×
The submission system is temporarily under maintenance. Please send your manuscripts to
Go to Editorial ManagerThe heat exchanger is a device used to transfer heat energy between two fluids, hot and cold. In this work, an output feedback adaptive sliding mode controller is designed to control the temperature of the outlet cold water for plate heat exchanger. The discontinuous gain value of the sliding mode controller is adapted according to a certain adaptation law, where the only information required is the measurement of the outlet cold temperature. A sliding mode differentiator was design to estimate time derivative of outlet hot water temperature. Two constraints which imposed on the volumetric flow rate of the hot water (control input) were considered within the rules of the proposed adaptation law in this work. These are the control input is positive only and has a maximum value. For constructing the sliding variable, the outlet hot water temperature and its time derivative are required. The maximum allowable desired outlet cold water has been estimated as function of heat exchanger parameters and maximum control input. The simulation results demonstrate the performance of the proposed adaptive sliding mode control where the outlet cold water was forced to follow desired temperature equal to . Additionally, the robustness of the proposed controller was tested for the case where the cold inlet temperature is not constant. The results reveal the robustness of the proposed controller.
In this paper, an Adaptive Sliding Mode Controller (ASMC) is designed and applied for a magnetic levitation system (Maglev) where a steel ball is desired to be stabilized at a desired position with existence of uncertainty in system model. Additionally, a sliding mode differentiator (SMD) is used for estimating the ball velocity since it’s needed for the controller to work properly. The designed controller and differentiator are applied practically to an experimental laboratory size magnetic levitation system and the results were plotted to show the behavior of the system under the effect of the designed controller. The experimental results reveal clearly the effectiveness and ability of the suggested controller in forcing the steel ball to follow various desired position.
In this paper, the robustness properties of sliding mode control (SMC) which is designed to produce a dynamic output feedback controller to achieve robustness for trajectory tracking of the nonlinear human swing leg system is presented. The human swing leg represents the support of human leg or the humanoid robot leg which is usually modeled as a double pendulum. The thigh and shank of a human leg will respect the pendulum links, hip and knee will connect the upper body to thigh and then shank respectively. The total moments required to move the muscles of thigh and shank are denoted by two external (servomotors) torques applied at the hip and knee joints. The mathematical model of the system is developed. The results show that the proposed controller can robustly stabilize the system and achieve a desirable time response specification.
In this paper, the H-infinity Sliding Mode Control (HSMC) is designed to produce a new dynamic output feedback controller for trajectory tracking of the nonlinear human swing leg system. The human swing leg system represents the support of human leg or the humanoid robot leg which is usually modeled as a double pendulum. The thigh and shank of a human leg is represented by two pendulum links and the hip joint will connect the upper body to the thigh and the knee joint will connect the thigh to the shank. The external torques (servo motors) are applied at the hip and knee joints to move the muscles of thigh and shank. The results show that the HSMC can robustly stabilize the system and achieve a desirable time response specification better than if only H-infinity or SMC is used. This controller achieves the following specifications: sec, for hip joint and sec, for knee joint.
In this work, the design procedure of a hybrid robust controller for crane system is presented. The proposed hybrid controller combines the linear quadratic regulator (LQR) properties with the sliding mode control (SMC) to obtain an optimal and robust LQR/SMC controller. The crane system which is represented by pendulum and cart is used to verify the effectiveness of the proposed controller. The crane system is considered one of the highly nonlinear and uncertain systems in addition to the under-actuating properties. The parameters of the proposed LQR/SMC are selected using Particle Swarm Optimization (PSO) method. The results show that the proposed LQR/SMC controller can achieve a better performance if only SMC controller is used. The robustness of the proposed controller is examined by considering a variation in system parameters with applying an external disturbance input. Finally, the superiority of the proposed LQR/SMC controller over the SMC controller is shown in this work.
In this work, the control of Translational Oscillations with a Rotational Actuator (TORA) system is presented in this paper. The optimal sliding mode controller is proposed to control the two DOF underactuated mechanical system. The nonlinear coupling from the rotational to the translational motion is the main problem that faces the controller design. The H2 sliding mode controller is designed to give a better performance if only sliding mode control is used. The results illustrate that the proposed H2 sliding mode controller can achieve the stabilization of the system with the variation in system parameters and disturbance.
DC servo motor is simple in construction and control and has many applications. However, the uncertainties due to its parameters changes such as load torque and friction are an evitable. Therefore, a robust controller has to be employed for keeping specified requirements irrespective to parameter variations. In the present work, two sliding mode controllers have been suggested to control the speed of DC motor under motor load changes; classical and integral sliding mode controllers. The integral slide mode control could show better tracking characteristics than its counterpart and also could compensate the change in system parameters.