Sliding Model Variable Structure Control Research Articles

Lateral roll control of vehicle based on UKF and sliding model control

A 3-DOF dynamical model of vehicle is built in this paper by using MATLAB/Simulink. Considering nonlinear tyre performance, the magic formula tyre model is used to improve the accuracy of the model. For the difficulty of measuring the roll angle and roll rate, an observer for the roll angle and roll rate based on the dynamical model of vehicle and kinematic relations is designed in this paper, tracking the roll angle and roll rate in the process of driving based on the easily measured status parameters, using unscented Kalman filter. Then, this method is tested through experiments. Finally, based on the estimated roll angle and roll rate, a roll stability controller based on the sliding model variable structure control theory is designed.

Compound Control of Sliding-Model Variable Structure and Fractional Order PID for Automatic Clutch of Vehicle AMT

A compound control method of sliding-model variable structure and fractional order PI λ D μ (SMC-FOPID) is proposed based on such factors as strong nonlinearity, time-varying parameters, disturbance, time delay, as well as the rapidity of a working clutch system in the process of automated manual transmission (AMT) clutch control. The self-tuning of the composite weight coefficient is realized by the fuzzy inference algorithm with single input and output. The coordinated control of the SMC-FOPID is realized through the real-time adjustment of the composite weight coefficient. The control performances of proportionalintegral-derivative (PID), fractional order PI λ D μ (FOPID), sliding-model variable structure control (SMC), and SMC-FOPID were compared based on the performance index integral of time multiplied by absolute value of error (ITAE) to study the position tracking of an AMT clutch in the working process. The simulation result showed that the SMC-FOPID control method had higher synthetic control performance compared with the PID, FOPID, and SMC control methods. The feasibility and superiority of the position tracking of an AMT clutch with an SMC-FOPID controller were verified.

Rotor Current Control of DFIG for Improving Fault Ride – Through Using a Novel Sliding Mode Control Approach

AbstractThe doubly fed induction generators (DFIG) have been recognized as the dominant technology used in wind power generation systems with the rapid development of wind power. However, continuous operation of DFIG may cause a serious wind turbine generators tripping accident, due to destructive over-current in the rotor winding which is caused by the power system fault or inefficient fault ride-through (FRT) strategy. A new rotor current control scheme in the rotor-side converter (RSC) ispresented to enhance FRT capacities of grid-connected DFIG. Due to the strongly nonlinear nature of DFIG and insensitive to DFIG parameter’s variations, a novel sliding mode controller was designed. The controller combines extended state observer (ESO) with sliding model variable structure control theory. The simulation is carried out to verify the effectiveness of the proposed control approach under various types of grid disturbances. It is shown that the proposed controller provides enhanced transient features than the classic proportional-integral control. The proposed control method can effectively reduce over-current in the RSC, and the transient pulse value of electromagnetic torque is too large under power grid fault.

Model Identification of Hydrostatic Center Frame Control System based on MATLAB

The composition and principle of an electro-hydraulic servo oil film stiffness control system of hydrostatic center frame will be introduced, and the system model identification as well as the verification will be carried out based on semi-physical simulation environment of Real-time Workshop (RTW) and system identification toolbox in MATLAB. A control strategy of fuzzy sliding model variable structure will be presented , and it is applied in the model achieved by identifications, adopting the method of fuzzy control system approximating equivalent control and designing switching controller based on fuzzy control gain dynamic regulation, could inhabit the buffeting existing in sliding model variable structure control. Simulation results show that performance of an electro-hydraulic servo oil film stiffness control system is improved significantly for hydrostatic center frame based on fuzzy sliding model variable structure controller, which can’t only effectively inhabit buffeting, reduce steady-state error, but also has strong robustness for uncertainties of structure parameter.

Research on Control Strategy of Oil Film Stiffness Control System of Hydrostatic Center Frame

Design a new type of electro-hydraulic servo control system of oil film in hydrostatic center frame, regulate and control oil film thickness adopting various controllable oil chambers, build mathematical models of control system and carry on system model identification and verification. Propose a control strategy about fuzzy sliding model variable structure, and it is applied in the model achieved by identification, adopt the method of fuzzy control system approximating equivalent control and design switching controller based on fuzzy control gain dynamic regulation, which could inhabit buffeting existing in sliding model variable structure control. Simulation results show that the controller can’t only effectively inhabit buffeting and reduce steady-state error, but also has strong robustness for structure parameter uncertainty.

Sliding Mode Variable Structure for Generator Excitation Control Based on the ESO

In this paper, a new ESO sliding mode controller that can improve the system stability was designed ,as to the strong nonlinear of generator excitation system and the characteristics of vulnerable to external disturbance, which application of feedback linearization, ESO and sliding model variable structure control theory. Firstly, it realized to linearization for nonlinear mould based on the feedback linearization theory, then it provide dynamic compensation for generator excitation system through constructing extended state observation device (ESO). The methods of factorial is used to design sliding mode switch function, theoretically, it guarantee generator rotor equation with expectations of poles. In order to reduce chattering ,through index near rate and quasi sliding mode control dynamic method to get the sliding control rate, it make the form conciseness, The results of simulation show that the speed , accuracy and stability of system are significantly improved by controller in dynamic and static . Introduction

High Precision Control for Hydraulic Servo Systems with Large Frictional Torques and Experimental Research

A novel control scheme for hydraulic servo systems with large frictional torques is proposed based on a sliding-mode variable structure controller combined with a frictional state observer. The sliding-model variable structure control law and the sliding-model frictional state observer are detailed. The LuGre dynamic friction model is adopted to estimate the frictional torques and reduce the effects caused by the nonlinear frictions. Experimental research on hollow hydraulic motor systems is carried out to validate the proposed control scheme. The experimental results show that the application of the proposed control scheme is successful and the good position-tracking performance with high precision is attained in the presence of dynamic frictions even with large frictional torques and very low velocities.