Robotic platform

• US 6,431,296 B1
• Filed: 06/25/2001
• Issued: 08/13/2002
• Est. Priority Date: 03/27/1998
• Status: Expired due to Term

• Current Assignee: Flir Detection, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: iRobot Corporation
• Inventors: Won, Chikyung
• Primary Examiner(s): DePumpo, Daniel G.
• Application Number:
  US09/888,760
• Time in Patent Office: 414 Days
• Field of Search: 180/8.1, 180/8.2, 180/8.7, 180/9.1, 180/9.32, 180/901, 901/1
• 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 an articulated tracked vehicle having a main tracked chassis and a pivoting forward arm to climb a series of stairs having a rise in elevation at a first stair and at each subsequent stair, comprising:

pivoting the arm to raise the arm higher than the rise of the first stair;

approaching the first stair until the arm contacts the first stair;

driving the main tracks to propel the vehicle until the main tracks contacts the first stair;

pivoting the arm to extend the tracked base of the vehicle; and

driving the main tracks to ascend the series of stairs.

2. The method of claim 1 further comprising:

after pivoting the arm to extend the tracked base of the vehicle, maintaining a substantially constant center of gravity of the vehicle relative to tracked base while driving the tracks to ascend the stairs.

3. The method of claim 2 wherein maintaining the substantially constant center of gravity includes maintaining said center of gravity at a location that maintains stability as the vehicle ascends the stairs.

4. The method of claim 3 wherein the series of stairs has a step span measured diagonally between successive stairs, and when ascending the stairs, the vertical projection of the center of gravity falls at least one step span in front of the rear most point of the tracked base and at least on step span behind the front most point of the tracked base.

5. The method of claim 1 wherein the pivoting arm has a pivoting end and an extreme end, and the method further comprises providing a weight at the extreme end of the pivoting arm to move the center of gravity forward when the arm is pivoted to extend the tracked base of the vehicle.

6. The method of claim 1 wherein pivoting the arm to extend the tracked base includes extending said tracked base to a length at least equal to two step spans, each measured diagonally between successive stairs.

7. The method of claim 1 wherein pivoting the arm to extend the tracked base includes forming a substantially planar tracked base, and driving the main tracks to ascend the series of stairs includes maintaining said planar tracked base while ascending the stairs.

8. A method for inverting an articulated tracked vehicle having a main tracked chassis and a pivoting arm, comprising:

supporting the vehicle on the main tracks in a first vertical orientation;

pivoting the arm to support the vehicle on the pivoting arm;

further pivoting the arm to pass the main chassis past a stable point; and

supporting the vehicle on the main tracks in a second vertical orientation, the second vertical orientation being inverted with respect to the first orientation.

9. The method of claim 8 further comprising, after pivoting the arm to pass the main chassis past the stable point, allowing the main chassis to fall until the vehicle is again supported on the main tracks.