Sensor Mounting Height Estimation Using Load Cells
By installing sensors on the vehicle and adjusting their height by using load changes, the problem that load changes affect the accuracy of the sensor is solved, and accurate measurement of vehicle object height and accurate alignment of trailer attachment is achieved, which improves safety and accuracy sex.
Patent Information
- Application Number
- CN201980086190.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2019-04-25
- Filing Date
- 2019-12-03
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2039-12-03
AI Technical Summary
The prior art is affected by changes in external load when estimating the height of objects on or near the vehicle relative to the ground level, resulting in a decrease in the accuracy of sensor readings, especially during the trailer hooking process, which makes it difficult to ensure the trailer hook and receiver. Alignment of the correctness.
The sensor installed on the vehicle adjusts its height relative to the ground through load changes, estimates the vehicle load using tire load or pressure sensors, and then adjusts the position of the sensor to consider load changes and ensures the accuracy of the sensor height.
Improves the accuracy of the sensor to the object height, ensures alignment of the trailer hook and receiver, enhances the safety and accuracy of the hooking process, reduces costs, and avoids the need for additional load sensors.
Smart Images
Figure CN113226807B_ABST
Abstract
Description
Technical Field
[0001] The present invention is a method and apparatus for using sensors on a vehicle to estimate the height of an object relative to ground level, which height may vary based on changes in load. Background Art
[0002] Advanced driver assistance systems (ADAS) include a variety of different types of vehicle systems that help drivers with the driving process. These intelligent systems use many different sensors to automate, adapt, and enhance vehicle systems for safety and better driving. For example, in some situations, it is important to know the height of objects on or near the vehicle relative to the ground. When hooking a trailer to a vehicle, for example, it is important to know the height of the trailer hitch and / or trailer receiver from the ground to determine whether the receiver on the trailer will be properly aligned with the hitch on the vehicle. However, external factors (such as, for example, different loads in the vehicle) can change the distance of the trailer hitch to the ground, which can reduce the accuracy of the sensor readings used to determine the height of the receiver and / or hitch. Summary of the invention
[0003] In one exemplary embodiment, a method provides at least one sensor mounted to a structure on a vehicle. The at least one sensor is located at a sensor height relative to ground level. A first object on the vehicle is positioned at a fixed distance from the at least one sensor and at a variable distance from ground level. The variable distance is estimated based on vehicle load. The sensor height is adjusted based on the variable distance to account for any changes in vehicle load. A second object is spaced a vertical distance from ground level. The adjusted sensor height is used to compare the vertical distance of the second object from ground level.
[0004] In another embodiment in accordance with the previous embodiment, the first object comprises a trailer hitch and the second object comprises a trailer receiver, and wherein the method comprises comparing the variable distance of the first object to the vertical distance of the second object.
[0005] In another embodiment according to any of the previous embodiments, the at least one sensor includes at least one camera.
[0006] In another embodiment according to any of the previous embodiments, the structure includes a tailgate or a lift gate.
[0007] In another embodiment according to any of the previous embodiments, the controller is configured to estimate the variable distance as a function of the vehicle load by determining a weight of the vehicle load.
[0008] In another embodiment according to any of the previous embodiments, the method includes determining the weight of the vehicle load is accomplished using at least one tire load or pressure sensor in communication with the controller.
[0009] In another embodiment according to any of the previous embodiments, the at least one tire load or pressure sensor is part of an electronic tire information system.
[0010] In another embodiment according to any of the previous embodiments, the vehicle load is located in a cargo area supported by rear tires of the vehicle, and wherein the at least one tire load sensor includes a plurality of tire load sensors, wherein at least one tire load sensor is associated with each rear tire, and wherein the method includes: estimating the load of each rear tire using tire load or pressure sensors in the rear tires; and estimating the variable distance using the average load on the rear tires.
[0011] In another embodiment according to any of the previous embodiments, the vehicle load is located in a cargo area supported by rear tires of the vehicle, and wherein the at least one tire load sensor includes a plurality of tire load sensors, wherein at least one tire load sensor is associated with each rear tire, and wherein the method includes: estimating the load of each rear tire using tire load or pressure sensors in the rear tires; and estimating the variable distance using the measured loads of all rear tires.
[0012] In another exemplary embodiment, an apparatus includes at least one sensor mounted to a structure on a vehicle. The at least one sensor is located at a sensor height relative to ground level. A first object is located on the vehicle at a fixed distance from the at least one sensor and at a variable distance from ground level. A second object is spaced a vertical distance from ground level. A controller is configured to: estimate the variable distance based on vehicle load; adjust the sensor height based on the variable distance to account for any changes in vehicle load; and use the adjusted sensor height to compare to the vertical distance.
[0013] In another embodiment according to any of the previous embodiments, the first object includes a trailer hitch and the second object includes a trailer receiver, and wherein the controller compares the variable distance to the vertical distance to determine whether the trailer hitch and the trailer receiver are aligned with each other in the longitudinal direction.
[0014] In another embodiment according to any of the previous embodiments, the structure includes a tailgate or a lift gate.
[0015] In another embodiment according to any of the previous embodiments, the at least one sensor is positioned near an upper edge of a tailgate or liftgate, and wherein the trailer hitch is located on a lower edge of the tailgate or liftgate, and wherein the fixed distance and the variable distance are added together to determine the distance of the at least one sensor from ground level.
[0016] In another embodiment according to any of the previous embodiments, the controller is configured to estimate the variable distance as a function of the vehicle load by determining a weight of the vehicle load.
[0017] In another embodiment according to any of the previous embodiments, the apparatus comprises at least one tire load or pressure sensor, and wherein the controller is configured to determine the weight of the vehicle load by using data from the at least one tire load or pressure sensor.
[0018] In another embodiment according to any of the previous embodiments, the at least one tire load or pressure sensor is part of an electronic tire information system in communication with the controller.
[0019] In another embodiment according to any of the previous embodiments, the vehicle load is located in a cargo area supported by rear tires of the vehicle, and wherein the at least one tire load or pressure sensor includes a plurality of tire load or pressure sensors, wherein at least one tire load or pressure sensor is associated with each rear tire, and wherein the controller uses data from the tire load or pressure sensors in the rear tires to estimate the load of each rear tire and uses the average load on the rear tires to estimate the variable distance.
[0020] In another embodiment according to any of the previous embodiments, the vehicle load is located in a cargo area supported by rear tires of the vehicle, and wherein the at least one tire load or pressure sensor includes a plurality of tire load or pressure sensors, wherein at least one tire load or pressure sensor is associated with each rear tire, and wherein the controller uses data from the tire load or pressure sensors in the rear tires to estimate the load of each rear tire and uses the measured loads of all rear tires to estimate the variable distance.
[0021] In another embodiment according to any of the previous embodiments, the controller adjusts the variable distance based on changes in vehicle load to provide an adjusted distance of the at least one sensor from ground level, and then compares the vertical distance of the second object from ground level to the adjusted variable distance.
[0022] In another embodiment according to any of the previous embodiments, the at least one sensor comprises at least one camera. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The present disclosure may be further understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:
[0024] Figure 1 is a schematic illustration of a vehicle and trailer having a height estimation system incorporating the present invention.
[0025] The embodiments, examples and alternatives of the preceding paragraphs, claims or the following description and drawings (including any of their various aspects or respective individual features) may be taken independently or in any combination. Features described in conjunction with one embodiment are applicable to all embodiments, unless such features are incompatible. DETAILED DESCRIPTION
[0026] Figure 1 A vehicle 10 and a trailer 12 to be hitched to the vehicle 10 are shown. In this example, the vehicle 10 is a pickup truck type train and includes a cargo box 14 extending over a pair of rear wheels 16 (only one rear wheel is shown). The vehicle 10 includes a tow ball or hitch 18 that is coupled to a receiver 20 on the trailer 12. At least one ADAS sensor 22 is located on a rear structure 24 of the vehicle 10. In this example, the rear structure 24 includes a tailgate; however, the rear structure may also include a lift gate or other similar structure. For example, the ADAS sensor 22 may include one or more of a motion sensor, an optical camera sensor, a radar sensor, a lidar sensor, a laser sensor, and / or an ultrasonic sensor. In this example, the ADAS sensor 22 includes at least one optical camera sensor.
[0027] Figure 1 A vertical direction Z and a horizontal or longitudinal direction X (i.e., direction of travel) are shown. The hook 18 is typically located at the lower edge of the vehicle body and extends outward from the frame or chassis in the longitudinal direction X. The ADAS sensor 22 is mounted near the upper edge of the tailgate and has a known fixed height H1 relative to the lower edge of the hook 18 or the vehicle body in the vertical direction Z. There is also a variable height ΔH between the lower edge of the hook 18 or the vehicle body and the ground G. This height ΔH can vary due to the load 26 placed in the cargo box 14. Heavier loads reduce the height ΔH, and when the load is lightened, the height ΔH increases. The receiver 20 extends from the trailer 12 toward the hook 18 in the longitudinal direction X. The receiver 20 is located at a height H2 above the ground G, which is known or measured.
[0028] Cameras and other vision-based sensors can be used to estimate the height of objects above the ground G away from the vehicle 10, such as the trailer receiver 20. An example method and system for determining the height of objects above the ground away from the vehicle 10 is found in US 16 / 364 / 151, assigned to the same assignee and hereby incorporated by reference.
[0029] In the disclosed example, the ADAS sensor 22 is used to determine whether the hitch 18 is aligned with the receiver 20 such that the hitch 18 will collide with the receiver 20 to connect the trailer 12 to the vehicle 10. To make this determination, the vertical position of the hitch 18 and the receiver 20 relative to the ground G must be known with a high degree of accuracy. In this case, monocular cameras are the preferred sensor type because they are used to implement numerous functions, such as automated trailer hitching, trailer back-up assist, driver rear view, etc.
[0030] In order to accurately estimate the height of an object above the ground G using such a sensor, the effective height of the sensor 22 above the ground must be known. The effective height of the sensor 22 relative to the ground G is determined by the fixed mounting height H1 between the sensor 22 and the hook 18 on the frame or chassis, which is then added to the variable height ΔH. The variable height component is vehicle load dependent. The system detects any changes in the height of the sensor 22 relative to the ground G due to changes in the load 26.
[0031] As discussed above, a load is located in the cargo box 14 supported by the rear wheels 16. Each wheel 16 includes a tire 28. In one example, a load or pressure sensor 30 in the rear tires 28 is used to estimate the load of each tire 28. Each rear tire 28 includes at least one load or pressure sensor 30. A load sensor 30 is schematically indicated at 30a. Figure 1 30a communicates tire pressure or load data to the controller C. For example, the controller C can monitor the tire pressure over time to determine any changes due to an increase or decrease in cargo load. Thus, the system is set with a first or initial height for ΔH, and then adjusts the height ΔH based on changes in cargo load.
[0032] In a simple solution example, the system uses the average load on the rear tires 28 to estimate the sensor height (H1 + ∆H) of the rear sensor 22 (e.g., camera). In a more complex solution example, the measured loads of all tires are used. Thus, the sensor height (H1 + ∆H) is constantly adjusted in response to changes in the variable height ∆H. This significantly improves the accuracy of the sensor height, thereby then allowing the sensor 22 to make a more accurate comparison of the variable height to the height H2.
[0033] In one example, the system uses the camera sensor 22 to estimate the height of the receiver 20 relative to the ground level G, such as estimating the height H2 of the receiver 20. The camera sensor 22 and the pressure sensor 30, 30a communicate data to the system controller C. The system uses the load data from the load or pressure sensor 30 to determine the variable height ΔH, which is then added to the fixed height H1 to determine the actual real-time height of the sensor 22 from the ground G. Therefore, the accuracy of the sensor 22 is improved because its height relative to the ground G has been corrected to adjust for the load 26. Therefore, the reading of the sensor to determine the height H2 of the receiver 20 relative to the ground is more accurate. Further, the determination of the variable height ΔH of the hook 18 relative to the ground G for comparison with the receiver height H2 is more accurate because the variable height ΔH takes into account the changes in the load 26.
[0034] In one example, the load sensor 30 is part of an electronic tire information system (eTIS). This system is an electronic system that uses tire sensors to monitor tire pressure, load, etc. Using sensors from this system reduces costs because no additional load sensors are required. The controller C can be part of the eTIS, or can be a separate controller that communicates with the eTIS.
[0035] The present invention provides improved accuracy over prior designs because the height of the camera sensor 22 is corrected or adjusted based on vehicle load information.
[0036] It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiments, other arrangements will benefit therefrom. Although a particular sequence of steps is shown, described, and claimed, it should be understood that unless otherwise indicated, the steps may be performed in any order, separately or in combination and will still benefit from the present invention.
[0037] Although the different examples have specific components shown in the drawings, embodiments of the invention are not limited to those specific combinations. It is possible to use some components or features from one of the examples in combination with features or components from another example.
[0038] Although example embodiments have been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. Therefore, the following claims should be studied to determine their true scope and content.
Claims
1. A method comprising: providing at least one sensor mounted to a structure on a vehicle, the at least one sensor being located at a sensor height (H1+ΔH) relative to ground level; positioning a first object on the vehicle at a fixed distance (H1) from the at least one sensor and at a variable distance (ΔH) from ground level; estimating the variable distance (ΔH) based on vehicle load; determining the sensor height (H1+ΔH) based on the variable distance (ΔH) to account for any changes in the vehicle load; estimating a height (H2) of a second object at a vertical distance from ground level based on the sensor height; and The sensor height is compared to the vertical distance of the second object from ground level.
2. The method according to claim 1, wherein: The first object comprises a trailer hitch and the second object comprises a trailer receiver.
3. The method according to claim 1, wherein: The at least one sensor includes at least one camera.
4. The method according to claim 1, wherein: The structure includes a tailgate or a liftgate.
5. The method according to claim 1, wherein: Estimating the variable distance based on a vehicle load includes determining a weight of the vehicle load.
6. The method according to claim 5, wherein: Determining the weight of the vehicle load includes determining the weight of the vehicle load using at least one tire load or pressure sensor.
7. The method according to claim 6, wherein: The vehicle load is located in a cargo area supported by rear tires of the vehicle, and wherein the at least one tire load sensor includes a plurality of tire load sensors, wherein at least one tire load sensor is associated with each rear tire, and wherein the method includes: estimating the load of each rear tire using the tire load or pressure sensors in the rear tires; and estimating the variable distance using an average load on the rear tires or using measured loads of all rear tires.
8. A device comprising: at least one sensor mounted to a structure on the vehicle, the at least one sensor being located at a sensor height relative to ground level; a first object located on the vehicle at a fixed distance from the at least one sensor and at a variable distance from ground level; as well as A controller configured to: estimating the variable distance based on vehicle load, The sensor height is determined based on the variable distance to account for any changes in the vehicle load, estimating a height of a second object at a vertical distance from ground level, and comparing the sensor height to the second object's vertical distance from ground level.
9. The device according to claim 8, wherein: The first object comprises a trailer hitch and the second object comprises a trailer receiver, and wherein the controller compares the variable distance to the vertical distance to determine whether the trailer hitch and trailer receiver are vertically aligned with each other.
10. The device according to claim 9, wherein: The structure includes a tailgate or a liftgate.
11. The device according to claim 10, wherein: The at least one sensor is positioned near an upper edge of the tailgate or liftgate, and wherein the trailer hitch is located on a lower edge of the tailgate or liftgate, and wherein the controller is configured to determine a distance of the at least one sensor from ground level by adding the fixed distance to the variable distance.
12. The device according to claim 11, wherein The controller is configured to estimate the variable distance based on the vehicle load by determining the weight of the vehicle load, and the device includes at least one tire load or pressure sensor, and wherein the controller is configured to determine the weight of the vehicle load by using data from the at least one tire load or pressure sensor.
13. The device according to claim 12, wherein: The at least one tire load or pressure sensor is part of an electronic tire information system in communication with the controller.
14. The device according to claim 13, wherein: The vehicle load is located in a cargo area supported by rear tires of the vehicle, and wherein the at least one tire load or pressure sensor includes a plurality of tire load or pressure sensors, wherein at least one tire load or pressure sensor is associated with each rear tire, and wherein the controller estimates the load of each rear tire using the data from the tire load or pressure sensors in the rear tires and estimates the variable distance using an average load on the rear tires or a measured load for all tires.