Auto binary signals proof 2018 trailers
The present application claims the filing benefits of U. The present invention relates generally to rear vision systems for vehicles and, more particularly, to rear vision systems having a auto binary signals proof 2018 trailers facing camera at a rear portion of a vehicle. Rear backup cameras and vision systems are known for use in vehicles. Examples of such systems are described in U. Such systems may display images for viewing by the driver of the vehicle that provide a view rearward of the vehicle.
The present invention provides a means for detecting the angle of a trailer being pulled behind a vehicle by using a rear view camera or multi-camera surround view system or the like. A camera is mounted at a rear end or rear portion of the pulling vehicle, with the camera having a rearward field of view auto binary signals proof 2018 trailers as a wide angle rearward field of view rearward of the vehicle.
A processor, such as a digital processor or FPGA or digital signal processor DSP or ASIC or camera imager SOC or other suitable processing means or the like, may process the images or image data as captured by the rearward facing camera of the trailer being pulled or towed by the vehicle and may determine the angle of the trailer in relation to the pulling vehicle in real time.
These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings. Referring now to the drawings and the illustrative embodiments depicted therein, a rear vision system for a vehicle is operable to detect the angle of a trailer 10 that is pulled behind a vehicle 12 by using rear view camera or multi-camera surround view system.
Auto binary signals proof 2018 trailers camera is mounted at the rear end portion of the pulling vehicle An image processor such as a digital processor or FPGA or DSP or ASIC or camera imager SOC or other suitable processor or processing means is operable to process the images of the trailer and determines the angle of the trailer in relation to the pulling vehicle in real time.
The detection of the trailer angle relative to the vehicle auto binary signals proof 2018 trailers accomplished by detecting a portion of the trailer and determining the location of the detected portion relative to the towing vehicle, whereby the angle can be determined or calculated based on known geometries of the trailer and vehicle and the location of the camera on the vehicle.
The detection of the trailer portion or target can be done with an added target 14 on the trailer 10 or without an added target on the trailer whereby the camera and processor may operate to detect a particular known or selected portion of the trailer. If a target or icon or indicia or the like is added to the trailer, the added target may, for example, be printed on a paper sheet, a plastic sheet or a reflective sheet or the like, which may be adhered to or otherwise disposed at or attached to a forward portion of the trailer, auto binary signals proof 2018 trailers optionally, the target may be otherwise established at or on the trailer, such as, for example, by painting or etching or otherwise establishing a target or icon or the like on a wall or panel or other forward portion of the trailer such as a portion or structure of the tongue or frame of the trailer or the like.
An example of a using an added target to a trailer is shown in FIG. By processing the images captured by the rearward facing camera and recognizing or identifying the target in the captured image and finding or auto binary signals proof 2018 trailers the coordinates of the target in a captured image, the trailer angle relative to the vehicle can be determined.
By repeating the above steps on multiple frames of the continuous video images, the change of trailer angle can be tracked continuously and in real time. The target 14 may comprise any suitable shape or icon or indicia or the like.
For example, the target may be in the shape of a cross, a triangle, a circle, or any other shape or shapes, or multiples of any suitable shape or shapes, or any suitable combination of shapes preferably having sharp lines or structure that can be readily detected and identified via image processing. The target can be mounted on a wall or a surface or a structure of the trailer that is near or facing the camera at the rear end of the pulling vehicle.
Optionally, the target can be mounted at or established on the tongue 1 Ob of the trailer, which is the structure that connects the trailer to the trailer hitch 12a of the towing or pulling vehicle The target may be detected and recognized via any suitable image processing and algorithms, For example, suitable or auto binary signals proof 2018 trailers target detecting algorithms include a regressive 2-D histogram that searches for and detects the center of a pattern such as a pattern like the cross or intersecting lines in FIG.
Another suitable type of algorithm is an edge detection algorithm. Optionally, and desirably, a target with designed high contrast edges may be used. With such an application, the processor can detect and track the trailer angle at the rear of the vehicle by detecting and locating and tracking or monitoring the coordinates of these signature edges.
Another suitable type of algorithm is image pattern matching, which will be described in detail below. In the case of detection without an added target, a part or structure of the trailer may be identified and used as the "target" for image processing. Because an added target such as described above can be worn off, blown away by wind, or soiled by dirt, the addition of a separate target may affect or reduce the trailer angle detection accuracy in certain situations.
Thus, a trailer angle detection system that does not include an add-on target on the trailer may be preferred. An example of such a trailer angle detection and tracking system is shown in FIG. As shown in FIG. An image processing algorithm, such as an image pattern matching algorithm running on the digital processor, finds and matches the template with the auto binary signals proof 2018 trailers in the captured image.
If the pattern is matched, the auto binary signals proof 2018 trailers pattern's coordinates in the image and the rotating angle of the matched pattern is determined by the algorithm. The trailer angle can then be calculated from these values.
The coordinates of the detected target in a captured image can be further transformed to the angle of trailer by applying a set of formulas. The formula can be implemented in the processor auto binary signals proof 2018 trailers the form of a set of arithmetic formulas, or may be implemented in the form of a look up table or tables. The formula is formed and determined by the dimensional.
The rear view camera-based trailer angle detection can be used in, but is not limited to, several applications, including a trailer sway detection system that detects a sway or swing of the trailer while the vehicle is towing the trailer in a forward direction along a road or highwaya rearward backup assist system that detects the angle of the trailer and determines a reversing path or trajectory of the trailer during a reversing maneuver of the vehicle and trailerand a trailer hitching system that detects the trailer and guides the driver during backing up of the vehicle towards a trailer so that the trailer hitch of the vehicle is generally aligned with the tongue of the trailer.
When a trailer is pulled behind a vehicle at a relatively high speed, a lateral swing or sway of trailer can cause instability of the trailer and its pulling vehicle. By detecting the trailer angle in real time, the system of the present invention can detect the auto binary signals proof 2018 trailers of lateral swing or sway of the trailer and may, responsive to such a detection, alert the driver of the swing or sway or control one or more vehicle or trailer systems or accessories to compensate for the detected swing or sway of the trailer.
For example, the system may, responsive to a detection of a threshold degree of a lateral swing or sway of the trailer relative to the vehicle, be operable to generate an alert signal to the driver of the auto binary signals proof 2018 trailers such as an audible alert or visual alert or haptic alert or the like to alert the driver of a potentially hazardous situation.
Optionally, a steering wheel angle control that may control or adjust the steering angle of the vehicle's wheels or the like can also be part of closed loop control of trailer sway. This reading can auto binary signals proof 2018 trailers used in real time trailer sway control.
The normal view of a backup camera on a trailer pulling vehicle is typically blocked by the trailer, and thus such a backup camera cannot provide visual backup assistance to the driver when the trailer is attached to the vehicle. However, the camera system of the present invention is operable to detect the angle of the trailer axis with respect to the pulling vehicle, and with the knowledge of the trailer dimensional characteristics such as wheel position and distance from the vehicle and the likethe processor can calculate and project a trajectory or reversing path of the trailer in the form of graphic overlay on the camera display or video display typically disposed in the vehicle, such as at or in or near an interior rearview mirror assembly of the vehicle to indicate to the driver viewing the video display a path or trajectory of where the trailer is backing up to.
In addition, when the trailer pulling or towing vehicle is equipped with side view cameras, the added views provided by the side cameras typically having fields of view directed generally rearwardly and sidewardly with respect to the direction of forward travel of the equipped vehicle can provide additional scene information of the trailer to assist the driver of the vehicle viewing the images at a video display of the vehicle during a reversing or backing up maneuver.
The calculated graphical trailer path can be overlaid to the side camera image to further assist the driver of the vehicle during a reversing or backing up maneuver.
The alert may comprise any suitable alert, such as an alarm or tone or audible alert or a visual alert such as a highlighting of the displayed video images or the like in response to a detection of an object rearward of or at or near the rearward path of the trailer. Backing up a vehicle to hitch a trailer is not always intuitive process.
If the position of the trailer hitching part is detected by identifying the tongue of the trailer that is to be attached to the vehicle, the processor can calculate a trajectory of the vehicle's hitch and guide the driver to turn the steering wheel of the vehicle and follow the trajectory to back the vehicle up to and in alignment with the trailer tongue for hitching the trailer to the vehicle. It is also envisioned that the control system may automatically turn the steering wheel of the vehicle to follow the calculated trajectory to position the vehicle's hitch at the trailer tongue for hitching the trailer to the vehicle.
During the backing up process, a real time detection and tracking of a target at or on the trailer provides feedback and adjustment to the turning or control of the steering wheel of the vehicle.
Thus, the present invention provides a trailer monitoring system that may detect the angle of a trailer being towed by a vehicle relative to a longitudinal axis of the towing vehicle. Optionally, the trailer angle detection system may assist the driver in backing up the trailer, such as via providing a graphic overlay at a video display of the vehicle, so as to guide the driver during a reversing maneuver with the trailer rearward of the vehicle.
Optionally, the trailer angle detection system may assist the driver in backing up to an unhitched trailer to assist the driver in aligning the vehicle hitch with the tongue of the trailer. As discussed above, a pattern searching image algorithm based on image histogram can be used to detect the target. A cross-shaped target such as a cross-shaped target at auto binary signals proof 2018 trailers trailer of FIG. The auto binary signals proof 2018 trailers can be a white cross on a black background such as shown in FIG.
Optionally, a colored cross shape pattern may also be used, but it is preferred that the colors be selected so that the cross and the background have good contrast in the captured images. An initial pattern search may be conducted in the image auto binary signals proof 2018 trailers roughly locate the cross shaped target. This may be achieved by a similar pattern matching that involves a pre-recorded pattern template. After the rough location of the center of the cross is located, a smaller window is drawn around the cross center.
The window may be, for example, about 32 by 32 pixels in size. The histogram is separately done in rows vertical histogram and columns horizontal histogram. Each row and auto binary signals proof 2018 trailers is one pixel wide. The pixel brightness is summed in each row and column. The row and column with maximum summed values represent or are indicative of the center of the target or cross.
The center of the target or the pixel auto binary signals proof 2018 trailers of the center of the cross is used to represent the trailer angle.
The histogram computation of the center of the target may be performed on every frame that the rear view camera generates. The target center coordinate may be used as the center of the histogram window for next frame. This provides a good tracking of the target when the trailer turns and target auto binary signals proof 2018 trailers in the image. A graphical depiction of the histogram is shown in the FIGS. In order to reach a higher or enhanced accuracy for a trailer angle reading from the cross- shaped target, the sub-pixel resolution of the target location may be utilized.
One example of such sub-pixel searching may, once the histogram of row and column in the search window produces a location of the cross target center coordinates, compute a sub-pixel center using the center of mass method. The center of mass computation is auto binary signals proof 2018 trailers separately to columns and rows.
In column center of mass computation, the following steps are taken:. Treating the column sums auto binary signals proof 2018 trailers mass, the center of mass is computed by the following.
The numerator auto binary signals proof 2018 trailers denominator are computed separately and converted from integer to floating point numbers, and the center of mass in column dimension coordinates is computed accordingly in the form of floating point number. The center of mass in row dimension is computed in the same method as the column center of mass.
The new and higher resolution center of target coordinate is thus calculated. With this approach, about a one degree of trailer angle resolution and accuracy may be achievable. Some deviation of the above formulas and computation can also produce the same or similar results. For example, instead of subtracting by the column average, auto binary signals proof 2018 trailers column could be subtracted by the minimum sum across all columns. The methods other than center of mass method described above can also be used to reach sub-pixel resolution.
It is in the same spirit of using a plurality of pixels to reach sub-pixel resolution. As described above, the system may utilize pattern matching of a feature on a trailer tongue to measure the trailer angle with a rear view camera in the trailer pulling vehicle. A pattern template maybe pre-generated and stored in the system memory and may be searched and matched in the real time camera images. When a pattern is matched, the position and angle of the pattern are calculated.
The position and angle information of the matched pattern in the image can be used to calculate the trailer angle. However, using a native feature on the trailer sometimes may not produce accurate enougli position and angle information, because the feature to be matched does not always stand distinctly from its surrounding; therefore pattern matching algorithm may produce inaccurate results. In order to address this potential issue, a technique of color pattern matching with a simple and effective is discussed below.
The color pattern matching technique of the present invention has the advantage of having one more matching criteria pattern and colorthan the pattern matching technique described above, which relies on only monochrome geometric features and auto binary signals proof 2018 trailers.
As a result, the matching reliability and accuracy of color pattern matching is improved and enhanced as compared to that of monochrome pattern matching. In the implementation of this invention, certain colors are preferable than others. For example, red and green color patterns are more readily discernible and processable as compared to, for example, blue, yellow and orange colors, since there are often dividing lines and signs on the road surface and parldng ground or areas with blue, yellow and orange colors, yet there are relatively fewer red and green dividing lines and signs on auto binary signals proof 2018 trailers road surface and parking ground or areas.
In addition, a pattern with a mix of different colors can be used to further increase pattern matching accuracy. In order to increase the pattern matching accuracy of the system, a simple color target may be disposed at or on the trailer tongue structure and the system may process the images to detect the orientation of the color target instead of using existing or native features or patterns on the trailer tongue.
The color target may comprise a color tape applied to certain portions of the trailer or trailer tongue such as colored duct tape or the like that one can easily purchase from a hardware store.
Put another way, auto binary signals proof 2018 trailers PrEP users do not get a prescription because they are apprehensive of potential judgment, and healthcare providers are wary of prescribing it for fear of giving license to riskier sexual behavior. One study showed that surveyed medical students were more likely to presuppose a hypothetical black MSM patient would engage in barebacking compared to a hypothetical white MSM patient; study participants were less willing to prescribe the auto binary signals proof 2018 trailers PrEP.
Another study showed limited racial bias from its sampled medical students, but those students expressing greater heterosexism more strongly anticipated increased risk behavior and adherence problems, which were associated with lower prescribing intention. At any rate, most of the sampled students expected more risk compensation should MSM patients be prescribed PrEP.