A versatile handheld tracking target: Experimental validation of coordinate and surface measurements

In photogrammetry, developing specialized measurement equipment tailored to diverse scenarios and requirements often results in heightened operational complexity and increased costs. To mitigate these challenges, this study introduces a Versatile Handheld Tracking Target (VHT-T) utilizing infrared markers. The VHT-T offers seamless integration with various terminal devices, ensuring a cost-effective and efficient solution for measurement needs. The VHT-T adopts a multi-marker staggered planar constraint structure, and a marker detection and tracking algorithm has been developed to enhance its robustness and adaptability. Experimental results demonstrate that the system achieves stable matching within the range of $-40^{\circ }$ to $+40^{\circ }$ when rotating around the X-axis and Y-axis, while maintaining robust matching across the full $360^{\circ }$ range when rotating around the Z-axis. This paper further explores the integration of the VHT-T with two typical terminal devices: (1) when combined with a measurement probe, forming Combined Structure A (CS-A), representing contact-based measurement. For this configuration, a self-calibration algorithm based on rotational spherical constraints and a multi-station tracking method are proposed, achieving handheld coordinate measurement functionality; (2) when combined with a structured light camera, forming Combined Structure B (CS-B), representing non-contact measurement. For this configuration, a self-calibration algorithm based on third-party corner features and a multi-station stitching method are introduced to facilitate handheld surface measurement. These two integration methods provide a feasible reference framework for combining the VHT-T with other terminal devices. Experimental results demonstrate that the VHT-T system can meet tracking requirements in various scenarios for both coordinate and surface measurements, achieving efficient and stable performance.