Robotic platform

• US 7,546,891 B2
• Filed: 08/06/2007
• Issued: 06/16/2009
• 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:
  US11/834,321
• Publication Number:
  US 20070267230A1
• Time in Patent Office: 680 Days
• Field of Search: 180/8.2, 180/9.1, 180/9.32, 180/9.4, 180/901, 180/9.62, 305/120, 305/127, 305/199, 305/126, 305/165, 305/195, 446/433, 280/5.2, 280/5.22, 280/5.28, 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. 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;

wherein the arm is pivotable in a continuous 360 degrees among different mobility modes of the articulated tracked vehicle, the mobility modes comprising;

an extended mobility mode in which the arm is pivoted, at an angle with respect to the main tracks, forward of the main section and a center of gravity of the articulated tracked vehicle is located at least 13 inches rearward of a distal end of the arm and at least 13 inches forward of the rear most point of the main tracks;

a stowed mobility mode in which the arm is pivoted to a position in which the arm is next to the main tracks in a compact configuration;

an inclined mobility mode in which the arm is pivoted to an angle with respect to the main tracks inclining the main section such that the articulated tracked vehicle travels on points of contact at the extreme ends of the main tracks and the arm; and

an upright mobility mode in which the arm is pivoted to an angle with respect to the main tracks to balance the main section on the arm.

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 an 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 4 wherein the arms are coupled to the main frame such that they rotate outside the main tracks.

9. The vehicle of claim 8 wherein the forward section includes a pair of flexible forward tracks one coupled to each of the two arms.

10. 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 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, the forward section including a second arm, also pivotably coupled to the main frame near its forward end, wherein the two arms are rigidly coupled and are rotated together by an 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; and

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;

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.

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 coupled to a corresponding side of the main frame and including a flexible continuous belt;

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 arm track coupled to each of the two arms; and

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;

wherein the arms are pivotable in a continuous 360 degrees among different mobility modes of the articulated tracked vehicle, the mobility modes comprising;

an extended mobility mode in which the arms are pivoted, at an angle with respect to the main tracks, forward of the main section and a center of gravity of the articulated tracked vehicle is located at least 13 inches rearward of a distal end of the arms and at least 13 inches forward of the rear most point of the main tracks;

a stowed mobility mode in which the arms are pivoted to a position in which the arms are next to the main tracks, and the arm tracks provide traction with the main tracks in a compact track configuration;

an inclined mobility mode in which the arms are pivoted to an angle with respect to the main tracks inclining the main section such that the articulated tracked vehicle travels on four points of contact at the extreme ends of the main tracks and arm tracks; and

an upright mobility mode in which the arms are pivoted to an angle with respect to the main tracks to balance the main section on the arms, and in which the articulated tracked vehicle is able to drive on the arm tracks and to pivot in place.

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. The vehicle of claim 11 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.

14. The vehicle of claim 11 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.

15. The vehicle of claim 11 wherein the two arms are rigidly coupled and are rotated together by an 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.

16. The vehicle of claim 15 wherein continuous rotation of the arms provides forward locomotion of the vehicle.

17. The vehicle of claim 15 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.

18. The vehicle of claim 11 wherein the pulleys and main frame are recessed within the volumes defined by the tracks.

19. 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 coupled to a corresponding side of the main frame and including a flexible continuous belt;

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 arm track coupled to each of the two arms, wherein the two arms are rigidly coupled and are rotated together by an 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;

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; and

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.

20. 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 coupled to a corresponding side of the main frame and including a flexible continuous belt;

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 arm 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; and

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.