Robotic platform

• US 8,113,304 B2
• Filed: 06/13/2008
• Issued: 02/14/2012
• Est. Priority Date: 03/27/1998
• Status: Expired due to Fees

• Current Assignee: Flir Detection, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: iRobot Corporation
• Inventors: Won, Chikyung
• Primary Examiner(s): Boehler, Anne Marie M.
• Application Number:
  US12/138,737
• Publication Number:
  US 20080236907A1
• Time in Patent Office: 1,341 Days
• Field of Search: 180/8.1, 180/8.2, 180/8.7, 180/9.1, 180/9.32, 180/901, 901/1, 280/5.22, 280/5.24
• US Class Current: 180/9.32
• CPC Class Codes: B25J 11/0025 handling explosives, bombs or hazardous objects
• CPC Class Codes: B25J 5/005 mounted on endless tracks or belts
• CPC Class Codes: B62D 55/065 Multi-track vehicles, i.e. more than two tracks soil-shifting machines E02F; mining machines E21C
• CPC Class Codes: B62D 55/0655 Articulated endless track vehicles steering specially adapted for trailers B62D13/00; articulated buses B62D47/025; tractor-trailer combinations or road trains comprising a uni-axle unit and a uni-axle trailer B62D53/02
• CPC Class Codes: B62D 55/075 Tracked vehicles for ascending or descending stairs, steep slopes or vertical surfacesmagnetic or pneumatic ground-engaging parts B62D55/265; chairs or multi-track cycles specially adapted for invalids A61G5/00
• CPC Class Codes: B62D 55/12 Arrangement, location, or adaptation of driving sprockets
• CPC Class Codes: B62D 55/14 Arrangement, location, or adaptation of rollers
• CPC Class Codes: B62D 55/244 Moulded in one piece, with either smooth surfaces or surfaces having projections, e.g. incorporating reinforcing elements
• CPC Class Codes: Y10S 180/901 Devices for traversing vertical surfaces
• CPC Class Codes: Y10S 280/901 Adaptation of nonspecialized vehicles to semitrailer tractors

Abstract

An articulated tracked vehicle that has a main section, which includes a main frame, and a forward section. The main frame has two sides and a front end, and includes a pair of parallel main tracks. Each main track includes a flexible continuous belt coupled to a corresponding side of the main frame. The forward section includes an elongated arm. One end of the arm is pivotally coupled to the main frame near the forward end of the main frame about a transverse axis that is generally perpendicular to the sides of the main frame. The arm has a length sufficiently long to allow the forward section to extend below the main section in at least some degrees of rotation of the arm, and a length shorter than the length of the main section. The center of mass of the main section is located forward of the rearmost point reached by the end of the arm in its pivoting about the transverse axis. The main section is contained within the volume defined by the main tracks and is symmetrical about a horizontal plane, thereby allowing inverted operation of the robot.

Claims

1. A method for operating a robotic platform to climb a set of stairs, the method comprising:

approaching the set of stairs with right and left front arms, mounted on a corresponding side of right and left main tracks disposed on corresponding sides of a main body, in a stowed position, in which the front arms are next to the right and left main tracks, each main track trained about a corresponding main drive pulley and a corresponding rear idler pulley;

rotating right and left front arms from the stowed position downward and away from the right and left main tracks, raising and supporting the main body on the front arms;

rotating the front arms to drive the upright main body past a vertical position, causing the robot to fall over and thereby invert the main body onto the set of stairs;

driving the main tracks to ascend the set of stairs; and

maintaining a center of mass of the robotic platform within an envelope of 360 degree rotation of the front arms.

2. The method of claim 1, further comprising:

driving the main tracks of the inverted robotic platform until the front arms contact the first stair; and

pivoting the front arms to extend a tracked base of the vehicle, before driving the main tracks to ascend the set of stairs.

3. The method of claim 1, further comprising pivoting each front arm about an articulation axis co-axially with the main drive pulleys to pivot with respect to the main body.

4. The method of claim 1, further comprising pivoting each front arm with an articulator drive motor coupled to an arm side plate of each front arm for rotation about the articulation axis.

5. The method of claim 4, further comprising pivoting the right and left front arms in unison by the corresponding coupled articulator drive motor.

6. The method of claim 5, further comprising pivoting the right and left front arms without rotation of the articulator drive motor when a torque between one of the front arms and the main body, caused by a force acting on the one front arm, exceeds a maximum torque that can be provided by the articulator drive motor.