scholarly journals Adaptive Under-Actuated Control for Capacitive Micro-Machined Ultrasonic Transducer Based On An Accurate Nonlinear Modeling

2021 ◽  
Author(s):  
Sima Darbasi ◽  
Mohammad Javad Mirzaei ◽  
Amir Musa Abazari ◽  
Ghader Rezazadeh
Keyword(s):  
Control Strategy ◽  
Closed Loop ◽  
Nonlinear Modeling ◽  
Ultrasonic Transducer ◽  
Convergence Time ◽  
Control Technique ◽  
Closed Loop Control ◽  
Loop Control ◽  
Output Pressure ◽  
Model Control

Abstract A capacitive micromachined ultrasonic transducer (CMUT) due to many benefits is being considered as an imaging and therapeutic technology recently. The critical challenge here is to stabilize the system beyond the pull-in voltage considering imposed perturbations. The CMUT system, on the other hand, has a low range of travel and it is intrinsically unstable, which can result in a pull-in phenomenon. Consequently, in order to use the CMUT systems in a variety of medical applications that require high tuning ratio, a closed-loop control technique has been designed for these systems aims at increasing the maximum capacitance and enhancing tunability as well. In this study, using the closed-loop control, the resistance of micro plate against the pull-in phenomenon has been examined. Also, in the description of the system a more accurate nonlinear modeling has been considered in the presence of an under-actuated sliding model control strategy with finite convergence time. Beside, adaptive protocols with unknown upper bounds have been designed to compensate the effects of uncertainty, unmodeled dynamics and external disturbances. The performance of controller in terms of improving output pressure, stabilizing the CMUT and its robustness to imposed perturbations have been investigated. Finally, numerical simulations are presented to verify the usefulness and applicability of the proposed control strategy.

A Control Strategy for Intelligent Stamp Forming Tooling

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
William J. Emblom ◽  
Klaus J. Weinmann
Keyword(s):  
Fuzzy Logic ◽  
Control Systems ◽  
Control Strategy ◽  
Pid Controller ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Linear Quadratic ◽  
Blank Holder ◽  
Loop Control ◽  
Stamp Forming

This paper describes the development and implementation of closed-loop control for oval stamp forming tooling using MATLAB®’s SIMULINK® and the dSPACE®CONTROLDESK®. A traditional PID controller was used for the blank holder pressure and an advanced controller utilizing fuzzy logic combining a linear quadratic gauss controller and a bang–bang controller was used to control draw bead position. The draw beads were used to control local forces near the draw beads. The blank holder pressures were used to control both wrinkling and local forces during forming. It was shown that a complex, advanced controller could be modeled using MATLAB’s SIMULINK and implemented in DSPACE CONTROLDESK. The resulting control systems for blank holder pressures and draw beads were used to control simultaneously local punch forces and wrinkling during the forming operation thereby resulting in a complex control strategy that could be used to improve the robustness of the stamp forming processes.

scholarly journals Using an Improved SIFT Algorithm and Fuzzy Closed-Loop Control Strategy for Object Recognition in Cluttered Scenes

PLoS ONE ◽  
2015 ◽  
Vol 10 (2) ◽  
pp. e0116323 ◽  
Author(s):  
Haitao Nie ◽  
Kehui Long ◽  
Jun Ma ◽  
Dan Yue ◽  
Jinguo Liu
Keyword(s):  
Object Recognition ◽  
Control Strategy ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Sift Algorithm ◽  
Loop Control

Research into the Variable Speed Pump Control System for Driving the Cutter Head of Shield Tunneling Machine

2009 ◽  
Vol 628-629 ◽  
pp. 257-262 ◽  
Author(s):  
Tong Xing
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Closed Loop ◽  
Control Method ◽  
Control Technique ◽  
Closed Loop Control ◽  
Variable Speed ◽  
Shield Tunneling ◽  
Loop Control ◽  
Cutter Head

The cutter head drive hydraulic system of φ1.8m simulate shield machine is introduced in this article, which has the variable speed pump control technique and the closed loop control method. The AMESim simulation model of the hydraulic system is built up, and the efficiency of the hydraulic system, speed control performance by open loop and closed loop control are analyzed. The result of the simulation shows that the variable speed pump control system has higher efficiency than the variable displacement pump control system about 4%-26% in the same condition when the cutter head speed is at the range of 0.5-4r/min, and the hydraulic system has good dynamic characteristics in closed-loop PID control.

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