scholarly journals Sistem Kendali Eddy Current Brakes Dinamometer menggunakan Linear Quadratic Regulator (LQR)

2021 ◽  
Vol 9 (4) ◽  
pp. 923
Author(s):  
MUHAMMAD ARROFIQ ◽  
LUKMAN SIDIQ NUGROHO ◽  
FAHMIZAL FAHMIZAL ◽  
ESA APRIASKAR
Keyword(s):  
Eddy Current ◽  
Pid Control ◽  
State Feedback ◽  
Linear Quadratic Regulator ◽  
Control Technique ◽  
Linear Quadratic ◽  
Matlab Simulink ◽  
Braking Performance ◽  
Full State ◽  
Full State Feedback

ABSTRAKMakalah ini memberikan analisis perbandingan antara teknik kendali klasik yaitu kendali PID dengan teknik kendali modern pada sistem Eddy current brakes dinamometer. Eddy current brakes merupakan sistem pengereman modern yang membutuhkan sebuah sistem kendali untuk menunjang kinerja pengereman. Selama ini kendali PID lebih sering digunakan, namun di beberapa kondisi dinilai kurang optimal. Dengan demikian, diperlukan pengembangan kendali yang modern dan optimal yaitu full state feedback Linear Quadratic Regulator (LQR). Perbandingan respon waktu pengereman disimulasikan menggunakan Matlab/Simulink. Hasil simulasi menunjukkan respon waktu pengereman pada kendali LQR lebih baik dibandingkan dengan kendali PID, dengan Ts = 2.12 detik, Tr = 1.18 detik, dan tanpa overshoot. Adapun kendali PID, meskipun menghasilkan Ts = 0.27 detik dan Tr = 0.18 detik, namun demikian masih terdapat overshoot sebesar 0.7%.Kata kunci: Eddy brakes, PID, LQR, Matlab ABSTRACTThis paper provides a comparative analysis between PID control as a classical control technique and modern control technique in the dinamometer Eddy current brakes system. Eddy current brakes is a modern braking system that requires a control system to support the braking performance. PID control is often used to be implemented but in some conditions it is less optimal. Therefore, it is necessary to develop a modern and optimal control, such as a full state feedback Linear Quadratic Regulator (LQR). The comparison of the braking time responses were simulated using Matlab/Simulink. The simulation results show that the response of LQR control is better than the PID, with Ts = 2.12 seconds, Tr = 1.18 seconds, and without overshoot. On the other side, PID control, although having Ts = 0.27 seconds and Tr = 0.18 seconds, there is still an overshoot about 0.7%.Keywords: Eddy brakes, PID, LQR, Matlab

scholarly journals Full-State Feedback Control Design for Shape Formation using Linear Quadratic Regulator

2020 ◽  
Vol 2 (2) ◽  
pp. 83
Author(s):  
Muhamad Rausyan Fikri ◽  
Djati Wibowo Djamari
Keyword(s):  
Feedback Control ◽  
State Feedback ◽  
Linear Quadratic Regulator ◽  
State Feedback Control ◽  
Linear Quadratic ◽  
Shape Formation ◽  
Full State ◽  
Full State Feedback ◽  
Input Response ◽  
Agent Coordination

This study investigated the capability of a group of agents to form a desired shape formation by designing the feedback control using a linear quadratic regulator. In real application, the state condition of agents may change due to some particular problems such as a slow input response. In order to compensate for the problem that affects agent-to-agent coordination, a robust regulator was implemented into the formation algorithm. In this study, a linear quadratic regulator as the full-state feedback of robust regulator method for shape formation was considered. The result showed that a group of agents can form the desired shape (square) formation with a modification of the trajectory shape of each agent. The results were validated through numerical experiments.

scholarly journals Application of LQR Full-State Feedback Controller for Rotational Inverted Pendulum

2021 ◽  
Vol 2111 (1) ◽  
pp. 012006
Author(s):  
N Setiawan ◽  
G N P Pratama
Keyword(s):  
State Feedback ◽  
Inverted Pendulum ◽  
Equilibrium Points ◽  
Linear Quadratic Regulator ◽  
Feedback Controller ◽  
Control Law ◽  
Linear Quadratic ◽  
State Feedback Controller ◽  
Full State ◽  
Full State Feedback

Abstract The rotational inverted pendulum is an interesting subject for some researchers, especially control engineers. Its nonlinear and underactuated characteristic make it quite challenging to stabilize it. Hence, a proper control law is a must to make it stable. Here, in this paper, we present a control law using LQR (Linear-Quadratic Regulator) to stabilize the rotational inverted pendulum. The experiments are carried out by linearizing the model and simulate the response in MATLAB. The results show that the controller succeeds to stabilize the states of rotational inverted pendulum to their respective equilibrium points. Even more, it provides zero settling errors.

Control of chaos in nonlinear systems with time-periodic coefficients

2006 ◽  
Vol 364 (1846) ◽  
pp. 2417-2432 ◽  
Author(s):  
S.C Sinha ◽  
Alexandra Dávid
Keyword(s):  
Nonlinear Systems ◽  
Periodic Orbit ◽  
Nonlinear Control ◽  
State Feedback ◽  
State Feedback Control ◽  
Control Technique ◽  
Periodic Coefficients ◽  
Full State ◽  
Full State Feedback ◽  
Time Periodic

In this study, some techniques for the control of chaotic nonlinear systems with periodic coefficients are presented. First, chaos is eliminated from a given range of the system parameters by driving the system to a desired periodic orbit or to a fixed point using a full-state feedback. One has to deal with the same mathematical problem in the event when an autonomous system exhibiting chaos is desired to be driven to a periodic orbit. This is achieved by employing either a linear or a nonlinear control technique. In the linear method, a linear full-state feedback controller is designed by symbolic computation. The nonlinear technique is based on the idea of feedback linearization. A set of coordinate transformation is introduced, which leads to an equivalent linear system that can be controlled by known methods. Our second idea is to delay the onset of chaos beyond a given parameter range by a purely nonlinear control strategy that employs local bifurcation analysis of time-periodic systems. In this method, nonlinear properties of post-bifurcation dynamics, such as stability or rate of growth of a limit set, are modified by a nonlinear state feedback control. The control strategies are illustrated through examples. All methods are general in the sense that they can be applied to systems with no restrictions on the size of the periodic terms.

scholarly journals Simulation Analysis of Linear Quadratic Regulator Control of Sagittal-Plane Human Walking—Implications for Exoskeletons

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Raviraj Nataraj ◽  
Antonie J. van den Bogert
Keyword(s):  
Sagittal Plane ◽  
Linear Quadratic Regulator ◽  
Whole Body ◽  
Linear Quadratic ◽  
Pd Control ◽  
Control Effort ◽  
Joint Torques ◽  
Lqr Control ◽  
Full State ◽  
Full State Feedback

The linear quadratic regulator (LQR) is a classical optimal control approach that can regulate gait dynamics about target kinematic trajectories. Exoskeletons to restore gait function have conventionally utilized time-varying proportional-derivative (PD) control of leg joints. But, these PD parameters are not uniquely optimized for whole-body (full-state) performance. The objective of this study was to investigate the effectiveness of LQR full-state feedback compared to PD control to maintain bipedal walking of a sagittal-plane computational model against force disturbances. Several LQR controllers were uniquely solved with feedback gains optimized for different levels of tracking capability versus control effort. The main implications to future exoskeleton control systems include (1) which LQR controllers out-perform PD controllers in walking maintenance and effort, (2) verifying that LQR desirably produces joint torques that oppose rapidly growing joint state errors, and (3) potentially equipping accurate sensing systems for nonjoint states such as hip-position and torso orientation. The LQR controllers capable of longer walk times than respective PD controllers also required less control effort. During sudden leg collapse, LQR desirably behaved like PD by generating feedback torques that opposed the direction of leg-joint errors. Feedback from nonjoint states contributed to over 50% of the LQR joint torques and appear critical for whole-body LQR control. While LQR control poses implementation challenges, such as more sensors for full-state feedback and operation near the desired trajectories, it offers significant performance advantages over PD control.

Analytical and Experimental Aeroelastic Wing Flutter Analysis and Suppression

2015 ◽  
Vol 15 (06) ◽  
pp. 1450084 ◽  
Author(s):  
Khalid A. Alsaif ◽  
Mosaad A. Foda ◽  
Hachimi Fellouah
Keyword(s):  
Nonlinear Models ◽  
Linear Quadratic Regulator ◽  
System Response ◽  
Linear Quadratic ◽  
Aeroelastic Response ◽  
Naca0012 Airfoil ◽  
Aerodynamic Model ◽  
Full State ◽  
Full State Feedback ◽  
And Control

Aeroelastic response and control of airfoil-flap wing exposed to unsteady aerodynamic loads is addressed. The aim is to suppress flutter and to maintain stability of the system. The analytical aerodynamic model is featuring plunging–pitching–flapping coupled motion. Both linear and nonlinear models are developed. Linear quadratic regulator theory is used to design a full state feedback controller in state-space. The control law is implemented through the flap torque to suppress flutter instability and enhance the aeroelastic response. The system response is investigated when it is flying beyond the flutter speed and the control is delayed by a few seconds. The effects of aircraft propeller excitation and the variation of the aspect ratio on the intitiation of flutter are investigated. Numerical simulations are complemented by experimental measurements in a wind tunnel for NACA0012 airfoil.

scholarly journals An LQR-Based Controller Design for an LCL-Filtered Grid-Connected Inverter in Discrete-Time State-Space under Distorted Grid Environment

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2062 ◽  
Author(s):  
Thuy Tran ◽  
Seung-Jin Yoon ◽  
Kyeong-Hwa Kim
Keyword(s):  
State Feedback ◽  
System State ◽  
State Variables ◽  
Linear Quadratic ◽  
Control Approach ◽  
Distorted Grid ◽  
Control Scheme ◽  
Full State ◽  
Full State Feedback ◽  
Grid Connected Inverter

In order to alleviate the negative impacts of harmonically distorted grid conditions on inverters, this paper presents a linear quadratic regulator (LQR)-based current control design for an inductive-capacitive-inductive (LCL)-filtered grid-connected inverter. The proposed control scheme is constructed based on the internal model (IM) principle in which a full-state feedback controller is used for the purpose of stabilization and the integral terms as well as resonant terms are augmented into a control structure for the reference tracking and harmonic compensation, respectively. Additionally, the proposed scheme is implemented in the synchronous reference frame (SRF) to take advantage of the simultaneous compensation for both the negative and positive sequence harmonics by one resonant term. Since this leads to the decrease of necessary resonant terms by half, the computation effort of the controller can be reduced. With regard to the full-state feedback control approach for the LCL-filtered grid connected inverter, additional sensing devices are normally required to measure all of the system state variables. However, this causes a complexity in hardware and high implementation cost for measurement devices. To overcome this challenge, this paper presents a discrete-time current full-state observer that uses only the information from the control input, grid-side current sensor, and grid voltage sensor to estimate all of the system state variables with a high precision. Finally, an optimal linear quadratic control approach is introduced for the purpose of choosing optimal feedback gains, systematically, for both the controller and full-state observer. The simulation and experimental results are presented to prove the effectiveness and validity of the proposed control scheme.

Flexible-Joint Humanoid Balancing Augmentation via Full-State Feedback Variable Impedance Control

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Emmanouil Spyrakos-Papastavridis ◽  
Jian S. Dai
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Impedance Control ◽  
Humanoid Robots ◽  
Flexible Joint ◽  
Model Free ◽  
Floating Base ◽  
Full State ◽  
Full State Feedback ◽  
Series Elastic Actuators

Abstract This paper attempts to address the quandary of flexible-joint humanoid balancing performance augmentation, via the introduction of the Full-State Feedback Variable Impedance Control (FSFVIC), and Model-Free Compliant Floating-base VIC (MCFVIC) schemes. In comparison to rigid-joint humanoid robots, efficient balancing control of compliant bipeds, powered by Series Elastic Actuators (or harmonic drives), requires the design of more sophisticated controllers encapsulating both the motor and underactuated link dynamics. It has been demonstrated that Variable Impedance Control (VIC) can improve robotic interaction performance, albeit by introducing energy-injecting elements that may jeopardize closed-loop stability. To this end, the novel FSFVIC and MCFVIC schemes are proposed, which amalgamate both collocated and non-collocated feedback gains, with power-shaping signals that are capable of preserving the system's stability/passivity during VIC. The FSFVIC and MCFVIC stably modulate the system's collocated state gains to augment balancing performance, in addition to the non-collocated state gains that dictate the position control accuracy. Utilization of arbitrarily low-impedance gains is permitted by both the FSFVIC and MCFVIC schemes propounded herein. An array of experiments involving the COmpliant huMANoid reveals that significant balancing performance amelioration is achievable through online modulation of the full-state feedback gains (VIC), as compared to utilization of invariant impedance control.

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