Simulation and Experimentation of a Precise Nonlinear Tracking Control Algorithm for a Rotary Servo-Hydraulic System With Minimum Sensors

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
M. H. Toufighi ◽  
S. H. Sadati ◽  
F. Najafi ◽  
A. A. Jafari
Keyword(s):  
Singular Perturbation ◽  
Hydraulic System ◽  
Control Algorithm ◽  
Small Error ◽  
Least Square ◽  
Real System ◽  
Singular Perturbation Theory ◽  
Control Analysis ◽  
Recursive Least Square ◽  
The Real

The dynamics of hydraulic systems involves slow and fast modes. These modes are associated with the mechanical components and those involving fluid flow, respectively. As such, controllers for electro-hydraulic servo systems (EHSS) can be designed and analyzed using singular perturbation theory. In this paper, a singular perturbation control (SPC) algorithm is proposed and investigated on a rotary EHSS modeled based on a two-time-scale behavior of the system. For modeling, the components of the hydraulic system, specifically the nonlinear model of the orifice in servo valve, are modeled. A mathematical modeling and nonlinear control analysis that validated by experiment is presented. The controlled system with the SPC algorithm tracks a fairly smooth trajectory with very small error. As well, the control algorithm is successfully verified by experiment as the main contribution of the paper. In addition, this is robust to variations in the hydraulic fluid bulk modulus such that only its nominal value is sufficient. Furthermore, the proposed control design will not require derivatives of the control pressures and any output acceleration feedback. Hence, it can be implemented easier in the real system setup. The controller design approach addresses the nonlinearities of the rotary EHSS. The parameters of the real system model are experimentally identified using the continuous recursive least square method.

An Adaptive Semiactive Control Algorithm for Vehicle Suspension Systems

2003 ◽  
Author(s):  
Xubin Song ◽  
Mehdi Ahmadian ◽  
Steve Southward
Keyword(s):  
Dynamic System ◽  
Adaptive Algorithm ◽  
Control Algorithm ◽  
Suspension System ◽  
Least Square ◽  
Vehicle Suspension ◽  
Semiactive Control ◽  
Vehicle Speed ◽  
Recursive Least Square ◽  
Line System

In general, a vehicle suspension system can be characterized as a nonlinear dynamic system that is subjected to unknown vibration sources, dependent on road roughness and vehicle speed. In this paper, we will present a nonlinear-model-based adaptive semiactive control algorithm developed for nonlinear systems exposed to broadband non-stationary random vibration sources that are assumed to be unknown or not measurable. If there exist unknown and/or varying parameters of the dynamic system such as mass and stiffness, then the adaptive algorithm can include a recursive least square (RLS) method for on-line system identification. Since the adaptive algorithm is developed for semiactive systems, stability is guaranteed based on the fact that the system is energy conservative. The convergence of the adaptive system, however is not guaranteed, and is investigated through a numerical approach for a specific case. The simulation results for a magneto-rheological seat suspension system with the suggested adaptive control are presented. The results are compared with low-damping and high-damping cases, as well æ other configurations of skyhook control, in order to show the extent of the procurement that can be expected with the suggested adaptive skyhook control provides a better broadbandk performance for the suspension, as compared to the other damping configurations that are included here.

Chaos Control in Bonhoeffer-van der Pol System Using Fuzzy Estimation

Volume 1 ◽  
2004 ◽  
Author(s):  
Aria Alasty ◽  
Hassan Salarieh
Keyword(s):  
Fuzzy Control ◽  
Transient Response ◽  
Control Algorithm ◽  
Chaos Control ◽  
Least Square ◽  
Delayed Feedback Control ◽  
Recursive Least Square ◽  
Van Der Pol ◽  
Time Dynamic ◽  
Energy Behavior

This paper illustrates the control of chaos using a fuzzy estimating system based on batch training and recursive least square methods for a continuous time dynamic system. The fuzzy estimator system is trained on both Ott-Geobogi-Yorke (OGY) control algorithm and Pyragas’s delayed feedback control algorithm. The system, considered for this study, is a Bonhoeffer-van der Pol (BVP) oscillator. It is found that the implemented fuzzy control system constructed on OGY algorithm results in smaller control transient response than that of the OGY control algorithm itself. The transient response of Pyragas fuzzy control does not show a significant improvement in compare to the Pyragas control itself. In general the proposed control techniques show very effective low cost energy behavior in chaos control in compare to conventional nonlinear control methods.

scholarly journals Manuscript shapes generated by novel bi-axis control algorithm based on a mathematical handwriting model

2016 ◽  
Vol 4 (3) ◽  
pp. 230
Author(s):  
Imene Mahmoud ◽  
Ines Chihi ◽  
Afef Abedlkrim ◽  
Mohamed Benrejeb
Keyword(s):  
Control Algorithm ◽  
Biological Process ◽  
Velocity Model ◽  
Least Square ◽  
Recursive Least Square ◽  
Output Data ◽  
Arabic Word ◽  
Identification Technique ◽  
Human Motions ◽  
Complex Activities

<span lang="EN-US">Handwriting movement is one of the most complex activities of human motions. It’s a blend of kinesthetic, cognitive, perceptual and motor components. The study of this biological process shows that bell-shaped velocity profiles are generally observed in the handwriting motion. In this paper, an identification technique, based on Recursive Least Square algorithm (RLS), is proposed to identify the pen-tip movement in human handwriting process, by using input and output data which present EMG signals and velocities according to x and y coordinates.  Using the estimated coordinates that have resulted from the velocity model; we propose a novel algorithm to generate handwritten graphic traces, which is inspired from the idea of tracing circles by Bresenham bi-axis control algorithm. The effectiveness of this approach should be observed on predicting cursive Arabic letters and Arabic word written on (</span><em><span lang="EN-US">x,y</span></em><span lang="EN-US">) plane, these shapes constituting a recorded experimental basis.</span>

Observer-Based Output Feedback Control of Nonlinear Systems Non-Affine in the Unmeasured States

2009 ◽  
Author(s):  
Yannick Morel ◽  
Alexander Leonessa
Keyword(s):  
Feedback Control ◽  
Nonlinear Systems ◽  
Control Problem ◽  
Output Feedback ◽  
Control Algorithm ◽  
Output Feedback Control ◽  
State Feedback Control ◽  
Real System ◽  
Control Law ◽  
The Real

The presented work addresses the output feedback control problem for a large class of nonlinear systems. The control strategy shares similarities to separation-based algorithms commonly found in the literature, in the sense that the control problem is solved using an observer-predictor, in conjunction with a state feedback control law. The approach however distinguishes itself in significant ways. In particular, the control algorithm is not designed to control the actual system’s output, as is usually the case in separation-based approaches, but it is rather designed to control the output of the observer-predictor. The latter is designed to ensure that, for any admissible control signal, its output converges to a neighborhood of the corresponding output of the real system. The observer-predictor is thus used to indirectly control the real system. Results of numerical simulations are provided to illustrate performance of the obtained control algorithm.

Adaptive Robust Control of Hydraulic Robots With Recursive Least Squares

2009 ◽  
Author(s):  
Longke Wang ◽  
Wayne J. Book ◽  
James D. Huggins
Keyword(s):  
Robot Control ◽  
Control Algorithm ◽  
Adaptive Robust Control ◽  
Least Square ◽  
Recursive Least Squares ◽  
Parameter Design ◽  
Recursive Least Square ◽  
Computationally Efficient ◽  
Control Approach ◽  
Simple Parameter

This paper proposes a robot control approach using a discrete recursive least square algorithm. The scheme shows robustness when the system suffers from measurement noise and has a fast parameter convergence rate. The control algorithm is computationally efficient and numerically stable. Guaranteed trajectory tracking can be achieved by simple parameter design if disturbances are bounded.

scholarly journals Renormalization group and fractional calculus methods in a complex world: A review

2021 ◽  
Vol 24 (1) ◽  
pp. 5-53
Author(s):  
Lihong Guo ◽  
YangQuan Chen ◽  
Shaoyun Shi ◽  
Bruce J. West
Keyword(s):  
Perturbation Theory ◽  
Renormalization Group ◽  
Fractional Calculus ◽  
Singular Perturbation ◽  
World View ◽  
Singular Perturbation Theory ◽  
Asymptotic Behavior Of Solutions ◽  
Quantum Field ◽  
Self Similarity ◽  
Way Of Thinking

Abstract The concept of the renormalization group (RG) emerged from the renormalization of quantum field variables, which is typically used to deal with the issue of divergences to infinity in quantum field theory. Meanwhile, in the study of phase transitions and critical phenomena, it was found that the self–similarity of systems near critical points can be described using RG methods. Furthermore, since self–similarity is often a defining feature of a complex system, the RG method is also devoted to characterizing complexity. In addition, the RG approach has also proven to be a useful tool to analyze the asymptotic behavior of solutions in the singular perturbation theory. In this review paper, we discuss the origin, development, and application of the RG method in a variety of fields from the physical, social and life sciences, in singular perturbation theory, and reveal the need to connect the RG and the fractional calculus (FC). The FC is another basic mathematical approach for describing complexity. RG and FC entail a potentially new world view, which we present as a way of thinking that differs from the classical Newtonian view. In this new framework, we discuss the essential properties of complex systems from different points of view, as well as, presenting recommendations for future research based on this new way of thinking.

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