Research Of Quadrotor Control

The Quadrotor concept has been around for a long time. The Breguet-Richet Quadrotor helicopter Gyroplane No.1 built in 1907 is reported to have lifted into flight. The great interest for Quadrotor has grown in the recent years. In this paper, we present the nonlinear Quadrotor helicopter model and based on its linear model, an H_∞loop shaping controller was designed for the robust stability and trajectory control.Firstly, Quadrotor is an omnidirectional VTOL (Vertical Take Off and Landing) vehicle ideally suited for stationary and quasi-stationary flight conditions, but on the other hand, it is an under-actuated dynamic rotorcraft with four input forces and six output coordinates. Unlike conventional helicopters that have variable pitch angle rotors, a Quadrotor has four fixed pitch angle rotors, and both sets of front-rear and left-right rotors turn in opposite directions and by varying rotor speeds, Quadrotor can change the lift forces, and therefore change its attitude and position. But Quadrotor using the variant rotor speeds to change the lift forces is dynamically unstable and therefore a control law is permanently required to ensure its stability. Therefore, a nonlinear modelling of the Quadrotor is presented in this paper, and so is its corresponding quasi-LPV model for H_∞loop shaping controller design to the Quadrotor.Next, H_∞loop shaping control problem of a Quadrotor helicopter is addressed in this paper. The H_∞loop shaping flight controller design procedure combines classic loop shaping and notion of bandwidth with model H_∞robust stabilization. This method which was first proposed by McFarlane and Glover has now been widely used. Based on its qusi-LPV model, an H_∞loop shaping controller is designed for vertical velocity, pitch angle, roll angle and yaw rate control.Next, to conduct corresponding experiment, a kind of PWM drive circuit based on the SG3524 and the IGBT voltage regulator is developed,and it's a kind of PWM driven circuit for Quadrotor. It has the characteristics of circuit simple, linear circuit good and voltage regulator strong.