TORQUE SENSING SYSTEM

This disclosure relates to a torque sensing system. The torque sensing system comprises a rotatable shaft (102) having a first part and a second part, the shaft comprising a spring structure (122) between the first and second part; a first readout structure (130) connected to the first part, the first readout structure (130) comprising first position indicators, and a second readout structure (132) connected to the second part, the second readout structure (132) comprising second position indicators; a detector system for detecting the first and second position indicators and generating a first detection signal indicating respective passing times for the first position indicators and a second detection signal indicating respective passing times for the second position indicators; and a processor. The processor is configured for determining an angular position of the first readout structure (130) occurring at a particular time instance based on a detected passing time of at least one first position indicator on the first readout structure (130) and on a first relation between angular position of the first readout structure (130) and time around said particular time instance; and determining an angular position of the second readout structure (132) occurring at the particular time instance based on a detected passing time of at least one second position indicator on the second readout structure (132) and optionally based on a second relation between angular position of the second readout structure (132) and time around said particular time instance; and, determining an angle of twist at the particular time instance based on the angular position of the first readout structure (130) and the angular position of the second readout structure (132), the angle of twist being associated with a torque applied to the first and/or second part of the rotatable shaft (102).