Alesamonti DEMO

Alesamonti is a manufacturer of boring/milling machine tools. Every structural component of its machines is manufactured internally, often using Alesamonti’s machine tools for boring/milling processes. Some of their components, produced in small batches, are quite big while their tolerances (flatness, squareness and parallelism) are typically within 50 ?m. For making the first part right, and avoid/reduce expensive and time consuming reworking and manual fitting of their components, they need to perform a thorough control of their processes. Therefore, their focus within the IFaCOM project has been on isolating and deeply analysing possible sources of geometric errors (part, machine, process) and to develop tools for controlling their processes, increasing their chances to have a zero defect manufacturing. In particular, Alesamonti’s main investigations during the project have been on minimizing the effect of thermally and mechanically induced part distortions; project work has been carried out in the Alesamonti’s dedicated test chamber, developed during the previous SOMMACT EU project which is equipped with a MAF45 machine and allows to control the room temperature and simulate different thermal operating conditions. The system implemented within the project follows the three-loops IFaCOM scheme with a • Short-term loop: quasi real-time compensation of thermal and clamping effects After several tests performed on the machine and on the workpieces in its test chamber, including also the development and test of a dedicated tool wear monitoring system, Alesamonti has developed a dedicated quasi real-time control system which allows to compensate part deformations and deriving tolerance errors due to several causes. The system relies on the application of several sensors (temperature, cutting force, power, etc.) and on improved control algorithms implemented in the FIDIA machine’s CNC. In particular, the system allows to compensate mechanical deformation induced on the workpiece by clamping forces (core of a patent application) and thermal deformations of the workpiece and of the machine. The system foresees workpiece thermal status measurements performed at programmed positions, defined in the part program, using a wireless temperature probe; the compensation is automatic (applied by the CNC) when some conditions are met, otherwise some corrective actions are proposed to the operator. • Medium and long-term loop: application of small batch Statistical Process Control The application of the medium and long-term control loop in the Alesamonti’s case show some challenges in the long-term process optimization, due to difficulty of developing learning, generalising and forecasting capabilities from small and single batch productions data. Therefore, the company developed a dedicated methodology for adapting the statistical process control to its production, and make processes repeatable and stable thus reducing variability of product characteristics also for small and single batches. The system developed during the project relies on the integration of different devices (sensors, monitoring systems) on the AT120 demo machine, and has required an ad-hoc upgrade of the FIDIA CNC software, including the development of new control algorithms based on the installed hardware inputs and applied methodologies. Customised user interfaces have been also included in the existing FIDIA’s interface.