Dynamic modelling and control strategy for the four anti-swing cables System of an offshore crane

Due to the oontinuous influences of waves, currents, and winds, achieving aocurate and fast lifting is difficult because of the large payload swing during the lifting Operation. Therefore, the four anti-swing cables System (FASCS) of an offshore crane was proposed and a tension control method to suppress the swing of the payload was designed by setting the tension constraints on the four flexible anti-swing cables. Concurrently, in order to achieve the coordinated motion between anti-swing cables, an adaptive synovial Controller with improved reaching law (ASC-IRL) was designed to control the changes of the length and speed of the anti-swing cables, which was used to prevent the occurrence of snap. The control effect was simulated and analyzed with MATLAB/Simulink. The analysis shows that the swing angle suppression effect reaches 80. 1% on average, and the projected area of the payload trajectory is reduced by 61.0%. In addition, the errors of both the length and speed between cables can approach 0 within 8 s. The maximum error between the anti-swing cables under ASC-IRL control is reduced by more than 75. 0% compared with the fuzzy proportional integral derivative control, and the chattering phenomenon is also reduced, which verifies the strong robustness of the cooperative motion of the anti-swing cables under ASC-IRL control. The research results are of great significance to further explore the anti-swing mechanism of the FASCS and the cooperative control of the anti-swing cables. © 2024 Chinese Vibration Engineering Society. All rights reserved.