Robotic platform

• US 20040216931A1
• Filed: 12/24/2003
• Published: 11/04/2004
• Est. Priority Date: 03/27/1998
• Status: Active Grant

• Current Assignee: Flir Detection, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: iRobot Corporation
• Inventors: Won, Chikyung
• Granted Patent: US 7,597,162 B2
• Time in Patent Office: Days
• US Class Current: 180/9.1
• 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. An articulated tracked vehicle comprising:

a main section including a main frame having two sides and a front end, and including a pair of parallel main tracks, each including a flexible continuous belt coupled to a corresponding side of the main frame; and

a forward section including an elongated arm having a proximal end and a distal end, the proximal end of the arm being pivotally coupled to the main frame near the forward end of the main frame about a transverse axis generally perpendicular to the sides of the main frame, the arm having 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;

wherein the center of mass of the main section is located forward of the rearmost point reached by the distal end of the arm in its pivoting about the transverse axis.

2. The vehicle of claim 1 wherein 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.

3. The vehicle of claim 1 wherein the vehicle is dimensioned for climbing a set of stairs, including at a first adjusted angle between the main section and the forward section, the forward section rising more than the rise of the bottom-most of the set of stairs, and at a second adjusted angle between the main section and the forward section, the length spanned by the combination of the main section and the forward section being greater than the diagonal span of two successive stairs, and the center of gravity of the vehicle is located in a position so that the vehicle remains statically stable as it climbs the stairs at the second adjusted angle.

4. The vehicle of claim 1 wherein the forward section includes a second arm, also pivotably coupled to the main frame near its forward end.

5. The vehicle of claim 4 wherein the two arms are rigidly coupled and are rotated together by the articulator motor, the articulator motor providing sufficient torque between the main frame and the arms to raise the rear end of the main section thereby supporting the vehicle on the front section.

6. The vehicle of claim 5 wherein continuous rotation of the arms provides forward locomotion of the vehicle.

7. The vehicle of claim 5 further comprising a harmonic drive coupled between the articulator motor and the two arm, the harmonic drive providing a torque to the two arms greater than the torque provided to it by the articulator motor.

8. The vehicle of claim 5 further comprising a clutch coupled between the articulator motor and the two arms, wherein the clutch allows rotation of the arms without rotation of the motor if the torque between the arms and the main section exceeds a limit.

9. The vehicle of claim 4 wherein the arms are coupled to the main frame such that they rotate outside the main tracks.

10. The vehicle of claim 9 wherein the forward section includes a pair of flexible forward tracks one coupled to each of the two arms.

11. An articulated tracked vehicle comprising:

a main section including a main frame having two sides and a front end, and including a pair of parallel main tracks, each including a flexible continuous belt coupled to a corresponding side of the main frame;

a forward section including a pair of elongated arms each having a proximal end and a distal end, the proximal ends of the arms being pivotally coupled to the main frame near the forward end of the main frame allowing rotation of the arms outside the main tracks around a transverse axis that is generally perpendicular to the sides of the main frame, the forward section further including a pair of forward tracks, each including a flexible continuous belt, one track coupled to each of the two arms;

on each side of the vehicle, a pair of drive pulleys for supporting and driving each of the main and forward tracks, respectively, the drive pulleys being coaxial with the transverse axis of rotation of the arms, and joined so that they rotate together.

12. The vehicle of claim 11 wherein the main section includes a pair of drive motors, each coupled to the main and forward drive pulleys on a corresponding side of the vehicle.

13. An impact resistance tracked vehicle comprising:

a main frame;

a pair of parallel main tracks, each including a flexible continuous belt; and

on each side of the main frame, two compliant pulleys coupled between one of the main tracks and the main frame, and a plurality of compliant track supports coupled between the tracks and the side plates;

wherein each pulley includes a compliant outer rim, a hub, and a plurality of compliant spoke segments coupled between the rim and the hub.

14. The vehicle of claim 13 further comprising a plurality of compliant longitudinal track supports coupled between the main frame and the continuous belts, each longitudinal track support having a series of open slots forming a series of rib sections between the upper and lower edges of the support.

15. The vehicle of claim 13 wherein the pulleys and main frame are recessed within the volumes defined by the tracks.

16. The vehicle of claim 13 wherein the tracks each includes a series of compliant cleats attached transversely on the outside of the flexible belt.

17. The vehicle of claim 13 wherein the main tracks each include a longitudinal rib coupled to the inside surface of the belt, and each of the pulleys includes a channel around its circumference which accepts the longitudinal rib, the channels being dimensioned larger than the rib thereby allowing debris to be caught between a pulley and a tracks without dislodging the track from the pulley.

18. A method for operating an articulated tracked vehicle having a main tracked chassis and a pivoting forward arm to climb a set of stairs, comprising:

pivoting the arm to raise the arm higher than the rise of the bottom-most stair of the set of stairs;

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

driving the main tracks 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 set of stairs.

19. 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;

supporting the vehicle on the pivoting arm;

pivoting the arm to raise the main chassis above the supporting surface;

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

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