A machining robot that bridges the gap between industrial robots and machine tools

Newly developed milling kinematics from Fraunhofer IFAM enable highly versatile, efficient, and ultra-precise machining—from fibre composites and aluminium to tempered steel—with manufacturing tolerances of up to 0.1 millimetres. This breakthrough marks a significant step toward merging the flexibility of industrial robots with the precision traditionally associated with machine tools.

A New Class of Machining Robot: Precision Meets Dynamics

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Stade has engineered an advanced machining robot concept that dramatically enhances both dynamic performance and precision. This achievement stems from the integration of intelligent, model-based control strategies with innovative drive technologies and a re-engineered robot structure optimised for stiffness and responsiveness. These technological developments work together to compensate for dynamic errors, suppress vibrations, and greatly improve path accuracy, even at high feed rates or during complex multi-axis motion.

A key innovation lies in the system’s optimised disturbance rejection, allowing it to maintain consistent precision even under highly dynamic process forces. As a result, the robot can achieve higher material removal rates and operate with more aggressive jerk settings, leading to significant productivity improvements. Bridging the gap between traditional industrial robots and full-scale machine tools, this Machine Tool Robot (MTR) is uniquely suited for demanding machining tasks—particularly those involving harder materials that have historically been challenging for robotic systems.

Alternative Machine Concept With Greater Flexibility

Industrial robots offer an entirely new machine concept when combined with workspace extensions such as moving platforms, supplementary translatory axes, or coordinated operation with additional robots. Compared to large gantry systems or conventional machine tools, this approach requires far less installation space, eliminates the need for specialised foundations, and provides a modular configuration that can adapt rapidly to evolving production requirements. This flexibility makes the concept particularly attractive for modern, reconfigurable smart factory environments where scalability is essential.

Expanded Capabilities Through the Combination of an Articulated Robot and Linear Axis

The pairing of serial articulated arm kinematics with a high-stiffness linear axis creates a compelling alternative to bulky gantry systems and special-purpose machinery. The reduced installation space and modularity of the linear axis allow for efficient system integration, while the use of two preloaded rack-and-pinion drives ensures high drive stiffness and eliminates reversal effects. The high structural rigidity of the axis minimises accuracy losses, even when long lever arms are involved, ensuring stable and reliable machining performance across extended work envelopes.

Further Precision Gains Through “CaliRob” Model-Based Calibration

To meet the highest industrial accuracy requirements, Fraunhofer IFAM has developed “CaliRob,” a model-based calibration software designed to refine the precision of robots and linear axes. Since industrial robots naturally exhibit geometric deviations due to manufacturing tolerances, uncalibrated systems can produce positioning errors of several millimeters. CaliRob addresses this through an extensive mathematical model containing more than 200 parameters that describe the robot’s kinematics on a linear axis. By identifying and compensating for these deviations, the software significantly improves absolute positioning accuracy, making the system suitable for high-precision machining tasks.

Future Outlook and Application Potential

Together with partners autonox Robotics GmbH and Siemens AG, Fraunhofer IFAM will next validate the new machining robot in demanding industrial applications. These tests aim to quantify performance gains and further refine the system for production deployment. Machine Tool Robots combined with linear axes open up a wide spectrum of industrial applications. In the aerospace sector, they can handle machining tasks for fiber composite structures and aluminum components. In rail, commercial vehicle, shipbuilding, and energy sectors, the technology is capable of machining harder materials such as steel and titanium. Until now, industrial robots have not been robust enough to machine such components effectively. The emergence of MTR technology fundamentally changes this outlook and provides a promising future for robotic machining in these sectors.

Project Support

The Niedersachsen Ministry for Economic Affairs, Transport and Housing, together with NBank, supported the LuFo research project “Robots Made in Lower Saxony 2” (RoMaNi 2; funding code: ZW1-80155399). Fraunhofer IFAM and its partners express their appreciation to the Ministry, NBank, and the German Aerospace Center (DLR) as the project management agency for their support and commitment.

Exhibition Note

A globally unique new development was showcased at automatica 2025, the leading exhibition for smart automation and robotics held from June 24–27, 2025 in Munich, Germany. The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Stade, together with autonox Robotics GmbH and Siemens AG, presented the innovation in Hall A4 at the autonox Robotics booth (A4-329) and Hall B6 at the Siemens booth (303).

Source: Fraunhofer IFAM