A T-Type Self-Decoupled and Passive Dynamic Tension and Torque Sensor: Design, Fabrication, and Experiments

Self-decoupled and passive characteristics are crucial requirements for a multi-dimensional sensor. A T-type self-decoupled and passive dynamic tension and torque sensor was proposed, analyzed, and fabricated. The sensor mainly consisted of a T-type torque deforming block, a force deforming ring, and a torque shaft. The T-type torque deforming block withstood the torque individually; the force deforming ring bore the tension force separately; and the decoupling of the tension force and torque was realized by the torque shaft. After that, the tension force and torque were measured, respectively. The decoupling operation was fully completed by mechanical structure. Two pieces of magnetostrictive material were pasted on the T-type torque deforming block and force deforming ring as the sensing units. The passive feature was fulfilled by the magnetostrictive material via the Villari effect. Finite Element Method (FEM) analysis was carried out to verify the decoupling principle. The sensor was fabricated, and then the experiments were conducted. The results showed that the sensor had a good decoupling ability. The sensor could work dynamically with a voltage deviation less than 0.5 mV. The force and torque ranges of the sensor were 1000 N and 6.5 $\text{N}\cdot \text{m}$ respectively. The sensor could also work effectively in a passive state. Furthermore, the sensor displayed the advantages of being wireless, the ability to work dynamically and in a liquid environment. Thus, this sensor could be mounted on a cutting tool of a machine center to detect the compound force on the cutting tool.