scholarly journals Dynamic modelling and open-loop control of a two-degree-of-freedom twin-rotor multi-input multi-output system

2004 ◽  
Vol 218 (6) ◽  
pp. 451-463 ◽  
Author(s):  
S M Ahmad ◽  
A J Chipperfield ◽  
M O Tokhi
Keyword(s):  
Dynamic Modelling ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Open Loop Control ◽  
Loop Control ◽  
Output System ◽  
Two Degree Of Freedom ◽  
Twin Rotor

scholarly journals Dynamic modelling and open-loop control of a twin rotor multi-input multi-output system

2002 ◽  
Vol 216 (6) ◽  
pp. 477-496 ◽  
Author(s):  
S M Ahmad ◽  
A J Chipperfield ◽  
M O Tokhi
Keyword(s):  
Mimo System ◽  
Dynamic Modelling ◽  
Open Loop ◽  
Open Loop Control ◽  
Performance Study ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Loop Control ◽  
Low Pass ◽  
Twin Rotor

A dynamic model for a one-degree-of-freedom (DOF) twin rotor multi-input multi-output (MIMO) system (TRMS) in hover is obtained using a black-box system identification technique. The behaviour of the TRMS in certain aspects resembles that of a helicopter; hence, it is an interesting identification and control problem. This paper investigates modelling and open-loop control of the longitudinal axis alone, while the lateral axis movement is physically constrained. It is argued that some aspects of the modelling approach presented are suitable for a class of new generation or innovative air vehicles with complex dynamics. The extracted model is employed for designing and implementing a feedforward/open-loop control. Open-loop control is often the preliminary step for development of more complex feedback control laws. Open-loop control strategies using shaped command inputs are accordingly investigated for resonance suppression in the TRMS. Digital low-pass and band-stop filter shaped inputs are used on the TRMS testbed, based on the identified vibrational modes. A comparative performance study is carried out and the corresponding results presented. The low-pass filter is shown to result in better vibration reduction.

Design of a 2 DOF Shape Memory Alloy Actuator Using SMA Springs

2021 ◽  
Author(s):  
Hussein F. M. Ali ◽  
Youngshik Kim
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Biologically Inspired ◽  
Loop Control ◽  
Actuator System ◽  
Sma Actuator ◽  
Sma Spring ◽  
Two Degree Of Freedom

Abstract In this paper, we developed two degree of freedom shape memory alloy (SMA) actuator using SMA springs. This module can be applied easily to various applications: device holder, artificial finger, grippes, fish robot, and many other biologically inspired applications, where small size and small wight of the actuator are very critical. This actuator is composed of two sets of SMA springs: one set is for the rotation around the X axis (roll angle) and the other set is for the rotation around the Y axis (pitch angle). Each set contains two elements: one SMA spring and one antagonistic SMA spring. We used an inertia sensor (IMU) and two potentiometers for angles feedback. The SMA actuator system is modeled mathematically and then tested experimentally in open-loop and closed-loop control. We designed and experimentally tuned a proportional integrator derivative (PID) controller to follow the set points and to track the desired trajectories. The main goal of the presented controller is to control roll and pitch angles simultaneously in order to satisfy set points and trajectories within the work space. The experimental results show that the two degree of freedom SMA actuator system follows the desired setpoints with acceptable rise time and overshoot.

Design and Analysis of a Micro-Positioning Stage

2011 ◽  
Author(s):  
Jau-Liang Chen ◽  
Yan-Ming Chen
Keyword(s):  
Piezoelectric Actuator ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Experimental Results ◽  
Flexure Hinge ◽  
Open Loop Control ◽  
Maximum Displacement ◽  
Rotational Angle ◽  
Loop Control ◽  
Positioning Stage

The purpose of this research is trying to design a 6 degree-of-freedom micro-precision positioning stage with monolithic mechanism. It is hoped that this stage can reach 10 μm strokes along linear axis and with rotational angle no less than 50 μrad. The dimension of this positioning stage should be less than 200 mm × 200 mm × 50 mm. By using flexure hinge and piezoelectric actuator, this stage can achieve nanometer resolution. From the experimental results, it is found that the stage can achieve a maximum displacement of 29.3 μm in X axis; 11.94 μm in Y axis; and 6.74 μm in Z axis. The stage can also achieve a maximum rotation of 405.41 μrad around Z axis; 57.18 μrad around X axis; and 63.72 μrad around Y axis. With open loop control, we have shown that the minimum step for the stage is 110 nm in X-axis; 45 nm in Y axis; and 30 nm in Z-axis.

Robust two-degree of freedom H∞ control design for a twin rotor multi-input multi-output system with external disturbances and model uncertainties

2020 ◽  
pp. 095965182095496
Author(s):  
Smruti Ranjan Jagadeb ◽  
Bidyadhar Subudhi ◽  
Asim Kumar Naskar
Keyword(s):  
Internal Model Control ◽  
Degree Of Freedom ◽  
Proportional Integral Derivative ◽  
Model Uncertainties ◽  
External Disturbances ◽  
Proportional Integral Derivative Controller ◽  
Proportional Integral ◽  
Output System ◽  
Two Degree Of Freedom ◽  
Twin Rotor

The control of twin rotor multi-input multi-output system is difficult as it is subjected to model uncertainties and external disturbances. Furthermore, there also exists a coupling between pitch and yaw positions, which makes the system more difficult to control them separately. Considering the above difficulties in twin rotor multi-input multi-output system control, [Formula: see text] robust controller is designed to handle the model uncertainties and external disturbances with two-degree-of-freedom. A mixed sensitivity approach is employed to represent the uncertainties and external disturbances arise in the twin rotor multi-input multi-output system. For performance analysis, first the proposed two-degree-of-freedom [Formula: see text] controller is compared with the ‘Linear Quadratic Regulator-Linear Matrix Inequality’–based robust proportional–integral–derivative controller and Internal Model Control–based proportional–integral–derivative controller in MATLAB/Simulation and then in experimentation. From the obtained results, it is confirmed that the proposed controller exhibits enhanced robustness, faster tracking performance and accurate disturbance attenuation, when compared with Linear Quadratic Regulator-Linear Matrix Inequality–based robust proportional–integral–derivative controller and Internal Model Control–based proportional–integral–derivative controller in face of external disturbances and uncertainties.

Multi-DOF compensation of piezoelectric actuators with recursive databases

2018 ◽  
Vol 66 (8) ◽  
pp. 656-664 ◽  
Author(s):  
Christopher Schindlbeck ◽  
Christian Pape ◽  
Eduard Reithmeier
Keyword(s):  
Tracking Control ◽  
Control Design ◽  
Cross Coupling ◽  
Piezoelectric Actuators ◽  
Nonlinear Effects ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Decoupling Control ◽  
Open Loop Control ◽  
Loop Control

Abstract Piezoelectric actuators are subject to nonlinear effects when voltage-driven in open-loop control. In particular, hysteresis and creep effects are dominating nonlinearities that significantly deteriorate performance in tracking control scenarios. In this paper, we present an online compensator suitable for piezoelectric actuators that is based on the modified Prandtl-Ishlinskii model and utilizes recursive databases for the compensation of nonlinearities. The compensator scheme is furthermore extended to systems with more than one degree of freedom (DOF) such as Cartesian manipulators by employing a decoupling control design to mitigate inherent cross-coupling disturbances. In order to validate our theoretical derivations, experiments are conducted with coupled trajectories on a commercial 3-DOF micro-positioning unit driven by piezoelectric actuators.

Open-loop control of compensation for optical propagation through a turbulent shear flow

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen
Keyword(s):  
Shear Flow ◽  
Open Loop ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Open Loop Control ◽  
Loop Control ◽  
Optical Propagation

Precise open-loop control of MEMS deformable mirror shape

2008 ◽  
Author(s):  
Thomas Bifano ◽  
Jason Stewart ◽  
Alioune Diouf
Keyword(s):  
Open Loop ◽  
Deformable Mirror ◽  
Open Loop Control ◽  
Loop Control

Responses and Optimization of a PID-Based Speed Regulating System of the Planetary Mixer

2011 ◽  
Vol 418-420 ◽  
pp. 1865-1868
Author(s):  
Ming Jin Yang ◽  
Xi Wen Li ◽  
Zhi Gang Wang ◽  
Tie Lin Shi
Keyword(s):  
Control System ◽  
Open Loop ◽  
Open Loop Control ◽  
Efficient Operation ◽  
Loop Control ◽  
Loop Control System ◽  
Response Optimization ◽  
Close Loop Control ◽  
Close Loop Control System

The performance of speed regulating is very important to the mixing process with safe, efficient operation and high quality of production. Strategies and practices of responses and optimization of a PID-based speed regulating system of a planetary mixer were presented in this paper. Research results show that: by means of the signal constraint function presented by Simulink Response Optimization, optimization PID parameters of the 2-DOF-PID controller can be obtained, and the response of close-loop control system has quite good performance of overshoot, response time, and stability compared with an open-loop control system.

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