A simulation of UAV path following stratagy under time varying wind.
An adaptive control scheme for Unmanned Aerial Vehicles (UAVs) path following under slowly time-varying wind is developed. The proposed control strategy integrates the path following law based on the vector field method with an adaptive term counteracting the effect of wind’s unknown component. The control strategy is developed and numerically simulated for straight line and orbit following scenarios. In particular, it is shown that the path following error is bounded under slowly time-varying unknown wind and converges to zero for unknown constant wind. Numerical simulations illustrate that, in environments with unknown and slowly time-varying wind conditions, the proposed method compensates for the lack of knowledge of the wind vector, and attains a smaller path following error than state-of-theart vector field method.
For details of method, please read the paper:
Bingyu Zhou, H. Satyavada and S. Baldi, "Adaptive path following for Unmanned Aerial Vehicles in time-varying unknown wind environments," 2017 American Control Conference (ACC), Seattle, WA, 2017, pp. 1127-1132. doi: 10.23919/ACC.2017.7963104
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7963104&isnumber=7962914
Two methods are implemented in the Matlab/Simulink platform.
#1. Standard vector field method:
The main file is BeardMethod.m. This file also calls the OrbitFollowing.slx and StraightLine.slx. For people who wants to know more about the method, plese read the paper:
D. R. Nelson, D. B. Barber, T. W. McLain, and R. W. Beard, “Vector field path following for miniature air vehicles,” IEEE Transactions on Robotics, vol. 23, no. 3, pp. 519–529, June 2007.
#2. Adaptive VF:
This is main contribution of our team. The main file is RevisedMethod.m, which calls the RevisedOrbitFollowing.slx and RevisedStraightLine.slx.
Another variant is named RevisedOrbitFollowing2.slx and RevisedStraightLine2.slx.
You can use this variant if you change the simulink file to RevisedOrbitFollowing2.slx and RevisedStraightLine2.slx in RevisedMethod.m.
The only difference between these two variants are the implementations of the wind disturbance.