Navigation system and method for a mobile robot
AssigneeHeath Company
InventorTerry A. Perdue
Life of this patent
Estimating the term…
Abstract
An opto/acoustic navigation system allows a mobile robot to detect and mate with a floating plug-equipped charging unit upon detection of the need for recharging of the robot's storage battery. A plurality of infrared (IR) emitters and sensors located on the robot and adjacent to the charger in combination with the robot's acoustic sensors allow the robot to locate the charger, move to within a predetermined distance of the charger, maneuver to a position directly in front of the charger, and then back into engagement with the charger's floating plug.
Claims16
In a mobile robot having a rechargeable storage battery, a method for guiding said robot to a charger positioned adjacent to a wall following detection of a low charge state in said storage battery, said method comprising:
- transmitting from the robot a first narrow beam infrared (IR) signal in a 360.degree. scan about the robot;
- detecting said first IR signal at the charger and transmitting a second generally omnidirectional IR signal from the charger in response to receipt of said first IR signal thereat;
- detecting said second IR signal at the robot and displacing said robot in a generally linear first direction toward the charger until the robot is within a predetermined distance from the charger;
- displacing the robot in a generally circular second direction when the robot is within said predetermined distance from the charger, wherein said second direction is initially transverse to said first direction and the charger is positioned at the center of the robot's circular displacement path;
- transmitting a third narrow beam IR signal from the robot in the direction of the charger during the circular displacement thereof;
- reflecting said third IR signal back to the robot when the robot is positioned directly in front of the charger;
- detecting the reflected third IR signal at the robot when the robot is positioned directly in front of the charger;
- displacing the robot in a third linear direction generally transverse to said second direction and toward the charger following detection of the reflected third IR signal at the robot to permit the robot to engage the charger for the recharging of its storate battery wherein the steps of transmitting the first and third IR signals includes directing the first and third IR signals through a generally vertically oriented narrow slot in a lateral portion of the robot.
For use with a mobile robot having an upper rotating head, a lower displaceable base and a rechargeable battery, a navigation system for directing said robot to a charger positioned adjacent to a wall following detection of a low charge state in said battery for the recharging thereof, said navigation system comprising:
- a first infrared (IR) signal source positioned in the rotating head of the robot for emitting first and second narrow beam IR signals wherein said first IR signal scans 360.degree. about the robot;
- wherein the upper rotating head of the robot includes a generally vertically oriented slot therein and said first IR signal source includes a plurality of light emitting (LED's) positioned within said rotating head and aligned in a liear array parallel with and adjacent to said head mounted slot;
- a second IR signal detector/source positioned adjacent to the charger and responsive to said first IR signal incident thereon for emitting a third, generally omnidirectional IR signal;
- a third IR signal detector positioned on the robot's rotating head and responsive to said third IR signal for providing a first direction of displacement from the robot to the charger;
- first sonar detection means positioned in the robot's base for detecting when the robot is at a predetermined distance from the charger along said first direction of displacement;
- second sonar detection means positioned in the robot's head for determining the direction the robot must turn to follow a generally circular path in positioning itself directly in front of the charger;
- and
- reflecting means positioned adjacent to the charger for reflecting the second IR signal back to the third IR signal detector when the robot is directly in front of the charger and for indicating to the robot when to turn for displacement toward and engagement with the charger.
The navigation system of claim 11 wherein said LED's and photodiodes are arranged to cover a 180.degree. sector forward of the wall adjacent to which the charger is positioned.
Dependencies are inferred from the claim text.