  This paper proposes techniques to calibrate six-axis force-torque sensors
that can be performed in situ, i.e., without removing the sensor from the
hosting system. We assume that the force-torque sensor is attached to a rigid
body equipped with an accelerometer. Then, the proposed calibration technique
uses the measurements of the accelerometer, but requires neither the knowledge
of the inertial parameters nor the orientation of the rigid body. The proposed
method exploits the geometry induced by the model between the raw measurements
of the sensor and the corresponding force-torque. The validation of the
approach is performed by calibrating two six-axis force-torque sensors of the
iCub humanoid robot.
