Robotic leg parallel to a ball screw

Patent metadata

Field	Value
Publication number	US-9475191-B1
Application number	US-201514616814-A
Country	US
Kind code	B1
Filing date	Feb 9, 2015
Priority date	Sep 3, 2014
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

Disclosed are robotic systems, methods, bipedal robot devices, and computer-readable mediums. For example, a robotic system may include a robotic body, a robotic hip connected to the robotic body, and a ball screw connected to the robotic hip. Further, the robotic system may include a robotic leg connected to the robotic hip parallel to the ball screw. Yet further, the robotic hip includes a motor that is linearly movable to one or more positions along the ball screw between one end of the robotic leg and an opposite end of the robotic leg.

First claim

We claim:

1. A robotic system comprising:
a robotic body;
a robotic hip connected to the robotic body;
a ball screw connected to the robotic hip; and
a robotic leg connected to the robotic hip parallel to the ball screw, wherein the robotic hip comprises a motor that is linearly movable to one or more positions along the ball screw between one end of the robotic leg and an opposite end of the robotic leg, wherein the robotic leg is fully rotatable around an axis of rotation defined by the robotic hip, and wherein a first robotic foot is connected to the one end of the robotic leg and a second robotic foot is connected to the opposite end of the robotic leg.

2. The robotic system of claim 1 , wherein a mass of the ball screw is approximately 0.1-5 kg, wherein a mass of the robotic leg is approximately 1-10 kg, and wherein a mass of the motor is approximately 10-20 kg.

3. The robotic system of claim 1 , wherein the robotic leg further comprises a torque limiter that determines an amount of torque applied by the motor, an encoder that determines a particular position of the motor from the one or more positions along the ball screw, and an electromagnetic brake that holds the motor at the particular position and releases the motor from the particular position.

4. The robotic system of claim 3 , wherein the robotic system further comprises a computer-readable medium having stored thereon program instructions that, when executed by one or more processors of the robotic system, cause the robotic system to perform operations comprising:
determining, by the torque limiter, that the amount of torque applied by the motor exceeds one or more torque thresholds;
based on determining the amount of torque applied, causing the electromagnetic brake to apply a friction to hold the motor at the particular position of along the ball screw; and
causing the motor to reduce the amount of torque applied by the motor below the one or more torque thresholds.

5. The robotic system of claim 4 , wherein the robotic system further comprises a temperature sensor that measures temperature of the robotic system based on the friction applied to hold the motor at the particular position along the ball screw.

6. The robotic system of claim 5 , wherein the operations further comprise:
determining that the measured temperature exceeds one or more temperature thresholds;
based on exceeding the one or more temperature thresholds, causing the electromagnetic brake to release the friction applied to hold the motor at the particular position along the ball screw; and
causing the motor to increase the amount of torque applied by the motor.

7. The robotic system of claim 1 , further comprising:
a second robotic hip connected to the robotic body;
a second ball screw connected to the second robotic hip; and
a second robotic leg connected to the second robotic hip parallel to the second ball screw, wherein the second robotic hip comprises a second motor that is linearly movable to one or more positions along the second ball screw between one end of the second robotic leg and an opposite end of the second robotic leg.

8. The robotic system of claim 1 , further comprising a liquid-cooled device configured to cool the motor.

9. A method comprising:
moving, by a robotic system, a motor of a robotic hip linearly along a ball screw connected parallel to a robotic leg, wherein the motor moves to one or more positions along the ball screw between one end of the robotic leg and an opposite end of the robotic leg, wherein the robotic hip is connected to a robotic body;
rotating, by the robotic system, the robotic leg around an axis of rotation defined by the robotic hip, wherein the robotic leg is fully rotatable around the axis of rotation defined by the robotic hip, and wherein a first robotic foot is connected to the one end of the robotic leg and a second robotic foot is connected to the opposite end of the robotic leg;
based on rotating the robotic leg, causing, by the robotic system, the robotic leg to take a step with the first robotic foot.

10. The method of claim 9 , wherein a mass of the ball screw is approximately 0.1-5 kg, wherein a mass of the robotic leg is approximately 1-10 kg, and wherein a mass of a ball screw motor is approximately 10-20 kg.

11. The method of claim 9 , wherein the robotic leg further comprises a torque limiter, an encoder, and an electromagnetic brake, the method further comprising:
determining, by the torque limiter, that an amount of torque applied by the motor exceeds one or more torque thresholds;
determining, by the encoder, a particular position of the motor from the one or more positions along the ball screw;
based on determining the particular position of the motor, causing the electromagnetic brake to apply a friction to hold the motor at the particular position along the ball screw; and
causing the motor to reduce the torque applied by the motor below the one or more torque thresholds.

12. The method of claim 11 , wherein the robotic system further comprises a temperature sensor, the method further comprising:
determining, by the temperature sensor, a temperature of the robotic system based on the friction applied to hold the motor at the particular position along the ball screw;
based on determining the temperature of the robotic system, causing the electromagnetic brake to release the friction applied to hold the motor at the particular position along the ball screw; and
causing the motor to increase the amount of torque applied by the motor.

13. The method of claim 9 , further comprising:
moving, by the robotic system, a second motor of a second robotic hip linearly along a second ball screw connected parallel to a second robotic leg, wherein the second motor moves to one or more positions along the ball screw between one end of the second robotic leg and an opposite end of the second robotic leg, wherein the second robotic hip is connected to the robotic body;
rotating, by the robotic system, the second robotic leg around a second axis of rotation defined by the second robotic hip; and
based on rotating the second robotic leg, causing, by the robotic device, the second robotic leg to take a step.

14. A bipedal robot device comprising:
a robotic body;
a robotic hip connected to the robotic body;
a ball screw connected to the robotic hip; and
a robotic leg connected to the robotic hip parallel to the ball screw, wherein the robotic hip comprises a motor that is linearly movable to one or more positions along the ball screw between one end of the robotic leg and an opposite end of the robotic leg, wherein the robotic leg is fully rotatable around an axis of rotation defined by the robotic hip, and wherein a first robotic foot is connected to the one end of the robotic leg and a second robotic foot is connected to the opposite end of the robotic leg.

15. The bipedal robot device of claim 14 , wherein a mass of the ball screw is approximately 0.1-5 kg, wherein a mass of the robotic leg is approximately 1-10 kg, and wherein a mass of the motor is approximately 10-20 kg.

16. The bipedal robot device of claim 14 , wherein the robotic leg further comprises a torque limiter that determines an amount of torque applied by the motor, an encoder that determines a particular position of the motor from the one or more positions along the ball screw, and an electromagnetic brake that holds the motor at the particular position and releases the motor from the particular position.

17. The bipedal robot device of claim 16 , wherein the bipedal robot device further com

Assignees

• Google Inc

Inventors

• Urata Junichi
• Ito Yoshito

Classifications

• B25J9/0006 Primary

  Exoskeletons, i.e. resembling a human figure · CPC title

• H02K9/00

  Arrangements for cooling or ventilating (channels or ducts in parts of the magnetic circuit H02K1/20, H02K1/32; channels or ducts in or between conductors H02K3/22, H02K3/24) · CPC title

• B25J9/1633 Primary

  compliant, force, torque control, e.g. combined with position control · CPC title

• G05B11/01

  electric · CPC title

• B62D57/022 Primary

  consisting of members having both rotational and walking movements · CPC title