• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.889-897
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• 2016

This paper presents an improved approach for compensating rotor position signal displacement in brushless DC (BLDC) motors with misaligned hall-effect sensors. Typically, the hall-effect sensors in BLDC motors are located in each phase and positioned exactly 120 electrical degrees apart. However, limitations in mechanical tolerances make it difficult to place hall-effect sensors at the correct location. In this paper, a position error compensator to counteract the hall-effect sensor positioning error is proposed. The proposed position error compensator uses least squares error analysis to adjust the relative position error and back-EMF information to reduce the absolute offset error. The effectiveness of the proposed approach is verified through several experiments.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1449-1455
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• 2017

The vector control technique using low-resolution Hall-effect sensors has been widely used especially in consumer electronics. Due to electrical and/or mechanical unevenness related to binary-type Hall sensors, the calculated or estimated position information has discontinuities so called bumps, which causes the deterioration of vector control performance. In order to obtain a linearly changing position signal from low-precision Hall-effect sensors, this paper proposes a simple bumps in position signal removal algorithm that consists of a first-order observer with low-pass filtering scheme. The proposed algorithm has the feature of no needs for system parameters and additional estimation processes. The validity of the proposed method is verified through simulation and experimental results.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.931-938
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• 2016

Application of vector control scheme for consumer products is enlarging to improve control performance. For the field-oriented control, accurate position detection is essential and generally requires expensive sensors. On the other hand, cost-reduction is important in home appliances, so that binary-type Hall-effect sensors are commonly used rather than using an expensive sensor such as an encoder. The control performance is directly influenced by the accuracy of the position information, and there exist non-uniformities related to Hall sensors in electrical and mechanical aspects, which result in distorted position information. Therefore, to get high-precision position information from low-resolution Hall sensors, this paper proposes a new position estimator consisting of a Kalman filter and feedforward compensation scheme, which generates a linearly changing position signal. The efficacy of the proposed scheme is verified by simulation and experimental results carried out with a 48-pole permanent magnet motor.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.315-317
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• 2003

This paper deals with the position control of an AC servo motor using linear hall-effect sensors. The price of these is very low, but it is possible to make position control of motor similar to a control using an encoder. This paper introduces the design of motor using linear hall-effect sensors and shows the results of control.

• Journal of Sensor Science and Technology
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• v.25 no.5
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• pp.310-319
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• 2016

Three types of gap sensors, a capacitive gap sensor, an eddy current gap sensor, and a Hall effect gap sensor are described and evaluated through experiments for the purpose of precise gap sensing for micrometer scale movement, and a novel type of differential hall effect gap sensor is proposed. Each gap sensor is analyzed in terms of resolution and environment dependency including temperature dependency. Furthermore, a transport system for AMOLED deposition is introduced as a typical application of gap sensors, which are recently receiving considerable attention. Based on the analyses, the proposed differential Hall effect gap sensor is found to be the most suitable gap sensor for precise gap sensing, especially for application to a transport system for AMOLED deposition. The sensor shows resolution of $0.63mV/{\mu}m$ for the overall range of the gap from 0 mm to 2.5 mm, temperature dependency of $3{\mu}m/^{\circ}C$ from $20^{\circ}C$ to $30^{\circ}C$, and a monotonic characteristic for the gap between the sensor and the target.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.114-115
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• 2014

This paper proposes a new speed and position estimation method for PMSM(Permanent Magnet Synchronous Motor) using low-resolution hall-effect sensors. In general, there are a variety of sensors to estimate rotor position for PMSM such as resolvers, and encoders. Position detection using hall-effect sensors that detect the flux of the rotor for rotor position is excellent method in terms of cost and space, but has low-resolution. To overcome this problem, this paper proposes a new speed and position estimation observer. The performance of the observer has been verified by simulations carried out using Matlab/Simulink.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.2
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• pp.53-57
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• 2017

This papers propose a Hall-effect sensors position error compensation method in a sunroof system using a BLDC motor with a low-cost MCU. If the BLDC motor is controlled with this wrong position, the torque ripple and operating current can be increased and the average torque also decreases. Generally, sunroof system has characteristics that operate at constant load for several seconds. It is possible to find the minimum operating current value while changing the position of the Hall-effect sensor during the sunroof operation by using these characteristics. Therefore, propose a method to change the Hall-effect sensor position and find the minimum current value. The validity of the proposed algorithm is verified through experiments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1809-1815
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• 2010

This paper presents an improved method for high-resolution rotor position estimation in the permanent magnet synchronous motor (PMSM) drives with low-resolution Hall-effect sensors. The proposed method adopts a gain-scheduled full-order speed observer. Since the quantized position signal, which is obtained from Hall-effect sensors, is basically used as the input of the observer, the sixth-order harmonics are essentially included in the estimated position. To eliminate the harmonic components, the quantized position is linearized by a linear extrapolation based on the estimated average speed and futhermore the speed-depentent observer gain scheduling strategy is developed. The observer gain is also scheduled by considering the motor acceleration to improve the dynamic performance according to the changes of the motor speed and load. Several experiments are performed for 800W PMSM drive and the results demonstrate the effectiveness of the proposed method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.7
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• pp.840-845
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• 2018

BLDC motor is widely used as a servo motor due to high efficiency, high power density, low inertia, and low maintenance. However, BLDC motor generally needs position and velocity sensors to control actuation system. Usually, analog tachometers and encoders have been used for velocity feedback sensors. However, using these types of sensors have problems such as the cost, space, and malfunction. So, This paper is to propose a new velocity measurement method using linear hall-effect and enhanced differentiator for BLDC motor. In order to verify the feasibility of the proposed method, several simulations and experiments are performed. It is shown that the proposed velocity measurement method can satisfy the requirements without using of velocity sensor.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.49-52
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• 2000

In the current development of magnetic sensors based on the Hall effect, the following two approaches can be distinguished. The first, one tries to build better sensor based on conventional Hall devices. The innovations come through a better understand of the details If the operating principle and secondary effects, and through the application If ever-improving microelectronics technology. In the second approach, one hopes to build better sensors by making use of the Hall effect in active devices, such as magneto-transistors and MAGFET. In this paper, we study magnetic properties of Hall device fabricated with series and parallel multilayers.