scholarly journals Performance Comparison of Wavefront-Sensorless Adaptive Optics Systems by Using of the Focal Plane

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Huizhen Yang ◽  
Zhen Zhang ◽  
Jian Wu
Keyword(s):  
Adaptive Optics ◽  
Focal Plane ◽  
Control Algorithm ◽  
Performance Comparison ◽  
Convergence Speed ◽  
Control Algorithms ◽  
System Control ◽  
Wavefront Aberrations ◽  
Intensity Measurements ◽  
Better Than

The correction capability and the convergence speed of the wavefront-sensorless adaptive optics (AO) system are compared based on two different system control algorithms, which both use the information of focal plane. The first algorithm is designed through the linear relationship between the second moment of the aberration gradients and the masked far-field intensity distribution and the second is stochastic parallel gradient descent (SPGD), which is the most commonly used algorithm in wavefront-sensorless AO systems. A wavefront-sensorless AO model is established with a 61-element deformable mirror (DM) and a CCD. Performance of the two control algorithms is investigated and compared through correcting different wavefront aberrations. Results show that the correction ability of AO system based on the proposed control algorithm is obviously better than that of AO system based on SPGD algorithm when the wavefront aberrations increase. The time needed by the proposed control algorithm is much less than that of SPGD when the AO system achieves similar correction results. Additionally, the convergence speed of the proposed control algorithm is independent of the turbulence strength while the number of intensity measurements needed by SPGD increases as the turbulence strength magnifies.

Vehicle lane keeping system based on TSK fuzzy extension control

2019 ◽  
Vol 234 (2-3) ◽  
pp. 762-773
Author(s):  
Hongbo Wang ◽  
Wei Cui ◽  
Zhi Xia ◽  
Wuhua Jiang
Keyword(s):  
Fuzzy Control ◽  
Control Strategy ◽  
Control Algorithm ◽  
Control Method ◽  
Driving Safety ◽  
Control Algorithms ◽  
System Control ◽  
Control Effect ◽  
Lane Keeping ◽  
Takagi Sugeno

In the traditional lane keeping system, a single control algorithm is used for global-region control, which often results in poor control effect in some control areas. In view of this problem, a control method combining the extension control and Takagi-Sugeno-Kang fuzzy control is proposed for lane keeping system control. The extension control strategy based on the idea of control with area division divides different control regions according to the states of the system, and adopts different control algorithms in different control areas to address the limitation of a single control algorithm. For the randomness and inaccuracy of artificial experience in control domain division, a method for control domain division based on the density distribution of characteristic plane is proposed in this article. In order to further improve and explore the performance of extension control, Takagi-Sugeno-Kang extension controller is designed with Takagi-Sugeno-Kang fuzzy control theory, and the extension control performance is improved when switching among different control algorithms. The proposed control strategy is simulated and tested on the CarSim/Simulink joint simulation platform and the CarSim/LabVIEW hardware-in-loop test bench, respectively. The results show that the proposed control strategy can effectively keep the vehicle near the center line of the lane, and both the lane keeping control accuracy and vehicle stability are improved, which guarantees driving safety and comfort.

Study on Control Algorithm of 3-DOF Parallel Robot

2010 ◽  
Vol 40-41 ◽  
pp. 774-777
Author(s):  
Qing Hua Cao ◽  
Li Fan
Keyword(s):  
Robust Control ◽  
Fuzzy Logic Control ◽  
Pid Controller ◽  
Control Algorithm ◽  
Parallel Robot ◽  
Control Algorithms ◽  
Logic Control ◽  
Hydraulic Servo ◽  
Hydraulic Servo System ◽  
Better Than

In order to improve control affect of 3-DOF parallel robot, the structure and work principle are presented in brief, control algorithm is introduced in great detail, three controller, which are PID controller , fuzzy logic control and robust control,are established, research of compare experiment show that robust control in hydraulic servo system is better than the other control algorithms.

Design a Robust RST Controller for Stabilization of a Tri-Copter UAV

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Zain Anwar Ali ◽  
Dao Bo Wang ◽  
Muhammad Aamir
Keyword(s):  
Control Algorithm ◽  
Control Structure ◽  
Flight Test ◽  
System Control ◽  
Test Results ◽  
Output Control ◽  
Aerial Robot ◽  
Mimo Model

<span>Research on the tri-rotor aerial robot is due to extra efficiency<span> over other UAV’s regarding stability, power and size<span> requirements. We require a controller to achieve 6-Degree<span> Of Freedom (DOF), for such purpose, we propose the RST<span> controller to operate our tri-copter model. A MIMO model<span> of a tri-copter aerial robot is challenged in the area of control<span> engineering. Ninestates of output control dynamics are treated<span> individually. We designed dynamic controllers to stabilize the<span> parameters of an UAV. The resulting system control algorithm<span> is capable of stabilizing our UAV to perform numerous<span> operations autonomously. The estimation and simulation<span> implemented inMATLAB, Simulink to verify the results. All<span> real flight test results are presented to prove the success of<span> the planned control structure.<br /><br class="Apple-interchange-newline" /></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

Chaos Glowworm Swarm Optimization Algorithm Based on Cloud Model for Face Recognition

2020 ◽  
Vol 34 (12) ◽  
pp. 2056009
Author(s):  
Guangyu Zhou ◽  
Aijia Ouyang ◽  
Yuming Xu
Keyword(s):  
Face Recognition ◽  
Cloud Model ◽  
Cuckoo Search ◽  
Global Optimum ◽  
Convergence Speed ◽  
Invasive Weed ◽  
Swarm Optimization ◽  
Hybrid Particle Swarm Optimization ◽  
Glowworm Swarm Optimization ◽  
Better Than

To overcome the shortcomings of the basic glowworm swarm optimization (GSO) algorithm, such as low accuracy, slow convergence speed and easy to fall into local minima, chaos algorithm and cloud model algorithm are introduced to optimize the evolution mechanism of GSO, and a chaos GSO algorithm based on cloud model (CMCGSO) is proposed in the paper. The simulation results of benchmark function of global optimization show that the CMCGSO algorithm performs better than the cuckoo search (CS), invasive weed optimization (IWO), hybrid particle swarm optimization (HPSO), and chaos glowworm swarm optimization (CGSO) algorithm, and CMCGSO has the advantages of high accuracy, fast convergence speed and strong robustness to find the global optimum. Finally, the CMCGSO algorithm is used to solve the problem of face recognition, and the results are better than the methods from literatures.

Synthesis Design and Analysis of a Hybrid Controller for Robotic Arms

2016 ◽  
Author(s):  
Dan Zhang ◽  
Bin Wei
Keyword(s):  
Pid Controller ◽  
Adaptive Controller ◽  
Convergence Speed ◽  
Model Reference ◽  
Robotic Arms ◽  
Hybrid Controller ◽  
Comparison Results ◽  
Convergence Performance ◽  
Model Reference Adaptive ◽  
Better Than

In this paper, a hybrid controller for robotic arms is proposed and designed by combining a proportional-integral-derivative controller (PID) and a model reference adaptive controller (MRAC) in order to further improve the accuracy and joint convergence speed performance. The convergence performance of the PID controller, the model reference adaptive controller and the PID+MRAC hybrid controller for 1-DOF and 2-DOF manipulators are compared. The comparison results show that the convergence speed and its performance for the MRAC and the PID+MRAC controllers are better than that of the PID controller, and the convergence performance for the hybrid control is better than that of the MRAC control.

scholarly journals Vibration Control of Buildings Using Magnetorheological Damper: A New Control Algorithm

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Aly Mousaad Aly
Keyword(s):  
Vibration Control ◽  
Control Algorithm ◽  
Fuzzy Logic Controller ◽  
Mr Damper ◽  
Maximum Energy ◽  
Magnetorheological Damper ◽  
Control Algorithms ◽  
Earthquake Loads ◽  
Building Model ◽  
Lyapunov Controller

This paper presents vibration control of a building model under earthquake loads. A magnetorheological (MR) damper is placed in the building between the first floor and ground for seismic response reduction. A new control algorithm to command the MR damper is proposed. The approach is inspired by a quasi-bang-bang controller; however, the proposed technique gives weights to control commands in a fashion that is similar to a fuzzy logic controller. Several control algorithms including decentralized bang-bang controller, Lyapunov controller, modulated homogeneous friction controller, maximum energy dissipation controller, and clipped-optimal controller are used for comparison. The new controller achieved the best reduction in maximum interstory drifts and maximum absolute accelerations over all the control algorithms presented. This reveals that the proposed controller with the MR damper is promising and may provide the best protection to the building and its contents.

The Use of Damping Based Semi-Active Control Algorithms in the Mechanical Smart-Spring System

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Wander Gustavo Rocha Vieira ◽  
Fred Nitzsche ◽  
Carlos De Marqui
Keyword(s):  
Active Control ◽  
Control Algorithm ◽  
Control Strategies ◽  
Vibration Reduction ◽  
Flow Analysis ◽  
Coupled Systems ◽  
Control Technique ◽  
Control Algorithms ◽  
Control Techniques ◽  
Spring Mechanism

In recent decades, semi-active control strategies have been investigated for vibration reduction. In general, these techniques provide enhanced control performance when compared to traditional passive techniques and lower energy consumption if compared to active control techniques. In semi-active concepts, vibration attenuation is achieved by modulating inertial, stiffness, or damping properties of a dynamic system. The smart spring is a mechanical device originally employed for the effective modulation of its stiffness through the use of semi-active control strategies. This device has been successfully tested to damp aeroelastic oscillations of fixed and rotary wings. In this paper, the modeling of the smart spring mechanism is presented and two semi-active control algorithms are employed to promote vibration reduction through enhanced damping effects. The first control technique is the smart-spring resetting (SSR), which resembles resetting control techniques developed for vibration reduction of civil structures as well as the piezoelectric synchronized switch damping on short (SSDS) technique. The second control algorithm is referred to as the smart-spring inversion (SSI), which presents some similarities with the synchronized switch damping (SSD) on inductor technique previously presented in the literature of electromechanically coupled systems. The effects of the SSR and SSI control algorithms on the free and forced responses of the smart-spring are investigated in time and frequency domains. An energy flow analysis is also presented in order to explain the enhanced damping behavior when the SSI control algorithm is employed.

Optimal actuator placement in adaptive optics systems

2021 ◽  
pp. 107754632110324
Author(s):  
Berk Altıner ◽  
Bilal Erol ◽  
Akın Delibaşı
Keyword(s):  
Cost Function ◽  
Adaptive Optics ◽  
Disturbance Attenuation ◽  
Linear Quadratic ◽  
Placement Problem ◽  
Convex Optimization Problem ◽  
Wavefront Aberrations ◽  
The Cost ◽  
Actuator Placement ◽  
Quadratic Cost Function

Adaptive optics systems are powerful tools that are implemented to degrade the effects of wavefront aberrations. In this article, the optimal actuator placement problem is addressed for the improvement of disturbance attenuation capability of adaptive optics systems due to the fact that actuator placement is directly related to the enhancement of system performance. For this purpose, the linear-quadratic cost function is chosen, so that optimized actuator layouts can be specialized according to the type of wavefront aberrations. It is then considered as a convex optimization problem, and the cost function is formulated for the disturbance attenuation case. The success of the presented method is demonstrated by simulation results.

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