## 1 Introduction  
Under modern production conditions, industrial robotic lines rely on automated robotic solutions, where rapid commissioning is a critical requirement. This demand has driven the development of methods aimed at improving deployment efficiency and system flexibility. Various strategies have been explored, including automated commissioning of offline-generated programs [1], true effectiveness in single-pass commissioning [2], low-code programming platforms [3], and rapid configuration techniques for robotic cells [4]. Lastly, [PERSON], [PERSON], and [PERSON] [5] examined efficient commissioning methods tailored for final automotive assembly lines, emphasizing time and cost savings during setup. The measurement process in implementing offline simulated programs is a crucial step in matching simulation of a production line with the real environment, the so-called base frame calibration. Base frame calibration refers to the process of determining the relative translation and rotation between the robot's WORLD frame and local coordinate system. It is essential for enabling accurate position and orientation transformations required for coordinated control of robot end-effectors [6]. The importance of accurate base frame calibration has grown alongside the widespread adoption of offline programming (OLP) and virtual commissioning (VC) practices in the automotive industry. Processes such as spot welding, arc welding, gluing, and riveeting rely heavily on simulated robot programs prepared using both proprietary and independent simulation software [7]. OLP and VC are closely linked to the digital twin (DT) concept, which plays a critical role in the Industry 4.0 revolution, facilitating the management, optimization, and commissioning of industrial robots [8]. There are three typical measurement methods for determining the reference position and orientation of the User Coordinate System (UCS) of tooling stations and other equipment of robotized cells:  
1. The robot's internal direct three-point measurement method--frequently inaccessible due to reference positions being out of reach. 2. The indirect measurement method using one of the AX = BY solutions. 3. Geometrical estimation of the robot world coordinate frame with aligned UCS in the measurement system. An equally critical measurement step for accurately transferring executable path programs from a simulated environment to a real-world system is the determination of the Tool Center Point (TCP), which defines the origin of the coordinate system of the tool mounted on the robot's flange. This can be accomplished using one of the following methods:  
1. Utilizing the robot's internal TCP measurement function;
2. Direct numerical import of CAD data from modeling software;
3. Tool measurement performed at the manufacturer's site prior to mounting on the flange. In this manner, successful implementation of offline-simulated path programs in real manufacturing environments requires two critical measurement processes: the accurate determination of the Tool Center Point (TCP), and the calibration of the robot's base frame, commonly referred to as base frame calibration. These two measurements are inherently interdependent, as both are necessary for aligning the simulated kinematics with the physical robot setup. This dual-calibration challenge is often mathematically formulated using the calibration equation **AX = YB**, where  
* **X** represents the unknown transformation from the robot's flange to the TCP (TCP translation);
* **B** is the known robot joint transformation computed from Denavit-Hartenberg (D-H) parameters [9];
* **Y** is the transformation from the WORLD coordinate system to the BASE (or UCS);
* **A** is the measured TCP position in the local UCS, often obtained from an external measurement system. Solving this equation ensures that the tool position and orientation in simulation can be accurately reproduced by the physical robot.