Optimal control for quadrotors during inspection of power utility assets

Abstract

Renewable energy and power utilities inspection by autonomous aircraft enables rapid and effective risk-free assessment of the state of systems, and provides a qualitative and accurate assessment of defects and damages. To realize maximum operational benefits of aerial inspections, effective controls for autonomous aircraft must be ensured and the system should be operated in an optimal policy. Hence, the objective of this paper is to consider optimal control strategies for a quadrotor helicopter type UAV. Based on some structural properties of the considered system, in particular the flatness property, we suggest a control strategy that ensures tracking a time parameterized path that connects two given points in the state space while minimizing the energy consumption. The proposed controller enables longer-endurance missions for the quadrotor and effective supervision and inspection of large energy systems and power plants. In this paper the analysis of the control law takes into consideration the highly nonlinear dynamic model of the quadrotor and the electrical actuator model. The current approach in solving the optimal control problem under consideration allows one to eliminate the differential equation and to reformulate the optimal control problem to a nonlinear dynamic programming problem. The approach can make monitoring operations of renewable energy plants by aerial vehicles, more efficient.