Response Variance Reduction of a Nonlinear Mechanical System via Sliding Mode Control

1998 ◽  
Vol 120 (3) ◽  
pp. 801-805 ◽  
Author(s):  
J. Q. Sun ◽  
Qing Xu
Keyword(s):  
Sliding Mode Control ◽  
Target Tracking ◽  
Mechanical System ◽  
Variance Reduction ◽  
Sliding Mode ◽  
The State ◽  
State Variables ◽  
Mode Control ◽  
Response Variance ◽  
Special Cases

An analysis of a target tracking mechanical system subject to random base excitations is presented in this paper. Sliding mode controls are proposed to minimize the random error of target tracking. Two special cases are studied. In the first case, it is assumed that all the system parameters are known and the state variables are measurable. A sliding mode control is then determined. This highly idealized example reveals the effect of sliding mode control parameters on the reduction of response variance and provides a benchmark for designing a robust controller that deals with systems with unknown parameters. The second case deals with a robust sliding mode control where some parameters of the system are assumed to fall in a known range of values. The proposed controls are proven stable in the mean square sense. The statistical aspects of the controlled system are studied by considering the first and second order moments of the state variables. The equations for these moments are derived and solved by using the method of Gaussian closure in order to investigate the variance reduction performance of the controls.

scholarly journals Control of desalination plants using sliding mode scheme with state observer

2021 ◽  
Author(s):  
Bui Duc Hong Phuc ◽  
Sam-Sang You ◽  
Hwan-Seong Kim ◽  
Sang-Do Lee
Keyword(s):  
Sliding Mode Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Water Productivity ◽  
State Observer ◽  
The State ◽  
State Variables ◽  
Mode Control ◽  
Product Water ◽  
Desalination Plants

Abstract This paper deals with real-time control with observer to manipulate desalination plants as well as to monitor system states for smart operations. The controller plays an important role in achieving stabilization of reverse osmosis (RO) systems to guarantee the desired water product and concentration. The super-twisting (STW) sliding mode control (SMC) algorithm guarantees performance while reducing chattering. Supposing that all the state variables are not available by sensors, the observer is implemented to provide state estimation. Since smart operations depend on control algorithm and sensor availability, the proposed strategy provides robustness to ensure the water productivity even under uncertainties or under failure of sensors. The robustness is guaranteed by active controller where 80% of disturbance is eliminated in product water flow and that of product water quality is approximately 95%. As well, the state observer can produce precise predictions of the unmeasured states. Sliding mode control with observer provides the system with stability, while assuring better performances against uncertainties. Finally, the active controller with state estimator can guarantee a robust control strategy and monitoring system to extend the life of the filters and membranes, while ensuring sustainability. This control strategy is highly recommended for smart operations of desalination plants.

A Target Tracking Approach for Nonholonomic Agents Based on Artificial Potentials and Sliding Mode Control

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Veysel Gazi ◽  
Barış Fidan ◽  
Raúl Ordóñez ◽  
M. İlter Köksal
Keyword(s):  
Sliding Mode Control ◽  
Target Tracking ◽  
Continuous Time ◽  
Sliding Mode ◽  
Control Techniques ◽  
Maneuvering Target ◽  
Mode Control ◽  
Time Control ◽  
Control Scheme ◽  
Simulation Results

In this paper, we consider the task of tracking a maneuvering target both with a single nonholonomic agent and a swarm of nonholonomic agents. In order to achieve the tracking task, a decentralized continuous-time control scheme, which combines artificial potentials and sliding mode control techniques, is developed via constructive analysis. The effectiveness of the proposed control scheme is established analytically and demonstrated via a set of simulation results.

General model and improved global sliding mode control of the four-rotor aircraft

2017 ◽  
Vol 232 (4) ◽  
pp. 383-389 ◽  
Author(s):  
Chunbo Xiu ◽  
Fengnan Liu ◽  
Guowei Xu
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Response Speed ◽  
Mode Control ◽  
Global Sliding Mode Control ◽  
Special Cases ◽  
Global Robustness ◽  
General Mathematical Model ◽  
Dynamic Sliding Mode

In order to improve the versatility of the control method of the four-rotor aircraft, a general mathematical model, the rectangular four-rotor aircraft, is modeled, and two special cases, square cross structure and square X structure, are deduced. Based on the conventional global sliding mode control, an improved global sliding mode control is proposed to control the position and the attitude of the four-rotor aircraft. The dynamic sliding mode surface of the improved global sliding mode control can evolve into the linear sliding mode surface in a limited time by changing the decay function of the dynamic sliding mode surface. In this way, the controlled system has not only the strong global robustness but also the quick response rate. Simulation results show that the position and the attitude of the four-rotor aircraft can be controlled by the improved global sliding mode control, and the control performances, for instance the response speed, can be improved.

scholarly journals Sliding mode control of biogas production by anaerobic digestion with addition of acetate

2019 ◽  
Vol 93 ◽  
pp. 03002
Author(s):  
Plamena Zlateva
Keyword(s):  
Anaerobic Digestion ◽  
Sliding Mode Control ◽  
Expert Knowledge ◽  
Sliding Mode ◽  
Biogas Production ◽  
External Disturbance ◽  
Control Input ◽  
State Variables ◽  
Mode Control ◽  
And Control

Biogas production by anaerobic digestion with addition of acetate is considered. Sliding mode control for regulation of the biogas flow rate using the addition of acetate as a control action is proposed. The control design is carried out with direct use of nonlinear model and expert knowledge. Chattering phenomena are avoided by realizing the sliding mode with respect to the control input derivative. The state variables, external disturbance, process output and control input are varied in the known intervals. The performance of the designed sliding mode control is investigated by varying the process set point and the uncertain process parameter, which reflecting the influence of the external disturbance. The excellent performance of presented control is proved through simulation investigations in MATLAB using Simulink.

Fault Tolerance of a Reconfigurable Tilt-Rotor Quadcopter Using Sliding Mode Control

2018 ◽  
Author(s):  
Siddharth Sridhar ◽  
Rumit Kumar ◽  
Kelly Cohen ◽  
Manish Kumar
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Control Technique ◽  
State Variables ◽  
Servo Motor ◽  
Tracking Errors ◽  
Tilt Rotor ◽  
Sliding Surfaces ◽  
Mode Control ◽  
Non Linear

Tilt-rotor quadcopters are a novel class of quadcopters with a servo motor attached on each arm that assist the quadcopter’s rotors to tilt to a desired angle thereby enabling thrust vectoring. Using these additional tilt angles, this type of a quadcopter can be used to achieve desired trajectories with faster maneuvering and can handle external disturbances better than a conventional quadcopter. In this paper, a non-linear controller has been designed using sliding mode technique for the pitch, roll, yaw motions and the servo motor tilt angles of the quadcopter. The dynamic model of the tilt-rotor quadcopter is presented, based on which sliding surfaces were designed to minimize the tracking errors. Using the control inputs derived from these sliding surfaces, the state variables converge to their desired values in finite-time. Further, the non-linear sliding surface coefficients are obtained by stability analysis. The robustness of this proposed sliding mode control technique is shown when a faulty motor scenario is introduced. The quadcopter transforms into a T-copter design upon motor failure thereby abetting the UAV to cope up with the instabilities experienced in yaw, pitch and roll axes and still completing the flight mission. The dynamics of the T-copter design and the derivation of the switching surface coefficients for this reconfigurable system are also presented.

scholarly journals Nonlinear Backstepping Control Design for Coupled Nonlinear Systems under External Disturbances

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Wonhee Kim ◽  
Chang Mook Kang ◽  
Young Seop Son ◽  
Chung Choo Chung
Keyword(s):  
Nonlinear Systems ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Backstepping Control ◽  
State Variables ◽  
External Disturbances ◽  
Mode Control ◽  
Disturbance Cancellation ◽  
The Stability ◽  
Nonlinear Backstepping Control

A nonlinear backstepping control is proposed for the coupled normal form of nonlinear systems. The proposed method is designed by combining the sliding-mode control and backstepping control with a disturbance observer (DOB). The key idea behind the proposed method is that the linear terms of state variables of the second subsystem are lumped into the virtual input in the first subsystem. A DOB is developed to estimate the external disturbances. Auxiliary state variables are used to avoid amplification of the measurement noise in the DOB. For output tracking and unmatched disturbance cancellation in the first subsystem, the desired virtual input is derived via the backstepping procedure. The actual input in the second subsystem is developed to guarantee the convergence of the virtual input to the desired virtual input by using a sliding-mode control. The stability of the closed-loop is verified by using the input-to-state stable (ISS) property. The performance of the proposed method is validated via numerical simulations and an application to a vehicle system based on CarSim platform.

scholarly journals Sliding Mode Control Based on Observer for a Class of State-Delayed Switched Systems with Uncertain Perturbation

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Zhaolan He ◽  
Xue Wang ◽  
Zongwei Gao ◽  
Jingjie Bai
Keyword(s):  
Sliding Mode Control ◽  
Switched Systems ◽  
Sliding Mode ◽  
Estimation Error ◽  
Matching Condition ◽  
State Observer ◽  
Sliding Surface ◽  
State Variables ◽  
Parameter Uncertainties ◽  
Mode Control

This paper is concerned with a state observer-based sliding mode control design methodology for a class of continuous-time state-delayed switched systems with unmeasurable states and nonlinear uncertainties. The advantages of the proposed scheme mainly lie in which it eliminates the need for state variables to be full accessible and parameter uncertainties to be satisfied with the matching condition. Firstly, a state observer is constructed, and a sliding surface is designed. By matrix transformation techniques, combined with Lyapunov function and sliding surface function, a sufficient condition is given to ensure asymptotic stability of the overall closed-loop systems composed of the observer dynamics and the estimation error dynamics. Then, reachability of sliding surface is investigated. At last, an illustrative numerical example is presented to prove feasibility of the proposed approaches.

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