Research of cable tension sensor with difference structure based on magnetoelastic effect

With a great deal of steel cables used in the various important machines and architecture establishments, health monitoring the cable tension becomes more and more important to ensure those equipments or establishments' safety in normal working. Contrasted with the method of vibration frequency and strain gages, the method of measurement steel cables tension based on magnetoelastic effect has a lot of merits, such as its frequency of dynamic response is high, its life-span is long and its capacity of protecting over-loading is strong etc., It meets the requirement of the health monitoring. But the structure of sensor is sleeve structure that measured steel cable serves as the core of primary and secondary solenoids. This structure makes fixing and maintenance difficult, and the change of temperature strongly influences measurement results, the purpose of compensating temperature error by using the temperature compensation curve is not satisfactory. In this article, the principle of cable tension sensor based on magnetoelastic effect is expounded; the theory of temperature influence is researched; the difference structure by single bypass excitation is designed; its magnetic loop is analyzed; the system of experiment is designed; and the experiments of pulling tension are carried on. The experiment results indicate that the structure of sensor is feasible, its errors of repetition are less than 0.15%, which meets the requirement of measurement.