Legged mobile robot leg structure

• US 7,240,747 B2
• Filed: 11/16/2001
• Issued: 07/10/2007
• Est. Priority Date: 11/17/2000
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Takahashi, Hideaki, Miyazaki, Susumu
• Primary Examiner(s): WINNER, TONY H
• Application Number:
  US10/416,900
• Publication Number:
  US 20040074679A1
• Time in Patent Office: 2,062 Days
• Field of Search: 180/8.5, 180/8.6, 180/8.1, 318/568.12
• US Class Current: 180/8.6
• CPC Class Codes: B25J 13/085 Force or torque sensors B25J13/082, B25J13/084 take precedence
• CPC Class Codes: B25J 17/0275 Universal joints, e.g. Hooke, Cardan, ball joints

Abstract

A legged mobile robot leg structure is provided in which a lower leg part (24) is connected to the lower end of an upper leg part (23) through a knee joint (27), a foot part (25) having a six-axis force sensor (60) is connected to the lower end of the lower leg part (24) through an ankle joint (28), and the ankle joint (28) supports the foot part (25) so that the foot part (25) can pitch around a lateral axis (Ly) and roll around a fore-and-aft axis (Lx) relative to the lower leg part (24). A pitch motor (34) for making the foot part (25) pitch around the lateral axis (Ly) is supported on the lower leg part (24) at a position above the ankle joint (28), and a roll motor (35) for making the foot part (25) roll around the fore-and-aft axis (Lx) is supported on the lower leg part (24) at a position above the ankle joint (28). The driving force for driving the lower leg part (24) can thereby be reduced by decreasing the moment of inertia around the knee joint (27), and the influence of noise of the motors (34, 35) on the six-axis force sensor (60) provided on the foot part (25) can be minimized.

Claims

1. A legged mobile robot leg structure in which a lower leg part (24) is connected to the lower end of an upper leg part (23) through a knee joint (27), a foot part (25) is connected to the lower end of the lower leg part (24) through an ankle joint (28), and the ankle joint (28) supports the foot part (25) so that the foot part (25) can pitch around a lateral axis (Ly) and roll around a fore-and-aft axis (Lx) relative to the lower leg part (24), the legged mobile robot leg structure comprising:

a pitch motor (34) for making the foot part (25) pitch around the lateral axis (Ly), the pitch motor (34) being supported on the lower leg part (24) at a position above the ankle joint (28); and

a roll motor (35) for making the foot part (25) roll around the fore-and-aft axis (Lx), the roll motor (35) being supported on the lower leg part (24) at a position above the ankle joint (28).

2. The legged mobile robot leg structure according to claim 1, further comprising:

a pitch shaft (36) supported on the lower leg part (24) such that the pitch shaft (36) can rotate around the lateral axis (Ly);

a pitch belt transfer means (42) for transferring rotation of an output shaft (34a) of the pitch motor (34) to the pitch shaft (36), the output shaft (34a) being disposed in the direction of the lateral axis (Ly); and

a roll mechanism (61) for rollably supporting the foot part (25) on the pitch shaft (36).

3. The legged mobile robot leg structure according to claim 2 wherein a sensor (60) for detecting a load imposed on the foot part (25) is provided on the foot part (25).

4. The legged mobile robot leg structure according to claim 1 wherein a sensor (60) for detecting a load imposed on the foot part (25) is provided on the foot part (25).

5. A legged mobile robot leg structure in which a lower leg part (24) is connected to the lower end of an upper leg part (23) through a knee joint (27), a foot part (25) is connected to the lower end of the lower leg part (24) through an ankle joint (28), and the ankle joint (28) supports the foot part (25) SO that the foot part (25) can pitch around a lateral axis (Ly) and roll around a fore-and-aft axis (Lx) relative to the lower leg part (24), the legged mobile robot leg structure comprising:

a pitch shaft (36) and a roll shaft (44) that are fixed so as to be perpendicular to each other and that rotate around the lateral axis (Ly) and the fore-and-aft axis (Lx) respectively;

a rotating member (46) that is rotatably supported on the outer periphery of one of the pitch shaft (36) and the roll shaft (44) and that rotates integrally with the foot part (25);

a first drive source (34) that rotates the other one of the pitch shaft (36) and the roll shaft (44);

a drive bevel gear (58) coaxially disposed within said other one of the pitch shaft (36) and the roll shaft (44);

a driven bevel gear (57) coaxially disposed within said one of the pitch shaft (36) and the roll shaft (44), the driven bevel gear (57) meshing with the drive bevel gear (58) and being connected to the rotating member (46); and

a second drive source (35) for rotating the drive bevel gear (58).

6. The legged mobile robot leg structure according to claim 5 wherein a sensor (60) for detecting a load imposed on the foot part (25) is provided on the foot part (25).

7. A legged mobile robot leg structure in which a lower leg part (24) is connected to the lower end of an upper leg part (23) through a knee joint (27), a foot part (25) is connected to the lower end of the lower leg part (24) through an ankle joint (28), and the ankle joint (28) supports the foot part (25) 50 that the foot part (25) can pitch around a lateral axis (Ly) and roll around a fore-and-aft axis (Lx) relative to the lower leg part (24), the legged mobile robot leg structure comprising:

a roll mechanism (61) for rollably supporting the foot part (25) on a pitch shaft (36), the roll mechanism (61) comprising;

a roll shaft (44) fixed to the pitch shaft (36) so as to be perpendicular thereto, a roll member (46) integrally fixed to the foot part (25) and rotatably supported on the outer periphery of the roll shaft (44);

a drive bevel gear (58) coaxially disposed within the pitch shaft (36);

a roll belt transfer means (55) for transferring rotation of an output shaft (35a) of a roll motor (35) to the drive bevel gear (58), the output shaft (35a) being disposed in the direction of the lateral axis (Ly); and

a driven bevel gear (57) coaxially disposed within the roll shaft (44), the driven bevel gear (57) meshing with the drive bevel gear (58) and being connected to the roll member (46).

8. The legged mobile robot leg structure according to claim 7 wherein a pitch reduction gear (43) is disposed between a pitch belt transfer means (42) and the pitch shaft (36), and a roll reduction gear (59) is disposed between the driven bevel gear (57) and the roll member (46).

9. The legged mobile robot leg structure according to claim 8 wherein a sensor (60) for detecting a load imposed on the foot part (25) is provided on the foot part (25).

10. The legged mobile robot leg structure according to either claim 7 or 8 wherein the outside of the roll member (46) is covered by a partially spherical cover (62, 63), and a predetermined gap (□

) is formed between the partially spherical cover (62, 63) and the lower end of a skeleton-forming lower leg link (33) of the lower leg part (24).

11. The legged mobile robot leg structure according to claim 10 wherein the partially spherical cover (62, 63) has the center thereof on the pitch shaft (36) or the roll shaft (44).

12. The legged mobile robot leg structure according to claim 11 wherein a sensor (60) for detecting a load imposed on the foot part (25) is provided on the foot part (25).

13. The legged mobile robot leg structure according to claim 7 wherein a sensor (60) for detecting a load imposed on the foot part (25) is provided on the foot part (25).