scholarly journals Model Reference Tracking Control Solutions for a Visual Servo System Based on a Virtual State from Unknown Dynamics

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 267
Author(s):  
Timotei Lala ◽  
Darius-Pavel Chirla ◽  
Mircea-Bogdan Radac
Keyword(s):  
Feedback Control ◽  
Output Feedback ◽  
State Feedback ◽  
Virtual State ◽  
System Model ◽  
Control Performance ◽  
Visual Servo ◽  
State Representation ◽  
Model Free ◽  
And Control

This paper focuses on validating a model-free Value Iteration Reinforcement Learning (MFVI-RL) control solution on a visual servo tracking system in a comprehensive manner starting from theoretical convergence analysis to detailed hardware and software implementation. Learning is based on a virtual state representation reconstructed from input-output (I/O) system samples under nonlinear observability and unknown dynamics assumptions, while the goal is to ensure linear output reference model (ORM) tracking. Secondary, a competitive model-free Virtual State-Feedback Reference Tuning (VSFRT) is learned from the same I/O data using the same virtual state representation, demonstrating the framework’s learning capability. A model-based two degrees-of-freedom (2DOF) output feedback controller serving as a comparisons baseline is designed and tuned using an identified system model. With similar complexity and linear controller structure, MFVI-RL is shown to be superior, confirming that the model-based design issue of poor identified system model and control performance degradation can be solved in a direct data-driven style. Apart from establishing a formal connection between output feedback control, state feedback control and also between classical control and artificial intelligence methods, the results also point out several practical trade-offs, such as I/O data exploration quality and control performance leverage with data volume, control goal and controller complexity.

H∞ Direct Output Feedback Control of High-Speed Elevator Systems

2011 ◽  
Author(s):  
Chang-Ching Chang ◽  
Chi-Chang Lin ◽  
Wu-Chung Su ◽  
Yuan-Po Huang
Keyword(s):  
Optimal Control ◽  
Feedback Control ◽  
Output Feedback ◽  
High Speed ◽  
Output Feedback Control ◽  
Control Force ◽  
Control Performance ◽  
Passenger Car ◽  
Horizontal Vibration ◽  
And Control

The more the development of super high-rise buildings, the faster the speed of elevator in order to shorten the riding time of elevator and the waiting time of passengers. With the increase of elevator speed, the horizontal vibration of passenger car becomes more significant resulting in the decrease of serviceability and safety of elevator, and the discomfort of passengers. The horizontal vibration is mainly generated from the elevator wheels running on rough and winding guide rails. In this paper, a four degree-of-freedom (DOF) elevator system was established to examine the characteristics of the excitations and to analyze the dynamic responses of the elevator. An active mass driver (AMD) was developed to reduce the horizontal acceleration of passenger car in the elevator based on H∞ direct output feedback control algorithm. The optimal control force is obtained from the multiplication of direct output measurements by a pre-calculated time-invariant gain matrix. To achieve optimal control performance, the strategy to select both control parameters γ and α was investigated extensively. Numerical verification results show that decrease in γ or increase in α yields better control performance with an acceptable magnitude of control force. The selective ranges of γ and α making a controlled system become overdamped or unstable were found. To assure system stability and control efficiency, the upper bound of α were derived and illustrated graphically. An optimum design flowchart was also proposed. Finally, a full-scaled high-speed elevator system was investigated to prove the applicability and control effectiveness of the proposed AMD system.

Robust Adaptive Control of Nonlinear Output Feedback Systems Under Disturbances With Unknown Bounds

2004 ◽  
Vol 126 (1) ◽  
pp. 229-235 ◽  
Author(s):  
Dong H. Kim ◽  
Hua O. Wang ◽  
Hai-Won Yang
Keyword(s):  
Output Feedback ◽  
State Feedback ◽  
Sliding Mode ◽  
Design Procedure ◽  
Adaptation Strategy ◽  
Robust Adaptive Control ◽  
Feedback Systems ◽  
Adaptive Controllers ◽  
Robust Adaptive ◽  
And Control

This paper describes a systematic procedure to design robust adaptive controllers for a class of nonlinear systems with unknown functions of unknown bounds based on backstepping and sliding mode techniques. These unknown functions can be unmodeled system nonlinearities, uncertainties and disturbances with unknown bounds. Both state feedback and output feedback designs are addressed. In the design procedure, the upper bounds of the unknown functions are estimated using an adaptation strategy, and the estimates are used to design stabilizing functions and control inputs based on the backstepping design methodology. The proposed controllers guarantee that the tracking errors converge to a residual set close to zero exponentially for both state feedback and output feedback designs, while maintaining the boundedness of all other variables.

H ∞ Control for Continuous-Time Switched Linear Systems

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Grace S. Deaecto ◽  
José C. Geromel
Keyword(s):  
Feedback Control ◽  
Linear Systems ◽  
Output Feedback ◽  
Continuous Time ◽  
Design Problem ◽  
State Feedback ◽  
Output Feedback Control ◽  
Control Design ◽  
Linear Matrix ◽  
Switched Linear Systems

This paper deals with the output feedback H∞ control design problem for continuous-time switched linear systems. More specifically, the main goal is to design a switching rule together with a dynamic full order linear controller to satisfy a prespecified H∞ level defined by the L2 gain from the input to the output signal. Initially, the state feedback version of this problem is solved in order to put in evidence the main difficulties we have to face toward the solution of the output feedback control design problem. The results reported in this paper are based on the so called Lyapunov–Metzler inequalities, which express a sufficient condition for switched linear systems global stability. The solution of the previously mentioned output feedback control design problem through a linear matrix inequality based method is the main contribution of the present paper. An academic example borrowed from literature is used for illustration.

State Feedback and Output Feedback Control of Polynomial Nonlinear Systems Using Fractional Lyapunov Functions

2007 ◽  
Author(s):  
Qian Zheng ◽  
Fen Wu
Keyword(s):  
Feedback Control ◽  
Nonlinear Systems ◽  
Lyapunov Function ◽  
Output Feedback ◽  
Lyapunov Functions ◽  
State Feedback ◽  
The State ◽  
State Feedback Control ◽  
Feedback Gain ◽  
Variation Rate

In this paper, we will study the state feedback control problem of polynomial nonlinear systems using fractional Lyapunov functions. By adding constraints to bound the variation rate of each state, the general difficulty of calculating derivative of nonquadratic Lyapunov function is effectively overcome. As a result, the state feedback conditions are simplified as a set of Linear Matrix Inequalities (LMIs) with polynomial entries. Computationally tractable solution is obtained by Sum-of-Squares (SOS) decomposition. And it turns out that both of the Lyapunov matrix and the state feedback gain are state dependent fractional matrix functions, where the numerator as well as the denominator can be polynomials with flexible forms and higher nonlinearities involved in. Same idea is extended to a class of output dependent nonlinear systems and the stabilizing output feedback controller is specified as polynomial of output. Synthesis conditions are similarly derived as using constant Lyapunov function except that all entries in LMIs are polynomials of output with derivative of output involved in. By bounding the variation rate of output and gridding on the bounded interval, the LMIs are solvable by SOS decomposition. Finally, two examples are used to materialize the design scheme and clarify the various choices on state boundaries.

Stabilization and equilibrium control of a new pneumatic cart-seesaw system

Robotica ◽  
2008 ◽  
Vol 26 (2) ◽  
pp. 219-227 ◽  
Author(s):  
J. Lin ◽  
J. H. Zhan ◽  
Julian Chang
Keyword(s):  
State Feedback ◽  
Initial Position ◽  
Degree Of Freedom ◽  
Test Results ◽  
Control Performance ◽  
Proportional Valve ◽  
Pneumatic Control ◽  
Supervisory Controller ◽  
Equilibrium Control ◽  
And Control

SUMMARYThis investigation describes the mechanical configuration and control environment for a novel cart-seesaw system. This mechanism is called a super articulated mechanical system (SAMS). The system comprises a cart that slides on the pneumatic rodless cylinder. The rodless cylinder is double-acting with the carrier bracket, on which a cart is a pinion mechanism for the tracks. The cart-seesaw system brings the cart from any initial position to a desired position on the seesaw by applying an appropriate force to the cart and thus adjusting the angle of the seesaw. The position of a cart denotes the first degree of freedom, which is activated by a pneumatic proportional valve, and the angle of the seesaw indicates the second degree of freedom that is not actuated. Consequently, the proposed new pneumatic cart-seesaw system is straightforward to construct and direct to operate in different scenarios of performance. A state feedback controller is applied for stabilization of the equilibrium point of the system. Moreover, this study adds a supervisory controller that takes control action in extreme situations. Test results reveal excellent properties in control performance. The proposed product can be extensively applied in SAMS and pneumatic control for robotics control laboratory.

Robust Observer Based Control for Stability of Linear Systems: Application to Polytopic Systems

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Mouna Belguith ◽  
Amel Benabdallah
Keyword(s):  
Feedback Control ◽  
Output Feedback ◽  
State Feedback ◽  
Linear Time ◽  
Sufficient Conditions ◽  
State Feedback Control ◽  
Robust Observer ◽  
Linear Time Invariant ◽  
Polytopic Systems ◽  
Linear Time Invariant Systems

This paper investigates the problem of global stabilization by output feedback for linear time-invariant systems. We give first a procedure to design a robust observer for the linear system. Then using this robust observer with the robust state feedback control law developed by Molander and Willems (1980, “Synthesis of State Feedback Control Laws With a Specified Gain and Phase Margin,” IEEE Trans. Autom. Control, 25(5), pp. 928–931), we construct an output feedback which yields a closed loop system with robustness characteristics. That is, we establish a separation principle. Finally, we give sufficient conditions to establish a robust output feedback for linear polytopic systems.

scholarly journals Optimisation of dynamic quantisation and control for quantised state feedback control system

2020 ◽  
Vol 2020 (7) ◽  
pp. 251-258
Author(s):  
Than Zaw Soe ◽  
Tadanao Zanma ◽  
Atsuki Tokunaga ◽  
Kenta Koiwa ◽  
Kang Zhi Liu
Keyword(s):  
Control System ◽  
Feedback Control ◽  
State Feedback ◽  
State Feedback Control ◽  
Feedback Control System ◽  
And Control
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