scholarly journals High-precision tracking of sperm swimming fine structure provides strong test of resistive force theory

2010 ◽  
Vol 213 (8) ◽  
pp. 1226-1234 ◽  
Author(s):  
B. M. Friedrich ◽  
I. H. Riedel-Kruse ◽  
J. Howard ◽  
F. Julicher
Keyword(s):  
Fine Structure ◽  
High Precision ◽  
Resistive Force ◽  
Precision Tracking ◽  
Resistive Force Theory

High-Precision Tracking Control of Machine Tool Feed Drives Based on ADRC

2016 ◽  
Author(s):  
Chengyong Zhang ◽  
Yaolong Chen
Keyword(s):  
Machine Tool ◽  
High Precision ◽  
Tracking Control ◽  
Position Control ◽  
Feedback System ◽  
Pi Controller ◽  
Ball Screw ◽  
Feed Drives ◽  
Precision Tracking ◽  
Precision Tracking Control

In this paper, the active-disturbance-rejection control (ADRC) is applied to realize the high-precision tracking control of CNC machine tool feed drives. First, according to the number of the feedback channel, the feed systems are divided into two types: signal-feedback system, e.g., linear motor and rotary table, and double-feedback system, e.g., ball screw feed drive with a load/table position feedback. Then, the appropriate controller is designed to ensure the closed-loop control performance of each type of system based on the idea of ADRC. In these control frameworks, the extended state observers (ESO) estimate and compensate for unmodeled dynamics, parameter perturbations, variable cutting load, and other uncertainties. For the signal-feedback system, the modified ADRC with an acceleration feedforward term is used directly to regulate the load/table position response. However, for the double-feedback system, the ADRC is applied only to the motor position control, and a simple PI controller is used to achieve the accurate position control of the load. In addition, based on ADRC feedback linearization, a novel equivalent-error-model based feedforward controller is designed to further improve the command following performance of the double-feedback system. The experimental results demonstrate that the proposed controllers of both systems have better tracking performance and robustness against the external disturbance compared with the conventional P-PI controller.

scholarly journals A High-Precision Tracking Algorithm for Mass Reconstruction of Heavy-Ion Fragments in the R3B Experiment at FAIR

2019 ◽  
Vol 214 ◽  
pp. 02038
Author(s):  
Dmytro Kresan ◽  
Michael Heil ◽  
Mohammad Al-Turany
Keyword(s):  
High Precision ◽  
Inverse Kinematics ◽  
Simulated Data ◽  
Heavy Ion ◽  
Particle Identification ◽  
Software Framework ◽  
Radioactive Beams ◽  
Momentum Resolution ◽  
Precision Tracking ◽  
Exotic Beams

The multi-purpose R3B (Reactions with Relativistic Radioactive Beams) setup at the future FAIR facility in Darmstadt will be used for various experiments with exotic beams in inverse kinematics. In front and after the reaction target a combination of detectors serves for particle identification and momentum measurements. In order to perform a high-precision charge identification of heavy-ion fragments and achieve a momentum resolution of 10-3 following is required: a time of flight (ToF) measurement with up to 15 ps accuracy, position determination on the order of less than 0.5 mm and a dedicated algorithm for the heavy-ion tracking in highly non-homogeneous dipole field. With these constraints a tracking package is being developed and tested within the R3B software framework, this package has to go into production in fall of 2018. An iterative approach has been chosen for simultaneous track finding and fitting. The design and concept of the package are introduced in this paper, also the tests and the resolution measured with simulated data are presented.

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