Sliding Mode Impedance Control for contact intervention of an I-AUV: Simulation and experimental validation

Abstract

Position/force control of an Intervention Autonomous Underwater Vehicle (I-AUV) is essential to many underwater intervention tasks (e.g., marine equipment maintenance, underwater welding and so on), and is challenging due to unknown fluid disturbances and model uncertainties. This paper applies the Sliding Mode Impedance Control (SMIC) to the full contact intervention of an I-AUV, from non-contact phase to contact phase. Both computational simulations and practical experiments are conducted to investigate the performance of SMIC. In simulations, considering model uncertainties and detailed fluid disturbances, accurate position and force tracking can be achieved, with the position tracking errors within ±3 × 10−3m and a Root Mean Square Error (RMSE) of 4 × 10−2N in tracking the desired contact force of 10N. For the purpose of experimental validation, the SMIC is implemented on an I-AUV developed in the University of Technology Sydney (UTS). The experimental results demonstrate the SMIC’s good performance in the contact intervention of the I-AUV, with the position tracking errors within ±1.6×10−2 m and a RMSE of 0.97N in maintaining the desired contact force of 10N.