Design and Validation of a Variable Reluctance Differential Solenoid Transducer

This paper presents a novel variable reluctance differential solenoid transducer (VRDST) that offers improved high-speed sensing performance over linear voltage differential transformers (LVDTs) and differential variable reluctance transformers (DVRTs). The VRDST has the unique ability to measure both position and velocity simultaneously using two independent measurements. This paper investigates a basic geometry for a VRDST. The position and velocity measurement methods are derived and implemented in a Simulink simulation. The simulated VRDST model is augmented with an FEA simulation to predict the magnetic characteristics of the investigated design. The results and predictions established by the simulation and analytical models are validated experimentally with a physical prototype. The similarity between the experimental and simulated results suggest the proposed FEA and Simulink simulations can be used to accurately predict the performance of a physical VRDST. The findings from the analytical modeling, simulation study and experimental validation all unanimously prove the position measurement performs well when measuring low-speed displacements, while the integrated-velocity measurement is useful for measuring high-speed displacements. The differing frequency ranges of these two independent measurements are found to complement each other and suggest the VRDST is superior compared to DVRTs or LVDTs for applications requiring wide bandwidth position measurements.