System and method for terrain feature tracking

• US 7,499,775 B2
• Filed: 10/22/2004
• Issued: 03/03/2009
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Allard, James, Svendsen, Selma, Filippov, Misha, Barrett, David S., Pack, Robert Todd
• Primary Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US10/971,725
• Publication Number:
  US 20060089764A1
• Time in Patent Office: 1,593 Days
• Field of Search: 701/23, 701/26, 701/28, 701/207, 701/209, 701/213, 701/300, 701/301, 340/903, 340/937, 340/939, 340/435, 340/436, 348/113, 348/142, 348/161, 348/163, 348/164, 348/135
• US Class Current: 701/23
• CPC Class Codes: G01S 13/726 Multiple target tracking
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9318 Controlling the steering
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/9319 Controlling the accelerator
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0248 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0251 extracting 3D information from a plurality of images taken from different locations, e.g. stereo vision stereoscopic image analysis H04N13/00; depth recovery from images G06T7/593
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/0257 using a radar radar systems designed for anti-collision purposes between land vehicles or between land vehicle and fixed obstacles G01S13/931
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00

Abstract

System and method for tracking obstacles by an autonomous vehicle. Localization sensors (i.e., sensors to measure pitch, roll, and yaw, and systems including an inertial navigation system, a compass, a global positioning system, or an odometer) detect the position of the vehicle. Perception sensors (e.g., LIDAR, stereo vision, infrared vision, radar, or sonar) assess the environment about the vehicle. Using these sensors, locations of terrain features relative to the vehicle are computed and kept up-to-date. The vehicle trajectory is adjusted to avoid terrain features that are obstacles in the path of the vehicle.

Claims

1. An autonomous vehicle comprising:

a localization sensor for determining a position of the autonomous vehicle;

a perception sensor for assessing an environment about the autonomous vehicle;

a detector for detecting a terrain feature in response to a change in an output of the perception sensor;

a controller in communication with the localization sensor, the perception sensor, and the detector for i) computing a location of the terrain feature relative to the position of the autonomous vehicle based at least in part on output of the localization sensor and ii) discarding the location of the terrain feature, without storing the location of the terrain feature, if the location of the terrain feature does not represent a hazard for the autonomous vehicle; and

a memory in communication with the controller for storing a location of a terrain feature that does represent a potential hazard for the autonomous vehicle.

2. The autonomous vehicle of claim 1, wherein the localization sensor comprises at least one of a pitch sensor, a roll sensor, a yaw sensor, an inertial navigation system, a compass, a global positioning system, and an odometer.

3. The autonomous vehicle of claim 1, wherein the perception sensor comprises at least one of a light detecting and ranging system, a stereo vision system, an infrared vision system, a radar system, and a sonar system.

4. The autonomous vehicle of claim 1, wherein the perception sensor is characterized at least in part by a persistence.

5. The autonomous vehicle of claim 1, wherein the stored location of the terrain feature comprises a mapped two dimensional representation of a three dimensional representation.

6. The autonomous vehicle of claim 1 further comprising memory logic for updating the stored location of the terrain feature based on a change in the output of the localization sensor.

7. The autonomous vehicle of claim 1 further comprising memory logic for updating the stored location of the terrain feature based on a change in the output of the perception sensor.

8. The autonomous vehicle of claim 1 further comprising memory logic for discarding the stored location of the terrain feature based at least in part on satisfying a predetermined condition.

9. The autonomous vehicle of claim 8, wherein the predetermined condition comprises failing to achieve a predetermined persistence of the terrain feature in the perception sensor after the detection of the terrain feature.

10. The autonomous vehicle of claim 8, wherein the predetermined condition comprises exceeding a predetermined displacement between the location of the terrain feature and the position of the autonomous vehicle.

11. The autonomous vehicle of claim 1 further comprising adjustment logic for adjusting a trajectory of the autonomous vehicle based at least in part on the location of the terrain feature stored in the memory.

12. The autonomous vehicle of claim 11, wherein the adjustment logic comprises a selector for selecting one preferred trajectory from a plurality of ranked alternative trajectories.

13. The autonomous vehicle of claim 1 further comprising an articulation control for operating equipment attached to the autonomous vehicle.

14. The autonomous vehicle of claim 13, wherein the equipment comprises a tilling apparatus.

15. The autonomous vehicle of claim 13, wherein the equipment comprises a blade.

16. The autonomous vehicle of claim 1 further comprising a drive control and an actuator mated thereto by a mechanical linkage, the controller capable of dictating control instructions to the actuator to operate the vehicle in an autonomous mode.

17. The autonomous vehicle of claim 16, wherein the drive control comprises a throttle.

18. The autonomous vehicle of claim 16, wherein the drive control comprises a brake.

19. The autonomous vehicle of claim 16, wherein the drive control comprises an accelerator.

20. The autonomous vehicle of claim 16, wherein the drive control comprises a transmission shifter.

21. The autonomous vehicle of claim 16, wherein the mechanical linkage comprises a lever and pivot joint.

22. The autonomous vehicle of claim 16, wherein the mechanical linkage comprises a rack and pinion device.

23. The autonomous vehicle of claim 1, wherein the vehicle comprises a tractor.