System and method for autonomous vehicle localization

• US 8,301,325 B2
• Filed: 07/28/2008
• Issued: 10/30/2012
• Est. Priority Date: 07/28/2008
• Status: Active Grant

• Current Assignee: Mtd Products Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Precise Path Robotics, Inc.
• Inventors: Traster, Elden D.
• Primary Examiner(s): Nguyen, Kim T
• Application Number:
  US12/180,844
• Publication Number:
  US 20100023195A1
• Time in Patent Office: 1,555 Days
• Field of Search: 701/10, 701/23, 701/32.3, 701/32.5, 701/116, 701/408, 701/410, 701/420, 701/444, 701/451, 701/469, 701/470, 701/472
• US Class Current: 701/23
• CPC Class Codes: G01S 15/86 Combinations of sonar systems with lidar systems; Combinations of sonar systems with systems not using wave reflection
• CPC Class Codes: G01S 15/88 Sonar systems specially adapted for specific applications seismic or acoustic prospecting or detecting G01V1/00
• CPC Class Codes: G01S 15/931 of land vehicles
• CPC Class Codes: G01S 2013/9329 cooperating with reflectors or transponders
• CPC Class Codes: G05D 1/0261 using magnetic plots

Abstract

An autonomous vehicle capable of determining its position in a space through improved communications with beacons is disclosed. The autonomous vehicle utilizes time of flight as well and angular information to determine position, and is capable of intelligent interaction with the beacons.

Claims

1. An autonomous vehicle comprising:

a mobile unit;

a sonic transmitter situated on the mobile unit and configured to transmit a sonic signal to a beacon located at a position that is remote from the mobile unit;

an electromagnetic receiver situated on the mobile unit configured to receive an electromagnetic signal generated by the beacon in response to the sonic signal from the transmitter and to determine an angle of reception of the received electromagnetic signal and time of flight information of the sonic signal over a path from the mobile unit to the beacon; and

a processor configured to utilize the determined angle of reception and time of flight information to determine a current position of the mobile unit relative to the beacon;

wherein said processor assigns a dynamic weight to each of the determined angle of reception and time of flight information.

2. The autonomous vehicle of claim 1, further comprising a sonic receiver situated on the mobile unit configured to receive the sonic signal and determine time of flight information of the sonic signal over a path from the transmitter to the sonic receiver.

3. The autonomous vehicle of claim 2, further comprising a plurality of sonic receivers configured to collect time of flight information of the sonic signal and calculate a sonic speed adjustment factor.

4. The autonomous vehicle of claim 1, further comprising a beacon.

5. The autonomous vehicle of claim 4, wherein the beacon comprises two or more sonic receivers configured to collect and evaluate an impact of the environment on the sonic signal from any direction.

6. The autonomous vehicle of claim 4, further comprising:

an inclinometer situated on the mobile unit and configured to provide compensation information; and

wherein said processor is further configured to utilize the determined time of flight information of the sonic signal and the provided inclinometer information to determine said current position.

7. The autonomous vehicle of claim 6, wherein the compensation information includes an angle of deviation of a central vertical axis of the autonomous vehicle from a specified vertical axis.

8. The autonomous vehicle of claim 6, wherein the receiver additionally determines an angle of reception of the received electromagnetic signal relative to the mobile unit and the processor is configured to further utilize the angle of reception in determining the position of the base of the mobile unit relative to a beacon.

9. The autonomous vehicle of claim 1, wherein the receiver comprises an array of electromagnetic sensing devices configured to calculate the angle of reception as a function of signal strength detected by one or more of the array of electromagnetic sensing devices.

10. The autonomous vehicle of claim of claim 9, wherein the received electromagnetic signal comprises light.

11. The autonomous vehicle of claim 1, wherein the receiver is configured to perform a temporal projection of vehicle position relative to the beacon based upon at least a prior position of the autonomous vehicle.

12. The autonomous vehicle of claim 11, further comprising an odometer situated on the mobile unit and configured to provide odometry information to enhance the future estimate of position.

13. The autonomous vehicle of claim 1, wherein:

the transmitted sonic signal comprises a ping;

the sonic transmitter is further configured to transmit a plurality of pings to a plurality of beacons; and

the electromagnetic receiver is further configured to receive the plurality of electromagnetic signals from a plurality of beacons in response to the plurality of pings.

14. The autonomous vehicle of claim 13, wherein the sonic transmitter is further configured to transmit the plurality of pings simultaneously.

15. The autonomous vehicle of claim 13, wherein the sonic transmitter is further configured to transmit the plurality of pings in a predetermined sequential pattern.

16. The autonomous vehicle of claim 13, wherein the sonic transmitter is further configured to transmit each ping within the plurality of pings in a specific direction.

17. The autonomous vehicle of claim 13, wherein each one of the plurality of pings includes a unique identifier.

18. The autonomous vehicle of claim 17, wherein the electromagnetic receiver is further configured to receive the electromagnetic signal from a beacon in response to one of the plurality of pings which includes a replication of the unique identifier of the received ping.

19. The autonomous vehicle of claim 1, wherein at least one of the sonic signal and the electromagnetic signal includes encoded data.