A Modified Line-of-Sight Method for Path Tracking Applied to Robotic Fish

Abstract

This paper proposes an improved line-of-sight method to navigate a two-joint-actuated tuna-like robotic fish. Based on the characteristics of thunniform swimmer, a simplified kinematic and dynamic model is constructed, and the intrinsic body swing is illustrated. To deal with the nonlinear and under-actuated dynamics of the robotic fish, the reference head angle is designed with cross-track error, which substantially simplifies the control of linear path tracking. Furthermore, with the physical constraint, co-simulation using Automatic Dynamic Analysis of Mechanical Systems (ADAMS) software and MATLAB simulink reveals the effectiveness. The obtained results show that the proposed method is able to make both the cross-track error and the heading error fluctuate in an acceptable range quickly.