Route-based autonomous driving and obstacle avoidance

Abstract

The method for autonomously defining a route for a vehicle according to the disclosed exemplary embodiment includes, inter alia: Detecting an object located within a predetermined path using a sensor system within the vehicle; defining an avoidance interval around the detected object using a vehicle control system within the vehicle; defining a line of sight distance about a portion of the vehicle using a vehicle control system; Detecting an intersection of an avoidance interval and a visibility interval using a vehicle control system; and altering the route of the vehicle based on the intersection of the avoidance interval and the visibility interval.

Description

[Technical Field]

[0001] The present invention relates to an autonomous vehicle control method and system for rerouting a vehicle around obstacles along a reference path. [Background technology]

[0002] Autonomous driving and driver assistance systems gather information about the environment surrounding a vehicle and use that information to plan and navigate along a desired path. Traveling along a desired path requires detection of any objects that are present in the environment surrounding the vehicle and along the path. If an object is detected along the path, the autonomous system may modify the path to move around or past the object. However, any modification may require additional information and may accumulate large amounts of information and data that may be difficult to process. Automobile manufacturers are constantly seeking more efficient methods of processing information to improve the operation of vehicle systems.

[0003] The discussion of the background art provided herein is intended to generally present the context for the present disclosure. The inventors' work is not admitted expressly or implicitly as prior art to the present disclosure to the extent described in this background art section, nor in described aspects that are not considered prior art at the time of filing. Summary of the Invention [Means for solving the problem]

[0004] A method for autonomously defining a path for a vehicle according to disclosed exemplary embodiments includes, among other things, detecting an object located in a predetermined path using a sensor system within the vehicle; defining an avoidance interval around the detected object using a vehicle control system within the vehicle; defining a sight interval centered on a portion of the vehicle using the vehicle control system; detecting an intersection of the avoidance interval and the sight interval using the vehicle control system; and altering the path of the vehicle based on the intersection of the avoidance interval and the sight interval.

[0005] In another exemplary embodiment of the above method, the avoidance interval around the detected object comprises a circular region centered on the object.

[0006] In another exemplary embodiment of any of the aforementioned methods, the circular area of ​​the avoidance clearance includes a radius equal to at least half the width of the vehicle.

[0007] In another exemplary embodiment of any of the aforementioned methods, the line-of-sight interval comprises a circular area and the vehicle portion comprises a midpoint of an axle of the vehicle that controls the direction in which the vehicle is headed.

[0008] In another exemplary embodiment of any of the aforementioned methods, the circular area of ​​the line of sight distance includes a radius that is at least half the width of the vehicle.

[0009] In another exemplary embodiment of any of the aforementioned methods, altering the route of the vehicle further includes realigning the predetermined route at an intersection between the avoidance interval and the line of sight interval.

[0010] In another exemplary embodiment of any of the aforementioned methods, the intersection between the avoidance interval and the line of sight interval includes two intersections.

[0011] Another example embodiment of any of the aforementioned methods further includes selecting one of the two intersections to realign the predetermined path.

[0012] In another exemplary embodiment of any of the aforementioned methods, selecting one of the two intersections includes comparing a distance between each of the two intersections to a constraint that limits movement of the vehicle, and selecting the intersection that is a greater distance from the constraint.

[0013] In another exemplary embodiment of any of the aforementioned methods, the constraints include predetermined boundaries separating different road surfaces.

[0014] In another exemplary embodiment of any of the aforementioned methods, the constraints include a predetermined boundary, the predetermined boundary including an object extending above the road surface.

[0015] According to another exemplary embodiment, an autonomous vehicle control system includes, among other things: A control device that can be mounted in a vehicle is provided, and the control device Detecting an object located within a predetermined path using a sensor system within the vehicle; defining an avoidance clearance around the detected object using a vehicle control system within the vehicle; defining a line of sight distance centered on a portion of the vehicle using a vehicle control system; Detecting an intersection between the avoidance interval and the visibility interval using a vehicle control system; modifying the vehicle's route based on the detected intersection between the avoidance interval and the line of sight interval; It is structured as follows.

[0016] In another embodiment of the aforementioned autonomous vehicle control system, the avoidance clearance around the detected object includes a circular region centered on the object having a radius equal to at least half the width of the vehicle.

[0017] In another embodiment of any of the aforementioned autonomous vehicle control systems, the line-of-sight interval includes a circular area and the vehicle portion includes a midpoint of the vehicle's axle that controls the direction the vehicle is heading.

[0018] In another embodiment of any of the aforementioned autonomous vehicle control systems, the controller is further configured to realign the predetermined path based on a location of an intersection between the avoidance interval and the line of sight interval.

[0019] In another embodiment of any of the aforementioned autonomous vehicle control systems, the intersection between the avoidance interval and the line of sight interval includes two intersections, and the controller is further configured to select one of the two intersections for realigning the predetermined path.

[0020] In another embodiment of any of the aforementioned autonomous vehicle control systems, the controller is configured to compare the distance between each of the two nodes to a constraint that limits the movement of the vehicle, and select the node that is the greater distance from the constraint.

[0021] In another embodiment of any of the aforementioned autonomous vehicle control systems, the controller is configured to recognize the constraint as one of predetermined boundaries separating different road surfaces and objects extending above the road surface.

[0022] 1. A non-transitory computer-readable storage medium containing instructions for operating an autonomous vehicle control system, comprising: According to another exemplary embodiment, a computer-readable storage medium includes, among other things: instructions to instruct the controller to detect objects located within the predetermined path using a sensor system within the vehicle; instructions to direct a controller to define, using a vehicle control system within the vehicle, an avoidance clearance around the detected object; instructions to direct a controller to define a line-of-sight interval centered on a portion of the vehicle using a vehicle control system; instructions to direct a controller to detect an intersection between an avoidance distance and a visibility distance using a vehicle control system; instructions to direct the controller to alter the path of the vehicle based on the detected intersection between the avoidance interval and the visibility interval; Includes:

[0023] Another embodiment of the aforementioned non-transitory computer-readable storage medium further includes instructions for directing the controller to compare a distance between each of the nodes and a constraint that limits movement of the vehicle, and to select the node having a farther distance from the constraint.

[0024] Although the different examples have specific components shown in the examples, embodiments of the present disclosure are not limited to those specific combinations. Some of the components or features from one of the examples can be used in combination with features or components from another one of the examples.

[0025] These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic diagram of one embodiment of a vehicle that includes an autonomous vehicle control system. [Figure 2] FIG. 2 is a schematic diagram of a map defined by an autonomous vehicle control system. [Figure 3] FIG. 3 is a schematic diagram of a vehicle positioned along a reference path relative to an obstacle. [Figure 4] FIG. 4 is another schematic diagram of a vehicle and the avoidance distance circles and line-of-sight distance intersections for an obstacle. [Figure 5] FIG. 5 is a schematic diagram of one embodiment of a vehicle navigating around an obstacle. [Figure 6] FIG. 6 is a flow diagram illustrating method steps for an exemplary autonomous control system. DETAILED DESCRIPTION OF THE INVENTION

[0027] Referring to FIG. 1 , a vehicle 22 is shown schematically, including a driver assistance control system 20. The driver assistance control system 20 utilizes information from multiple sensors to detect objects within a reference path and to make any necessary path modifications to account for the detected obstacles. The vehicle 22 is positioned along a centerline 26, and the vehicle 22 has a width 24. In the disclosed embodiment, the control system 20 obtains information from at least one of a radar sensor system 38, a camera system 40, and / or a lidar system 42. While several sensor systems are disclosed as examples, it should be understood that other sensor systems may be utilized within the scope and spirit of the present disclosure.

[0028] The control system 20 receives information from a vehicle controller 30. The exemplary vehicle controller 30 includes a processor 32 and a memory device 34. A plurality of instructions 36 are stored in the memory device 34 that instruct the controller to operate the control system to move the vehicle along a desired reference path.

[0029] The exemplary controller 30 may be a separate controller dedicated to the control system 20 or may be part of an overall vehicle control system. Thus, the exemplary controller 30 relates to devices and systems for performing the necessary calculations or computational operations of the control system 20. The controller 30 may be specially constructed for the operation of the control system 20, or may comprise at least a general-purpose computer selectively activated or reconfigured by software instructions 36 stored in a memory device 34. The computing system may also consist of a network of (different) processors.

[0030] The exemplary vehicle controller 30 includes a processor 32 and a memory device 34. The memory device 34 provides storage of software instructions 36 that facilitate the operation of the controller 30 and the control system 20. The software instructions 36 may be embodied in a computer program that uses data obtained from sensor systems 38, 40, and 42 and data stored in the memory device 34 that may be required for its execution.

[0031] Instructions 36 for configuring and operating controller 30, control system 20, and processor 32 are embodied in software instructions that may be stored on a computer-readable medium, generally designated 35. Computer-readable medium 35 may be embodied in any type of disk, including, but not limited to, a floppy disk, an optical disk, a CD-ROM, a magneto-optical disk, read-only memory (ROM), random-access memory (RAMS), an EPROM, an EEPROM, a magnetic or optical card, an application-specific integrated circuit (ASIC), or any type of medium suitable for storing electronic instructions, and each structure coupled to a computer system bus. The disclosed computer-readable medium may be a non-transitory medium, such as these examples provided.

[0032] Additionally, the software instructions 36 may be stored in a memory device 34. The disclosed memory device 34 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.). The software instructions 36 in the memory device 34 may include one or more separate programs, each of which includes an ordered list of executable instructions for implementing a logical function. The disclosed controller 30 is configured to execute the software instructions 30 stored in the memory device 34, communicate data to and from the memory device 34, and generally control operations in accordance with the software. The software in the memory may be read, in whole or in part, by the processor 32, possibly buffered within the processor, and then executed.

[0033] With continued reference to FIG. 1 and with reference to FIG. 2, a map 44 is defined by the control system 20 with information obtained from the sensor systems 38, 40, 42 to provide definition of a reference path 48. The map 44 may be created according to instructions 36 stored in the memory device 34. In the disclosed embodiment, the map 44 defines a boundary 46 and a reference path 48 for the vehicle to follow to a target destination 45. The boundary 46 may be a boundary indicating the edge of a driving surface. In either of these examples, the map 44 is utilized by the vehicle control system 20 to operate the vehicle 22 along the reference path 48.

[0034] 3 with continued reference to FIG. 1, in some cases, an obstacle 50 is detected along the reference path 48. In such cases, the vehicle control system 20 utilizes information from the sensor systems 38, 40, 42 to modify the reference path 48 to go around the obstacle 50.

[0035] The control system 20 first modifies the reference path 48 by defining an avoidance circle 52 around the obstacle 50. The avoidance circle 52 includes a diameter 64. The diameter 64 provides sufficient clearance around the obstacle 50 that the vehicle 22 can navigate without colliding with the obstacle. In one embodiment, the diameter 64 is at least equal to the vehicle width 24. The vehicle control system 20 also defines a line of sight circle 54.

[0036] The line-of-sight circle 54 is at the center of the axle 28 that provides steering for the vehicle 22. The line-of-sight circle 54 includes a diameter 66 that also provides sufficient clearance for the vehicle 22 to navigate around the obstacle 50. In one disclosed embodiment, the diameter 66 is at least equal to the width 24 of the vehicle 22. The axle axis 28 is the axis that provides steering for the vehicle 22. In this disclosed example, the axle is the front axle 28, and the steering wheel's front wheels rotate relative to the centerline 26 of the vehicle 22 to steer the vehicle along the reference path 48 or along a differential reference path for navigating around the obstacle 50.

[0037] The avoidance circle 52 and the line of sight circle 54 are utilized to determine intersection points 58, 56. The intersection points 58, 56 indicate potential interference between the vehicle 22 and the obstacle 50. The intersection points 56, 58 are also utilized to determine which direction the vehicle 22 should proceed around the obstacle 50.

[0038] In one disclosed embodiment, the control system 20 determines the distance between each node 56, 58 and other obstacles or objects, such as the boundary 46, that constrain where the vehicle can travel. In this example, the node 56 is located at a distance 60 from the boundary 46. The node 58 is located at a distance 62 from the boundary 46. The distance 62 is greater than the distance 60, thus providing greater clearance between the potential reference corrected path and the boundary 46. As can be seen from FIG. 3 , the first node 56 would result in the vehicle traveling across the boundary 46 and would therefore not be a suitable direction for modifying the reference path 48. In contrast, the node 58 is at a greater distance from the boundary 46, allowing the vehicle to navigate around the obstacle 50.

[0039] Thus, one exemplary operation of vehicle control system 20 steers vehicle 22 away from the reference path toward node 58. Control system 20 continuously determines distance 60 and distance 62 as the position of vehicle 22 relative to obstacle 50 changes.

[0040] Continuing with reference to Figure 3, and with reference to Figure 4, as the vehicle 22 moves around the obstacle 50, the intersection points 56, 58 change depending on the relative position between the obstacle 50 and the vehicle 54. As will be appreciated, as the relative position between the vehicle 22 and the obstacle 50 changes, the relative position between the avoidance circle 52 and the line of sight circle 54 also changes. While the avoidance circle 52 and the line of sight circle 54 maintain the same diameter, the intersection points 56, 58 also move relative to the vehicle 22 and the obstacle 50, respectively.

[0041] 4, as vehicle 22 navigates around obstacle 50, control system 20 continues to calculate the distance between each node 56, node 58 and any boundary 46 defined in map 44. In this example, node 58 remains at an ever-increasing distance from boundary 46, and the vehicle follows node 58 as it navigates around obstacle 50. Vehicle control system 20 maneuvers vehicle 22 toward node 58 until vehicle 22 can return toward original reference path 48.

[0042] 5, with continued reference to Figures 3 and 4, vehicle 22 travels in a direction toward intersection point 58, which is furthest from boundary 46. In this example, intersection point 58 is at the greatest distance from boundary 46, and a portion of line of sight circle 54 passes through the center of obstacle 50. As the vehicle passes obstacle 50, it maintains a distance of at least diameter 66 of line of sight circle 54.

[0043] The vehicle 22 can return to the original path 48 when the path 48 is closer to the vehicle 22 than the intersection 58. In this embodiment, once the vehicle 22 has passed the obstacle 50, it can return to the originally defined reference path 48 without coming into contact with the obstacle 50.

[0044] 3-5, and now referring to FIG. 6, a flow chart 64 illustrates steps performed by the control system 20 to provide a route around an obstacle 50. In this example, the first step involves detecting an object located within the previously determined reference path 48, as indicated at 66. In this example, the obstacle 50 is directly within the reference path 48, and therefore the vehicle 22 is guaranteed an alternate route around the obstacle 50. The detection of the obstacle 50 is performed by one or all of several sensor systems 38, 40, 42 onboard the vehicle 22.

[0045] The control system 20 defines an avoidance circle 52 around the detected obstacle 50, as shown at 68. The avoidance circle 52 is located at the center of the obstacle 50, and the avoidance circle 52 has a diameter 64 sufficient to allow the vehicle to pass through the obstacle 50 without contacting it.

[0046] The vehicle control system 20 simultaneously defines a line-of-sight circle 54, as shown at 70, centered on the steerable axle 28 of the vehicle 22. The line-of-sight circle 54 is generated with a diameter 66 that ensures sufficient clearance for the vehicle 22 around the obstacle 50.

[0047] Intersection points 56, 58 between the avoidance circle 52 and the line-of-sight circle 54 have been determined as shown at 72. The control system 20 uses the intersection points 56, 58 as potential target points to steer the vehicle around the obstacle 50. One of the intersection points 56, 58 is selected by determining the distance from other obstacles around the vehicle 22, such as the exemplary boundary 46. While the boundary is described as an example, it should be understood that other objects, such as other vehicles, buildings, and / or any other features that constrain the movement of the vehicle 22, are within the contemplation and scope of the present disclosure.

[0048] The intersection furthest from any other boundary indicates the preferred direction for the vehicle to proceed. In the disclosed embodiment, intersection 58 is at a greater distance from boundary 46. Therefore, control system 20 directs vehicle 22 toward intersection 58, as shown at 74.

[0049] As the vehicle passes the obstacle, the line of sight circle 54 and the avoidance circle provide a predetermined minimum separation between the vehicle 22 and the obstacle 50. Once the vehicle 22 passes the obstacle 50, it returns toward the previously defined reference path 48. Thus, the disclosed control system 20 provides for maneuvering the vehicle 22 around the obstacle 50.

[0050] Although different non-limiting embodiments are shown as having particular components or steps, embodiments of the present disclosure are not limited to those particular combinations, and some of the components or features from any of the non-limiting embodiments can be used in combination with features or components from any of the other non-limiting embodiments.

[0051] It should be understood that like reference numerals identify corresponding or similar elements throughout the several views. Although particular component arrangements are disclosed and illustrated in these exemplary embodiments, it should be understood that other arrangements can benefit from the teachings of the present disclosure.

[0052] The foregoing description should be interpreted as illustrative and not in any limiting sense. Those skilled in the art will recognize that certain modifications may fall within the scope of the present disclosure. For these reasons, the following claims should be studied to determine the true scope and content of the present disclosure.

Claims

1. 1. A method for autonomously defining a route for a vehicle, comprising: The method comprises the following steps: detecting an object located within a predetermined path using a sensor system within the vehicle; defining an avoidance clearance around the detected object using a vehicle control system within the vehicle; defining a line-of-sight separation centered on a portion of the vehicle using a vehicle control system; detecting, with a vehicle control system, two intersections between an avoidance interval and a visibility interval, the vehicle control system using the two intersections as potential target points for maneuvering the vehicle around the object; modifying the route of the vehicle based on the intersection between the avoidance interval and the visibility interval; A method comprising:

2. The method of claim 1 , including dynamically varying the size of the line-of-sight interval so that it does not extend beyond a center point of the detected object.

3. The method of claim 1 , wherein the avoidance interval around the detected object comprises a circular region centered on the object.

4. The method of claim 3 , wherein the circular area of ​​the avoidance clearance includes a radius equal to at least half the width of the vehicle.

5. The method of claim 3 , wherein the line-of-sight interval comprises a circular area and the vehicle portion comprises a midpoint of an axle of the vehicle that controls the heading direction of the vehicle.

6. The method of claim 5 , wherein the circular area of ​​the line of sight includes a radius that is at least half the width of the vehicle.

7. The method of claim 5 , wherein altering the vehicle's route further comprises realigning the predetermined route at an intersection between the avoidance interval and the visibility interval.

8. The method of claim 1 , further comprising selecting one of the two intersection points for realigning the predetermined path.

9. 9. The method of claim 8, wherein selecting one of the two intersections includes comparing a distance between each of the two intersections to a constraint that limits movement of the vehicle, and selecting the intersection that is a greater distance from the constraint.

10. The method of claim 9 , wherein the constraints include predetermined boundaries separating different road surfaces.

11. The method of claim 9 , wherein the constraints include a predetermined boundary, the predetermined boundary including an object extending above a road surface.

12. The method of claim 1 , further comprising realigning a path of the vehicle to the predetermined path in response to the line-of-sight interval passing through a detected intersection.

13. An autonomous vehicle control system including a control device that can be mounted in a vehicle, The control device Detecting an object located within a predetermined path using a sensor system within the vehicle; defining an avoidance interval around the detected object using a vehicle control system within the vehicle; defining a line of sight distance centered on a portion of the vehicle using a vehicle control system; detecting two intersections between an avoidance interval and a visibility interval using a vehicle control system, the vehicle control system using the two intersections as potential target points for maneuvering the vehicle around the object; modifying the vehicle's route based on the detected intersection between the avoidance interval and the line of sight interval; It is configured as follows: Autonomous vehicle control systems.

14. 14. The autonomous vehicle control system of claim 13, wherein the controller is configured to dynamically change the size of the line-of-sight interval so that it does not extend beyond a center point of the detected object.

15. 14. The autonomous vehicle control system of claim 13, wherein the avoidance clearance around the detected object comprises a circular region centered on the object having a radius equal to at least half a width of the vehicle.

16. 16. The autonomous vehicle control system of claim 15, wherein the controller is further configured to realign the predetermined path based on a location of the intersection between the avoidance interval and the line of sight interval.

17. The autonomous vehicle control system of claim 16, wherein the control device is further configured to select one of the two intersections to realign the predetermined path.

18. 18. The autonomous vehicle control system of claim 17, wherein the control device is configured to compare the distance between each of the two nodes with a constraint that limits movement of the vehicle, and select the node that is a greater distance from the constraint.

19. 1. A non-transitory computer-readable storage medium containing instructions for operating an autonomous vehicle control system, comprising: The computer-readable storage medium comprises: instructions to instruct the controller to detect objects located within the predetermined path using a sensor system within the vehicle; instructions to direct a controller to define, using a vehicle control system within the vehicle, an avoidance clearance around the detected object; instructions to instruct a controller to use the vehicle control system to define a line-of-sight interval centered on a portion of the vehicle; instructions to direct a controller to use the vehicle control system to detect two intersections between an avoidance distance and a visibility distance, the vehicle control system using the two intersections as potential target points for maneuvering a vehicle around an object; and instructions to direct the controller to alter the path of the vehicle based on the detected intersection between the avoidance interval and the visibility interval; 1. A computer-readable storage medium comprising:

20. 20. The non-transitory computer-readable storage medium of claim 19, further comprising instructions for instructing the controller to compare a distance between each of the nodes and a constraint that limits movement of the vehicle, and to select the node that is a greater distance from the constraint.

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