Atsushi Fujimori

Leader-follower formation control with obstacle avoidance using sonar-equipped mobile robots

This article presents a leader–follower formation control of sonar-equipped mobile robots in obstacle scattered environments. The follower robots need to distinguish the leader robot from obstacles by using multiple sonars. In this article, multiple sonars equipped on the follower robots are adaptively assigned to either tracking the leader robot or detecting obstacles. Furthermore, the position of the leader robot is estimated by the follower robots to improve the accuracy of the relative distance and angle. The effectiveness of the proposed techniques is examined in experiments using real mobile robots Pioneer 1 and Pioneer 2.

Autonomous flight control system for longitudinal motion of a helicopter

This paper presents a flight control design for longitudinal motion of helicopter to establish autopilot techniques of helicopter-type unmanned aerial vehicles (UAVs). The characteristics of the linearized equation of the helicopter is changed during a specified flight mission because the trim values of the nonlinear equation are also varied. In this paper, the longitudinal motion of the helicopter is modeled by a linear interpolative polytopic model whose varying parameter is the flight velocity. A flight control systems with a gain scheduling state feedback law is designed to stabilize the vehicle and track a reference which realizes the flight mission. The effectiveness of the proposed flight control system is evaluated by computer simulation.