{'fraction_non_alphanumeric': 0.017543859649122806, 'fraction_numerical': 0.0, 'mean_word_length': 5.101604278074866, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
On-line trajectory generation for autonomous unmanned vehicles in the presence of no-fly zones

In this article, an algorithm for three-dimensional path generation and tracking for unmanned air vehicles in the presence of no-fly zones is proposed. The algorithm is based on a local optimization procedure aimed to find the shortest path between the waypoints in compliance with all path constraints. Vehicle structural and envelope limitations are accounted for by simple geometric constraints such as minimum curvature radius and flight path angle limitations, while no-fly zones are defined as cylindrical objects with infinite altitude. The algorithm is simple and it has a limited computational burden, at most quadratic with the number of zones to avoid. This makes the algorithm very suitable for real-time applications even in case of a high number of forbidden zones. Algorithm effectiveness has been demonstrated by means of numerical simulations in scenarios including the presence of no-fly zones not known before flight (for instance, in the case of sudden changes of weather conditions and/or detection of new fixed obstacles).