scholarly journals Robust Fractional-Order Control Using a Decoupled Pitch and Roll Actuation Strategy for the I-Support Soft Robot

Mathematics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 702
Author(s):  
Jorge Muñoz ◽  
Francesco Piqué ◽  
Concepción A. Monje ◽  
Egidio Falotico
Keyword(s):  
Fractional Order ◽  
Classical Solutions ◽  
Soft Robot ◽  
Robust Controller ◽  
Computational Costs ◽  
Open Issue ◽  
Comparative Results ◽  
Very High ◽  
Fopi Controller ◽  
A Current

Tip control is a current open issue in soft robotics; therefore, it has received a good amount of attention in recent years. The desirable soft characteristics of these robots turn a well-solved problem in classic robotics, like the end-effector kinematics and dynamics, into a challenging problem. The high redundancy condition of these robots hinders classical solutions, resulting in controllers with very high computational costs. In this paper, a simplification is proposed in the actuation setup of the I-Support soft robot, allowing the use of simple strategies for tip inclination control. In order to verify the proposed approach, inclination step input and trajectory-tracking experiments were performed on a single module of the I-Support robot, resulting in zero output error in all cases, including those where the system was exposed to disturbances. The comparative results of the proposed controllers, a proportional integral derivative (PID) and a fractional order robust (FOPI) controller, validate the feasibility of the proposed approach, showing a clear advantage in the use of the fractional robust controller for the tip inclination control of the I-Support robot compared to the integer order controller.

On Robust Control of Fractional Order Plants: Invariant Phase Margin

2015 ◽  
Vol 10 (5) ◽  
Author(s):  
Mohammad Hossein Basiri ◽  
Mohammad Saleh Tavazoei
Keyword(s):  
Robust Control ◽  
Fractional Order ◽  
Phase Margin ◽  
Crossover Frequency ◽  
Large Uncertainty ◽  
Robust Controller ◽  
Numerical Examples

Recently, a robust controller has been proposed to be used in control of plants with large uncertainty in location of one of their poles. By using this controller, not only the phase margin and gain crossover frequency are adjustable for the nominal case but also the phase margin remains constant, notwithstanding the variations in location of the uncertain pole of the plant. In this paper, the tuning rule of the aforementioned controller is extended such that it can be applied in control of plants modeled by fractional order models. Numerical examples are provided to show the effectiveness of the tuned controller.

THREE-INPUTS-ONE-OUTPUT CURRENT-MODE UNIVERSAL BIQUAD USING TWO CURRENT CONVEYORS

2013 ◽  
Vol 22 (09) ◽  
pp. 1340001 ◽  
Author(s):  
JIUN-WEI HORNG ◽  
TO-YAO CHIU ◽  
CHING-PAO HSIAO ◽  
GUANG-TING HUANG
Keyword(s):  
Integrated Circuit ◽  
Current Mode ◽  
Current Conveyors ◽  
Output Terminal ◽  
Biquadratic Filter ◽  
Component Matching ◽  
High Output Impedance ◽  
Very High ◽  
A Current ◽  
High Output

A current-mode universal biquadratic filter with three input terminals and one output terminal is presented. The architecture uses two current conveyors (CCs), two grounded capacitors and two grounded resistors; and can realize all standard second-order filter functions — highpass, bandpass, lowpass, notch and allpass. Moreover, the circuit still offers the following advantage features: very low active and passive sensitivities, using of grounded capacitors and resistors which is ideal for integrated circuit implementation, without requirements for critical component matching conditions and very high output impedance. The workability of the proposed circuit has been verified via HSPICE simulations using TSMC 0.18 μm, level 49 MOSFET technology.

Design and High Accuracy Numerical Implementation of Fractional Order PI Controller for a PMSM Speed System

2021 ◽  
Author(s):  
Baokun Wang ◽  
Shaohua Wang ◽  
Ying Luo
Keyword(s):  
Fractional Order ◽  
Permanent Magnet Synchronous Motor ◽  
High Accuracy ◽  
System Control ◽  
Numerical Implementation ◽  
Implementation Method ◽  
Improved Performance ◽  
Fractional Order Pi Controller ◽  
Discretization Orders ◽  
Fopi Controller

Abstract In this paper, a systematic design and high accuracy implementation of fractional order proportional integral (FOPI) controller is proposed for a permanent magnet synchronous motor (PMSM) speed system, and the numerical implementation performance of the fractional order operator is evaluated with comprehensive investigation using different implementation methods. Three commonly used numerical implementation methods of fractional operators are investigated and compared in this paper. Futhermore, for the impulse response invariant method, the effects of different discretization orders on the system control performance are compared. The simulation results show that the high accuracy numerical implementation method of the designed high-order FOPI controller has improved performance over normal accuracy fractional order operation implementation.

scholarly journals Performance Evaluation of Fractional Order Pid and Sliding Mode Control with Optimization Tuning Access

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1448-1454
Keyword(s):  
Fractional Order ◽  
Pid Controller ◽  
World Economy ◽  
Sliding Mode ◽  
Proportional Integral Derivative ◽  
Robust Controller ◽  
The Past ◽  
Control Schemes ◽  
Different Types ◽  
Fractional Order Pid

The statistical analyses in the past showing the important properties of the electrohydraulic actuator (EHA) system, especially in the growth of the world economy. Dealing with the existing drawback in the EHA system, various types of control schemes have been introduced in the past. In this paper, to produce a more insightful view of the performance and the capabilities of the controller, three different types of controllers have been designed and compared. The favourite controller in the industry field, which is the proportional-integral-derivative (PID) controller will be first introduced. Follow by the improved PID controller, named Fractional Order (FO-PID) controller will be designed. Then, the prominent robust controller in the control field, called sliding mode controller (SMC) will be established. Instead of obtaining the controller’s parameters without any appropriate technique, the well-known tuning technique in computer science, named particle swarm optimization (PSO) will be utilized. Referring to the performances produced by these controllers, it can be concluded that the SMC is capable to generate most desired control performance that produced the highest accuracy with the smallest error in the analyses.

scholarly journals AN EVOLUTIONARY ALGORITHM FOR FAST INTENSITY BASED IMAGE MATCHING BETWEEN OPTICAL AND SAR SATELLITE IMAGERY

2018 ◽  
Vol IV-3 ◽  
pp. 83-90 ◽  
Author(s):  
Peter Fischer ◽  
Philipp Schuegraf ◽  
Nina Merkle ◽  
Tobias Storch
Keyword(s):  
Evolutionary Algorithm ◽  
Satellite Imagery ◽  
Image Matching ◽  
Optimal Solution ◽  
Search Problem ◽  
Computational Costs ◽  
Radar Sensors ◽  
Function Calls ◽  
Point Detection ◽  
Very High

This paper presents a hybrid evolutionary algorithm for fast intensity based matching between satellite imagery from SAR and very high-resolution (VHR) optical sensor systems. The precise and accurate co-registration of image time series and images of different sensors is a key task in multi-sensor image processing scenarios. The necessary preprocessing step of image matching and tie-point detection is divided into a search problem and a similarity measurement. Within this paper we evaluate the use of an evolutionary search strategy for establishing the spatial correspondence between satellite imagery of optical and radar sensors. The aim of the proposed algorithm is to decrease the computational costs during the search process by formulating the search as an optimization problem. Based upon the canonical evolutionary algorithm, the proposed algorithm is adapted for SAR/optical imagery intensity based matching. Extensions are drawn using techniques like hybridization (e.g. local search) and others to lower the number of objective function calls and refine the result. The algorithm significantely decreases the computational costs whilst finding the optimal solution in a reliable way.

Analytical Design of Fractional Order Proportional Integral Controller for Spherical Tank

2014 ◽  
Vol 573 ◽  
pp. 279-284 ◽  
Author(s):  
Neenu Elizabeth Cherian ◽  
K. Sundaravadivu
Keyword(s):  
Fractional Order ◽  
Dead Time ◽  
Transfer Functions ◽  
Design Method ◽  
Analytical Design ◽  
Proportional Integral ◽  
First Order ◽  
Spherical Tank ◽  
Proportional Integral Controller ◽  
Fopi Controller

This paper presents an analytical design method for fractional order proportional integral (FOPI) controller for the spherical tank which is modelled as a first order plus dead time (FOPDT) process. The design is based on the Bode’s ideal transfer function and fractional calculus. By using frequency domain, the proposed FOPI tuning rules are directly derived for a generalized first order plus dead time process and then applied to the transfer functions obtained at various operating points of the spherical tank. The performance of the designed FOPI controller is compared with the conventional integer order proportional integral derivative (IOPID) controller in simulation.

scholarly journals Design of Cascaded and Shifted Fractional-Order Lead Compensators for Plants with Monotonically Increasing Lags

2020 ◽  
Vol 4 (3) ◽  
pp. 37
Author(s):  
Guido Maione
Keyword(s):  
Fractional Order ◽  
Transfer Functions ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Robust Controller ◽  
Simulation Experiments ◽  
Rational Transfer ◽  
Serial Connection ◽  
Efficiency Performance ◽  
Two Stages

This paper concerns cascaded, shifted, fractional-order, lead compensators made by the serial connection of two stages introducing their respective phase leads in shifted adjacent frequency ranges. Adding up leads in these intervals gives a flat phase in a wide frequency range. Moreover, the simple elements of the cascade can be easily realized by rational transfer functions. On this basis, a method is proposed in order to design a robust controller for a class of benchmark plants that are difficult to compensate due to monotonically increasing lags. The simulation experiments show the efficiency, performance and robustness of the approach.

scholarly journals Fractional-Order Derivatives Defined by Continuous Kernels: Are They Really Too Restrictive?

2020 ◽  
Vol 4 (3) ◽  
pp. 40
Author(s):  
Jocelyn Sabatier
Keyword(s):  
Fractional Calculus ◽  
Fractional Order ◽  
Fractional Differential Equations ◽  
Initial Conditions ◽  
Fractional Integration ◽  
Current Trend ◽  
Singular Kernels ◽  
Fractional Differential ◽  
Definition Of ◽  
A Current

In the field of fractional calculus and applications, a current trend is to propose non-singular kernels for the definition of new fractional integration and differentiation operators. It was recently claimed that fractional-order derivatives defined by continuous (in the sense of non-singular) kernels are too restrictive. This note shows that this conclusion is wrong as it arises from considering the initial conditions incorrectly in (partial or not) fractional differential equations.

Sign in / Sign up

Export Citation Format

Share Document