Kensaku Hazawa

Model-based optimal attitude and positioning control of small-scale unmanned helicopter

In this paper, we propose a model-based control system design for autonomous flight and guidance control of a small-scale unmanned helicopter. Small-scale unmanned helicopters have been studied by way of fuzzy and neural network theory, but control that is not based on a model fails to yield good stabilization performance. For this reason, we design a mathematical model and a model-based controller for a small-scale unmanned helicopter system. In order to realize a fully autonomous small-scale unmanned helicopter, we have designed a MIMO attitude controller and a trajectory controller equipped with a Kalman filter-based LQI for a small-scale unmanned helicopter. The design of the trajectory controller takes into consideration the characteristics of attitude closed-loop dynamics. Simulations and experiments have shown that the proposed scheme for attitude control and position control is very useful.

H/sub /spl infin// hovering and guidance control for autonomous small-scale unmanned helicopter

This paper describes autonomous hovering control and horizontal guidance control with H/sub /spl infin// controller and performance verification with flight experimental results for the hobby-class small-scale unmanned helicopter. A simple black-box system identification method was applied, and single-input/single-output (SISO) non-cross coupling stable models were obtained. Cross-validation results showed close agreement in the respective output signals obtained by simulation and by experiment. Attitude control was designed as a minor feedback loop of proportional-integral (PI) blocks with a feed-forward compensator for improvement of reference-following performance. An H/sub /spl infin// horizontal velocity control system was constructed as an outer feedback loop of an attitude control. The H/sub /spl infin// controllers were designed in the frequency domain using four closed-loop control specifications and were repeatedly tuned according to the time domain specifications. Position control was constructed by a proportional-derivative (PD) controller serving as an outer feedback loop of H/sub /spl infin// horizontal velocity control. In the flight experiments, hovering performance within a 1-m diameter circle and 15-m square point-to-point horizontal guidance control were achieved. Good consistency between experimental data and simulation data demonstrates the high accuracy of the models and the adequacy of the modeling method.