicle speed of the semi-trailer truck, and the gear position of the semi-trailer truck. Obtaining the vehicle body data and motion data of the semi-trailer truck at the current calculation moment includes: Obtaining the steering wheel angle of the semi-trailer truck; Obtaining the correspondence between the steering wheel angle of the semi-trailer truck and the front wheel angle of the semi-trailer truck; Based on the steering wheel angle of the semi-trailer truck and the correspondence, obtaining the front wheel angle of the semi-trailer truck.

6. The determination method according to claim 1, characterized in that, The obtaining the third articulation angle based on the vehicle body data, the motion data, and the second articulation angle includes: Calculating the vehicle body data, the motion data, and the second articulation angle according to a preset calculation rule to obtain a fifth articulation angle; If the fifth articulation angle is less than 0, taking 0 as the third articulation angle; If the fifth articulation angle is greater than the maximum articulation angle, taking the maximum articulation angle as the third articulation angle; If the fifth articulation angle is greater than or equal to 0 and less than or equal to the maximum articulation angle, taking the fifth articulation angle as the third articulation angle.

7. The determination method according to claim 1, characterized in that The determining the fourth articulation angle at the current calculation moment based on the first articulation angle and the third articulation angle includes: Based on the first articulation angle and the third articulation angle, obtaining the absolute value of the difference between the first articulation angle and the third articulation angle; If the absolute value is less than or equal to a first threshold, taking the third articulation angle as the fourth articulation angle; If the absolute value is greater than the first threshold, taking the minimum value of the first articulation angle and the third articulation angle as the fourth articulation angle.

8. A vision adjustment method, characterized in that, Applied to a semi-trailer truck, the semi-trailer truck includes a tractor, a first trailer, and an electronic outside rearview mirror device. The electronic outside rearview mirror device includes a camera and a display screen. The adjustment method includes: Determining the fourth articulation angle at the current calculation moment by using the determination method according to any one of claims 1-7; Obtaining the third pixel coordinate information of the secondary field of view map in the full field of view map of the camera at the previous calculation moment; According to the fourth articulation angle, the third pixel coordinate information, and a preset display rule, determining the fourth pixel coordinate information of the secondary field of view map in the full field of view map of the camera at the current calculation moment; Cropping the full field of view map of the camera according to the fourth pixel coordinate information to obtain the secondary field of view map, and displaying the secondary field of view map on the display screen.

9. The display method according to claim 8, wherein The determining the fourth pixel coordinate information of the secondary field of view map in the full field of view map of the camera at the current calculation moment according to the fourth articulation angle, the third pixel coordinate information, and a preset display rule includes: If the fourth articulation angle is less than or equal to a second threshold, taking the third pixel coordinate information as the fourth pixel coordinate information; If the fourth hinge angle is greater than the second threshold, obtain a first dimension of the first trailer in the full field of view of the camera at the minimum hinge angle, and a second dimension of the first trailer in the full field of view of the camera at the maximum hinge angle, and obtain the fourth pixel coordinate information according to the fourth hinge angle, the third pixel coordinate information, the first dimension, and the second dimension.

10. The display method according to claim 9, characterized in that, If the fourth hinge angle is greater than the second threshold, then crop the full field of view of the camera according to the fourth pixel coordinate information to obtain the secondary field of view, and display the secondary field of view on the display screen, including: Obtain the display times; Based on the fourth pixel coordinate information and the display times, obtain fifth pixel coordinate information of the secondary field of view in the full field of view of the camera each time it is displayed; Based on each of the fifth pixel coordinate information, crop the full field of view of the camera in sequence to obtain the secondary field of view each time it is displayed, and sequentially display the secondary field of view on the display screen.

11. The display method according to claim 10, wherein The display method further includes: Display an icon for starting the field of view follow-up state on the display screen.

12. A control unit, characterized in that, Including: At least one processor; And, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method according to any one of claims 1 to 11.

13. An electronic outside rearview mirror device, characterized in that, Including a camera, a display screen, and a control unit according to claim 12; The control unit is electrically connected to the camera and the display screen.

14. A semi-trailer, characterized in that, Including: A tractor, a first trailer, and an electronic outside rearview mirror device according to claim 13; The electronic outside rearview mirror device is provided on the tractor, and the tractor is connected to the first trailer.

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