Discrete sliding mode control of piezo actuator in nano-scale range

In this paper Discrete Sliding Mode Control (SMC) of Piezo actuator is demonstrated in order to achieve a very high accuracy in Nano-scale with the desired dynamics. In spite of the fast dynamics of the Piezo actuator the problem of chattering is eliminated with the SMC control structure. The Piezo actuator suffers from hysteresis loop which is the inherent property and it gives rise to the dominant non-linearity in the system. The proposed SMC control structure has been proved to deliver chattering free motion along with the compensation of the non linearity present due to hysteresis in the system. To further enhance the accuracy of the closed loop system and to be invariant to changes in the plant parameters a robust disturbance observer is designed on SMC framework by taking into consideration the lumped nominal plant parameters. Experimental results for closed loop position are presented in order to verify the Nano-scale accuracy

Scaled bilateral teleoperation using discrete-time sliding mode controller

In this paper, the design of a discrete-time slidingmode controller based on Lyapunov theory is presented along with a robust disturbance observer and is applied to a piezostage for high-precision motion. A linear model of a piezostage was used with nominal parameters to compensate the disturbance acting on the system in order to achieve nanometer accuracy. The effectiveness of the controller and disturbance observer is validated in terms of closed-loop position performance for nanometer references. The control structure has been applied to a scaled bilateral structure for the custom-built telemicromanipulation setup. A piezoresistive atomic force microscope cantilever with a built-in Wheatstone bridge is utilized to achieve the nanonewtonlevel interaction forces between the piezoresistive probe tip and the environment. Experimental results are provided for the nanonewton-range force sensing, and good agreement between the experimental data and the theoretical estimates has been demonstrated. Force/position tracking and transparency between the master and the slave has been clearly demonstrated after necessary scalin

Input-output linearization of DC-DC converter with discrete sliding mode fuzzy control strategy

The major thrust of the paper is on designing a fuzzy logic approach has been combined with a well-known robust technique discrete sliding mode control (DSMC) to develop a new strategy for discrete sliding mode fuzzy control (DSMFC) in direct current (DC-DC) converter. Proposed scheme requires human expertise in the design of the rule base and is inherently stable. It also overcomes the limitation of DSMC, which requires bounds of uncertainty to be known for development of a DSMC control law. The scheme is also applicable to higher order systems unlike model following fuzzy control, where formation of rule base becomes difficult with rise in number of error and error derivative inputs. In this paper the linearization of input-output performance is carried out by the DSMFC algorithm for boost converter. The DSMFC strategy minimizes the chattering problem faced by the DSMC. The simulated performance of a discrete sliding mode fuzzy controller is studied and the results are investigated

Discrete-time sliding mode control of input-delay systems applied on a power generation system

This paper presents two discrete sliding mode control (SMC) design. The first one is a discrete-time SMC design that doesn't take into account the time-delay. The second one is a discrete-time SMC design, which takes in consideration the time-delay. The proposed techniques aim at the accomplishment simplicity and robustness for an uncertainty class. Simulations results are shown and the effectiveness of the used techniques is analyzed. © 2006 IEEE

Discrete-time sliding mode control using an H∞ filter for a quadruple tank system

The quadruple tank system is a challenging multi-variable model consisting of four interconnected tanks, two level sensors and two input pumps. This paper deals with the control and estimation of such a system. All the four levels of the system are controlled by H∞ filter based discrete sliding mode control (SMC). A nonlinear stable sliding surface is constructed using full state information, to enhance the overall performance of the closed loop plant. In this multi-input multi-output quadruple tank system, only the first two states are available for feedback and hence it is not suitable to use any full state feedback control methods directly. To circumvent this problem, the remaining two states, which are required for the SMC design are estimated using a robust H∞ filter. The efficacy of the proposed method is demonstrated by simulations

Discrete sliding mode control of piezo actuator in nano-scale range

In this paper Discrete Sliding Mode Control (SMC) of Piezo actuator is demonstrated in order to achieve a very high accuracy in Nano-scale with the desired dynamics. In spite of the fast dynamics of the Piezo actuator the problem of chattering is eliminated with the SMC control structure. The Piezo actuator suffers from hysteresis loop which is the inherent property and it gives rise to the dominant non-linearity in the system. The proposed SMC control structure has been proved to deliver chattering free motion along with the compensation of the non linearity present due to hysteresis in the system. To further enhance the accuracy of the closed loop system and to be invariant to changes in the plant parameters a robust disturbance observer is designed on SMC framework by taking into consideration the lumped nominal plant parameters. Experimental results for closed loop position are presented in order to verify the Nano-scale accuracy

Data-Driven Model-Free Adaptive Sliding Mode Control Based on FFDL for Electric Multiple Units

The electric multiple units (EMUs) have become a very convenient and powerful means of transportation in our daily life. Safe and punctual trajectory tracking control is the key to improve the performance of the EMUs system, but it is difficult to realize due to the influence of environmental uncertainty, coupling and nonlinearity. In this paper, a model-free adaptive sliding mode control (MFASMC) method is proposed for the EMUs. This method can solve the dependence of the model-based control method on the train model and eliminate the influence of external disturbances on the robust performance of the system. In this method, the running process of the EMUs is equivalent to a full format dynamic linearization (FFDL) data model, and a model-free adaptive controller (MFAC) is designed based on the data model. Then, to reduce the influence of measurement disturbance and improve the robustness of the system, a discrete sliding mode control (SMC) algorithm is introduced. Furthermore, to prevent the control input from being too large, the parameter estimation error is introduced as an additional correction term of the algorithm. In the end, the simulation experiment is carried out with CRH380A EMUs as the object. Compared with the traditional MFAC and the traditional SMC, the speed tracking effect of each power unit of the MFASMC algorithm is more effective, the change of control force is stable, the acceleration meets the requirements of driving, and has a strong inhibitory effect on external disturbances