Robot Hand-Eye Calibration Target Selection and Design: From Planar Targets to Calibration-Free Methods

Robot hand-eye calibration is a fundamental procedure for establishing the spatial relationship between a robot's end-effector and its vision sensor, which is critical for precision tasks in automation. The accuracy and efficiency of this calibration process are heavily dependent on the proper selection of calibration targets. However, existing surveys predominantly focus on solution algorithms while lacking a systematic treatment of target design. This paper reviews four categories of calibration targets in hand-eye calibration—2D planar targets, 3D standard bodies, single-plane/natural workpieces, and calibration-free methods—examining their design principles, applicable conditions, and representative contributions. A systematic comparison is conducted across dimensions including manufacturing cost, calibration accuracy, operational convenience, sensor compatibility, and online calibration friendliness. Based on this analysis, a decision framework for selecting calibration targets in engineering applications is proposed to guide calibration scheme design under different scenarios.