scholarly journals Multi-input multi-output fractional-order control of an underactuated continuum mechanism

2020 ◽  
Vol 17 (6) ◽  
pp. 172988142096957
Author(s):  
Bastian Deutschmann ◽  
Concepción A Monje ◽  
Christian Ott
Keyword(s):  
Rigid Body ◽  
Fractional Order ◽  
Nonlinear Feedback ◽  
Single Input Single Output ◽  
Control Approach ◽  
Fast Transient Response ◽  
Single Output ◽  
Single Input ◽  
Fractional Order Controller ◽  
The Continuum

This article treats the design and implementation of a multi-input multi-output fractional-order controller for a nonlinear system composed of a tendon-driven continuum mechanism. As the continuum can be deformed along all Cartesian directions, it is suitable for the application as a flexible neck of a humanoid robot. In this work, a model-based control approach is proposed to control the position of the head, that is, the rigid body attached to the top of the continuum mechanism. Herein, the system is modeled as a rigid body on top of a nonlinear Cartesian spring, with an experimentally obtained deflection characteristic which provides a simple and real-time capable model. By nonlinear feedback, the output dynamics are linearized and decoupled, which enables the design of single-input single-output fractional-order controllers for the regulation of each output independently. The design of a fractional-order [Formula: see text] controller is discussed to incorporate robustness and a fast transient response. The proposed control approach is tested in several experiments on the real system.

Optimal Decoupled Disturbance Observers for Dual-Input Single-Output Systems

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Xu Chen ◽  
Masayoshi Tomizuka
Keyword(s):  
Disturbance Observer ◽  
Filter Design ◽  
Spectral Characteristics ◽  
Hard Disk Drives ◽  
Disk Drives ◽  
Single Input Single Output ◽  
Control Approach ◽  
Single Output ◽  
Dual Stage ◽  
Single Input

The disturbance observer (DOB) has been a popular robust control approach for servo enhancement in single-input single-output systems. This paper presents a new extension of the DOB idea to dual- and multi-input single-output systems, and discusses an optimal filter design technique for the related loop-shaping. The proposed decoupled disturbance observer (DDOB) provides the flexibility to use the most suitable actuators for compensating disturbances with different spectral characteristics. Such a generalization is helpful, e.g., for modern dual-stage hard disk drives, where enhanced servo design is becoming more and more essential in the presence of vibration disturbances.

scholarly journals Generalized Minimum Variance Control for MDOF Structures under Earthquake Excitation

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Lakhdar Guenfaf ◽  
Mohamed Azira
Keyword(s):  
Control Method ◽  
Minimum Variance ◽  
Soil Parameters ◽  
Seismic Excitations ◽  
Earthquake Excitation ◽  
Single Input Single Output ◽  
Control Approach ◽  
Single Output ◽  
Single Input ◽  
Siso Systems

Control of a multi-degree-of-freedom structural system under earthquake excitation is investigated in this paper. The control approach based on the Generalized Minimum Variance (GMV) algorithm is developed and presented. Our approach is a generalization to multivariable systems of the GMV strategy designed initially for single-input-single-output (SISO) systems. Kanai-Tajimi and Clough-Penzien models are used to generate the seismic excitations. Those models are calculated using the specific soil parameters. Simulation tests using a 3DOF structure are performed and show the effectiveness of the control method.

An Approach to Design Controllers for MIMO Fractional Order System Based on RFN Method

2021 ◽  
Author(s):  
Tingxue Li ◽  
Dingyu Xue ◽  
Xinshu Cui
Keyword(s):  
Fractional Order ◽  
Controller Design ◽  
Order System ◽  
Fractional Order Systems ◽  
Control Effect ◽  
Loop Control ◽  
Single Input Single Output ◽  
Single Output ◽  
Single Input ◽  
Value Decomposition

Abstract Fractional calculus has attracted more and more attention and is applied in different fields. However the controller design techniques for fractional order systems mostly focus on single input single output (SISO) ones. This paper deals with the design of controllers for multiple inputs multiple outputs (MIMO) fractional order systems. A method to synthetize controller based on the eigenvalue function and singular value decomposition (SVD) is proposed with aid of fractional order transfer function (FOTF) MATLAB toolbox for the computation and fitting. Instead of setting specification to the controller, the method proposed aiming at achieving the target closed-loop control effect of the system as a whole. Several models evolved from fractional-order Proportional-Integral-Derivative (fPID) controller are selected to form the designed multivariable controller. The effectiveness and robustness of the proposed method are illustrated by an example via simulation.

Comparative analysis of SISO and wavelength diversity-based FSO systems at different transmitter power levels

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Varun Srivastava ◽  
Abhilash Mandloi ◽  
Dhiraj Kumar Patel
Keyword(s):  
Optical Signal ◽  
Free Space Optical ◽  
Optical Source ◽  
Transmit Power ◽  
Single Input Single Output ◽  
Transmitter Power ◽  
Single Output ◽  
Communication Links ◽  
Single Input ◽  
Matching Performance

AbstractFree space optical (FSO) communication refers to a line of sight technology, which comprises optical source and detector to create a link without the use of physical connections. Similar to other wireless communication links, these are severely affected by losses that emerged due to atmospheric turbulence and lead to deteriorated intensity of the optical signal at the receiver. This impairment can be compensated easily by enhancing the transmitter power. However, increasing the transmitter power has some limitations as per radiation regulations. The requirement of high transmit power can be reduced by employing diversity methods. This paper presents, a wavelength-based diversity method with equal gain combining receiver, an effective technique to provide matching performance to single input single output at a comparatively low transmit power.

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