Abstract:
The multicopter flying robot has been a hot topic due to its excelency in stability, and is attracting ever-increasing attention. In some particular applications, such as: delivering a multicopter from a large aircraft, and recovery from transient instability, there is the necessity for the multicopter to switch from a highly instable and non-zero initial status to a safe and stable flight status immediately, and this is so-called large scale stability control problem. The main difficulty in this control scenario is to avoid the actuator saturation in the adjustment process, which casuses the periodic spin and out of control of the quadrotor. To cope with this problem, taking quadrotor flying robot as research object, the control constraint is first analyzed. A simplified model is obtained from a 6-DOF model, and a two dimension nonlinear dynamic model is extracted with considering the control input constraint. Based on the Lyapunov function, an improved generalized point-wise min-norm control strategy is designed, and the large scale stability of quadrotor with input constraint is achieved. The introduced method possesses analyze control structure, and successes in stabilize the quadrotor with actuator constraint. The simulation results in constrast with the regular linear control strategy show that the designed controller with the control constraint manages to stabilize the quadrotor in large scale.