Trailer backup track overlay for camera monitor system using vehicle speed based correction

Abstract

A camera monitoring system (CMS) for use with a vehicle towing a trailer displays a predicted trailer path trajectory during a backing operation.SOLUTION: A method of determining a trailer trajectory of a trailer includes, while the trailer is moving, determining a trailer position based on at least one captured image, determining a trailer angle rate of change based on the at least one captured image, determining the trailer trajectory based on the trailer position and the trailer angle rate of change, and displaying an overlay associated with the trailer trajectory. The method includes determining a steering change while the trailer is below the threshold speed, modifying a trailer trajectory based on the steering change, and displaying a modified overlay associated with the trailer trajectory based on the steering change.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a camera monitor system (CMS) for use on a vehicle towing a trailer, and more particularly to a system for displaying the predicted trailer path trajectory during a reversing maneuver. [Background technology]

[0002] Mirror replacement systems, and camera systems that complement mirror views, are utilized in commercial vehicles to enhance the vehicle operator's ability to view the surrounding environment. Camera monitoring systems (CMS) utilize one or more cameras positioned around the vehicle to provide the vehicle operator with an extended field of view. In some instances, the mirror replacement system within a CMS can cover a wider field of view than a traditional mirror or can include views not fully obtainable through a traditional mirror.

[0003] The area behind the trailer is a typical blind spot in conventional mirror systems, making reversing maneuvers difficult while a trailer is attached. Further contributing to the difficulty of vehicle maneuvering is the fact that trailer behavior during reversing maneuvers differs from trailer behavior during forward maneuvers, and driver assistance systems and estimation techniques available for forward maneuvers are typically unavailable during reversing maneuvers.

[0004] One method for determining trailer trajectory during a reverse maneuver has several drawbacks, such as not considering the effect of the tractor's steering angle. If the driver changes the steering wheel at zero vehicle speed, the predicted path cannot be updated. Traditional prediction models lose accuracy when the trailer angular velocity is large, resulting in poor maneuvering performance when the trailer turns rapidly. Traditional prediction models assume that the trailer angular velocity remains the same during the prediction period, which is incorrect because the trailer angular velocity can change depending on vehicle dynamics. This assumption can lead to large long-term prediction errors.

[0005] However, using the steering angle of the towing vehicle can also be inaccurate. Therefore, other methods for determining trailer trajectory during a reverse maneuver are also lacking. For example, this method does not consider the towing vehicle's motion and trailer speed, and only uses a simple virtual steering angle for the trailer (to generate a circular arc of radius) to calculate its predicted path. Therefore, this method is highly inaccurate. Summary of the Invention

[0006] In one exemplary embodiment, a method for determining a trailer trajectory of a trailer includes: a) while the trailer is moving, a1) determining a trailer position based on at least one captured image; a2) determining a trailer angle change rate based on the at least one captured image; a3) determining a trailer trajectory based on the trailer position and the trailer angle change rate; and a4) displaying an overlay associated with the trailer trajectory; and b) while the trailer is below a threshold speed, b1) determining a steering change; b2) modifying the trailer trajectory based on the steering change; and b3) displaying a modified overlay associated with the trailer trajectory based on the steering change.

[0007] In a further embodiment of any of the above, steps a) and b) are performed while the trailer is reversing.

[0008] In a further embodiment of any of the above, step a1) is carried out by identifying at least one of the trailer wheels and the trailer ends.

[0009] In a further embodiment of any of the above, step a2) is carried out by determining the trailer angle, the change in said trailer angle over the section, and the change in said trailer position over the section.

[0010] In a further embodiment of any of the above, the interval is at least one of time and distance.

[0011] In a further embodiment of any of the above, step a3) is performed using the trailer positions over the section.

[0012] In a further embodiment of any of the above, steps a4) and b3) are performed by displaying an overlay of the trailer trajectory on the displayed captured image.

[0013] In a further embodiment of any of the above, the displayed captured image is different from the at least one captured image.

[0014] In a further embodiment of any of the above, the displayed captured image is part of a bird's eye view or a trailer rear view.

[0015] In a further embodiment of any of the above, the displayed captured image is the same as the at least one captured image.

[0016] In a further embodiment of any of the above, the threshold speed is 2 miles per hour.

[0017] In a further embodiment of any of the above, the threshold speed is zero miles per hour.

[0018] In a further embodiment of any of the above, the trailer angle rate is zero.

[0019] In a further embodiment of any of the above, step b1) is performed by obtaining the steering angle from a CAN bus.

[0020] In one exemplary embodiment, a camera mirror system (CMS) for a vehicle includes at least one rear-facing camera configured to obtain at least one captured image, at least one display configured to render the at least one captured image, and a CMS controller including a memory and a processor, the CMS controller in communication with the at least one rear-facing camera and the at least one display, the memory configured to, by the processor, perform the following: a) while the trailer is moving, a1) determine a trailer position based on the at least one captured image; a2) determining a trailer angle change rate based on the at least one captured image; a3) determining a trailer trajectory based on the trailer position and the trailer angle change rate; a4) displaying an overlay related to the trailer trajectory on one of the at least one display; and b) while the trailer is below a threshold speed, b1) determining a steering change; b2) modifying the trailer trajectory based on the steering change; and b3) displaying a modified overlay related to the trailer trajectory based on the steering change.

[0021] In a further embodiment of any of the above, steps a) and b) are performed while the trailer is reversing, and step b1) is performed by obtaining the steering angle from a CAN bus.

[0022] In a further embodiment of any of the above, step a1) is performed by identifying at least one of a trailer wheel and a trailer end, step a2) is performed by determining a trailer angle, a change in the trailer angle over the section, and a change in the trailer position over the section, and step a3) is performed using the trailer position over the section.

[0023] In a further embodiment of any of the above, steps a4) and b3) are performed by displaying an overlay of the trailer trajectory on the displayed captured image.

[0024] In a further embodiment of any of the above, the threshold speed is 2 miles per hour.

[0025] In a further embodiment of any of the above, the threshold speed is zero miles per hour and the trailer angle rate is zero. [Brief explanation of the drawings]

[0026] The present disclosure can be further understood by reference to the following detailed description taken in conjunction with the accompanying drawings. [Figure 1A] FIG. 1 is a schematic front view of a commercial truck equipped with a camera monitor system (CMS) used to provide at least Class II and Class IV views. [Figure 1B] FIG. 1 is a schematic top view of a commercial truck equipped with a camera mirror system providing Class II, Class IV, Class V, Class VI, and Class VIII views. [Figure 2] 1 is a schematic view of the interior of a vehicle cab. [Figure 3] 10A and 10B show schematic illustrations of a rearview displacement display scene including a predicted trailer trajectory. [Figure 4] 4 illustrates a method for creating a rear view trajectory overlay for the displayed rear view shown in FIG. 3. [Figure 5]

[0013] The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or their respective individual features, may be employed independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, except where such features are incompatible. DETAILED DESCRIPTION OF THE INVENTION

[0027] Schematic diagrams of a commercial vehicle 10 are shown in Figures 1A and 1B. Figure 2 is a schematic top perspective view of the cab of vehicle 10, including a display. Vehicle 10 includes a vehicle cab or tractor 12 for towing a trailer 14. It should be understood that vehicle cab 12 and / or trailer 14 may be in any configuration (e.g., different types or quantities of trailers). While commercial trucks are contemplated in this disclosure, the invention may be applied to other types of vehicles.

[0028] Vehicle 10 incorporates a camera monitor system (CMS) 15 (FIG. 2) that includes driver and passenger side camera arms 16a, 16b (generally "16") mounted on the exterior of vehicle cab 12. If desired, camera arms 16a, 16b may also include conventional mirrors integrated therewith, although CMS 15 may also be used to replace mirrors entirely. In additional examples, multiple camera arms may be included on each side, with each arm housing one or more cameras and / or mirrors.

[0029] Each camera arm 16a, 16b includes a base fixed to, for example, the cab 12. A pivoting arm is supported by the base and may be articulated relative thereto. If desired, the camera arms 16 may instead be fixed. At least one rear-facing camera 20a, 20b (generally "20") is disposed within each camera arm 16, respectively. Each of the exterior cameras 20a, 20b has an exterior field of view (FOV) that includes at least one of a Class II (narrow angle) view and a Class IV (wide angle) view (FIG. 1B), which are types of views legally defined in the commercial trucking industry. EX1 , FOV EX2The camera arms 16a, 16b may provide captured images of the vehicle's surroundings. If desired, multiple cameras may be used in each camera arm 16a, 16b to provide these views. For example, Class II and Class IV views are defined in the European R46 legislation, and the United States and other countries have similar driving visibility requirements for commercial trucks. Specific views may be defined in regulations such as SAE J3155 or other regulations. References to "class" views are not intended to be limiting, but rather as an illustration of the types of views provided to the display by particular cameras. Each arm 16a, 16b may also provide a housing enclosing electronics configured to provide various features of the CMS 15.

[0030] First and second video displays 18a, 18b (generally "18") are positioned on or near A-pillars 19a, 19b on the driver's and passenger's sides, respectively, within the vehicle cab 12 and display streaming video of captured images of Class II and Class IV views on each side of the vehicle 10 from a rear-facing side view captured by external cameras 20a, 20b.

[0031] If video of Class V and / or Class VI views is also required, a camera housing 16c and camera 20c may be positioned at or near the front of the vehicle 10 to provide these views ( FIG. 1B ). In one example, camera 20c is integrated into one of the camera arms 16 (e.g., the camera arm opposite the vehicle operator). A third display 18c positioned within the cab 12 near the top center of the windshield can be used to display Class V and Class VI views forward of the vehicle 10 to the driver. Displays 18a, 18b, and 18c face a driver area 24 within the cab 22, where the driver is seated in a driver's seat 26. The position, size, and field of view(s) streamed to a particular display may vary from the configurations described herein and still encompass the invention of this disclosure.

[0032] If Class VIII view video is required, camera housings can be positioned on the sides and rear of vehicle 10 to provide a field of view that includes some or all of the vehicle's Class VIII zone. As shown, the Class VIII view includes a view that surrounds the immediate vicinity of the trailer and a rearward close-up view of the vehicle that includes the area behind the trailer. In one example, the rearward close-up view of the vehicle is generated by a rear-facing trailer-mounted camera ( FIG. 1B ) positioned at the rear of the vehicle (e.g., behind trailer 14) and may include both an immediate rearward close-up view and a traditional rearward view (e.g., a field of view extending rearward to the horizon provided by a rearview mirror on a vehicle without a trailer). In such an example, third display 18c may include one or more frames displaying the Class VIII view. Alternatively, additional displays may be added near first, second, and third displays 18a, 18b, and 18c to provide dedicated displays that provide Class VIII views.

[0033] Additional displays may be provided and used by CMS 15, such as a display provided in the center console area of ​​vehicle cabin interior 24, typically located in the center of the lower half of the vehicle cabin and used for navigation, infotainment, etc. (i.e., secondary information display). The display may be part of an instrument cluster (i.e., primary information display) located, for example, behind the steering wheel.

[0034] CMS 15 is also configured to utilize imagery from cameras 20a, 20b, 30, as well as imagery from other cameras, ultrasonic, LiDAR, radar, etc. that may be positioned around the vehicle to determine vehicle characteristics, identify objects, and facilitate driver assistance features such as display overlays and semi-autonomous driver assistance systems.

[0035] These features and functions of the CMS 15 are used to implement multiple CMS 15 systems that assist in the operation of the vehicle. Note that a controller 28 (e.g., processor and memory 29, FIG. 2) for the CMS 15 can be used to implement the various functions disclosed in this application.

[0036] The controller 28, which communicates with the display 18 and the cameras 20, 30, may include one or more separate units. For example, a centralized architecture may have a common controller located on the vehicle 10, while a distributed architecture may use a controller located on each of the displays 18, for example. Furthermore, part of the controller 28 may be located on the vehicle 10, while another part of the controller 28 may be located elsewhere, for example on the camera arm 16. In another example, a master-slave display configuration may be used, where one display includes the controller 28 and the other display receives commands from the controller 28.

[0037] In terms of hardware architecture, such a controller may include a processor, memory (e.g., memory), and one or more input and / or output (I / O) device interfaces communicatively coupled via a local interface. The local interface may include, for example, but is not limited to, one or more buses and / or other wired or wireless connections. The local interface may also include additional elements, such as controllers, buffers (caches), drivers, repeaters, and receivers that enable communication, which are omitted for simplicity. Additionally, the local interface may include address, control, and / or data connections to enable appropriate communication between the aforementioned components.

[0038] Controller 28 may be a hardware device for executing software, particularly software stored in a memory, such as memory 29. Controller 28 may be a custom or commercially available processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the controller, a semiconductor-based microprocessor (in the form of a microchip or chipset), or any device for general-purposely executing software instructions.

[0039] The memory may include any one or combination of volatile memory elements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM, VRAM, etc.)) and / or non-volatile memory elements (e.g., ROM, hard drive, tape, CD-ROM, etc.). Furthermore, the memory may incorporate electronic, magnetic, optical, and / or other types of storage media. The memory may have a distributed architecture where various components are located remotely from each other but are accessible by the processor.

[0040] Software in memory may include one or more separate programs, each containing an ordered list of executable instructions for implementing a logical function. A system component embodied as software may be constructed as a source program, an executable program (physical code), a script, or any other entity containing a set of instructions to be executed. If constructed as a source program, the program is translated via a compiler, assembler, interpreter, etc., which may or may not be contained in memory.

[0041] Input / output devices of the present disclosure that may be coupled to the system I / O interface(s) may include, but are not limited to, input devices such as a keyboard, mouse, scanner, microphone, camera, mobile device, proximity device, etc. They may also include, but are not limited to, output devices such as a printer, display, etc. Finally, input / output devices may further include devices that communicate as both input and output, such as, but are not limited to, a modulator / demodulator (i.e., for accessing another device, system, or network), a radio frequency (RF) or other transceiver, a telephone interface, a bridge, a router, etc.

[0042] When controller 28 is in operation, the processor may be configured to execute software stored in the memory, communicate data to and from the memory, and generally control the operation of the computing device in accordance with the software. The software in the memory is read, in whole or in part, by the processor and often buffered within the processor before being executed.

[0043] In various examples, controller 28 includes one or more modules having algorithm(s), equation(s), and / or decision manager(s) that receive input(s) from sensors and / or stored values. During vehicle operation, controller 28 may use outputs (e.g., display 18, speaker, etc.) to communicate information to the driver, fleet operator, or others.

[0044] One disclosed CMS system is a reversing assistance system that generates trailer trajectory predictions for a reversing maneuver of a vehicle 10. Accurately predicting trailer trajectory during reversing is particularly challenging. One way to improve accuracy is to use an image-based trailer tracking approach, in which a rear-facing camera “searches” for trailer movement and then uses a kinematic model to track the trailer movement. One such approach is described in PCT / US2023 / 079589, filed November 14, 2023, and entitled “TRAILER BACKUP TRAJECTORY OVERLAY USING TRAILER CAMERA DISPLAY SYSTEM.” However, during a reversing maneuver of a commercial truck, the operator must often bring the vehicle to a complete stop, during which the operator may make additional trailer path adjustments via the steering wheel. While there is no trailer movement to track when the vehicle is stopped, determining trailer trajectory based on steering wheel inputs is also unreliable. To address these competing issues, the disclosed method for determining trailer trajectory uses a trailer motion image-based approach, but modifies the trailer trajectory based on steering angle changes if the trailer motion image-based approach is ineffective.

[0045] The trailer trajectory may be used by CMS 15 for a variety of purposes. For example, the trailer trajectory may be used to depict an overlay of a predicted trailer path on one of the displays and / or to predict and avoid potential collisions between the trailer and an object. An example of a displayed output on one of the displays of CMS system 15 is shown in rear-view scene 100 in FIG. 3. The illustrated scene 100 includes a single person 120 and a single tree 130 for ease of explanation, but it will be understood that in an actual example, scene 100 may include more objects, a greater variety of objects, roads, multiple types of objects, etc. In the illustrated example, scene 100 includes at least a portion of the rear end of trailer 14. Scene 100 is displayed on one or more of monitors 18a, 18b, 18c and / or another monitor within the vehicle.

[0046] During a reverse maneuver, CMS 15 determines a predicted rear trajectory (i.e., the expected path of the rear end of trailer 14 and / or the trailer wheel path) and provides the predicted trajectory as an overlay 110 on top of scene 100. Overlay 110 extends from the rear end of trailer 14 into scene 100 and tracks the expected position of the rear end of trailer 14 over time and / or distance. If the predicted trailer trajectory intersects with an object (e.g., person 120), CMS 15 may generate a warning, for example, indicating that a potential collision may occur. The warning may take the form of an audio output to the operator, a shaded identifier 122 in overlay 110, a color change, or any combination thereof. In other examples, any other method of drawing the operator's attention to object 120 may be utilized.

[0047] With continued reference to the scene 100 of FIG. 3, FIG. 4 schematically illustrates a process 300 for generating an overlay 110 related to a trailer trajectory. Initially, CMS 15 receives images from rear-facing camera(s) 20a, 20b, and / or 30, Class II / IV cameras, and other cameras within CMS 15. CMS 15 then uses image analysis techniques to determine the trailer position, for example, by identifying the trailer wheels and / or trailer end positions in three-dimensional (real-world) space from the captured images. The angle of the trailer relative to tractor 12 at the hitch point is also determined from this image analysis technique in a "Determine Trailer End Position and Angle" step 310. In one example, the trailer angle and end position are determined using image analysis alone, without using angle sensors or other sensors other than the image sensors (cameras) of CMS 15 and the captured images. Additionally, during this step, the CMS 15 receives multiple parameters from the vehicle controller, including truck speed, yaw rate, steering angle, gear, and other camera external parameters from the vehicle's CAN bus and / or other sources.

[0048] As the vehicle 10 moves, the trailer end position and angle are calculated multiple times from the images, and the rate of change of the trailer angle and trailer position is determined in step 320, "Estimate Trailer Angle Rate of Change." The rate of change is over a period that can be over time, over distance, or a combination of both. Steps 310 and 320 together comprise a trailer motion image-based approach 305 for determining the trailer trajectory. In one example, the rate of change of the trailer position is determined by applying a Kalman filter to the determined trailer position and trailer angle and additional parameters received from the vehicle controller, with the output of the Kalman filter being the rate of change. The rate of change tracks the change of the trailer position in 3D space and is redetermined at each iteration of process 300. In one example, the trailer angle rate of change and truck speed are converted to trailer position in two perpendicular (x and y) directions. An integral formula calculates the change in trailer end position over a predetermined period (e.g., 1 second, 2 seconds, etc.). With a prediction of the trailer position over the calculated period, a trajectory is obtained by connecting the points.

[0049] Once the trailer rate of change is determined, CMS 15 calculates what the estimated trailer position will be in three-dimensional space at a given time and / or distance interval in "Calculate Trailer End Position" step 330. Process 300 loops (at 335) through step 330 multiple times, with each loop determining the estimated end position at a distinct time and / or distance interval. The time and / or distance intervals, in some examples, are fixed intervals stored in memory of CMS 15. In alternative examples, the time and / or instantaneous intervals may depend on speed, yaw rate, or any other parameter.

[0050] After determining the trailer position for each leg, process 300 combines the trailer positions to generate a predicted trajectory for the end of the trailer in a "Determine Trailer Trajectory in 3D Space" step 340. The trailer trajectory is the route that the trailer (e.g., the trailer end and / or trailer wheels) is expected to travel in three-dimensional space as the trailer end moves from each determined leg to the next determined leg.

[0051] In one example, the complete trajectory connecting the trailer positions in each determined leg is determined using least squares filtering of the trailer's endpoints in each leg, and the resulting curve is the predicted trajectory.

[0052] After determining the 3D trajectory of the trailer end, the 3D trajectory is converted to a two-dimensional graphical overlay in a "Convert 3D Trajectory to 2D Overlay" step 350. This conversion converts the three-dimensional trailer end route into a two-dimensional trajectory through the scene 100 and creates a transparent overlay 110 of the trajectory.

[0053] Once the transparent overlay 110 is created, in an "Apply 2D Overlay to Rear View Display" step 360, the overlay 110 is applied to the image and displayed to the operator.

[0054] The above approach does not consider situations where image analysis cannot be used to accurately track trailer position, such as when the trailer 14 is traveling below a threshold speed (e.g., less than 2 miles per hour (mph)). This is especially true when the vehicle is stationary (0 mph) and the trailer angle rate of change is also zero. In such cases, the trailer trajectory correction 345 method is used.

[0055] Once a zero or near-zero vehicle speed is determined (step 347), the trailer trajectory is corrected (step 348); instead of visually "figuring out" the trailer position based on captured images, changes in the driver's steering angle are determined and a kinematic model is used to predict the trailer trajectory. The trailer trajectory overlay is then corrected based on the steering changes. Once the trailer is moving again so that the trailer motion image-based approach 305 is sufficiently accurate, changes in steering angle do not need to be referenced, although they may be referenced if the driver suddenly changes steering angle.

[0056] In one example, the disclosed method displays (e.g., on displays 18a, 18b, 18c, etc.) an overlay of the trailer trajectory on a displayed captured image from one of the rear-facing cameras (e.g., cameras 20a, 20b, and / or 30). The displayed captured image may be different from or the same captured image used to identify the trailer location. The displayed captured image may be part of a bird's-eye view, a trailer rear view, or other display view (e.g., scene 100 of FIG. 3) for visual communication with the driver.

[0057] In some examples, after determining the trajectory and before applying the overlay to the scene 100, the CMS 15 identifies any objects 120, 130 in the scene 100 that intersect with the trajectory and outputs a warning to the vehicle operator. The warning can take the form of an audio output, a visual indicator (as in the example scene 110), a color change, or any similar warning. Figure 5 shows a method 400 for achieving this warning.

[0058] First, CMS 15 uses image-based object identification techniques to identify objects 120, 130 in scene 100 and identify the two-dimensional positions of the objects in scene 100 in "identify objects in view" step 410. Next, the two-dimensional positions of objects 120, 130 in scene 110 are converted to three-dimensional positions of objects 120, 130 in real space. After determining the three-dimensional trajectories of the ends of trailer 14, CMS 15 compares the three-dimensional position of each object to this trajectory in "compare object positions to trajectory" step 420 and displays a warning if the end of trailer 14 passes through the same three-dimensional space as objects 120, 130 in "generate display warning" step 430.

[0059] In more complex systems, the trajectory of a moving object (e.g., person 120) can be estimated using a similar trajectory estimation process, and the predicted trajectory of the moving object is compared to the predicted trajectory of the end of trailer 14. In such an example, an alert is generated if the object's trajectory intersects with the trajectory of trailer 14 simultaneously or within a predetermined time window (e.g., in the range of 0-10 seconds).

[0060] The disclosed method can perform trailer trajectory prediction at zero vehicle speed by incorporating the dynamic characteristics of steering wheel changes, which provides better accuracy even at large trailer angular velocities during severe maneuvers. As a result, the disclosed method maintains high accuracy even in long-term predictions because it introduces a complete formulation that incorporates trailer angle changes.

[0061] While exemplary embodiments have been disclosed, those of ordinary skill in this art would recognize that certain modifications would come within the scope of the following claims, and for that reason the following claims should be studied to determine their true scope and content.

Claims

1. 1. A method for determining a trailer trajectory of a trailer, comprising: a) while the trailer is moving; a1) determining a trailer position based on at least one captured image; a2) determining a trailer angle rate based on the at least one captured image; a3) determining a trailer trajectory based on the trailer position and the trailer angle rate; a4) displaying an overlay related to the trailer trajectory; b) while the trailer is below a threshold speed; b1) determining a steering change; b2) modifying the trailer trajectory based on the steering change; b3) displaying a modified overlay related to the trailer trajectory based on the steering change; A method comprising:

2. 2. The method of claim 1, wherein steps a) and b) are performed while the trailer is reversing.

3. The method of claim 1 , wherein step a1) is performed by identifying at least one of a trailer wheel and a trailer end.

4. 4. The method of claim 3, wherein step a2) is performed by determining a trailer angle, a change in said trailer angle over the section, and a change in said trailer position over the section.

5. The method of claim 4 , wherein the interval is at least one of a time and a distance.

6. The method of claim 4, wherein step a3) is performed using the trailer positions over the section.

7. The method of claim 1 , wherein steps a4) and b3) are performed by displaying an overlay of the trailer trajectory on a displayed captured image.

8. The method of claim 7 , wherein the displayed captured image is different from the at least one captured image.

9. The method of claim 8 , wherein the displayed captured image is a portion of a bird's eye view or a trailer rear view.

10. The method of claim 7 , wherein the displayed captured image is the same as the at least one captured image.

11. The method of claim 1 , wherein the threshold speed is 2 miles per hour.

12. The method of claim 1 , wherein the threshold speed is zero miles per hour.

13. The method of claim 12 , wherein the trailer angle rate is zero.

14. 2. The method of claim 1, wherein step b1) is performed by obtaining the steering angle from a CAN bus.

15. A camera monitor system (CMS) for a vehicle, comprising: at least one rear-facing camera configured to obtain at least one captured image; at least one display configured to depict the at least one captured image; a CMS controller including a memory and a processor; the CMS controller in communication with the at least one rear-facing camera and the at least one display; The memory is configured by the processor to: a) While the trailer is moving, a1) determining a trailer position based on said at least one captured image; a2) determining a trailer angle rate based on the at least one captured image; a3) determining a trailer trajectory based on the trailer position and the trailer angle rate; a4) displaying an overlay related to the trailer trajectory on one of the at least one display; b) while the trailer is below a threshold speed; b1) determining a steering change; b2) modifying the trailer trajectory based on the steering change; b3) displaying a modified overlay related to the trailer trajectory based on the steering change; a camera monitor system storing instructions for causing the camera monitor system to perform the above steps;

16. Steps a) and b) are performed while the trailer is reversing; 16. The camera monitor system of claim 15, wherein step b1) is performed by obtaining the steering angle from a CAN bus.

17. Step a1) is performed by identifying at least one of a trailer wheel and a trailer end; Step a2) is carried out by determining a trailer angle, a change in said trailer angle over the section, and a change in said trailer position over the section; 16. The camera monitor system of claim 15, wherein step a3) is performed using the trailer position over the section.

18. 16. The camera monitor system of claim 15, wherein steps a4) and b3) are performed by displaying an overlay of the trailer trajectory on the displayed captured image.

19. 16. The camera monitor system of claim 15, wherein the threshold speed is 2 miles per hour.

20. the threshold speed is zero miles per hour; 16. The camera monitor system of claim 15, wherein the trailer angle change rate is zero.

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