A Simultaneous Calibration Method for Dual-Arm Robots Based on Optical Trackers
Abstract
This paper presents a unified calibration method for the full parameters of the dual-arm robotic system, encompassing hand-eye, kinematic, and tool center point (TCP) parameters. Firstly, the closed-loop equation, AXP=YCQ, is established in three-dimensional space and solved by neglecting kinematic parameter errors, thereby obtaining the initial parameters. Subsequently, a calibration model incorporating all parameter errors is established and formulated as a constrained nonlinear least-squares optimization problem, thereby significantly enhancing the calibration precision and accuracy. The main contributions include: (1) constructing a spatial closed-loop equation and utilizing the Kronecker product for initial parameter calculation, which minimizes human annotation errors while improving data acquisition efficiency; and (2) establishing a unified error model that treats calibration as an optimization task to further refine accuracy. Simulation results demonstrate that the proposed method substantially suppresses positioning errors. In generalization tests, the maximum, mean, and root mean square (RMS) values of absolute position errors are reduced from 8.3871 mm, 3.1416 mm, and 3.4662 mm to 0.2983 mm, 0.1442 mm, and 0.1580 mm, respectively, validating the effectiveness and generalization capability of the method.