Experimental verification of a control law for the position and attitude of two objects using multiple coils

2017 ◽  
Vol 28 (17) ◽  
pp. 2450-2457 ◽  
Author(s):  
Ayako Torisaka ◽  
Sho Masuda ◽  
Satoru Ozawa ◽  
Nobuyuki Kobayashi ◽  
Hiroshi Yamakawa
Keyword(s):  
Experimental Verification ◽  
Relative Position ◽  
Attitude Control ◽  
Control Method ◽  
Three Dimensional ◽  
Current Control ◽  
Space Structures ◽  
Electromagnetic System ◽  
Magnetic Forces ◽  
Dipole System

This article presents a method for relative position and attitude control for reconfigurable space structures using magnetic force with a multi-dipole system. This technology can be applied to the docking phases of space structures that can restructure themselves by assembling basic structural units. The focus of this research is on current control of dipoles, which produces strong nonlinear magnetic forces, and on the development of a method to control a strong nonlinear electromagnetic system. In a previous study, the feasibility of using this method to perform relative position and attitude control was investigated by conducting a series of three-dimensional simulations of position and attitude control. In this study, experimental verification of the control method is conducted to determine whether magnetic forces can be used to correct position and attitude simultaneously. The good agreement obtained between the simulation results and the experimental results confirms the effectiveness of our proposed method.

scholarly journals Autonomous Rendezvous and Docking with Nonfull Field of View for Tethered Space Robot

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Panfeng Huang ◽  
Lu Chen ◽  
Bin Zhang ◽  
Zhongjie Meng ◽  
Zhengxiong Liu
Keyword(s):  
Relative Position ◽  
Attitude Control ◽  
Visual Servoing ◽  
Control Method ◽  
Region Growing ◽  
Space Robot ◽  
Field Of View ◽  
Autonomous Rendezvous ◽  
Rendezvous And Docking ◽  
Typical Point

In the ultra-close approaching phase of tethered space robot, a highly stable self-attitude control is essential. However, due to the field of view limitation of cameras, typical point features are difficult to extract, where commonly adopted position-based visual servoing cannot be valid anymore. To provide robot’s relative position and attitude with the target, we propose a monocular visual servoing control method using only the edge lines of satellite brackets. Firstly, real time detection of edge lines is achieved based on image gradient and region growing. Then, we build an edge line based model to estimate the relative position and attitude between the robot and the target. Finally, we design a visual servoing controller combined with PD controller. Experimental results demonstrate that our algorithm can extract edge lines stably and adjust the robot’s attitude to satisfy the grasping requirements.

Disorganization of a hole tone feedback loop by an axisymmetric obstacle on a downstream end plate

2014 ◽  
Vol 757 ◽  
pp. 908-942 ◽  
Author(s):  
K. Matsuura ◽  
M. Nakano
Keyword(s):  
Nozzle Exit ◽  
Passive Control ◽  
Control Method ◽  
Three Dimensional ◽  
Acoustic Power ◽  
Shear Layers ◽  
Mean Velocity ◽  
End Plate ◽  
Air Jet ◽  
Practical Engineering

AbstractThis study investigates the suppression of the sound produced when a jet, issued from a circular nozzle or hole in a plate, goes through a similar hole in a second plate. The sound, known as a hole tone, is encountered in many practical engineering situations. The mean velocity of the air jet $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}u_0$ was $6\text {--}12\ \mathrm{m}\ {\mathrm{s}}^{-1}$. The nozzle and the end plate hole both had a diameter of 51 mm, and the impingement length $L_{im}$ between the nozzle and the end plate was 50–90 mm. We propose a novel passive control method of suppressing the tone with an axisymmetric obstacle on the end plate. We find that the effect of the obstacle is well described by the combination ($W/L_{im}$, $h$) where $W$ is the distance from the edge of the end plate hole to the inner wall of the obstacle, and $h$ is the obstacle height. The tone is suppressed when backflows from the obstacle affect the jet shear layers near the nozzle exit. We do a direct sound computation for a typical case where the tone is successfully suppressed. Axisymmetric uniformity observed in the uncontrolled case is broken almost completely in the controlled case. The destruction is maintained by the process in which three-dimensional vortices in the jet shear layers convect downstream, interact with the obstacle and recursively disturb the jet flow from the nozzle exit. While regions near the edge of the end plate hole are responsible for producing the sound in the controlled case as well as in the uncontrolled case, acoustic power in the controlled case is much lower than in the uncontrolled case because of the disorganized state.

scholarly journals Continuous Control Set Predictive Current Control for Induction Machine

2021 ◽  
Vol 11 (13) ◽  
pp. 6230
Author(s):  
Toni Varga ◽  
Tin Benšić ◽  
Vedrana Jerković Štil ◽  
Marinko Barukčić
Keyword(s):  
Control Method ◽  
Induction Machine ◽  
Current Control ◽  
Continuous Control ◽  
Loop Model ◽  
Voltage Reference ◽  
Control Loop ◽  
Speed Tracking ◽  
Finite Control ◽  
Control Set

A speed tracking control method for induction machine is shown in this paper. The method consists of outer speed control loop and inner current control loop. Model predictive current control method without the need for calculation of the weighing factors is utilized for the inner control loop, which generates a continuous set of voltage reference values that can be modulated and applied by the inverter to the induction machine. Interesting parallels are drawn between the developed method and state feedback principles that helped with the analysis of the stability and controllability. Simple speed and rotor flux estimator is implemented that helps achieve sensorless control. Simulation is conducted and the method shows great performance for speed tracking in a steady state, and during transients as well. Additionally, compared to the finite control set predictive current control, it shows less harmonic content in the generated torque on the rotor shaft.

scholarly journals Extended Permanent Magnet Synchronous Motors Speed Range Based on the Active and Reactive Power Control of Inverters

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3549
Author(s):  
Pham Quoc Khanh ◽  
Viet-Anh Truong ◽  
Ho Pham Huy Anh
Keyword(s):  
Power Control ◽  
Permanent Magnet ◽  
Reactive Power ◽  
Control Method ◽  
Speed Control ◽  
Torque Ripple ◽  
Current Control ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors ◽  
Speed Range

The paper proposes a new speed control method to improve control quality and expand the Permanent Magnet Synchronous Motors speed range. The Permanent Magnet Synchronous Motors (PMSM) speed range enlarging is based on the newly proposed power control principle between two voltage sources instead of winding current control as the conventional Field Oriented Control method. The power management between the inverter and PMSM motor allows the Flux-Weakening obstacle to be overcome entirely, leading to a significant extension of the motor speed to a constant power range. Based on motor power control, a new control method is proposed and allows for efficiently reducing current and torque ripple caused by the imbalance between the power supply of the inverter and the power required through the desired stator current. The proposed method permits for not only an enhanced PMSM speed range, but also a robust stability in PMSM speed control. The simulation results have demonstrated the efficiency and stability of the proposed control method.

scholarly journals Design and validation of an MPC controller for CMG-based testbed

2021 ◽  
Author(s):  
Matteo Facchino ◽  
Atsushi Totsuka ◽  
Elisa Capello ◽  
Satoshi Satoh ◽  
Giorgio Guglieri ◽  
...  
Keyword(s):  
Predictive Control ◽  
Attitude Control ◽  
High Speed ◽  
Control Method ◽  
Input Constraints ◽  
Virtual Reference ◽  
Control Moment ◽  
Pyramidal Configuration ◽  
Actuation Systems ◽  
Constraints Satisfaction

AbstractIn the last years, Control Moment Gyros (CMGs) are widely used for high-speed attitude control, since they are able to generate larger torque compared to “classical” actuation systems, such as Reaction Wheels . This paper describes the attitude control problem of a spacecraft, using a Model Predictive Control method. The features of the considered linear MPC are: (i) a virtual reference, to guarantee input constraints satisfaction, and (ii) an integrator state as a servo compensator, to reduce the steady-state error. Moreover, the real-time implementability is investigated using an experimental testbed with four CMGs in pyramidal configuration, where the capability of attitude control and the optimization solver for embedded systems are focused on. The effectiveness and the performance of the control system are shown in both simulations and experiments.

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