scholarly journals A Sliding Mode Control Strategy for Uncertain Systems with Time Delay

2007 ◽  
Author(s):  
Shaocheng. Qu
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Control Strategy ◽  
Uncertain Systems ◽  
Sliding Mode ◽  
Mode Control

scholarly journals Sliding Mode Control with Dynamical Correction for Time-Delay Piezoelectric Actuator Systems

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 132 ◽  
Author(s):  
Javier Velasco ◽  
Oscar Barambones ◽  
Isidro Calvo ◽  
Joseba Zubia ◽  
Idurre Saez de Ocariz ◽  
...  
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Mode Control ◽  
Control Response ◽  
Dynamical Correction

In piezoelectric actuators (PEAs), which suffer from inherent nonlinearities, sliding mode control (SMC) has proven to be a successful control strategy. Nonetheless, in micropositioning systems with time delay, integral proportional control (PI), and SMC, feedback control schemes have a tendency to overcompensate and, consequently, high controller gains must be rejected. This may produce a slow and inaccurate response. This paper presents a novel control strategy that deals with time-delay micropositioning systems aimed at achieving precise positioning by combining an open-loop control with a modified SMC scheme. The proposed SMC with dynamical correction (SMC-WDC) uses the dynamical system model to adapt the SMC inputs and avoid undesirable control response caused by delays. In order to develop the SMC-WDC scheme, an exhaustive analysis on the micropositioning system was first performed. Then, a mixed control strategy, combining inverse open-loop control and SMC-WDC, was developed. The performance of the presented control scheme was analyzed and compared experimentally with other control strategies (i.e., PI and SMC with saturation and hyperbolic functions) using different reference signals. It was found that the SMC-WDC strategy presents the best performance, that is, the fastest response and highest accuracy, especially against sudden changes of reference setpoints (frequencies >10 Hz). Additionally, if the setpoint reference frequencies are higher than 10 Hz, high integral gains are counterproductive (since the control response increases the delay), although if frequencies are below 1 Hz the integral control delay does not affect the system’s accuracy. The SMC-WDC proved to be an effective strategy for micropositioning systems, dealing with time delay and other uncertainties to achieve the setpoint command fast and precisely without chattering.

scholarly journals Discrete-Time Sliding Mode Control for Uncertain Networked System Subject to Time Delay

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Saulo C. Garcia ◽  
Marcelo C. M. Teixeira ◽  
José Paulo F. Garcia ◽  
Uiliam N. L. T. Alves ◽  
Jean M. S. Ribeiro
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Discrete Time ◽  
Uncertain Systems ◽  
Sliding Mode ◽  
Delay System ◽  
Control Law ◽  
Time Delay System ◽  
Mode Control ◽  
Uncertain Time

We deal with uncertain systems with networked sliding mode control, subject to time delay. To minimize the degenerative effects of the time delay, a simpler format of state predictor is proposed in the control law. Some ultimate bounded stability analyses and stabilization conditions are provided for the uncertain time delay system with proposed discrete-time sliding mode control strategy. A numerical example is presented to corroborate the analyses.

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