Robotic Platform

• US 20090065271A1
• Filed: 06/17/2008
• Published: 03/12/2009
• 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 8,365,848 B2
• Time in Patent Office: Days
• US Class Current: 180/9.320
• 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 robotic platform comprising:

a main body;

right and left main tracks disposed on corresponding sides of the main body, each main track trained about a corresponding main drive pulley and a corresponding rear idler pulley;

right and left front tracks pivotally coupled to a forward portion of the main body in between the right and left main tracks, each front track trained about a corresponding front drive pulley and a corresponding front idler pulley, each front drive pulley being concentric with and coupled to rotate in unison with the corresponding main drive pulley;

right and left track motors respectively driving the right main and front drive pulleys and left main and front drive pulleys, the right and left track motors being differentially driven to provide skid steering; and

at least one articulator drive motor coupled to right and left front tracks, the articulator drive motor rotating the right and left front tracks in a continuous 360 degrees between a stowed position, in which the front tracks are next to the main body and the front tracks provide traction with the main tracks in a compact track configuration, and at least one deployed position, in which the front tracks are pivoted at an angle with respect to the main tracks.

2. The robotic platform of claim 1, further comprising an articulator axle coupled to the front tracks and passing through the main drive pulleys and front drive pulleys to pivot with respect to the main body, the front tracks pivoting in unison.

3. The robotic platform of claim 1, wherein the combination of main tracks and front tracks, trained about the right main drive pulley and front drive pulley and the left main drive pulley and front drive pulley, provide an extended wheel base, all the right main drive pulley, right front drive pulley, left main drive pulley, and left front drive pulley being of substantially similar diameter, and wherein the extended wheel base is sufficiently long to span a minimum of two stair steps of 7″

rise by 11″

tread stairs at all times, and the center of gravity of the robotic platform is located so that the robotic platform remains statically stable as it climbs stair steps of 7″

rise by 11″

tread stairs.

4. The robotic platform of claim 1, wherein the front drive pulleys have a larger diameter than the front idler pulleys, thereby tapering the front tracks.

5. The robotic platform of claim 1, wherein the front tracks are narrower than the main tracks.

6. The robotic platform of claim 5, wherein a width of each front track is about ⅔

a width of one of the main tracks.

7. The robotic platform of claim 1, further comprising a camera housed in a forward portion of the main body and arranged to provide a forward field of view along a driving direction of the robotic platform that is unobstructed by movement of the front tracks.

8. The robotic platform of claim 1, further comprising a slip clutch coupled between the articulator drive motor and the front tracks, the slip clutch enabling rotation of the front tracks without rotation of the articulator drive motor when a torque between at least one front tracks and the main body, caused by a force acting on the at least one track, exceeds a maximum torque that can be provided by the articulator drive motor.

9. The robotic platform of claim 8, further comprising a drive coupling the articulator drive motor to the slip clutch, the slip clutch is coupled to an articulator axle coupled to the front tracks to rotate the front arms about the main drive pulley axis, the drive providing a gear reduction between the articulator drive motor and the articulator axle.

10. The robotic platform of claim 8, wherein the slip clutch slips in excess of a torque of approximately 127 N-m applied to the front arms permitting the front tracks to rotate with respect to the drive.

11. The robotic platform of claim 1, wherein the main body defines a volume less than a main tracks volume defined between the right and left main tracks.

12. The robotic platform of claim 1, wherein each track support compliantly supports the corresponding track.

13. A robotic platform comprising:

a main body;

right and left main tracks disposed on corresponding sides of the main body, each main track trained about a corresponding main drive pulley and a corresponding rear idler pulley;

right and left front arms pivotally coupled by an articulator axle passing through a forward portion of the main body to pivot with respect to the main body, each front arm being mounted between the corresponding main track and the main body, and including;

an arm plate having proximal and distal ends;

a front drive pulley rotatably coupled to the proximal end of the arm plate, the front drive pulley being concentric with and coupled to rotate in unison with the corresponding main drive pulley;

a front idler pulley rotatably mounted at the distal end of the arm plate, and

a front arm track trained about the front drive pulley and front idler pulley;

right and left track motors respectively driving the right main and front drive pulleys and left main and front drive pulleys, the right and left track motors being differentially driven to provide skid steering; and

an articulator drive motor coupled to the articulator axle, the articulator axle rigidly coupling the arm plates of the front arms, the articulator drive motor pivoting the articulator axle and front arms in unison among different mobility modes of the robotic platform, including;

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

an inclined mobility mode in which the front arms are pivoted to an angle with respect to the main tracks inclining the main body such that the robotic platform travels on four points of contact at the extreme ends of the main tracks and front tracks; and

an upright mobility mode in which the front arms are pivoted to an angle with respect to the main tracks to balance the main body on the front arms, and in which the robotic platform is able to drive on the front tracks and to pivot in place.

14. The robotic platform of claim 13, wherein the front drive pulleys have a larger diameter than the front idler pulleys, thereby tapering the front tracks.

15. The robotic platform of claim 13, further comprising a camera housed in a forward portion of the main body and arranged to provide a forward field of view along a driving direction of the robotic platform that is unobstructed by movement of the front tracks.

16. The robotic platform of claim 13, further comprising a slip clutch coupled between the articulator drive motor and the front arms, the slip clutch enabling rotation of the front arms without rotation of the articulator drive motor when a torque between at least one front arm and the main body, caused by a force acting on the at least one arm, exceeds a maximum torque that can be provided by the articulator drive motor.

17. The robotic platform of claim 16, further comprising a drive coupling the articulator drive motor to the slip clutch, the slip clutch is coupled to an articulator axle coupled to the front arms to rotate the front arms about the main drive pulley axis, the drive providing a gear reduction between the articulator drive motor and the articulator axle.

18. The robotic platform of claim 16, wherein the slip clutch slips in excess of a torque of approximately 127 N-m applied to the front arms permitting the front arms to rotate with respect to the drive.

19. A robotic platform comprising:

a main body;

right and left main tracks disposed on corresponding sides of the main body, each main track trained about a corresponding main drive pulley and a corresponding rear idler pulley;

right and left main track supports supporting the corresponding right and left main tracks, each main track support disposed between the corresponding main drive pulley and rear idler pulley;

right and left front tracks pivotally coupled to a forward portion of the main body in between the right and left main tracks, each front track trained about a corresponding front drive pulley and a corresponding front idler pulley, each front drive pulley being concentric with and coupled to rotate in unison with the corresponding main drive pulley;

right and left front track supports supporting the corresponding right and left front tracks, each front track support disposed between the corresponding front drive pulley and front idler pulley;

right and left track motors respectively driving the right main and front drive pulleys and left main and front drive pulleys, the right and left track motors being differentially driven to provide skid steering; and

an articulator drive motor coupled to right and left front tracks, the articulator drive motor rotating the right and left front tracks between at least one angled position, in which the front arms are pivoted at an angle with respect to the main tracks and an extended position, in which the front arms are pivoted to align substantially parallel to the main tracks.

20. The robotic platform of claim 19, further comprising an articulator axle coupled to the front tracks and passing through the main drive pulleys and front drive pulleys to pivot with respect to the main body, the front tracks pivoting in unison.

21. The robotic platform of claim 19, wherein the combination of main tracks and front tracks, trained about the right main drive pulley and front drive pulley and the left main drive pulley and front drive pulley, provide an extended wheel base, all the right main drive pulley, right front drive pulley, left main drive pulley, and left front drive pulley being of substantially similar diameter, and wherein the extended wheel base is sufficiently long to span a minimum of two stair steps of 7″

rise by 11″

tread stairs at all times, and the center of gravity of the robotic platform is located so that the robotic platform remains statically stable as it climbs stair steps of 7″

rise by 11″

tread stairs.

22. The robotic platform of claim 19, wherein the front drive pulleys have a larger diameter than the front idler pulleys, thereby tapering the front tracks.

23. The robotic platform of claim 19, wherein the front tracks are narrower than the main tracks.

24. The robotic platform of claim 23, wherein a width of each front track is about ⅔

a width of one of the main tracks.

25. The robotic platform of claim 19, further comprising a camera housed in a forward portion of the main body and arranged to provide a forward field of view along a driving direction of the robotic platform that is unobstructed by movement of the front tracks.

26. The robotic platform of claim 19, further comprising a slip clutch coupled between the articulator drive motor and the front tracks, the slip clutch enabling rotation of the front tracks without rotation of the articulator drive motor when a torque between at least one front tracks and the main body, caused by a force acting on the at least one track, exceeds a maximum torque that can be provided by the articulator drive motor.

27. The robotic platform of claim 26, further comprising a drive coupling the articulator drive motor to the slip clutch, the slip clutch is coupled to an articulator axle coupled to the front tracks to rotate the front arms about the main drive pulley axis, the drive providing a gear reduction between the articulator drive motor and the articulator axle.

28. The robotic platform of claim 26, wherein the slip clutch slips in excess of a torque of approximately 127 N-m applied to the front arms permitting the front tracks to rotate with respect to the drive.

29. The robotic platform of claim 19, wherein the main body defines a volume less than a main tracks volume defined between the right and left main tracks.