US 9,618,937 B1Granted

Slip detection using robotic limbs

AssigneeGoogle Inc.

InventorsKevin Blankespoor, Alex Perkins, Marco da Silva

Life of this patent

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Abstract

An example method may include i) determining a first distance between a pair of feet of a robot at a first time, where the pair of feet is in contact with a ground surface; ii) determining a second distance between the pair of feet of the robot at a second time, where the pair of feet remains in contact with the ground surface from the first time to the second time; iii) comparing a difference between the determined first and second distances to a threshold difference; iv) determining that the difference between determined first and second distances exceeds the threshold difference; and v) based on the determination that the difference between the determined first and second distances exceeds the threshold difference, causing the robot to react.

Claims17

Dependent claims

A method comprising:

determining, by a robot comprising a set of sensors, based on first data received from the set of sensors, a first distance between a pair of feet of the robot at a first time, wherein the pair of feet is in contact with a ground surface;
determining, by the robot, based on second data received from the set of sensors, a second distance between the pair of feet of the robot at a second time, wherein the pair of feet remains in contact with the ground surface from the first time to the second time;
comparing a difference between the determined first and second distances to a threshold difference;
determining that the difference between the determined first distance between the pair of feet and the determined second distance between the pair of feet exceeds the threshold difference;
and
based on the determination that the difference between the determined first distance between the pair of feet and the determined second distance between the pair of feet exceeds the threshold difference, causing the robot to react, wherein causing the robot to react comprises causing a third foot, which is not in contact with the ground surface, to make contact with the ground surface.

3 more elements

A robot comprising:

a body;
a first foot and a second foot coupled to the body;
a first set of sensors;
a second set of sensors;
a processor;
a non-transitory computer readable medium;
and
program instructions stored on the non-transitory computer readable medium that, when executed by the processor, cause the robot to perform functions comprising:
determining, by the robot based on first data received from the first set sensors, a first estimate of a distance travelled by the body of the robot in a time period, wherein the first estimate is based on the first foot of the robot in contact with a ground surface;
determining, by the robot, based on second data received from a second set of sensors, a second estimate of the distance travelled by the body of the robot in the time period, wherein the second estimate is not based on any foot of the robot that is in contact with the ground surface;
comparing a difference between the first estimate and the second estimate to a threshold difference;
determining that the difference between the first estimate of the distance travelled by the body of the robot and the second estimate of the distance travelled by the body of the robot exceeds the threshold difference;
and
based on the determination that the difference between the first estimate of the distance travelled by the body of the robot and the second estimate of the distance travelled by the body of the robot exceeds the threshold difference, causing the robot to react, wherein causing the robot to react comprises causing the second foot, which is not in contact with the ground surface, to make contact with the ground surface.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/468,146Filed 25 Aug 2014
Granted: 11 Apr 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

B62D 57/02
Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels…
B25J 9/1633
Characterised by the control loop: compliant, force, torque control, e.g. combined with position control
B25J 9/1653
Characterised by the control loop: parameters identification, estimation, stiffness, accuracy, error analysis
B25J 9/1694
Program controls: characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception…