### Fixed-Time Leader-Following Formation Control of Fully-Actuated Underwater Vehicles Without Velocity Measurements

GAO Zhenyu, ZHANG Yi, GUO Ge

1. School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China
• Received:2021-12-21 Published:2022-04-13
• Contact: GAO Zhenyu. Email: 18840839109@163.com
• Supported by:
This work was supported by the National Natural Science Foundation of China under Grant Nos. U1808205 and 62173079, the Natural Science Foundation of Hebei Province under Grant No. F2020501018, and the Youth Foundation of Hebei Educational Committee under Grant No. QN2020522.

GAO Zhenyu, ZHANG Yi, GUO Ge. Fixed-Time Leader-Following Formation Control of Fully-Actuated Underwater Vehicles Without Velocity Measurements[J]. Journal of Systems Science and Complexity, 2022, 35(2): 559-585.

This paper is concerned with formation control of fully-actuated underwater vehicles (FUVs), focusing on improving system convergence speed and overcoming velocity measurement limitation. By employing the fixed-time control theory and command filtering technique, a full state feedback formation algorithm is proposed, which makes the follower track the leader in a given time with all signals in the system globally practically stabilized in fixed time. To avoid degraded control performance due to inaccurate velocity measurement, a fixed-time convergent observer is designed to estimate the velocity of FUVs. Then the authors give an observer-based fixed-time control method, with which acceptable formation performance can be achieved in fixed time without velocity measurement. The effectiveness and performance of the proposed method are demonstrated by numerical simulations.