Model-Free Control to Maneuver an Uncertain 2-DOF Manipulator Robot

A novel active suspension control design method is proposed for attenuating vibrations caused by road disturbance inputs in vehicle suspension systems. For the control algorithm, we propose an intelligent PD controller structure that effectively rejects online estimated disturbances. The main theoretical techniques used in this paper consist of an ultra-local model which replaces the mathematical model of quarter car system and a new algebraic estimator of unknown information. The measurement of only input and output variables of the plant is required for achieving the reference tracking task and the cancellation of unmodeled exogenous and endogenous perturbations such as roughness road variation, unpredictable variation of vehicle speed and load variation. The performance and robustness of the proposed active suspension algorithm are compared with ADRC control and LQR control. Numerical results are provided for showing the improvement of passenger comfort criteria with model-free control.

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Model-Free Control Approach of a Three-Tank System Using an Adaptive-Based Control

Volume 6: 13th International Conference on Multibody Systems, Nonlinear Dynamics, and Control ◽

10.1115/detc2017-67487 ◽

2017 ◽

Cited By ~ 1

Author(s):

Elmira Madadi ◽

Yao Dong ◽

Dirk Söffker

Keyword(s):

Tracking Error ◽

Identification Problem ◽

Dynamical Structure ◽

Modified Model ◽

Control Approach ◽

Model Free ◽

Tank System ◽

Model Free Control ◽

Complex Nonlinear Systems ◽

Error Optimization

For improving the dynamics of systems in the last decades model-based control design approaches are continuously developed. The task to design an accurate model is the most relevant and related task for control engineers, which is time consuming and difficult if in the case of complex nonlinear systems a complex modeling or identification problem arises. For this reason model-free control methods become attractive as alternative to avoid modeling. This contribution focuses on design methods of a model-free adaptive-based controller and modified model-free adaptive-based controller. Modified approach is based on the same adaptive model-free control algorithm performing tracking error optimization. Both approaches are designed for non-linear systems with uncertainties and in the presence of disturbances in order to assure suitable performance as well as robustness against unknown inputs. Using this approach, the controller requires neither the information about the systems dynamical structure nor the knowledge about systems physical behaviors. The task is solved using only the system outputs and inputs, which are measurable. The effectiveness of the proposed method is validated by experiments using a three-tank system.

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A Model-Free Control Scheme for Attitude Stabilization of Quadrotor Systems

Electronics ◽

10.3390/electronics9101586 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1586

Author(s):

Jaemin Baek ◽

Jinmyung Jung

Keyword(s):

Pole Placement ◽

Tracking Errors ◽

Attitude Stabilization ◽

Delayed Information ◽

Model Free ◽

System A ◽

Control Scheme ◽

Fast Convergence Rate ◽

Model Free Control ◽

Quadrotor System

This paper presents an extended time-delayed control (ETDC) scheme and applies it to a quadrotor system. The proposed ETDC scheme uses a one-sample delayed information of the system for canceling out the uncertainties and disturbances in nonlinear quadrotor system, which involves a combination of pole-placement term to deal with the pole assignment. Thus, the proposed one requires no prior knowledge about the quadrotor dynamics, which is called model-free control scheme, and then assures fast convergence rate while providing simplicity structure. To suppress time-delayed estimation (TDE) errors generated by using one-sample delayed information of the system, a new auxiliary control scheme is designed in the proposed ETDC scheme. It results in a proper switching gain without undesirable side effect, including chattering and input fluctuation. Moreover, given that it does not require any number of additional parameters, the number of the parameters in the proposed ETDC scheme has no change compared to that in conventional time-delayed control. From these benefits, the proposed one can be recognized as a simple and effective alternative to the quadrotor system with nonlinearity and complexity. The tracking errors are proved to be uniformly ultimately bounded through Lyapunov function. The effectiveness of the proposed ETDC scheme is verified by the simulation with the quadrotor system, which is compared to that of the conventional time-delayed control scheme.

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