Optimized path planner for an autonomous valet parking system for a motor vehicle

• US 9,896,091 B1
• Filed: 08/19/2016
• Issued: 02/20/2018
• Est. Priority Date: 08/19/2016
• Status: Active Grant

• Current Assignee: Ohio State Innovation Foundation (Ohio State University), New Eagle LLC (Woodward Incorporated)
• Original Assignee: Dura Operating LLC (Dura Automotive Systems), Ohio State Innovation Foundation (Ohio State University)
• Inventors: Kurt, Arda, Redmill, Keith, Ozguner, Umit, Thomas, Gordon
• Primary Examiner(s): Troost, Aaron L
• Application Number:
  US15/242,169
• Publication Number:
  US 20180050691A1
• Time in Patent Office: 550 Days
• CPC Class Codes: B60W 2510/109 Direction of power flow
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2520/06 Direction of travel
• CPC Class Codes: B60W 30/06 Automatic manoeuvring for parking
• CPC Class Codes: B62D 15/0285 Parking performed automatically
• CPC Class Codes: G01C 21/3446 Details of route searching algorithms, e.g. Dijkstra, A*, arc-flags, using precalculated routes
• CPC Class Codes: G01C 21/3461 Preferred or disfavoured areas, e.g. dangerous zones, toll or emission zones, intersections, manoeuvre types, segments such as motorways, toll roads, ferries
• CPC Class Codes: G05D 1/0088 characterized by the autonomous decision making process, e.g. artificial intelligence, predefined behaviours using knowledge based models G06N5/00
• CPC Class Codes: G05D 1/0212 with means for defining a desired trajectory involving a plurality of land vehicles G05D1/0287
• CPC Class Codes: G05D 1/0217 in accordance with energy consumption, time reduction or distance reduction criteria
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: G08G 1/143 inside the vehicles
• CPC Class Codes: G08G 1/144 on portable or mobile units, e.g. personal digital assistant [PDA]
• CPC Class Codes: G08G 1/146 where the parking area is a limited parking space, e.g. parking garage, restricted space

Abstract

A method for autonomously parking or un-parking a motor vehicle includes locating the motor vehicle relative to a parking area, selecting a destination location within the parking area, generating a path from the location of the motor vehicle to the destination location, wherein the path includes a plurality of linked nodes, each node having a cost associated therewith, wherein the cost of a child node is equal to an inherited cost plus a base cost and a change cost, wherein the change cost is a function of characteristics of a parent node, and autonomously driving the motor vehicle along the path from the location of the motor vehicle to the destination location.

Claims

1. A method for autonomously parking or un-parking a motor vehicle, the method comprising:

locating the motor vehicle relative to a parking area;

selecting a destination location within the parking area;

generating a path from the location of the motor vehicle to the destination location, wherein the path includes a plurality of linked nodes, each node having a cost associated therewith, wherein the cost of a child node is equal to an inherited cost plus a base cost and a change cost, wherein the change cost is a function of characteristics of a parent node;

autonomously driving the motor vehicle along the path from the location of the motor vehicle to the destination location.

2. The method of claim 1 wherein the change cost includes a turning cost and a direction cost.

3. The method of claim 2 wherein the characteristics include a location of the plurality of linked nodes in the parking area and a heading.

4. The method of claim 3 further comprising increasing the turning cost of the child node if a difference between the heading of the parent node and the child node is greater than a predetermined amount.

5. The method of claim 3 further comprising increasing the direction cost of the child node if the parent node required a gear change between forward and reverse the child node also requires a gear change between forward and reverse.

6. The method of claim 3 wherein the turning cost is zero if the child node has the same heading as the parent node.

7. The method of claim 3 wherein the turning cost is a function of a difference between a steering angle of the parent node and a steering angle of the child node.

8. The method of claim 3 further comprising determining whether the location of the child node is within an obstructed area and only generating a path having nodes outside the obstructed area plus a safety factor.

9. The method of claim 8 wherein the safety factor is approximately six inches.

10. The method of claim 8 wherein the safety factor is a function of the type of obstructed area.

11. The method of claim 1 wherein the base cost of the child node is a function a distance from the child node to the destination location.

12. The method of claim 11 wherein the base cost of the child node is also a function of a distance from the parent node to the destination location.

13. The method of claim 1 wherein the base cost is the difference between the distance from the child node to the destination location and the distance from the parent node to the destination location.

14. The method of claim 1 wherein the inherited cost of the child node is equal to the cost of the parent node.

15. A method for autonomously parking or un-parking a motor vehicle, the method comprising:

locating the motor vehicle relative to a parking area;

setting a destination location within the parking area;

generating a path comprising the steps of;

(a) generating a first set of nodes from the location of the motor vehicle;

(b) assigning a cost to each node in the first set of nodes;

(c) selecting a lowest cost node from the first set of nodes;

(d) generating another set of nodes from the selected node;

(e) assigning a cost to each of the newly generated nodes, wherein the cost is equal to an inherited cost plus a base cost and a change cost, wherein the change cost is a function of a previously generated node;

(f) selecting a lowest cost node from all of the nodes;

(g) repeating steps (d)-(f) until a lowest cost node is located at the destination location; and

(h) setting a path from the location of the motor vehicle to the destination location comprising the last selected lowest cost node and parent nodes connected to the last selected lowest cost node; and

autonomously driving the motor vehicle along the path from the location of the motor vehicle to the destination location.

16. The method of claim 15 wherein the change cost includes a turning cost and a direction cost, and generating the path further includes increasing the turning cost if a difference between a heading of the selected lowest cost node and the newly generated node is greater than a predetermined amount.

17. The method of claim 16 further comprising increasing the direction cost of the newly generated node if the selected lowest cost node required a gear change between forward and reverse the newly generated node also requires a gear change between forward and reverse.

18. The method of claim 17 wherein the turning cost is zero if the newly generated node has the same heading as the selected lowest cost node.

19. The method of claim 18 wherein generating the path further includes determining whether the location of the child node is within an obstructed area and only generating a path having nodes outside the obstructed area plus a safety factor.

20. A method for autonomously parking or un-parking a motor vehicle, the method comprising:

locating the motor vehicle relative to a parking area;

setting a destination location within the parking area;

generating a path comprising the steps of;

(a) generating a first set of nodes from the location of the motor vehicle;

(b) assigning a cost to each node in the first set of nodes;

(c) selecting a lowest cost node from the first set of nodes;

(d) generating another set of nodes from the selected node;

(e) assigning a cost to each of the newly generated nodes, wherein the cost is equal to an inherited cost plus a base cost and a change cost, wherein the change cost includes a turning cost and a direction cost, and the turning cost is zero if the newly generated node has the same heading as the selected lowest cost node, the turning cost is increased if a difference between a heading of the selected lowest cost node and the newly generated node is greater than a predetermined amount, and the direction cost is increased if the selected lowest cost node required a gear change between forward and reverse the newly generated node also requires a gear change between forward and reverse;

(f) selecting a lowest cost node from all of the nodes;

(g) repeating steps (d)-(f) until a lowest cost node is located at the destination location; and

(h) setting a path from the location of the motor vehicle to the destination location comprising the last selected lowest cost node and parent nodes connected to the last selected lowest cost node; and

autonomously driving the motor vehicle along the path from the location of the motor vehicle to the destination location.