Design Optimization of PCB-Based Rotary-Inductive Position Sensors

Abstract

This paper introduces a novel methodology to optimize the design of a ratiometric rotary inductive position sensor (IPS) fabricated in printed circuit board (PCB) technology. The optimization aims at reducing the linearity error of the sensor and amplitude mismatch between the voltages on the two receiving (RX) coils. Distinct from other optimization techniques proposed in the literature, the sensor footprint and the target geometry are considered as a non-modifiable input. This is motivated by the fact that, for sensor replacement purposes, the target has to fit a predefined space. For this reason, the original optimization technique proposed in this paper modifies the shape of the RX coils to reproduce theoretical coil voltages as much as possible. The optimized RX shape was obtained by means of a non-linear least-square solver, whereas the electromagnetic simulation of the sensor is performed with an original surface integral method, which are orders of magnitude faster than commercial software based on finite elements. Comparisons between simulations and measurements performed on different prototypes of an absolute rotary sensor show the effectiveness of the optimization tool. The optimized sensors exhibit a linearity error below 0.1% of the full scale (FS) without any signal calibration or post-processing manipulation.

Modelling, Linearity Analysis and Optimization of an Inductive Angular Displacement Sensor Based on Magnetic Focusing in Ships

“…In recent years, researchers optimized sensor structures or related parameters through various optimization algorithms. The algorithms used are surface integral method [82], particle swarm optimization (PSO) [83] and response surface method [38]. PSO is suitable for solving global optimization problems.…”

P39 - Real-time Characterization of Inductive Position Sensors

“…The surface integral method is not widely used because the produced matrix is full and its entries are difficult to compute accurately because their computation involves the evaluation of a singular integral. The use of surface integral method for inductive position sensors has been introduced in [3][4].…”

Methodology for Eddy Current Losses Calculation in Linear Variable Differential Transformers (LVDTs)

“…New designs of transformer position sensors are constantly developed and analysed to improve their industrial applicability. Finite element method (FEM) is often used for modeling and analysis of new sensor design [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. In [ 1 ], the electromagnetic behavior of an LVDT sensor in the presence of magnetic interference is modeled using FEM, and the quality of the simulation is verified through comparisons with experimental results.…”

“…In [ 3 ], the electromagnetic behavior of differential inductive displacement sensors is modelled using FEM, and the parameters impacting the sensor’s time drift stability are analysed. FEM is utilized in [ 4 ] to model the electromagnetic behavior of PCB-based rotary-inductive position sensors, and in [ 5 ] to model the electromagnetic behavior of inductive displacement sensors with large range and nanoscale resolution. In [ 6 ], FEM is used to simulate the electromagnetic behavior of LVDT sensors in order to improve sensor design.…”