Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - MARS (ModulAR Plug-in Mechatronic DeviceS for vibration suppression in manufacturing equipment)

Teaser

The vibrations phenomenon represents one of the main problems in metal cutting Machine Tools (MTs) sector, since it causes poor surface quality, unacceptable inaccuracy, excessive noise, reduced material removal rate, increased production time, waste of energy and related high...

Summary

The vibrations phenomenon represents one of the main problems in metal cutting Machine Tools (MTs) sector, since it causes poor surface quality, unacceptable inaccuracy, excessive noise, reduced material removal rate, increased production time, waste of energy and related high environmental impact.
The conventional approaches were based on customized solutions introduced in the early engineering stage to address definite end-user requirements, including passive controls and dumpers, while active method is remaining exceptional, not flexible, not scalable and then not cost-effective to implement.
CeSI (www.cesi.net) addressed the mentioned concerns through the development of an Active Vibration Absorber (AViA) add-on kit, which is a flexible, modular, plug-and-play device able to suppress vibration in the frequency range of 50÷500Hz.
The AViA is characterized by:
-High flexibility: the module can be integrated connecting the end-effector (spindle) to the machine. It will be implemented in two versions AViA-R (Reaction force actuators) and AViA-T (Tilting) to cover all the materials processing, from aluminum to titanium, and all the metal cutting tasks, in rough milling, superfinishing and micro machining.
-Compactness and Modularity: the module is very compact, completely scalable to address different machine size. The controller will be optimized to work both broadband on all the frequency and narrowband focusing on particular (dominant) frequencies.
-Ready-to-use (RTU): AViA is a plug-and-play device, requiring minimum tuning. Flexibility and modularity features of the product provide RTU abilities in most of the commercial machines on the market, from Hw and Sw perspectives.
Within MARS a detailed assessment of AViA add on kit has been carried out. The focus was the optimisation of the mechatronic hardware and the smart control system to enable all-in-one integration into a wide range of MTs/metal cutting equipment and exploitation in a wide process applications domain in a cost-effective way.
Moreover in the feasibility study carried within MARS, a detailed analysis of the best-fitting market segments within the MTs sector have been conducted, including the involvement of pilot customers for the validation of the business idea, as well as the elaboration of a thorough business plan for commercialization. The findings of the feasibility study are planned to be integrated into a subsequent SME Phase 2 project to foster the market introduction of AViA kit.

Work performed

CeSI Centro Studi Industriali (CeSI) has progressed a product development project for advance an innovative mechatronic system (AviA). The device is based on piezoelectric stack actuators able to guarantee the vibration control and suppression in manufacturing equipment sector. AViA (Active Vibration Absorber) is a flexible, modular, plug-and-play device able to reduce vibration up to 70% in 50÷500Hz frequency range. Two version are foreseen:
-AViA-T (Tilting actuation) based on the Stewart platform, with three degrees of freedom (DOFs) (two rotations on X, Y axes and one displacement on the Z axis). It can be integrated as an add-on kit (mechanical Hw, controller and Sw) to suppress vibration of Spindle and/or Table. This system includes two circular plate made of an Al alloy. The fixed plate is bound to the machine tool’s vertical axis, and the mobile is linked to the frame of the spindle. Three piezo-actuators multi-stack actuators (PZT) permit the relative movement of these two platforms. When a deviation is measured at the tool tip point (TTP), 3 actuators are switched on in order to smooth pulsations and limit their consequences on the surface. AViA-T is particularly effective in case of high machining forces, but the loss of stiffness introduced by the configuration of the actuators can become critical for some machining process.
-AViA-R (Reaction force actuators) is based on active proof-mass damping principle, has been designed featuring on 2 piezo-actuators acting on 2 oscillating masses which produce counter-phase forces to suppress vibration in X-Y plan avoiding losing vertical stiffness. This configuration is also more simple and easier to control with respect to AViA-T. AViA-R focuses on compensation of forced vibration generated by lower cutting forces respect to AViA-T.
Within the feasibility analysis carried out in this SME-Phase 1 the market and the scientific environments have been explored (Technology survey) to find out promising competing technologies or original innovative solutions that can compromise the effective exploitation of AViA modules. A patent exploration and freedom to operate analysis are extended to exclude any IP violation or overlap.
Moreover, a roadmap towards the market uptake of the proposed AViA product has been provided. Such a roadmap outlines:
i) the areas of improvements to achieve the effective industrialization of the product
ii) the IPR management strategy to protect the new knowledge obtained from the project,
iii) the Business Plan which includes the market and the economic analysis
iv) the identification of an industrial stakeholder group and finally
v) the risk analysis and management procedures
The mentioned results have been fully achieved at the end of the period.

Final results

Vibrations in manufacturing equipment domain are a well-known issue and various solutions have been investigated in the past to mitigate this problem. Nonetheless it is worth to underline that most of them never reached the market and common practice is adopting no further vibration suppression methods to improve the inherent design of the machine/equipment. Whenever present, mitigation approaches can be divided in main 3 groups: Sw-based methods, passive methods and active (actuated system) methods. Even if various solutions are also under investigations no commercial product came out until now from the previously cited active structural developments making them of marginal impact on the MTs industry. Whenever applied, active technologies are currently custom-made, and even if effective, they present the main drawback of being expensive. The attempt to apply modular solutions to milling machines had limited success since the huge size of these devices make them very difficult to apply in the industrial environment. On the other hand, passive solutions are cheap, but they lack of effectiveness, not guaranteeing the same performance level of active vibration suppression. Similarly, process methods are limited in performance by the need for the phenomenon to show up, with consequences in terms of part quality. AViA modules differentiate themselves from the other solutions on the market, since they have been designed and developed starting from the beginning focusing on modularity, plug-in ability, flexibility and readiness to use.
Expected results and Impact:
AViA modules are compact devices combining high performances (up to 70% in vibration suppression) with cost effectiveness: reducing the machining time of about 20% (the machine can work with more demanding parameters, due the active vibration compensation, thus reducing machining steps, e.g. no need of grinding) and then reducing up to 15% the life cycle cost as direct consequence of the latter.
AViA solution will be an add-on kit, therefore it can be sold directly with the milling machine to new customers, but can be also provided as a retrofitting solution for already installed machines, requiring only minimum customisation.
Regarding sustainability issue the project results are expected to contribute to the reduction of scraps parts and waste due to an increase of the output quality of manufacturing processed derived from vibration suppression.
A great and concrete contribution to employment creation can be also envisaged. European Machine tools industry market, with approx. 1500 industrial enterprises in Europe (over 80% of which are SMEs), worth about 24 Billion Euro and represent about 35% of worldwide market. Mechatronic devices market for active vibration control is still undeveloped and it is expected to sharply grow in the future. MARS project results will then act as a leverage for stimulating the creation of new jobs.

Website & more info

More info: http://www.cesi.net/MARS/marsproject-sme.htm.