Adaptive optimal 3D nonlinear compound line-of-sight trajectory tracking control for over-actuated AUVs in attitude space

Three‐dimensional path following control of underactuated autonomous underwater vehicles with nonzero roll dynamics: A novel line‐of‐sight‐guided approach

“…Remark 4. For spatial path following problem of the underactuated AUVs, the following formula is mostly employed to describe the error dynamics (e.g., References 10,16,19,and 20):…”

“…Remark For spatial path following problem of the underactuated AUVs, the following formula is mostly employed to describe the error dynamics (e.g., References 10,16,19, and 20): $$$$ {\dot{\boldsymbol{P}}}_e={\boldsymbol{S}}_I^F{\boldsymbol{P}}_e+{\boldsymbol{R}}_W^F\left({\chi}_e,{\vartheta}_e\right){\boldsymbol{v}}_W-{\boldsymbol{v}}_q, $$$$ where $$$ {\chi}_e $$$ and $$$ {\vartheta}_e $$$ are rotation angles from the flow frame $$$ \left\{W\right\} $$$ to the path frame $$$ \left\{F\right\} $$$. However, the effect of nonzero roll dynamics on path following accuracy cannot be revealed in a comprehensive manner.…”

“…In Reference 18, with the help of a roll stabilization controller, a hyperbolic‐tangent LOS guidance law was designed to avoid radical yaw and pitch maneuvers. In References 19 and 20, an improved 3D LOS guidance law was designed based on the equivalent coordinate transformations. The methods in the References 18–20 have verified to achieve good tracking performance under nonzero roll angle, however, the sideslip and attach angles should be available to implement these guidance laws.…”

“…In References 19 and 20, an improved 3D LOS guidance law was designed based on the equivalent coordinate transformations. The methods in the References 18–20 have verified to achieve good tracking performance under nonzero roll angle, however, the sideslip and attach angles should be available to implement these guidance laws. This is unfavorable in practice, because the sideslip and attack angles are difficult to measure or calculate precisely, due to expensive equipment, measurement noise and constrained installation space 13 .…”

“…Different from the error model described in References 10,16, and 19, the effect of nonzero roll angle on the path following accuracy can be explicitly revealed, so that the guidance law design and stability analysis can be simplified. An improved LOS guidance law is developed to compensate for the negative effect induced by nonzero roll dynamics. Compared with References 18–20 the proposed guidance law removes the dependence on the measurement of sideslip and attack angles, and can be implemented to both underactuated and fully actuated underwater vehicles. In contrast to References 21,23,31, and 32, the designed attitude tracking controller is guaranteed to be inherently bounded in the presence of large tracking errors. As an extension of $$$ \tanh $$$‐based bounded controller in References 29 and 30 adaptive technique is incorporated to compensate for the lumped uncertainty without the knowledge of its upper bound.…”