Preliminary study of a direction estimation method of a hard object to the grasped area by the grasping forceps for tumor position estimation in organs

2018 ◽  
Vol 2018 (0) ◽  
pp. 1B13_1
Author(s):  
Shougo Kanou ◽  
Kohei Yamamoto ◽  
Akihito Nakai ◽  
Haruhiko Nakamura ◽  
Takeyoshi Dohi ◽  
...  
Keyword(s):  
Estimation Method ◽  
Position Estimation ◽  
Direction Estimation ◽  
Preliminary Study

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 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.

Evaluation of Crowd Motion Direction Based on Wavelet Transform

2013 ◽  
Vol 846-847 ◽  
pp. 1106-1110
Author(s):  
Guo Qing Yang ◽  
Rong Yi Cui
Keyword(s):  
Wavelet Decomposition ◽  
Estimation Method ◽  
Motion Vectors ◽  
Motion Direction ◽  
Main Research ◽  
Object A ◽  
Coordinate Form ◽  
Direction Estimation ◽  
Polar Coordinate ◽  
Crowd Motion

Taking the wavelet decomposed approximate image as the main research object, a direction estimation method for moving object was proposed in this paper. Firstly, the approximate image for the frame of the video was obtained via wavelet decomposition; and furthermore, the motion estimation on the approximate image was achieved to obtain the motion vectors. Finally, the motion vectors were described as polar coordinate form to compute the number of motion vectors in specified angles and the information entropy of the motion directions. The experiment results show that the proposed method can remove the effect of noise and the results of direction estimation are consistent with the actual motion directions.

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