Legged mobile robot

• US 7,366,587 B2
• Filed: 12/04/2003
• Issued: 04/29/2008
• Est. Priority Date: 12/05/2002
• Status: Active Grant

• Current Assignee: Jinichi Yamaguchi, Sony Corporation (Sony Group Corp.)
• Original Assignee: Jinichi Yamaguchi, Sony Corporation (Sony Group Corp.)
• Inventors: Yamaguchi, Jinichi, Iribe, Masatsugu
• Primary Examiner(s): Tran; Khoi H.
• Assistant Examiner(s): Marc; McDieunel
• Application Number:
  US10/726,597
• Publication Number:
  US 20040172165A1
• Time in Patent Office: 1,608 Days
• Field of Search: 700/245, 700/247, 700/249, 700/250, 700/252, 700/253, 700/258, 700/260, 700/264, 901/1, 901/2, 901/9, 901/46, 180/8.1, 180/8.6, 318/568.1, 318/568.11, 318/568.12, 318/568.16, 318/568.17, 318/568.22, 318/568.25
• US Class Current: 700/245
• CPC Class Codes: B62D 57/032 with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid B62D57/024 takes precedence

Abstract

The characteristics of actuators themselves and the characteristics of controllers for the actuators are dynamically or statically controlled to achieve stable and highly efficient movements. In a stage in which a leg in the flight state is uplifted such that the reactive force from the floor received by the foot sole of the leg is zero, the characteristics of the respective actuators for the knee joint pitch axis and the ankle pitch and roll axes of the leg in the flight state are set for decreasing the low range gain, increasing the quantity of phase lead and for decreasing the viscous resistance of the actuators, in order to impart mechanical passiveness and fast response characteristics. The followup control for the high frequency range may be achieved as the force of impact at the instant of touchdown is buffered.

Claims

1. A legged mobile robot including a plurality of joint sites and a plurality of mobile legs, comprising:

a controlling unit configured to control characteristics of an actuator at one of said plurality of joint sites for controlling, in combination, of a gain and a phase compensation of a servo controller belonging to said actuator and for controlling a viscous resistance of an actuator motor.

2. The legged mobile robot according to claim 1, wherein said controlling unit sets, when the actuator is in need of high precision positioning control and/or orientation stability, a low range gain to a large value, a quantity of phase lead in the high frequency range to a small value, and the viscous resistance of the actuator motor to a large value.

3. The legged mobile robot according to claim 1, wherein said controlling unit sets, when the actuator is in need of mechanical passiveness and fast response characteristics, a low range gain to a small value, a quantity of phase lead to a large value, and the viscous resistance of the actuator motor to a small value.

4. The legged mobile robot according to claim 1, wherein said controlling unit sets, when the actuator is in need of buffering a force of impact and performing followup control of a high frequency range, a low range gain to a small value, a quantity of phase lead to a large value, and the viscous resistance of the actuator motor to a small value.

5. The legged mobile robot according to claim 1, wherein said controlling unit switches between first actuator characteristics of setting the actuator to a large value of a low range gain, a small quantity of a phase lead, and a large value of the viscous resistance of the actuator motor and second actuator characteristics of setting the actuator to a small value of the low range gain, a large quantity of the phase lead, and a small value of the viscous resistance of the actuator motor, at each step of a shifting operation on legs.

6. The legged mobile robot according to claim 5, wherein said controlling unit switches between first actuator characteristics of setting the actuator to a large value of the low range gain, a small quantity of the phase lead, and a large value of the viscous resistance of the actuator motor and second actuator characteristics of setting the actuator to a small value of the low range gain, a large quantity of the phase lead, and a small value of the viscous resistance of the actuator motor, at each step of a walking movement on legs.

7. The legged mobile robot according to claim 6, wherein said controlling unit sets, at a stage of commencing the walking movement, characteristics of actuators for joint sites of a knee joint pitch axis, ankle roll and pitch axes, body trunk roll, pitch, and yaw axes, hip joint roll and pitch axes, and a neck pitch axis to a large value of the low range gain, a small quantity of phase lead in a high frequency range, and a large value of the viscous resistance of the actuator motor, and said controlling unit sets the characteristics of actuators for joints of a shoulder pitch axis and an elbow pitch axis to a small value of the low range gain, a large quantity of the phase lead, and a small value of the viscous resistance of the actuator motor.

8. The legged mobile robot according to claim 6, wherein said controlling unit sets, at a stage when a leg in a flight state is uplifted and a reactive force from a floor received by a foot sole is equal to zero, for characteristics of actuators for a knee joint pitch axis, ankle roll axis and an ankle pitch axis of the leg in the flight state, a small value of the low range gain, a large quantity of the phase lead, and a small value of the viscous resistance of the actuator motor.

9. The legged mobile robot according to claim 6, wherein said controlling unit sets, at a stage when the walking movement of a leg in a flight state proceeds and the leg touches a floor, with a reactive force from the floor received by a foot sole approximately equal to that when both legs are in a stance position, characteristics of actuators for a knee joint pitch axis, ankle roll axis, and an ankle pitch axis of the leg previously in the flight state to a large value of the low range gain, a small quantity of the phase lead in a high frequency range, and a large value of the viscous resistance of the actuator motor.

10. The legged mobile robot according to claim 6, wherein, in each stage of the walking movement, said controlling unit sets, for characteristics of actuators for driving joints in which emphasis is placed on a positioning accuracy, first characteristics in which the low range gain is of a large value, the quantity of phase lead is of a small value, and the viscous resistance of the actuator motor is of a large value.

11. The legged mobile robot according to claim 6, wherein, in each stage of the walking movement, said controlling unit sets, for characteristics of actuators for driving joints in which emphasis is placed on a mechanical passiveness or on fast response characteristics, second actuator characteristics in which the low range gain is of a small value, the quantity of phase lead is of a large value, and the viscous resistance of the actuator motor is of a small value.

12. The legged mobile robot according to claim 6, wherein, in each stage when a link state formed by a floor touchdown site of the body of the legged mobile robot and a floor surface is changed between an open link state and a closed link state, said controlling unit switches, during the walking movement, the characteristics of the actuators driving respective joints between first actuator characteristics and second actuator characteristics.

13. The legged mobile robot according to claim 5, wherein, in each stage of the legged mobile robot going up or down stairs, said controlling unit switches characteristics of actuators of respective joint sites between first actuator characteristics in which the low range gain is of a large value, the quantity of the phase lead is of a small value, and the viscous resistance of the actuator motor is of a large value and second actuator characteristics in which the low range gain is of a small value, the quantity of the phase lead is of a large value, and the viscous resistance of the actuator motor is of a small value.

14. The legged mobile robot according to claim 13, wherein, in a stage when both legs are in a stance position prior to going up or down the stairs, in an operation of going up or down the stairs, said controlling unit sets characteristics of the actuator at each joint site to the first actuator characteristics in which the low range gain is of a large value, the quantity of the phase lead in a high frequency range is of a small value, and the viscous resistance of the actuator motor is of a large value.

15. The legged mobile robot according to claim 13, wherein, in a stage when a first step is made for going up or down the stairs, in an operation of going up or down the stairs, said controlling unit sets the characteristics of the actuators of a knee joint pitch axis and an ankle roll and pitch axes of a leg in a flight condition to second actuator characteristics in which the low range gain is of a small value, the quantity of the phase lead is of a large value, and the viscous resistance of the actuator motor is of a small value.

16. The legged mobile robot according to claim 13, wherein, in a stage when a leg of a first step has touched a tread face one step higher or lower, in going up or down the stairs, said controlling unit sets the characteristics of the actuator at each joint site to first actuator characteristics in which the low range gain is of a large value, the quantity of the phase lead in a high frequency range is of a small value, and the viscous resistance of the actuator motor is of a large value.

17. The legged mobile robot according to claim 13, wherein, in a stage when a leg which touches a tread one step higher or lower reaches a stance state, and another leg in a stance position is uplifted, in going up or down stairs, said controlling unit sets the characteristics of the actuators of an ankle roll axis and an ankle pitch axis of the uplifted leg to second actuator characteristics in which the low frequency range gain is of a small value, the quantity of the phase lead is of a large value, and the viscous resistance of the actuator motor is of a small value.

18. The legged mobile robot according to claim 13, wherein, in a stage when a second step has touched a tread two steps higher in going up or down stairs, said controlling unit sets characteristics of the actuator at each joint site to first actuator characteristics in which the low range gain is of a large value, the quantity of the phase lead in a high frequency range is of a small value, and the viscous resistance of the actuator motor is of a large value.

19. The legged mobile robot according to claim 13, wherein, in each stage of going up or down the stairs, said controlling unit sets the characteristics of the actuators for driving respective joints for which emphasis is placed on positioning accuracy, to first actuator characteristics in which the low range gain is of a large value the quantity of the phase lead is of a small value, and the viscous resistance of the actuator motor is of a large value.

20. The legged mobile robot according to claim 13, wherein, in each stage of going up or down stairs, said controlling unit sets the characteristics of the actuators for driving respective joints for which emphasis is placed on mechanical passiveness or fast response characteristics to second actuator characteristics in which the low range gain is of a small value, the quantity of the phase lead is of a large value, and the viscous resistance of the actuator motor is of a small value.

21. The legged mobile robot according to claim 13, wherein, in each stage of switching a link state defined by a floor touching site of the body of the legged mobile robot and a floor surface, in going up or down the stairs, between an open link state and a closed link state, said controlling unit switches the characteristics of the actuators driving respective joints between the first actuator characteristics and the second actuator characteristics.

22. The legged mobile robot according to claim 5, wherein, in each stage of a turning movement of the body of the legged mobile robot, said controlling unit switches actuators of the respective joint sites between first actuator characteristics in which the low range gain is of a large value, the quantity of the phase lead is of a small value, and the viscous resistance of the actuator motor is of a large value and second actuator characteristics in which the low range gain is of a small value, the quantity of the phase lead is of a large value, and the viscous resistance of the actuator motor is of a small value.

23. The legged mobile robot according to claim 22, wherein, in a stage of commencing a turning movement of the body of the legged mobile robot, said controlling unit sets characteristics of the actuator at each joint site forming the body of the legged mobile robot to a large value of low range gain, a small quantity of phase lead in a high frequency range, and a large value of viscous resistance of the actuator motor.

24. The legged mobile robot according to claim 22, wherein, in a stage when a leg in a flight state is uplifted and a reactive force from a floor received by a foot sole is zero, said controlling unit sets characteristics of the actuators of a, knee joint pitch axis and ankle roll and pitch axes of the leg in the flight state to a small value of low range gain, a large quantity of phase lead, and a small value of viscous resistance of the actuator motor.

25. The legged mobile robot according to claim 22, wherein, in a stage when the turning movement of the body of the legged mobile robot progresses such that a leg in a flight state touches a floor and a reactive force from the floor received by a foot sole is approximately equal to a reactive force when both legs are in the flight state, said controlling unit sets characteristics of the actuators of a knee joint pitch axis and ankle roll and pitch axes of a leg in a stance state to a large low range gain, a small quantity of phase lead in the high frequency range, and a large viscous resistance of the actuator motor.

26. The legged mobile robot according to claim 22, wherein, in each stage of the turning movement, said controlling unit sets characteristics of the actuators for driving joints for which emphasis is placed on positioning accuracy to first actuator characteristics in which the low range gain is of a large value, the quantity of the phase lead is of a small value, and the viscous resistance of the actuator motor is of a large value.

27. The legged mobile robot according to claim 22, wherein, in each stage of the turning movement, said controlling unit sets characteristics of the actuators for driving joints for which emphasis is placed on mechanical passiveness or fast response characteristics to second actuator characteristics in which the low range gain is of a small value, the quantity of the phase lead is of a large value, and the viscous resistance of the actuator motor is of a small value.

28. The legged mobile robot according to claim 22, wherein, in each stage in which a link state defined by a floor touch site of the body of the legged mobile robot and a floor surface of the turning movement is switched between an open link state and a closed link state, said controlling unit switches characteristics of the actuators for driving respective joints between first actuator characteristics and second actuator characteristics.