23 research outputs found
Fundamental Analysis Of Three-Dimensional `near Fling'
A series of experiments on three-dimensional ‘near fling ’ was carried out. Two pairs of plates, rectangular and triangular, were selected, and the distance between the rotation axes of the two plates of each pair was varied. The motion of the plates as well as the forces and the moment were measured, and the interference between the two plates of a pair was studied. In addition, a method of numerical calculation was developed to aid in the understanding of the experimental results. The interference between the two plates of a pair, which acted to increase both the added mass of each plate and the hydrodynamic force due to dynamic pressure, was noted only when the opening angle between the plates was small. The hydrodynamic forces were strongly influenced by separated vortices that occurred during the rotation. A method of numerical calculation, which took into account the effect both of interference between the plates and of separated vortices, was developed to give adequate accuracy in analyzing beating wings in ‘near fling’
Flight Controller Design and Autonomous Flight Tests of 60cm-sized UAV
This paper describes the design of flight controller for a fixed-wing small-sized UAV and the autonomous flight tests. The UAV which has been developed by the authors has 0.6m span and its weight is 0.27kg. It cruises at 6-12m/s. The flight controller is composed of attitude stability augment systems, feedforward filters, and guidance systems. The flight controller is designed for longitudinal and lateral-directional motions, separately. The UAV has advantages in safety and portability due to its light weight and low cruising speed. In order to ensure robust stability, the attitude stability augment systems are designed for these motions with µ-synthesis. The feedforward filters are designed in order to shape the command from guidance system to the inner closed-loop appropriately. The longitudinal guidance system, which is designed with PID-control manner, keeps the UAV at a desired altitude. The lateral-directional guidance system guides the UAV to the pre-defined waypoints with avoiding known obstacles. It is designed using the Artificial Potential Field Method. These flight controllers are implemented on the small on-board computer we have also developed. Autonomous flight experiments show that the developed UAV is able to fly autonomously, passing over pre-defined waypoints, and that the UAV has the ability of avoiding the known obstacle