Gripping device, robot and method for sensing force information

A gripping device, comprising:

• a case;
• a plurality of linkage gripping assemblies being mutually matched to grip an object, and each of the plurality of linkage gripping assemblies comprising:
• a fingertip configured to grip the object;
• a first link fixedly connected to the fingertip;
• a second link, wherein a first end of the second link is rotatably connected to a first end of the first link and a second end of the second link is rotatably connected to the case;
• and
• a third link, wherein a first end of the third link is rotatably connected to a second end of the first link and a second end of the third link is rotatably connected to the case;
• a driving assembly being in transmission connection with the second end of the second link and configured to rotate the second link;
• and
• a plurality of load cells, each of the plurality of load cells being disposed in a respective one of at least three of the first link, the second link, the third link and the driving assembly, and being configured to measure an axial force of the respective one of at least three of the first link, the second link, the third link and the driving assembly of the gripping device in static equilibrium, for computing force information output by the fingertip.

A robot, comprising:

• a gripping device comprising:
• a case;
• a plurality of linkage gripping assemblies being mutually matched to grip an object, and each of the plurality of linkage gripping assemblies comprising:
• a fingertip configured to grip the object;
• a first link fixedly connected to the fingertip;
• a second link, wherein a first end of the second link is rotatably connected to a first end of the first link and a second end of the second link is rotatably connected to the case;
• and
• a third link, wherein a first end of the third link is rotatably connected to a second end of the first link and a second end of the third link is rotatably connected to the case;
• a driving assembly being in transmission connection with the second end of the second link and configured to rotate the second link;
• and
• a plurality of load cells, each of the plurality of load cells being disposed in a respective one of at least three of the first link, the second link, the third link and the driving assembly, and being configured to measure an axial force of the respective one of at least three of the first link, the second link, the third link and the driving assembly of the gripping device in static equilibrium, for computing force information output by the fingertip;
• a position measuring device configured to measure structural parameters and position parameters of each of the first link, the second link and the third link;
• wherein the structural parameters comprise a length of each of the first link, the second link and the third link, the position parameters comprise an attitude vector of each of the first link, the second link and the third link;
• and
• a control system configured to acquire measurements of the position measuring device and measured values of the plurality of load cells responsive to the gripping device being in static equilibrium, to establish a static model of each of the first link, the second link, the third link and the driving assembly, and to compute the force information output by the fingertip.

A method for sensing force information, applied to a gripping device comprising:

• a case;
• a plurality of linkage gripping assemblies being mutually matched to grip an object, and each of the plurality of linkage gripping assemblies comprising:
• a fingertip configured to grip the object;
• a first link fixedly connected to the fingertip;
• a second link, wherein a first end of the second link is rotatably connected to a first end of the first link and a second end of the second link is rotatably connected to the case;
• and
• a third link, wherein a first end of the third link is rotatably connected to a second end of the first link and a second end of the third link is rotatably connected to the case;
• a driving assembly being in transmission connection with the second end of the second link and configured to rotate the second link;
• and
• a plurality of load cells, each of the plurality of load cells being disposed in a respective one of at least three of the first link, the second link, the third link and the driving assembly, and being configured to measure an axial force of the respective one of at least three of the first link, the second link, the third link and the driving assembly of the gripping device in static equilibrium, for computing force information output by the fingertip;
• the method comprising:
• obtaining force measurements of the plurality of load cells responsive to the gripping device being in static equilibrium;
• measuring structural parameters and positional parameters of the first link, the second link and the third link;
• and
• establishing a static model of each of the first link, the second link, the third link and the driving assembly based on the force measurements, the structural parameters and the positional parameters, and computing the force information output by the fingertip.