An Improved Motion Strategy With Uncertainty Perception for the Underwater Robot Based on Thrust Allocation Model

With the increasing research on underwater robots, the research on the stable motion mode and control strategy of underwater robots that consider practical constraints and the underwater disturbance from complex environment is still immature. There is a lack of quantitative analysis and comparison on the effect of disturbance on the controller. In this letter, a thrust allocation model suitable for underwater robot is established, so that it can adapt to the complex three-dimensional motion in Marine. Then, a motion control strategy of underwater robot is proposed based on the thrust allocation method. This strategy includes an improved linear active disturbance rejection controller (LADRC) and considers the propeller constraints of underwater robots. Finally, a more practical and comprehensive disturbance model is established. The performance of the proposed motion control strategy under different types and intensities of disturbances is analyzed in detail. In addition, this letter also analyzes the influence mechanism of the proposed strategy on the performance, which provides reference for controller design.