Comparison of manipulator motion control systems for unmanned underwater vehicles

BACKGROUND: As technology advances and the need for ocean exploration increases, unmanned underwater vehicles with manipulators are becoming critical tools for complex underwater missions. Efficient manipulator control systems ensure high operational precision, reliability, and safety in hard-to-reach locations, making their development a relevant science and technology objective. AIM: This study aims to compare different manipulator motion control systems used in unmanned underwater vehicles. METHODS: The study uses modelling techniques for kinematic diagrams of manipulators based on 3D technologies and graphic designs. The study reviews open and closed loop control algorithms with pick position feedback. A PI controller is used to stabilize the position. RESULTS: The model showed that the manipulator moves harmonically with open loop control, but the system becomes unstable with permanent load. The introduction of pickup position feedback results in self-oscillations. However, they can be avoided by using a PI controller. The resulting transient curve shows improved stability and controllability of the manipulator. CONCLUSION: The closed-loop and controller approach to manipulator control enables consistent and accurate underwater operations.