With the complex aerodynamics, the accurate system model of the flapping-wing micro aerial vehicle required for precise control is hard to acquire, meanwhile, due to the unique control strategy, the coupling between the actuators also brings a great challenge to the control of the vehicle. In this paper, we establish a theoretical model of the vehicle. Based on this model, we propose a multiaxial adaptive controller with the reference generator for the attitude and altitude control using the backstepping design method, the stability of this controller is proved by the Lyapunov function. Moreover, a control allocation algorithm is proposed to coordinate the different actuators such that they together produce the desired virtual control efforts. In addition, we detail the lightweight design of the flapping-wing micro aerial vehicle with altitude and attitude sensing onboard. Then, the effectiveness of the proposed control scheme is verified by the simulation and the flight test with multi-axis simultaneous control conducted on this lightweight vehicle. The experimental results show that the controller can maintain hovering flight and ensure the convergence of the adaptive parameters even when the unilateral thrust of the vehicle is not enough due to manufacturing and assembly errors. This work provides an idea for us to explore how insects maintain stable flight in the face of changes in their model parameters.
Keywords: micro aerial vehicle; flapping wing; adaptive control; decoupling control