Crosstalk (Inter-Axis Coupling)

When a multi-axis force sensor loaded along only one direction still shows nonzero readings on the other axes.

Crosstalk is a metric for evaluating multi-axis force sensors, such as six-axis force sensors: when a load is applied along only one axis — say, a pure vertical push — the other channels that should read zero (Fx, Fy, and the torques) show a reading anyway. This happens because the strain gauges inside the sensor respond to loads from multiple directions at once, compounded by manufacturing and mounting errors in the elastic body. Manufacturers usually calibrate a decoupling matrix that converts the raw signals into three forces and three torques; the crosstalk that remains after calibration is typically expressed as a percentage of full scale (%FS), tested with both single-axis loading and simultaneous multi-axis loading. It directly affects force-control accuracy: in tasks like assembly or polishing, coupling error can make a robot believe it feels a lateral force that isn’t really there, triggering an incorrect compliant motion.

ExampleA six-axis force sensor loaded with only 100 N straight down reads 1 N on the Fx channel; if Fx has a 100 N range, this crosstalk figure is 1% FS.

Also called

Cross-Axis Coupling, Inter-Axis Interference

Related

Six-Axis Force/Torque Sensor · Strain Gauge · Wrench · Sensor Drift · Force Control · Joint Torque Sensor

Sources

A Novel 6-axis Force/Torque Sensor Using Inductance Sensors (arXiv 2505.09069)
ATI Industrial Automation: Six-Axis F/T Transducer Installation and Operation Manual