Position Control of a Magnetically Levitated Robot Based on Magnetic Flux Measurement

2011 ◽  
Author(s):  
Moein Mehrtash ◽  
Naoaki Tsuda ◽  
Tatsuya Nobori ◽  
Mir Behrad Khamesee
Keyword(s):  
Position Control ◽  
Estimation Method ◽  
Flux Measurement ◽  
Position Estimation ◽  
Horizontal Axis ◽  
Laser Sensor ◽  
Magnetic Actuation ◽  
Laser Sensors ◽  
Hall Sensors ◽  
Future Work

Magnetic actuation has opened a new horizon in biological/biomedical applications. A novel magnetic actuation platform has been developed at Maglev Microrobotics Laboratory, University of Waterloo. In the previous work, laser sensors were used for positioning the levitated microrobot. This technique can be used only in transparent environment. In this paper, for applications in an enclosed environment, which may not be transparent, a novel position estimation method was proposed. The proposed method uses hall sensors, mounted on the disk pole-piece. The hall sensors’ optimal installation position has been investigated, and a function which relates hall sensors’ output and the position of robot was derived. Based on this function, position control of horizontal axis using hall sensors in place of laser sensor can be achieved. Usability of two dimensional controls in horizontal axis without laser sensors will be experimentally validated as future work of this research.

scholarly journals Sinusoidal Control of a Brushless DC Motor with Misalignment of Hall Sensors

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3845
Author(s):  
Krzysztof Kolano ◽  
Bartosz Drzymała ◽  
Jakub Gęca
Keyword(s):  
Control Method ◽  
Acoustic Noise ◽  
Negative Impact ◽  
Estimation Method ◽  
Large Error ◽  
Position Estimation ◽  
Actual System ◽  
Brushless Dc ◽  
Hall Sensors ◽  
Torque Ripples

This article presents an estimation method of the BLDC rotor position with asymmetrically arranged Hall sensors. Position estimation is necessary to control the motor by methods other than block commutation. A sinusoidal control method was selected for the research, which significantly reduces torque ripples and acoustic noise and is quite simple to implement. Inaccurate performance of the elements determining the position of the BLDC motor rotor causes a large error in the position estimation and has a negative impact on the operation of the drive controlled in this way. Using the developed control algorithms, it is possible to correctly determine the mechanical position of the rotor even for multi-pole motors. The proposed method is relatively easy to implement and does not require modification of control systems, being limited to changes only in the software of such devices. The tests of the actual system clearly show the usefulness of such a control method and its effectiveness.

scholarly journals Calibration Method of Array Errors for Wideband MIMO Imaging Radar Based on Multiple Prominent Targets

2021 ◽  
Vol 13 (15) ◽  
pp. 2997
Author(s):  
Zheng Zhao ◽  
Weiming Tian ◽  
Yunkai Deng ◽  
Cheng Hu ◽  
Tao Zeng
Keyword(s):  
Multiple Input Multiple Output ◽  
Estimation Method ◽  
Target Position ◽  
Position Estimation ◽  
Least Square ◽  
Antenna Structure ◽  
Imaging Radar ◽  
Position Errors ◽  
Calibration Methods ◽  
Array Errors

Wideband multiple-input-multiple-output (MIMO) imaging radar can achieve high-resolution imaging with a specific multi-antenna structure. However, its imaging performance is severely affected by the array errors, including the inter-channel errors and the position errors of all the transmitting and receiving elements (TEs/REs). Conventional calibration methods are suitable for the narrow-band signal model, and cannot separate the element position errors from the array errors. This paper proposes a method for estimating and compensating the array errors of wideband MIMO imaging radar based on multiple prominent targets. Firstly, a high-precision target position estimation method is proposed to acquire the prominent targets’ positions without other equipment. Secondly, the inter-channel amplitude and delay errors are estimated by solving an equation-constrained least square problem. After this, the element position errors are estimated with the genetic algorithm to eliminate the spatial-variant error phase. Finally, the feasibility and correctness of this method are validated with both simulated and experimental datasets.

scholarly journals Design of a magnetic encoder using Hall effect

2019 ◽  
Vol 13 (2) ◽  
pp. 254-261
Author(s):  
William Alejandro López-Contreras ◽  
José Danilo Rairán-Antolines
Keyword(s):  
Hall Effect ◽  
Relative Motion ◽  
Direct Current ◽  
Permanent Magnets ◽  
Position Control ◽  
Angular Position ◽  
Linearization Method ◽  
Acquisition Process ◽  
Voltage Variation ◽  
Hall Sensors

We present the design of a magnetic encoder to measure angular position. The proposed encoder includes two Hall sensors in quadrature in a fixed platform. In addition, and over the sensors, there are two permanent magnets in a shaft. The relative motion between the fixed and the movable components generate a voltage variation in the sensors, which serve to generate the approximation of the angular position. We detail the acquisition process and the linearization method, because we consider that these are the most important contributions of this work. Lastly, we show the application of the encoder in the position control of a direct current motor to show the performance of the encoder estimating fast and slow angular position changes.

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