Control System Design On The Transition Stage Of Quad Titlrotor Aircraft

QTR has the advantage of large carrying capacity and cruising speed without the takeoff runway. Compared to V-22, V-44 has a greater advantage in carrying capacity and cruising speed. However, since V-44 has four tilting rotors, the designing of control system is not the superposition of helicopters and fixed-wing aircraft, especially in transition process. In order to achieve a smooth transition, we study on the control system of transition process in this paper.First, we should make it clear that what is the flight principle of V-44. So we establish the dynamic models of helicopter mode and nacelle tilting mode separately. And then establish the small perturbation model of longitudinal movement. We also determine to use fixed height conversion programs in nacelle tilting stage. Then we formulate pitch attitude control and tension manipulation program, deduce the relationships between speed and nacelle angle and plot corridor curve.Second, by collecting the experiment data, we deduce the open loop transfer function of the implementing agencies and drive, design and calibrate the control law of pitch channel and speed loop in helicopter mode, so we achieve a smooth flight before the plane reached the initial conversion speed. Nacelle tilting mode is divided into two stage, one is when the nacelle angle is small, at this time we use the joint control of the elevator and the cycle variable torque. With the increase of nacelle angle, cyclic pitch control is disabled and it only individually controlled by the elevator. According to it, we design the pitch attitude control law in nacelle tilting mode. Because there are several parameters, which influence each other, we use Particle Swarm Optimization to set the parameters.Finally we design the hardware structure of the control system. We select ADuc7026 as the core chip of the controller. Besides, we choose the appropriate sensors, actuators and so on, design the circuits and build an aircraft mode. Then we design the program of the control law which we designed before and the interface to the controller. At last we debug this system, the results show that the control system we designed succeed in meeting the initial requirements.