See discussion in https://github.com/robotology/icub-models-generator/pull/240 . In a nutshell, on the URDF model the sensor names are l_arm_ft, l_leg_ft, ..., while the real devices on the iCub 2.* and 3 robots name the sensor l_arm_ft_sensor, l_leg_ft_sensor, ... .
See discussion in https://github.com/robotology/icub-models-generator/pull/240 . In a nutshell, on the URDF model the sensor names are
l_arm_ft
,l_leg_ft
, ..., while the real devices on the iCub 2.* and 3 robots name the sensorl_arm_ft_sensor
,l_leg_ft_sensor
, ... .