Development of a Multiturn Linear Variable Reluctance Resolver With Integrated Ferromagnetic Core

Linear motors are increasingly used in different industries, and linear position sensors play a critical role in their control systems. Among linear position sensors, the linear resolver is a suitable option to use in harsh environments. In highly accurate applications, the multispeed resolvers are commonly used. However, they have a major drawback: they lose absolute position information during operation. The new generation of resolvers, called multiturn resolvers, solves this problem and improves position detection reliability. Traditionally, these resolvers consist of two individual resolvers with four distinct cores, all housed within a single frame. This article proposes an integrated multiturn linear variable reluctance (VR) resolver configuration that uses just two shared cores. A magnetic equivalent circuit (MEC)-based analytical model is developed to quickly analyze the resolver's performance. The MEC model is also used to compensate for the longitudinal end effect (LEE) and optimize resolver dimensions to reduce resolver position error. The success of the innovative configuration is then verified through time-stepping finite element method (TSFEM) simulations. Finally, the integrated multiturn linear resolver is constructed and tested in real-world conditions. The experimental results clearly show that the proposed sensor is effective.