A Temperature-Compensation Technique for Improving Resolver Accuracy.

Wandee Petchmaneelumka,Vanchai Riewruja,Kanoknuch Songsuwankit,Apinai Rerkratn

doi:10.3390/s21186069

Wandee Petchmaneelumka, Vanchai Riewruja + Show 2 more

Open Access

https://doi.org/10.3390/s21186069

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Abstract

Variation in the ambient temperature deteriorates the accuracy of a resolver. In this paper, a temperature-compensation technique is introduced to improve resolver accuracy. The ambient temperature causes deviations in the resolver signal; therefore, the disturbed signal is investigated through the change in current in the primary winding of the resolver. For the proposed technique, the primary winding of the resolver is driven by a class-AB output stage of an operational amplifier (opamp), where the primary winding current forms part of the supply current of the opamp. The opamp supply-current sensing technique is used to extract the primary winding current. The error of the resolver signal due to temperature variations is directly evaluated from the supply current of the opamp. Therefore, the proposed technique does not require a temperature-sensitive device. Using the proposed technique, the error of the resolver signal when the ambient temperature increases to 70 °C can be minimized from 1.463% without temperature compensation to 0.017% with temperature compensation. The performance of the proposed technique is discussed in detail and is confirmed by experimental implementation using commercial devices. The results show that the proposed circuit can compensate for wide variations in ambient temperature.

Highlights

A resolver, which is a kind of inductive transducer, is a useful device in instrumentation and measurement systems
The operation of a resolver is identical to a variable transformer, which consists of a primary winding as a rotor and two secondary windings placed at right angles from each other as stators [1,2,3,4]
This technique requires the output signals of the transducer to be in linear form, which is only suitable for transducers used for the measurement of linear displacement, such as linear variable differential transformers (LVDTs)

Summary

Introduction

A resolver, which is a kind of inductive transducer, is a useful device in instrumentation and measurement systems. A technique to minimize the error of the shaft-angle determination caused by amplitude imbalance and imperfect quadrature was proposed [18]. The authors of [27] constructed a closed-loop technique to compensate for the temperature of the inductive transducer without using a temperature sensor This technique requires the output signals of the transducer to be in linear form, which is only suitable for transducers used for the measurement of linear displacement, such as linear variable differential transformers (LVDTs). The attractions of the proposed technique are its performance, simple configuration, and low cost

Principle

Temperature-Compensation Technique

Performance Analysis

Experimental Results

A Linear