Sliding Mode Control of Quadrotor UAV Using Parabolic Sliding Surface

This paper is about the sliding mode control of quadrotor UAV’s using nonlinear parabolic sliding surface. Quadrotor has six degrees of freedom and four actuators. It has the ability to vertically take off and land. It is necessary to have control over six degrees of freedom for proper drive. For many years sliding mode control of quadrotor has been used. There are some disadvantages of sliding mode control using linear surfaces, for example, it requires a large amount of control effort, and it may not work for global dynamics properties of a system because of the linear nature of the controller. These above-mentioned disadvantages are lessen using nonlinear parabolic sliding surfaces by adding the nonlinearity in the controller purposefully. Sliding mode control using nonlinear sliding surface guarantees the fast convergence as compared to the sliding mode control. This nonlinear parabolic surface is formed on a new coordinate system. Which uses the linear sliding surface of conventional sliding mode control as its one coordinate and the other coordinate is orthogonal to previous coordinate. Control of yaw angle, x-position, y-position and z-position is presented here and the results of sliding mode control using nonlinear parabolic sliding surfaces are compared with the results of conventional sliding mode control. Their results show that the sliding mode control using nonlinear parabolic sliding surfaces has some benefits over the sliding mode control, for example, new control method for the quadrotor has decreased the reaching time, robust to the disturbances and it has smooth phase plane.