Systems, devices, articles, and methods for prehension

Abstract

An end-effector may include a base, a plurality of underactuated fingers coupled to the base; and an adhesion gripper coupled to the base. An end-effector may include a base, an actuator, a first underactuated finger comprising a proximal link and a distal link, the proximal link including a distal end, a guide for a first tendon spaced a first distance away from the distal end of the proximal link and the distal link including a lever arm disposed on a proximal side to the distal pad and which extends in a volar direction from a first axis, and a node disposed on the lever arm sized and shaped to receive a first tendon. The end-effector may include a first revolute joint compliant in a first direction disposed between the base and the proximal link; and a second revolute joint compliant in the first direction disposed between the proximal link and the distal link.

1 . A device comprising:
 a base;   an actuator coupled to the base;   a first underactuated finger coupled to the base, wherein the first finger includes:
 a proximal link coupled to the base, wherein the proximal link comprises:
 a distal end; and 
 a guide for a first tendon spaced a first distance away from the distal end of the proximal link; 
 
 a distal link coupled to the proximal link and which extends along a first axis, wherein the distal link comprises:
 a lever arm disposed on a proximal side to the distal pad and which extends in a volar direction from the first axis; and 
 a node disposed on the lever arm sized and shaped to receive a first tendon. 
 
   
     
     
         2 . The device of  claim 1  further comprising:
 a first revolute joint compliant in a first direction disposed between the base and the proximal link; and 
 a second revolute joint compliant in the first direction disposed between the proximal link and the distal link. 
 
     
     
         3 . The device of  claim 2  further comprising:
 a first spring that biases the proximal link to a first open position; and 
 a second spring that biases the distal link to a second open position. 
 
     
     
         4 . The device of  claim 3  wherein:
 a first net torque biases the proximal link to the first open position; 
 a second net torque biases the distal link to the second open position; and 
 the first net torque is less than the second net torque. 
 
     
     
         5 . The device of  claim 3  wherein:
 a first tensile force along the first tendon actuates the proximal link relative to the base; 
 a second tensile force along the first tendon actuates the distal link relative to the proximal link; and 
 the first tensile force is less than the second tensile force. 
 
     
     
         6 . The device of  claim 1  wherein the distal link further comprises:
 a distal pad disposed on a volar side of the first axis. 
 
     
     
         7 . The device of  claim 1  wherein the proximal link further comprises:
 a proximal pad disposed on a volar side of the proximal link. 
 
     
     
         8 . The device of  claim 1  further comprising:
 a second finger. 
 
     
     
         9 . A system comprising:
 a base;   an actuator coupled to the base;   a plurality of fingers coupled to the base, wherein at least one of the plurality of fingers includes:
 a proximal link comprising a first body and a guide; 
 a first joint that couples the proximal link to the base, wherein the first joint is compliant in a first direction; 
 a distal link comprising:
 a first axis; 
 a distal pad disposed on a volar side of the first axis; and 
 a lever arm disposed on a proximal side to the distal pad and which extends in a volar direction from the first axis; and 
 
 a second joint that couples the distal link to the proximal link; and 
   a plurality of tendons, wherein a first respective tendon in the plurality of tendons:
 is associated with the first respective finger; 
 couples to a first lever arm of a first distal link of the first respective finger; 
 routes through a first guide included in a first proximal link of the first respective finger; and 
 couples to the actuator. 
   
     
     
         10 . The system of  claim 9  further comprising:
 an adhesion gripper coupled to the base. 
 
     
     
         11 . An end-effector comprising:
 a base;   a plurality of underactuated fingers coupled to the base; and   an adhesion gripper coupled to the base.   
     
     
         12 . The end-effector of  claim 11  wherein the adhesion gripper is a vacuum gripper comprising:
 a suction cup facing a distal direction; 
 a vacuum passage in fluid communication with the suction cup; and 
 a vacuum source in fluid communication with the vacuum passage. 
 
     
     
         13 . The end-effector of  claim 12  wherein:
 the base comprises a rest; 
 the suction cup comprises a distal periphery; and 
 the distal periphery of the suction cup sits proud of the rest. 
 
     
     
         14 . The end-effector of  claim 12  wherein the adhesion gripper is an electrostatic gripper comprising:
 a dielectric body coupled to the base; 
 a plurality of electrodes embedded in the dielectric body; and 
 a power source selectively electrically coupled to the plurality of electrodes. 
 
     
     
         15 . A system comprising:
 a robot including an end-effector;   at least one processor communicatively coupled to the end-effector; and   at least one nontransitory processor-readable storage device communicatively coupled to the at least one processor and which stores processor-executable instructions which, when executed by the at least one processor, cause the at least one processor to:
 receive, at the at least one processor, tactile sensor data from a plurality tactile sensors; 
 temporally difference, by the at least one processor, the tactile sensor data; 
 compute, by the at least one processor, a plurality of correlations for the temporally differenced tactile sensor data; 
 mask, by the at least one processor, a set of masked pairs of tactile sensor data in the tactile sensor data; 
 detect, by the at least one processor, one or more non-zero correlations in the plurality of correlations; and 
 create, by the at least one processor, at least one output signal that includes information that represents the one or more non-zero correlations in the plurality of correlations. 
   
     
     
         16 . The system of  claim 15  wherein the plurality of tactile sensors includes a plurality of force sensors, or a plurality of pressure sensors. 
     
     
         17 . The system of  claim 15  wherein the plurality of tactile sensors is coupled to the end-effector. 
     
     
         18 . The system of  claim 15 , wherein to receive the tactile sensor data from a plurality tactile sensors, when executed, the processor-executable instructions further cause the at least one processor to:
 receive, at the at least one processor, a plurality of spatial values and a plurality of temporal values.   
     
     
         19 . The system of  claim 18 , wherein, when executed, the processor-executable instructions further cause the at least one processor to:
 store the plurality of spatial values and the plurality of temporal values.   
     
     
         20 . The system of  claim 18 , wherein to compute the plurality of correlations for the temporally differenced tactile sensor data, when executed, the processor-executable instructions further cause the at least one processor to:
 compute, by the at least one processor, a covariance matrix from the plurality of spatial values and the plurality of temporal values.   
     
     
         21 . The system of  claim 15 , wherein to mask the set of masked pairs of tactile sensor data in the tactile sensor data, when executed, the processor-executable instructions further cause the at least one processor to:
 mask, by the at least one processor, a set of correlations in the plurality of correlations for the temporally differenced tactile sensor data that correspond to the set of masked pairs of tactile sensor data.   
     
     
         22 . The system of  claim 15 , wherein, when executed, the processor-executable instructions further cause the at least one processor to:
 cause an increase in prehension on an item in contact with the end-effector.   
     
     
         23 . The system of  claim 15 , wherein:
 the end-effector includes a plurality of fingers; and   to cause the increase in prehension on the item in contact with the end-effector, when executed, the processor-executable instructions further cause the at least one processor to:
 tighten a grip on the item by the plurality of fingers. 
   
     
     
         24 . The system of  claim 15 , wherein the end-effector includes an adhesion gripper; and wherein to cause the increase in prehension on the item in contact with the end-effector, when executed, the processor-executable instructions further cause the at least one processor to:
 actuate the adhesion gripper.   
     
     
         25 . - 28 . (canceled)