Kenzo Nonami

Autonomous flight control of hobby-class small unmanned helicopter: trajectory following control by using preview control considering heading direction

In this paper, we design a feed-forward trajectory following controller by using optimal preview control theory for a helicopter, based on a transition model and an LQI position controller derived from previous work. In order to apply optimal preview control theory to trajectory following control at any given yaw angle, we propose a correction method for eliminating the disturbances due to attitude perturbations on the magnetic direction sensor. We show that there is a problem with the axis transform of position and velocity, and as a result it cannot be applied to optimal preview control at any given yaw angle. To solve this problem, we propose an alternative axis transform method. Finally, the performance of the proposed preview controller and axis transform were verified by circular and s character trajectory following experiments.

Development of the Autonomous Battery Exchanging System for Industrial Multi Rotor Helocopters

This paper presents a hardware platform of an autonomous battery exchanging system for industrial UAVs (Unmanned Air Vehicle). It is designedxa0 for outdoor surveillance and UAV-UGV (Unmanned Ground Vehicle) cooperation missions. The system is composed of a UAV and a battery exchanging ground station. The battery exchanging station has an exchanging hand-arm, a battery magazine, an heliport, and the UAV has a battery receiver. The hand-arm enables rapid mechanical locking of the battery in the receiver by grasping and unlocking the battery simultaneously. The battery is stored in a special case that has clips to lock in the receiver, and the magazine can store and recharge it up to 8 batteries. The heloport is designed to handel orientation and positioning landing errors of the UAV of more than 20o and/or 20 cm. This would be useful as outdoor autonomous precise landings are difficult to achieve compared to indoor autonomous landings such as a previous research [1] which has utilized motion capturing system. The proposed system can alos help overcome the crucial limitation of flight time of industrial electric-powered UAV.