{'fraction_non_alphanumeric': 0.026743075453677174, 'fraction_numerical': 0.0066857688634192934, 'mean_word_length': 5.1647058823529415, '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}}
FH-FSK Remote Control Acoustic Release System with Mechanical Push-Off Mechanism

Acoustic Release is an acoustic remote control and mechanical release system. To meet the requirements of robust remote control and robust release in shallow water. In this paper, frequency-hopping frequency-shift keying (FH-FSK) communication scheme and mechanical push-off mechanism are proposed. Frequency hopping sequences are applied to mitigate the multipath interference to realize more robust and security acoustic communication. The release mechanism is designed with a push-off structure in which the non-metal nut is driven off by the rotation of the motor. The acoustic released system is developed with function of release, lock, battery & tilt monitoring and range measurement. The working depth is 500m, communication distance is 2km, and payload is 500kg. The performance has been tested and verified in HEU acoustic channel pool, Songhua River, and Qiandao Lake. In addition, it has been successfully applied to an underwater sensor network system.