2018 Moscow Workshop on Electronic and Networking Technologies (MWENT) 978-1-5386-3498-1/18/$31.00 © 2018 IEEE The problems of route and motion planning for an autonomous flight vehicle in uncertain environment* Khachumov M.V. Institute for Systems Analysis, Federal Research Center “Computer Science and Control” of RAS Moscow, Russia khmike@inbox.ru Khachumov V.M. Department of information technologies Peoples' Friendship University of Russia Moscow, Russia vmh48@mail.ru Abstract—Major route and motion planning problems for an autonomous flight vehicle (FV) in uncertain environment are considered. The first problem is planning a flight route between two given points with an obligatory mission of visiting all reference points from a given set. The route planning task is complicated by the presence of wind flows that affect the speed and trajectory of a flight vehicle. Time cost required to move between two points is suggested as a generalized optimization criterion. Quasi-optimal route planning algorithm is proposed that use the Hungarian method for the assignment problem as an auxiliary tool. The second problem is dynamic motion planning in the presence of obstacles in unknown environment. An algorithm for planning locally optimal routes for the purposeful low-altitude flight in the yaw plane is proposed. We assume that the map of the area is a priori not known and decisions are made only on the basis of information coming from the environment in real time. The last problem is controlling flight vehicle motion along the given route under wind loads. Simulating aircraft motion in an uncertain environment is performed with allowance for the constant and dynamic (random) components of wind flows. Simulation system is implemented in MATLAB Simulink program and contains mathematical models of a flight vehicle and wind loads, as well as a special intelligent control module for rapid response to changes in the external environment. Keywords—flight vehicle; route planning; Hungarian method; obstacles avoidance; trajectory tracking; wind disturbances; intelligent control; rule-based control system; simulation I. INTRODUCTION The choice of optimal flight path with regard for obstacles, wind loads and other impacts on the flight vehicle (FV) motion helps to reduce operating costs by selecting the most economical routes and increasing the safety of flights. There is an increase in the number of research papers related to route planning for robotic systems in the presence of obstacles using digital elevation and special maps. In [1, 2] the authors consider 3D path planning problems for an aircraft in the presence of uncertainty and propose original heuristic search algorithms on a spatial grid. In this paper, a novel formulation of the route planning problem is proposed that is of a great interest as its optimal solution is not represented in the scientific literature. A procedure is given for determining the quasi-optimal route between two points with visiting all reference points from a given set and with relatively low computational costs. The Hungarian method [3, 4] for solving the assignment problem with imposed restrictions is used as an auxiliary tool. Dynamic motion planning is considered as one of the major functions of intelligent control systems. Unmanned flight vehicles are currently widely used in search, science and research missions. In this view the problem of motion planning for purposeful low-altitude flight in urban, mountainous or forest terrain becomes urgent. The task is complicated by the presence of obstacles and often by the absence of detailed territory map [5, 6]. In [7] the authors consider intelligent motion control system based on rules, which is able to respond rapidly to changes in the real dynamic environment. In this paper, motion planning is carried out in the yaw plane at a certain altitude and is realized by heuristic algorithms. Decisions are made only on the basis of information coming from the environment in real time. Once the nearest route is obtained it is necessary to solve the problem of controlling flight vehicle motion in a perturbed environment. In papers [8, 9] the authors considered the problem of controlling UAV in the process of performing various flight missions that include passage through the specified control points in the required timestamps with constraints on the state variables and control. Mathematical statements of optimization control problems and existing exact and approximate methods of their solution are time-consuming and the development of effective but simple in realization onboard control algorithms is of a great interest. In the present paper the problem of controlling aircraft motion along the given route in a perturbed environment is solved in accordance with the strategies that simulate behavior of the pilot (human operator) [10-12]. Strategies are realized by sets of rules with control constraints and under acting wind loads. The proposed approach allows to achieve an acceptable control accuracy by simple means which can be implemented directly in onboard control systems of small autonomous aircrafts. *This research was supported by the Russian Science Foundation (Project No. 16-11-00048).