Nowadays, aerial robots or Unmanned Aerial Vehicles (UAV) have many applications in civilian and military fields. For example, of these applications is aerial monitoring, picking loads and moving them by different grippers. In this research, a quadrotor with a cable-suspended load with eight degrees of freedom is considered. The purpose is to control the position and attitude of the quadrotor on a desired trajectory in order to move the considered load with constant length of cable. So, the purpose of this research is proposing and designing an antiswing control algorithm for the suspended load. To this end, control and stabilization of the quadrotor are necessary for designing the antiswing controller. Furthermore, this paper is divided into two parts. In the first part, dynamics model is developed using Newton-Euler formulation, and obtained equations are verified in comparison with Lagrange approach. Consequently, a nonlinear control strategy based on dynamic model is used in order to control the position and attitude of the quadrotor. The performance of this proposed controller is evaluated by nonlinear simulations and, finally, the results demonstrate the effectiveness of the control strategy for the quadrotor with suspended load in various maneuvers.
The demand for water and energy in today’s developing world is enormous and has become the key to the progress of societies. Many methods have been developed to desalinate water, but energy and environmental constraints have slowed or stopped the growth of many. Capacitive Deionization (CDI) is a very new method that uses porous carbon electrodes with significant potential for low energy desalination. This process is known as deionization by applying a very low voltage of 1.2 volts and removing charged ions and molecules. Using capacitive principles in this method, the absorption phenomenon is facilitated, which is known as capacitive deionization. In the capacitive deionization method, unlike other methods in which water is separated from salt, in this technology, salt, which is a smaller part of this compound, is separated from water and salt solution, which in turn causes less energy consumption. With the advancement of science and the introduction of new porous materials, the use of this method of deionization has increased greatly. Due to the limitations of other methods of desalination, this method has been very popular among researchers and the water desalination industry and needs more scientific research to become more commercial.
The concept of two-wheeled mobile manipulator (TWMM) has been proposed for its significant advantage due to high maneuverability particularly in confined internal spaces. However, its unbalanced structure imposes restrictions for widespread application. Note that the nonholonomic property of a TWMM makes its control a more challenging task. In this paper, a new stabilization mechanism of TWMM is presented, and a new control method based on dynamical balancing algorithm is proposed that could effectively resolve those restrictions. To this end, a reaction wheel is considered to control the position of center of gravity (COG), leading to a smoother motion of the robot manipulator. To make the robot be able to manipulate an object, a double inverted pendulum model (DIPM) is considered as a simplified model of the system. DIPM dynamics is used to identify and simplify the dynamics of TWMM and subsequently a supervisory control is employed to stabilize the robot via its COG position. This in turn improves the robustness of the proposed algorithm during manipulation maneuver of an object with unknown mass parameters. Results are compared to those of an ideal model-based algorithm that reveal the merits of the proposed control strategy.