In this report, the process of aircraft dynamic simulation in MATLAB/Simulink by using the AeroSim blocks has been investigated. For this purpose, at first, an aircraft has been chosen as a target and its dynamic behaviors are analyzed. Basically, in this research an unmanned flying device is the case of study. These behaviors are analyzed in different states and modes. In this stage, the open loop simulation ends. Open loop simulation consists of the aerodynamic modeling of the flying device and the modeling for solving the nonlinear equations with six degrees of freedom. The main part of the work depends on this stage. In the following, the close loop process begins. In this stage, the target is the designing of a controller for the flying device. This project has focused on PID controller design. Extraction of PID coefficients has been done manually. Finally, the conduction code has been written in DTW form and has been added to the simulation.
Capabilities and Results:
1- solution and structure of AeroSim
2-AeroSim block set
3- The block which is shown in figure , computes the wind-axes velocity based on instantaneous ground and aircraft speeds, instantaneous sound velocity, airspeed bound parameters, sideslip angle range and the angle-of-attack. Instantaneous Mach, angle of attack variations and sideslip angle according to time, are other outputs of this block. It should be noted that, this block is as the input for other blocks, which will be described.
4- The block which is shown in the following figure, computes the airplane lift coefficient (CL) as a linear combination of individual contributions of various flight parameters.
5- The block computes the aircraft Drag coefficient
6-The block computes the airplane side force coefficient as a linear combination for various flight parameters
7-The block computes the airplane pitch moment coefficient as a linear combination
8-The block computes the airplane non-dimensional roll moment coefficient (Cl) as a linear combination
What is the achievements of this project:
Based on the explanation presented so far, an openloop unmanned aircraft with electrical engine can be simulated. Of course, simulation and codes is usable for all aircrafts if the piston propulsion system would be added. It can be done according to the information which was presented in the propulsion section. So far, the openloop simulation has been carried out and we can connect joystick to computer and observe the flight behavior in the FlightGear software. The image of flight behavior in the FlightGear software is shown in the following figure.