Six axis force sensor employing multiple shear strain gages

A method of determining the magnitude and direction of forces applied to a generally hollow and cylindrical force sensor having axial and transverse axes and having three or more legs each of which has at least a first shear strain gage oriented to detect primarily force components in the axial direction and a second shear strain gage oriented to detect primarily force components along one of the transverse axes, the method comprising the following steps:

• monitoring shear strain detected by the first strain gages and caused primarily by forces acting in the axial direction and/or moments about one of the transverse axes;
• monitoring shear strain detected by the second strain gages and caused primarily by forces acting along one or more transverse axes and/or moments about the axial axis;
• processing the shear strains detected by the first and second strain gages to determine the magnitude and direction of any forces and/or moments applied to the force sensor.

A force sensor for measuring forces interacting between bodies connected to opposite sides of the force sensor, on a sensor body structure in at least two dimensions, the force sensor comprising:

• an L-shaped leg integrated in the sensor body and having a first arm and a second arm mutually integrally connected to form the L-shaped leg and each arm having a direction substantially perpendicular to that of the other arm, said first and second arms being connected in series between support regions respectively associated to said opposite sides of the force sensor;
• a first shear strain gage mounted on the first arm of the L-shaped leg such that the first strain gage primarily measures shear forces which are perpendicular to the direction of the first arm;
• a second shear strain gage mounted to the second arm of the L-shaped leg such that the second strain gage primarily measures shear forces which are perpendicular to the direction of the second arm.

A method of determining the magnitude and direction of forces applied to a generally hollow and cylindrical force sensor having axial and transverse axes and having three or more Lshaped legs each of which has a first arm and a second arm mutually integrally connected such that each arm has a direction substantially perpendicular to that of the other arm and each L-shaped leg having at least a first shear strain gage mounted on the first arm and oriented to detect primarily force components in the axial direction and a second shear strain gage mounted on the second arm and oriented to detect primarily force components along one of the transverse axes, the method comprising the following steps:

• monitoring shear strain detected by the first strain gages and caused primarily by forces acting in the axial direction and/or moments about one of the transverse axes;
• monitoring shear strain detected by the second strain gages and caused primarily by forces acting along one or more transverse axes and/or moments about the axial axis;
• processing the shear strains detected by the first and second strain gages to determine the magnitude and direction of any forces and/or moments applied to the force sensor.