Parking assist system for vehicle

• US 10,214,206 B2
• Filed: 07/11/2016
• Issued: 02/26/2019
• Est. Priority Date: 07/13/2015
• Status: Active Grant

• Current Assignee: Magna Electronics Incorporated (Magna International Incorporated)
• Original Assignee: Magna Electronics Incorporated (Magna International Incorporated)
• Inventors: Latotzki, Ralph
• Primary Examiner(s): Badii, Behrang
• Assistant Examiner(s): Greene, Daniel L
• Application Number:
  US15/206,801
• Publication Number:
  US 20170015312A1
• Time in Patent Office: 960 Days
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2420/408 Radar; Laser, e.g. lidar
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: B60W 2554/4029 Pedestrians
• CPC Class Codes: B60W 2554/408 Traffic behavior, e.g. swarm
• CPC Class Codes: B60W 2554/60 Traversable objects, e.g. speed bumps or curbs
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 2720/125 Lateral acceleration
• CPC Class Codes: B60W 2720/24 Direction of travel
• CPC Class Codes: B60W 30/06 Automatic manoeuvring for parking
• CPC Class Codes: B62D 15/027 Parking aids, e.g. instruction means
• CPC Class Codes: B62D 15/0285 Parking performed automatically

Abstract

A parking assist system of a vehicle includes a plurality of sensors disposed at a vehicle and having respective fields of sensing exterior of the vehicle. A vehicle control is operable to determine a target parking space responsive to the processor. The control (i) uses two intersecting lines, with one passing through a start node and one passing through an end node, (ii) uses circles that are tangent to respective ones of the intersecting lines, with each circle having a radius that approximates a minimum turning radius of the vehicle, and (iii) determines possible paths of travel using straight path sections tangent to one or more of the circles and curved path sections that follow a curvature of one or more of the circles. The control selects a target path of travel in accordance with a plurality of objectives for the path of travel of the vehicle.

Claims

1. A parking assist system of a vehicle, said parking assist system comprising:

a plurality of sensors disposed at a vehicle and having respective fields of sensing exterior of the vehicle;

a processor operable to process data captured by said sensors;

a vehicle control operable to determine a target parking space responsive to processing by said processor of data captured by said sensors;

wherein said vehicle control is operable to determine a plurality of possible paths of travel from a current location of the vehicle to the target parking space;

wherein the plurality of possible paths of travel is determined by said control approximating possible turns of the vehicle between a start node outside of the target parking space and an end node in the target parking space via an algorithm that (i) uses two intersecting lines, with one passing through the start node and one passing through the end node, (ii) uses circles that are tangent to respective ones of the intersecting lines, wherein each circle has a radius that approximates a minimum turning radius of the vehicle, and (iii) determines possible paths of travel using straight path sections tangent to one or more of the circles and curved path sections that follow a curvature of one or more of the circles;

wherein said control selects a target path of travel of the vehicle from the determined plurality of possible paths of vehicles in accordance with a plurality of objectives for the path of travel of the vehicle; and

wherein said control controls steering of the vehicle to maneuver the vehicle along the selected target path of travel from the current location of the vehicle to the target parking space.

2. The parking assist system of claim 1, wherein said control evaluates multiple possible path approximations and selects the target path of travel based at least in part on traffic, number of maneuvers, curbs, obstacles and pedestrians in the possible paths.

3. The parking assist system of claim 1, wherein the target path of travel is selected based on one or more objectives selected from the group consisting of (i) avoiding traffic, (ii) minimizing the number of turns, (iii) minimizing the area required for maneuvering the vehicle, (iv) avoiding curbs, and (v) avoiding objects.

4. The parking assist system of claim 1, wherein said control determines control parameters for controlling the vehicle along the target path of travel of the vehicle.

5. The parking assist system of claim 1, wherein selection of the target path of travel is based on an optimization procedure based on a prior approximated path of travel.

6. The parking assist system of claim 5, wherein optimization of the prior approximated path of travel is done in sections between the start node and end nodes.

7. The parking assist system of claim 6, wherein optimization of the prior approximated path of travel is done in sections between the start node and end nodes and at least one node between the start node and end node.

8. The parking assist system of claim 7, wherein the circles are tangent to the determined path of travel at the nodes.

9. The parking assist system of claim 7, wherein optimization of path sections is done by an optimal control algorithm using a cost function.

10. The parking assist system of claim 9, wherein said cost function has at least one of the objectives of (i) comfort ride of the vehicle occupants by optimizing the speed, acceleration and jerk of the vehicle, (ii) a time needed to complete the parking maneuver by minimizing the time for executing the driving maneuvers, (iii) avoiding steering in standstill by minimizing nodes where the vehicle speed is zero, and (iv) avoiding abrupt or fast steering by minimizing a change of steering angle between consecutive nodes.

11. The parking assist system of claim 10, wherein said cost function comprises at least one constraint selected from the group consisting of (i) the current condition of vehicle, (ii) the planned condition of vehicle at a next node, (iii) the drivable area, (iv) the dynamic capabilities of the vehicle, (v) the capability of the steering system of the vehicle, and (vi) the geometry of the vehicle.

12. The parking assist system of claim 1, wherein one of the intersecting lines passes through the start node in a direction of travel of the vehicle at the start node and the other of the intersecting lines passes through the end node in the direction of travel of the vehicle at the end node.

13. The parking assist system of claim 12, wherein said control uses a third intersecting line that bisects an angle between the two intersecting lines, and wherein said control applies circles that are tangent to the third intersecting line.

14. A parking assist system of a vehicle, said parking assist system comprising:

a plurality of sensors disposed at a vehicle and having respective fields of sensing exterior of the vehicle;

a processor operable to process data captured by said sensors;

a vehicle control operable to determine a target parking space responsive to processing by said processor of data captured by said sensors;

wherein said vehicle control is operable to determine a plurality of possible paths of travel from a current location of the vehicle to the target parking space;

wherein the plurality of possible paths of travel is determined by said control approximating possible turns of the vehicle between a start node outside of the target parking space and an end node in the target parking space via an algorithm that (i) uses two intersecting lines, with one passing through the start node in a direction of travel of the vehicle at the start node and one passing through the end node in a direction of travel of the vehicle at the end node, (ii) uses circles that are tangent to respective ones of the intersecting lines, wherein each circle has a radius that approximates a minimum turning radius of the vehicle, and (iii) determines possible paths of travel using straight path sections tangent to one or more of the circles and curved path sections that follow a curvature of one or more of the circles;

wherein said control selects a target path of travel of the vehicle from the determined plurality of possible paths of vehicles in accordance with a plurality of objectives for the path of travel of the vehicle;

wherein the target path of travel is selected based on one or more objectives selected from the group consisting of (i) avoiding traffic, (ii) minimizing the number of turns, (iii) minimizing the area required for maneuvering the vehicle, (iv) avoiding curbs, and (v) avoiding objects; and

wherein said control controls steering of the vehicle to maneuver the vehicle along the selected target path of travel from the current location of the vehicle to the target parking space.

15. The parking assist system of claim 14, wherein multiple nodes are determined along one of the intersecting lines and between the start node and the end node, and wherein said algorithm uses circles tangent to the respective intersecting line at each of the nodes.

16. The parking assist system of claim 14, wherein said control selects a target path of travel of the vehicle from the determined plurality of possible paths of vehicles in accordance with a cost function.

17. The parking assist system of claim 16, wherein said cost function has at least one of the objectives of (i) comfort ride of the vehicle occupants by optimizing the speed, acceleration and jerk of the vehicle, (ii) a time needed to complete the parking maneuver by minimizing the time for executing the driving maneuvers, (iii) avoiding steering in standstill by minimizing nodes where the vehicle speed is zero, and (iv) avoiding abrupt or fast steering by minimizing a change of steering angle between consecutive nodes.

18. The parking assist system of claim 16, wherein said cost function comprises at least one constraint selected from the group consisting of (i) the current condition of vehicle, (ii) the planned condition of vehicle at a next node, (iii) the drivable area, (iv) the dynamic capabilities of the vehicle, (v) the capability of the steering system of the vehicle, and (vi) the geometry of the vehicle.

19. A parking assist system of a vehicle, said parking assist system comprising:

a plurality of sensors disposed at a vehicle and having respective fields of sensing exterior of the vehicle;

a processor operable to process data captured by said sensors;

a vehicle control operable to determine a target parking space responsive to processing by said processor of data captured by said sensors;

wherein said vehicle control is operable to determine a plurality of possible paths of travel from a current location of the vehicle to the target parking space;

wherein the plurality of possible paths of travel is determined by said control approximating possible turns of the vehicle between a start node outside of the target parking space and an end node in the target parking space via an algorithm that (i) uses three intersecting lines, with a first line passing through the start node in a direction of travel of the vehicle at the start node, a second line passing through the end node in a direction of travel of the vehicle at the end node and a third line passing through the intersection of the first and second lines and bisecting an angle between the first and second lines, (ii) uses circles that are tangent to respective ones of the intersecting lines, wherein each circle has a radius that approximates a minimum turning radius of the vehicle, and (iii) determines possible paths of travel using straight path sections tangent to one or more of the circles and curved path sections that follow a curvature of one or more of the circles;

wherein said control selects a target path of travel of the vehicle from the determined plurality of possible paths of vehicles in accordance with a plurality of objectives for the path of travel of the vehicle;

wherein said control selects a target path of travel of the vehicle from the determined plurality of possible paths of vehicles in accordance with a cost function;

wherein said cost function has at least one of the objectives of (i) comfort ride of the vehicle occupants by optimizing the speed, acceleration and jerk of the vehicle, (ii) a time needed to complete the parking maneuver by minimizing the time for executing the driving maneuvers, (iii) avoiding steering in standstill by minimizing nodes where the vehicle speed is zero, and (iv) avoiding abrupt or fast steering by minimizing a change of steering angle between consecutive nodes; and

wherein said control controls steering of the vehicle to maneuver the vehicle along the selected target path of travel from the current location of the vehicle to the target parking space.

20. The parking assist system of claim 19, wherein said cost function comprises at least one constraint selected from the group consisting of (i) the current condition of vehicle, (ii) the planned condition of vehicle at a next node, (iii) the drivable area, (iv) the dynamic capabilities of the vehicle, (v) the capability of the steering system of the vehicle, and (vi) the geometry of the vehicle.