A Real-Time 6-DoF Posture Estimation Method for High-Speed 6-Axis Industrial Manipulator Control Using a 2D Laser Profiler

Abstract

6-DoF posture estimation is a critical technique in robotics. However, a significant gap exists between the two primary approaches—camera-based methods and laser tracker systems—in terms of cost and performance. To bridge this gap, this work proposes a method to calculate the 6-DoF posture of a manipulator’s end-effector using the 2D profile of a custom-designed metallic gauge. The core principle relies on a one-to-one correspondence between the measured profile and the manipulator's posture. A mathematical model was developed to derive a closed-form solution, which is further refined via maximum likelihood estimation to enhance robustness and accuracy. Simulation studies assessed the influence of geometric parameters on estimation accuracy and noise robustness. Real-world experiments demonstrated that the refined solution significantly outperforms the closed-form solution alone. Furthermore, a speed benchmark against a camera-based system highlighted the proposed method's advantage in operating frequency. Finally, the method was successfully integrated into a real-time position control task for a 6-axis industrial manipulator, verifying its practical applicability in real-time robotic control.