Reducing Sensitivity of a Force/Torque Sensor to Variations in Boundary Conditions
AssigneeATI Industrial Automation, Inc.
InventorsJoseph Lipsey, Andrew Glusiec
Life of this patent
Estimating the term…
Abstract
Both mathematical and mechanical methods improve observed accuracies when F/T sensors deployed are mounted to tools in the field. Due to differences in boundary conditions between manufacturer tooling and the field tooling when deployed, differences may arise in calibration matrices calculated at time of manufacture and those required for use in the field. Mathematical methods of correcting or creating new calibration matrices are disclosed. Additionally, one or two boundary condition normalizing plates present uniform forces and torques to deformable members, regardless of boundary conditions.
Claims21
A method of reducing or eliminating the effect of changing boundary conditions on a force and/or torque (F/T) sensor, comprising:
- performing a manufacture calibration procedure, the manufacture calibration procedure yielding a manufacture calibration matrix that maps transducer outputs of the F/T sensor to applied forces and/or torques under a first set of boundary conditions;
- obtaining transducer outputs under a second set of boundary conditions representative of use of a deployed F/T sensor coupled to a field robotic tool;
- and
- calculating a scaling of the manufacture calibration matrix to a scaled calibration matrix that maps transducer outputs of the F/T sensor to applied forces and/or torques under the second set of boundary conditions.
A force and/or torque (F/T) sensor having reduced sensitivity to changes in boundary conditions, comprising:
- a first substructure configured to be attached to a first object;
- a second substructure configured to be attached to a second object;
- a plurality of measurement deformable members connecting the first and second substructures;
- and
- a plurality of transducers attached to at least some measurement deformable members, the transducers configured to sense tensile and/or compressive strains in the measurement deformable members and transduce the forces into output signals;
- and
- a controller configured to calculate a manufacture calibration matrix mapping transducer output signals to force and/or torque between the first and second objects under a first set of boundary conditions.
Dependencies are inferred from the claim text.