Sub‐Micrometer‐Precision Path Following of Piezo‐Actuated Mobile Robot

This study demonstrates the high‐precision, path‐following capability of a small robot over multiple spatial ranges for robotic motion control. This study utilizes Holonomic‐Beetle (HB), a small mobile robot with piezoelectric actuators and a high‐resolution optical encoder. Conventional precision stages, widely used for precision positioning, have a limited range of movement, while mobile robots often lack positioning accuracy. The HB combines the characteristics of both, achieving a high positioning resolution despite being a mobile robot. By employing a two‐dimensional scale and proportional‐integral‐derivative (PID) control, the HB successfully tracks straight and complex paths over a multiscale range of 100 µm to 10 mm. The system achieves root mean square errors (RMSEs) of 0.08–1.03 µm and a normalized path error of 0.00010, substantially lower than the previously reported values for other robots (0.00733). Notably, this highlights the potential for real‐time, low‐cost, and high‐precision mobile robotics. The findings suggest significant applicability for HB in microfabrication, medicine, and optics, where precise and flexible positioning is essential. This work introduces a new paradigm in robotic motion control that helps bridge the performance gap between mobile robots and ultraprecise positioning technology by adapting a simple control method to a piezo‐actuated mobile robot with high‐resolution measurement.