Design of the Linear Quadratic Control Strategy and the Closed-Loop System for the Active Four-Wheel-Steering Vehicle

2015 ◽  
Vol 8 (1) ◽  
pp. 354-363 ◽  
Author(s):  
Zhiyun Zhang ◽  
Miaohua Huang ◽  
Meixia Ji ◽  
Shuanglong Zhu
Keyword(s):  
Control Strategy ◽  
Closed Loop ◽  
Loop System ◽  
Linear Quadratic Control ◽  
Closed Loop System ◽  
Linear Quadratic

scholarly journals Nonlinear modelling and optimal control via Takagi-Sugeno fuzzy techniques: A quadrotor stabilization

2020 ◽  
Vol 71 (1) ◽  
pp. 1-10
Author(s):  
Miroslav Pokorný ◽  
Tomáš Dočekal ◽  
Danica Rosinová
Keyword(s):  
Closed Loop ◽  
Fuzzy Controller ◽  
Fitness Function ◽  
Fuzzy Model ◽  
Loop System ◽  
Linear Matrix ◽  
Closed Loop System ◽  
Linear Quadratic ◽  
Fuzzy Aggregation ◽  
Takagi Sugeno

AbstractUsing the principles of Takagi-Sugeno fuzzy modelling allows the integration of flexible fuzzy approaches and rigorous mathematical tools of linear system theory into one common framework. The rule-based T-S fuzzy model splits a nonlinear system into several linear subsystems. Parallel Distributed Compensation (PDC) controller synthesis uses these T-S fuzzy model rules. The resulting fuzzy controller is nonlinear, based on fuzzy aggregation of state controllers of individual linear subsystems. The system is optimized by the linear quadratic control (LQC) method, its stability is analysed using the Lyapunov method. Stability conditions are guaranteed by a system of linear matrix inequalities (LMIs) formulated and solved for the closed loop system with the proposed PDC controller. The additional GA optimization procedure is introduced, and a new type of its fitness function is proposed to improve the closed-loop system performance.

Active Vibration Control of Beams by Combining Precompressed Layer Damping and ACLD Treatment: Performance Comparison of Various Robust Control Techniques

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Rajiv Kumar
Keyword(s):  
Robust Control ◽  
Closed Loop ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Performance Comparison ◽  
Loop System ◽  
Flexible Beam ◽  
Closed Loop System ◽  
Linear Quadratic ◽  
System Parameters

It is a well known fact that system parameters of the flexible structures keep on changing due to several reasons. Ordinary controllers lose their effectiveness in changed situations and do not guarantee the stability of the closed loop system. However, controllers designed based on robust control theory not only maintain the closed loop stability of the perturbed system with a large variation in system parameters but also maintain the best performance. H∞ loop shaping controller is designed and implemented experimentally on a smart flexible beam treated with precompressed layer damping and ACLD treatment. It outperforms linear quadratic Gaussian and standard H∞ controller both in terms of robust stability and robust performance. Relative merits and demerits of the μ-synthesis based controller are also discussed. Afterwards, these controllers were digitized at certain sampling frequencies and applied to the experimental flexible structure. Certain time domain parameters of the closed loop system discuss the relative superiority of these controllers which otherwise cannot be captured using frequency domain results alone.

Two Degree-of-Freedom Hysteresis Compensation for a Dynamic Mirror With Antagonistic Piezoelectric Stack Actuation

2013 ◽  
Author(s):  
James A. Mynderse ◽  
George T. C. Chiu
Keyword(s):  
Input Signal ◽  
Control Strategy ◽  
Closed Loop ◽  
Loop System ◽  
Degree Of Freedom ◽  
Closed Loop System ◽  
Loop Control ◽  
Hysteresis Compensation ◽  
Hysteresis Control ◽  
Two Degree Of Freedom

A methodology for designing a low-computation, high-bandwidth strategy for closed-loop control of a hysteretic system without a priori knowledge of the desired trajectory is presented. The resulting two degree-of-freedom hysteresis control strategy is applied to a dynamic mirror with antagonistic piezoelectric stack actuation. Hysteresis compensator is performed by a finite state machine switching polynomials for hysteresis inversion based on the input signal slope. Residual error after hysteresis compensation is corrected by an LQR feedback controller. Experimental results demonstrate effectiveness of the hysteresis compensator and closed-loop system under the proposed hysteresis control strategy. For the triangular input signal tested, the closed-loop system achieves a 91.5% reduction in hysteresis uncertainty with 60 kHz sample rate.

Analysis and Feedback Control of Planar SOFC Systems for Fast Load Following in APU Applications

2006 ◽  
Author(s):  
Handa Xi ◽  
Jing Sun
Keyword(s):  
Feedback Control ◽  
Closed Loop ◽  
High Efficiency ◽  
Open Loop ◽  
Loop System ◽  
System Response ◽  
Closed Loop System ◽  
Linear Quadratic ◽  
Load Following ◽  
Model Linearization

Solid Oxide Fuel Cell (SOFC) based Auxiliary Power Unit (APU) systems have many practical advantages given their high efficiency, low emissions and flexible fueling strategies. This paper focuses on model-based analysis and feedback control design for planar SOFC systems to achieve fast load following capability. A dynamic model is first developed for the integrated co-flow planar SOFC and CPOX (Catalytic Partial Oxidation) system aiming at APU applications. Simulation results illustrate that an open-loop system with optimal steady-state operating setpoints exhibits a slow transient power response when load increases. Feedback control is then explored to speed up the system response by controlling the flow rates of fuel and air supplies to the system. Model linearization, balanced truncation and Linear Quadratic Gaussian (LQG) approaches are used to derive the low-order observer-based controller. With the feedback controller developed, we show, through simulations, that the closed-loop system can have faster load following capability. Different feedback strategies are also considered and their impacts on closed-loop system performance are analyzed.

scholarly journals Harnessing the Kelvin–Helmholtz instability: feedback stabilization of an inviscid vortex sheet

2018 ◽  
Vol 852 ◽  
pp. 146-177 ◽  
Author(s):  
Bartosz Protas ◽  
Takashi Sakajo
Keyword(s):  
Degrees Of Freedom ◽  
Closed Loop ◽  
Linear Quadratic Regulator ◽  
Vortex Sheet ◽  
Shear Layers ◽  
Feedback Stabilization ◽  
Loop System ◽  
Closed Loop System ◽  
Linear Quadratic ◽  
Mass Fluxes

In this investigation, we use a simple model of the dynamics of an inviscid vortex sheet given by the Birkhoff–Rott equation to obtain fundamental insights about the potential for stabilization of shear layers using feedback control. As actuation, we consider two arrays of point sinks/sources located a certain distance above and below the vortex sheet and subject to the constraint that their mass fluxes separately add up to zero. First, we demonstrate using analytical computations that the Birkhoff–Rott equation linearized around the flat-sheet configuration is in fact controllable when the number of actuator pairs is sufficiently large relative to the number of discrete degrees of freedom present in the system, a result valid for generic actuator locations. Next, we design a state-based linear-quadratic regulator stabilization strategy, where the key difficulty is the numerical solution of the Riccati equation in the presence of severe ill-conditioning resulting from the properties of the Birkhoff–Rott equation and the chosen form of actuation, an issue that is overcome by performing computations with a suitably increased arithmetic precision. Analysis of the linear closed-loop system reveals exponential decay of the perturbation energy and the corresponding actuation energy in all cases. Computations performed for the nonlinear closed-loop system demonstrate that initial perturbations of non-negligible amplitude can be effectively stabilized when a sufficient number of actuators is used. We also thoroughly analyse the sensitivity of the closed-loop stabilization strategies to the variation of a number of key parameters. Subject to the known limitations of inviscid vortex models, our findings indicate that, in principle, it may be possible to stabilize shear layers for relatively large initial perturbations, provided that the actuation has sufficiently many degrees of freedom.

Closed-Loop System Improves Glucose Control

2010 ◽  
Vol 40 (4) ◽  
pp. 42-43
Author(s):  
MIRIAM E. TUCKER
Keyword(s):  
Glucose Control ◽  
Closed Loop ◽  
Loop System ◽  
Closed Loop System

Safety and Performance of the Omnipod®Hybrid Closed-Loop System in Adolescents with Type 1 Diabetes over Five Days Under Free-Living Conditions

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1376-P
Author(s):  
GREGORY P. FORLENZA ◽  
BRUCE BUCKINGHAM ◽  
JENNIFER SHERR ◽  
THOMAS A. PEYSER ◽  
JOON BOK LEE ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Living Conditions ◽  
Loop System ◽  
Closed Loop System ◽  
Free Living ◽  
And Performance ◽  
Free Living Conditions

1066-P: Improvement in Time-in-Range (TIR) with Real-Life Use of Hybrid Closed-Loop System in Patients with Type 1 Diabetes (T1D)

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 1066-P
Author(s):  
HALIS K. AKTURK ◽  
DOMINIQUE A. GIORDANO ◽  
HAL JOSEPH ◽  
SATISH K. GARG ◽  
JANET K. SNELL-BERGEON
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Real Life ◽  
Loop System ◽  
Closed Loop System ◽  
Time In Range

Safety and Performance of the Omnipod® Hybrid Closed-Loop System in Adults with Type 1 Diabetes over Five Days Under Free-Living Conditions

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 207-OR
Author(s):  
BRUCE A. BUCKINGHAM ◽  
JENNIFER SHERR ◽  
GREGORY P. FORLENZA ◽  
THOMAS A. PEYSER ◽  
JOON BOK LEE ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Living Conditions ◽  
Loop System ◽  
Closed Loop System ◽  
Free Living ◽  
And Performance ◽  
Free Living Conditions
Sign in / Sign up

Export Citation Format

Share Document