Javad Masrour, Seyed Hossein Sadati and Morteza Shahravi
This study aims to simulate gust effects on the aeroelastic behavior of a flexible aircraft. The dynamic response of the system for different discreet gust excitations is obtained…
Abstract
Purpose
This study aims to simulate gust effects on the aeroelastic behavior of a flexible aircraft. The dynamic response of the system for different discreet gust excitations is obtained using numerical simulations.
Design/methodology/approach
Coupled dynamics, including rigid and flexible body coordinates, are considered for modeling the dynamic behavior of the aircraft. Wing is considered flexible and other parts are considered rigid. Wing is modeled with nonlinear Euler Bernoulli beam. Moreover, unsteady aerodynamics based on the Wagner function are used for aerodynamic loading, and the results are compared with those of quasi-steady aerodynamics.
Findings
Von Kármán continuous gust is applied to this aircraft. In addition, the discrete “1- cosine” gust with different gust lengths is applied to the aircraft, and the maximum and minimum accelerations are computed. It is shown that the nonlinear modeling of the system represents the actual behavior and causes limit cycle oscillation phenomena.
Originality/value
This methodology can yield a relatively simple dynamic model for high aspect ratio aircrafts to provide insights into the vehicles’ dynamics, which can be available early in the design cycle.
Details
Keywords
Mohammad Hadi Amoozgar, Khalil Alipour and Seyed Hossein Sadati
This paper seeks to present a novel approach for formation control of non‐holonomic wheeled mobile robots (WMRs). The use of a general geometrical structure has led the considered…
Abstract
Purpose
This paper seeks to present a novel approach for formation control of non‐holonomic wheeled mobile robots (WMRs). The use of a general geometrical structure has led the considered robotic team form any desired configuration. Although various methodologies have been suggested for solving such formation control problem in the literature, the proposed kinematical method of the present investigation has several advantages in terms of its robustness, tracking performance, and superior energy consumption due to the fuzzy logic scheme developed.
Design/methodology/approach
In an attempt to make the follower robot to assume the proper orientation, a new concept is presented which defines an appropriate heading angle. This concept is based on the natural human behavior as corresponds to situations of tracking a certain trajectory. The proposed heading angle planner is based on a two‐stage fuzzy logic system, providing appropriate heading angles for the mobile robot at each instant. In order to adjust the linear/angular velocity of the robots then, two further fuzzy controllers are devised.
Findings
The results obtained from the computer simulation studies reveal the merits as well as effectiveness of the proposed method for formation control of a group of WMRs in the presence of usual control input constraints, noisy sensor data, and external disturbances.
Originality/value
A novel method based on a fuzzy leader‐follower method is presented for the formation control of a group of robots.