Showing 4 results for Sliding Mode Control
P. Bayat, H. Mojallali, A. Baghramian, P. Bayat,
Volume 6, Issue 2 (6-2016)
Abstract
In this paper, a two-surfaces sliding mode controller (TSSMC) is proposed for the voltage tracking control of a two input DC-DC converter in application of electric vehicles (EVs). The imperialist competitive algorithm (ICA) is used for tuning TSSMC parameters. The proposed controller significantly improves the transient response and disturbance rejection of the two input converters while preserving the closed-loop stability. The combination of the proposed controller and ICA, realizes a fast transient response over a wide transient load changes and input voltage disturbances. For modeling the equations governing the system, state-space average modeling technique is used. In order to analyzing the results, the two input converter equipped with the proposed controller, was modeled in MATLAB/SIMULINK environment. Simulation results are reported to validate the theoretical predictions and to confirm the superior performance of the proposed nonlinear controller when it is compared with a conventional pure SMC.
Hamed Davardoust, Dr. Golamreza Molaeimanesh, Sepehr Mousavi,
Volume 10, Issue 1 (3-2020)
Abstract
Due to the increasing level of air pollution and the reduction of fossil fuels, the need for new technologies and alternative fuels is felt more than ever. Proton exchange membrane fuel cells (PEMFCs) are one of these technologies, which have been of great interest to the researchers due to the benefits of non-contamination, high efficiency, fast start-up, and high power density. The proper functioning of the fuel cell requires thermal management and water management within the cells. To this end, in this work, the effect of different parameters on the performance of PEM fuel cell was investigated. The results demonstrated that the performance of the cell increases with increasing the pressure in the low current densities, while in the high current density, performance decreases with increasing the pressure of the cell. Also, the study of the effect of relative humidity shows that increasing the relative humidity of the cathode does not have much effect on the performance of the cell while increasing the relative humidity of the anode improves the performance of the cell.
Mr. Hamid Rahmanei, Dr. Abbas Aliabadi, Prof. Ali Ghaffari, Prof. Shahram Azadi,
Volume 13, Issue 2 (6-2023)
Abstract
The coordinated control of autonomous electric vehicles with in-wheel motors is classified as over-actuated control problems requiring a precise control allocation strategy. This paper addresses the trajectory tracking problem of autonomous electric vehicles equipped with four independent in-wheel motors and active front steering. Unlike other available methods presenting optimization formulation to handle the redundancy, in this paper, the constraints have been applied directly using the kinematic relations of each wheel. Four separate sliding mode controllers are designed in such a way that they ensure the convergence of tracking errors, in addition to incorporating the parametric and modeling uncertainties. The lateral controller is also designed to determine the front steering angles to eliminate lateral tracking errors. To appraise the performance of the proposed control strategy, a co-simulation is carried out in MATLAB/Simulink and Carsim software. The results show that the proposed control strategy has enabled the vehicle to follow the reference path and has converged the errors of longitudinal and lateral positions, velocity, heading angle, and yaw rate. Furthermore, the proposed control system shows promising results in the presence of uncertainties including the mass and moment of inertia, friction coefficient, and the wind disturbances.
Dr. Abbas Soltani, Mr. Milad Arianfard,
Volume 13, Issue 2 (6-2023)
Abstract
In this study, an adaptive sliding mode controller (ASMC) based on estimation of tire-road friction coefficient is proposed for engagement control of automotive dry clutch. The control of clutch engagement is one of the most important parts of gear-shift process for automated manual transmission. Accurate amount of drive shaft torque in modelling of powertrain system is essential to guarantee smooth engagement of the clutch and rapid response of the control system. As the tire-road friction coefficient has significant influence on drive shaft torque, an estimator is designed to calculate this parameter. The ASMC is proposed for the clutch control to overcome the system uncertainties and a proportional integral (PI) controller is adopted to engine speed control. In addition, a nonlinear estimator utilizing unscented Kalman filter is applied to estimate the state variables that are measured hardly such as wheel slip and longitudinal vehicle velocity. The simulation results demonstrate the high effectiveness of the combined use of presented controller and road friction coefficient estimator for improving the smooth clutch engagement in comparison to the control system without estimator.
