| The benthic AUV is a new type of offshore oil survey equipment that combines an underwater autonomous vehicle and seismic detection technology.During operation,it is released from a mother ship and can navigate autonomously to a fixed position near the seabed,hovering at a fixed point and then sit on the bottom of the seabed Long-term exploration of nearby petroleum resources at a fixed location.The trajectory tracking motion control and point stabilization control are the basic technical guarantees for the benthic AUV to successfully complete the accurate bottom sitting,which has high research value.In this context,this article analyzes the difficult problems in the motion control of the benthic AUV,and focuses on the study of the benthic AUV movement control method.Firstly,a mathematical model of the benthic AUV was established considering the external disturbance of ocean currents,and the model was reasonably simplified to facilitate the design of the controller.Meanwhile,motion control characteristics of the benthic AUV were analyzed.Secondly,the AUV trajectory tracking control algorithms based on unknown external disturbance is studied.In order to overcome the influence of external disturbance on the stability of the controller while ensuring the better convergence performance of the control system,an adaptive non-singular fast terminal sliding mode control(ANFTSMC)method is proposed;at the same time,to weaken the chattering phenomenon that appears in sliding mode control adopts the Fractional Power Continuous Function(CFFP).Through comparative simulation experiments,the feasibility and superiority of the proposed ANFTSMC controller algorithm are verified.Then,the AUV trajectory tracking control method based on unknown external disturbance,system modeling uncertainty and input saturation is studied,and an ADS adaptive sliding mode control method(Auxiliary Dynamic System-adaptive Nonsingular Fast Terminal Sliding Mode Control,ADS-NFTMC)is designed.In order to overcome the influence of the total disturbance of the system on the stability,an adaptive control algorithm is designed.At the same time,in order to eliminate the influence of the control input saturation on the control performance,the ADS control method is introduced.The designed controller can realize the finite time convergence of the control system.Through simulation comparison test,the feasibility and superiority of the designed ADS-NFTMC controller are verified.Finally,the AUV point stabilization control method based on unknown external disturbance and system modeling uncertainty is studied,and an adaptive chattering-free integral sliding mode control method(Adaptive Chattering-free Integral Sliding Mode Control,ACFIMC)is designed.In order to overcome the influence of the total disturbance of the system on the stability of the control system,an adaptive Super-Twisting extended state observer is adopted.In order to ensure better convergence performance and eliminate chattering in sliding mode control,an adaptive second-order integral sliding mode controller is designed.The designed controller can achieve finite time convergence of the control system.Through simulation and comparison experiments,the feasibility and superiority of the designed ACFIMC controller are verified. |
