High-Accuracy Magnetic Rotary Encoder

Wang, Shuang; Li, Tiecai; Li, Guoying

doi:10.1007/978-3-642-34381-0_9

Cited by 11 publications

(6 citation statements)

References 6 publications

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“…Different layouts have been analyzed with the aim of improving sensing performances according to specific application needs. In several designs the output of the shaft angle sensor has sinusoidal-like output and multiple HS are employed to provide 360° of measuring range and absolute angle sensing [9,10]. In other designs, miniaturization is highly sought-after and custom CMOS circuits that integrate miniaturized HS are purposely developed [11–13].…”

Section: Introductionmentioning

confidence: 99%

Novel Magnetic Sensing Approach with Improved Linearity

Fontana

Salsedo

Bergamasco

2013

Sensors

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This paper introduces a novel contactless sensing principle conceived for measuring the rotation angle of a shaft. The sensor is based on a smart combination of low-cost components that can be effectively integrated in a mechanical assembly of a rotary joint. The working principle is based on the relative rotation of a small diametrically magnetized cylindrical or annular magnet and at least one Hall effect sensor. One of the main strengths of the new sensing principle is to be adaptable to any assigned dimensions and encumbrances without typical design limitations given by the use of standard components. A numerical model is developed for predicting the sensor output characteristic on the base of the concept of magnetic charge. Such a model is validated against results from laboratory experiments. The parameters that define the geometry and layout of the sensor are optimized in order to maximize linearity over an assigned angular range of measurement. Two examples of mechatronic systems that employ the new sensing principle are presented in order to show the possibility of obtaining with the new principle a compact/integrated sensor-design.

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Section: Introductionmentioning

confidence: 99%

Novel Magnetic Sensing Approach with Improved Linearity

Fontana

Salsedo

Bergamasco

2013

Sensors

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“…The structure with the magnetic collector can improve the magnetic field distribution. In order to eliminate the output deviation of the magnetic encoder, the signal correction algorithm based on the least square estimation is proposed [4]. An error compensation method for a single pair-pole encoder is proposed; it can compensate position error, and the precision of magnetic encoder which used this method could reach ±1° [5].…”

Section: Introductionmentioning

confidence: 99%

Suppression Method of Jump Points for Multipole Magnetic Encoder at Low Temperature Based on Single-Pole Angle Value Fitting

et al. 2019

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To eliminate the jump points of multipole angle values after subdivision at low temperature, the magnetic field and temperature field characteristics of a multipole magnetic encoder are analyzed in this study, and the effect of changes in magnetic field strength and temperature field on the precision of angle values is studied. To eliminate the jump point of multipole angle values caused by changes in the temperature field, the suppression method based on single-pole angle value fitting is proposed. The error between the single-pole and multipole angle values is tabulated by the oversampling linear interpolation method, and the precision of fitting single-pole to multipole angle values is effectively improved. The error of the angle value caused by changes in the temperature field is studied and analyzed, and the relationship between the jump angle values and the pole number of the multipole magnetic encoder is obtained. Furthermore, the jump point is compensated for by the jump range of the multipole angle values. Finally, the angle accuracy of the multipole magnetic encoder in a cryogenic chamber is experimentally verified. The experimental results show that the low-temperature jump point compensation method proposed for the multipole magnetic encoder in this paper can effectively suppress the jump of the angle values.

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“…Permanent magnets have been widely utilised in various applications [1][2][3][4][5][6][7][8][9][10]. Amongst them, cylindrical and ring shaped permanent magnets with diametrical magnetization have been widely used in electrical motors [11][12][13][14] and in position sensory systems [15][16][17][18] including human intention recognition [19]. The requirement for an accurate and fast-computed analytical expression of the magnetic field generated by a diametrically magnetised permanent magnet that can facilitate the design optimization of magnetic devices and modelling dynamical systems [20,21], leads to various ways of expressing the magnetic field of a permanent magnet of this kind.…”

Section: Introductionmentioning

confidence: 99%

Analytical Expression of the Magnetic Field Created by a Permanent Magnet With Diametrical Magnetization

Nguyen¹,

Lu²

2018

PIER C

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Cylindrical/ring-shaped permanent magnets with diametrical magnetization can be found in many applications, ranging from electrical motors to position sensory systems. In order to correctly calculate the magnetic field generated by a permanent magnet of this kind with low computational cost, several studies have been reported in literature providing analytical expressions. However, these analytical expressions are either limited for an infinite cylinder or for computing the magnetic field only on the central axis of a finite cylinder. The others are derived to calculate the magnetic field at any point in three-dimensional (3D) space but only with low accuracy. This paper presents an exact analytical model of the magnetic field, generated by a diametrically magnetized cylindrical/ring-shaped permanent magnet with a limited length, which can be used to calculate the magnetic field of any point in 3D space fast and with very high accuracy. The expressions were analytically derived, based on geometrical analysis without calculating the magnetic scalar potential. Also, there is no approximation in the derivation steps that yields the exact analytical model. Three components of the magnetic field are analytically represented using complete and incomplete elliptical integrals, which are robust and have low computational cost. The accuracy of the developed analytical model was validated using Finite Element Analysis and compared against existing models.

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High-Accuracy Magnetic Rotary Encoder

Cited by 11 publications

References 6 publications

Novel Magnetic Sensing Approach with Improved Linearity

Novel Magnetic Sensing Approach with Improved Linearity

Suppression Method of Jump Points for Multipole Magnetic Encoder at Low Temperature Based on Single-Pole Angle Value Fitting

Analytical Expression of the Magnetic Field Created by a Permanent Magnet With Diametrical Magnetization

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