Synthesis study of magnetic torque sensors

There exist numerous solutions to measure the torque applied to a structure or a shaft, and we first present the available devices. They fall into two groups; some measure the torsion angle resulting from the applied torque, others use the shaft material property changes due to the induced stresses, We then present our contribution in this area: a synthesis study of torque sensors with variable-reluctance magnetic circuits excited by permanent magnets or coils. Among these sensors are new structures not only for stationary devices, but also for fully rotating devices. The advantages of structures of these types lie in their great design and implementation simplicity. The structures' study shows how to choose the different parameters of the sensors to meet specifications, It also demonstrates the advantages of some new designs in terms of performance-the ones using "overlapping" teeth for example.