Andreas Archenti

• PhD
• Chair Professor at KTH Royal Institute of Technology

Advanced manufacturing systems demand the utilization of technologies, methods and capabilities to improve production efficiency or productivity, while ensuring environmental and societal sustainability. Digitalization emerges as an alternative solution for improving the monitoring capabilities of manufacturing systems and consequently enhance the...

Surface roughness plays an indispensable and fundamental role as a leading indicator of the surface quality of machined parts in the manufacturing process. The precise and effective monitoring and prediction of surface roughness is crucial for surface quality control. In this regard, the development of an in-process surface quality monitoring syste...

The performance of a machine tool is directly influenced by the characteristics of the floor, subsoil, and their interaction with the installed machine. Installing a machine tool in its operational environment poses a distinct challenge that bridges mechanical and civil engineering disciplines. This interdisciplinary issue is often overlooked withi...

The optimal combination of machine tool support and foundation type is vital for high precision manufacturing. However, there is limited knowledge and few models available for predicting the behavior of a machine tool, including its operational environment. The study presents the estimation of the machine tool-support-foundation-subsoil system para...

In the turning process, the surface roughness of the machined part is considered a critical indicator of quality control. Provided the conventional offline quality measurement and control is time-consuming, with slow feedback and an intensive workforce, this paper presents an online monitoring and prediction system for the effective and precise pre...

The early identification of a defect that is developing in a bearing is crucial for avoiding failures in rotating machinery. Frequency domain analysis of the vibration signals has been shown to contribute to a better understanding of the nature of a developing defect. Early signs of degradation might be more noticeable in certain frequency bands. T...

New automated laser radar measurement systems at the Saab Inc. West Lafayette, USA, facility will make airframe assembly of the aft body for the new eT7-A aircraft a quicker, more cost-efficient process. Digital twin concepts realized through simulation and off-line programming show advantageous results when studying future state scenarios or inves...

This article presents the measurement and analysis of the influence of velocity on the quasi-static deflections of industrial manipulators of three different manufacturers. Quasi-static deflection refers to the deflection of the end effector position of articulated robots during movement at low velocity along a predefined trajectory. Based on earli...

A novel elasto-geometric model is introduced that simultaneously estimates joint compliances and geometric error parameters by employing the loaded double ball bar apparatus. The model parameters are estimated from tests at different force levels by distinguishing between errors that change with the applied force (compliance effect) from those that...

Quality inspection is traditionally considered non-productive. That is why the manufacturing industries aim to decrease inspection times to a bare minimum without sacrificing part quality. Alongside the implementation of the Industry 4.0 paradigm, data-driven in-situ quality control is a potential enabler for minimizing inspection times. In that, t...

High-power impulse magnetron-sputtering thick metal/carbon–nitride-doped metal-matrix multilayer nano-composite coating can be applied to cutting-tool holder components to improve cutting insert’s life. One of the challenges of such an add-on solution is the poor adhesion between the thick coating and the hard alloy substrate, such as WC-Co shim. T...

The design and testing of different optical heads were performed to evaluate the pitch deviation of a diffraction scale grating with a small diffraction angle. Based on the proposed pitch deviation evaluation method employing optical angle sensors based on laser autocollimation, a modified optical head with position-sensitive detectors (PSDs) is fi...

Industrial manipulators are rarely used in high-force processes even though they provide flexibility, adaptability, relatively low cost, and a large workspace. This limited utilization is mainly due to their inherent low stiffness, which results in significant deformation. Hence, it is necessary to improve their accuracy in order to achieve high-pr...

Industrial articulated robots appeal to high force processes such as material removal applications mainly due to their high flexibility and large working space. However, due to the articulated robot´s lower stiffness, significant deformations arise in the presence of process forces which reduces the robot´s positioning accuracy. To improve the posi...

A novel elasto-geometric model is introduced that simultaneously estimates joint compliances and geometric error parameters by employing the loaded double ball bar apparatus. The model parameters are estimated from tests at different force levels by distinguishing between errors that change with the applied force (compliance effect) from those that...

This paper describes a comparison of the mechanical structures (a double-sided beam and a cantilever beam) of a probe in a tool edge profiler for the measurement of a micro-cutting tool. The tool edge profiler consists of a positioning unit having a pair of one-axis DC servo motor stages and a probe unit having a laser displacement sensor and a pro...

Machine tools require high geometric accuracy and stiffness. Both of these characteristics affect the radius of a radially loaded circular test. By using various loads, the machine's volumetric compliance can be studied as a function of position, orientation, and load. Further processing of the data using a kinematic and compliance model of the mac...

Dynamic stiffness is an important characteristic of production machinery, as it contributes to its ability to maintain the position of the tool centre point accurately and precisely under loads. For machine tools, it directly affects the geometric dimensions and surface properties of produced parts. This work presents a measurement procedure for id...

As long as industrial robots are programmed by teach programming, their positioning accuracy is unimportant. With a wider implementation of offline programming and new applications such as machining, ensuring a higher positioning accuracy of industrial robots over the entire working space has become very important. In this paper, we first review th...

This article presents a procedure for the quasi-static compliance calibration of serial articulated industrial manipulators. Quasi-static compliance refers to the apparent stiffness displayed by manipulators at low-velocity movements, i.e., from 50 to 250 mm/s. The novelty of the quasi-static compliance calibration procedure lies in the measurement...

The industrial robot is more precisely an “automatically controlled, reprogrammable, multipurpose manipulator, programmable in three or more axes, which can be either fixed in place or mobile” (ISO 8373:2012). According to the International Federation of Robotics, by 2018, more than 400,000 new units were being installed annually, and the global av...

The implementation of precision engineering principles in the design of precision systems is fundamental to achieve high accuracy. Although these principles may be independent of the system working range, their implementation is not. The working range, the accuracy, and the load of the system limit, for instance, the selection of materials, the str...

Industrial manipulators are desired to be commonly used for material removal applications due to their high flexibility, low cost, and large working space. However, their lower stiffness (compared to a machine tool) leads to a reduction in path accuracy. This reduction directly affects the dimensional accuracy of the machined part. Additionally, th...

Machine tool calibration can be employed to optimise tool path trajectories through on- and off-line compensation of anticipated deflections, which result from a process plan, and to assess the machine tools capability to comply with the geometric dimensions and tolerances of a process plan. This work presents a measurement for the identification o...

Friction control is a vital green technology for reaching sustainable development goals, and surface texturing is effective and efficient at reducing friction. In this study, a novel preparation scheme involving dimpled groove texture is proposed. A pulsed laser marking system is used to make the dimpled grooves. Due to the unique design and proces...

The research work in this paper was carried out to reach advanced positioning capabilities of unmanned aerial vehicles (UAVs) for indoor applications. The paper includes the design of a quadcopter and the implementation of a control system with the capability to position the quadcopter indoor using onboard visual pose estimation system, without the...

This research outlines the methodology and application of quasi-static loaded circular testing on serial articulated industrial robots using the Loaded Double Ball Bar (LDBB). The article focuses on measuring the quasi-static path accuracy and repeatability of industrial manipulators to evaluate their performance in industrial contact applications...

The fast evolution in computational and sensor technologies brings previously niche solutions to a wider userbase. As such, 3D reconstruction technologies are reaching new use-cases in scientific and everyday areas where they were not present before. Cost-effective and easy-to-use solutions include camera-based 3D scanning techniques, such as photo...

Condition-based maintenance (CBM) is a maintenance strategy used to gain updated information about equipment condition and is today considered a natural part of the engineering field. The replacement of the traditional scheduled maintenance strategy in favor of CBM has the potential to significantly improve the safety of the system operating in har...

Stiffness is an important characteristic of production machinery, as it contributes to its ability to precisely maintain the pose between a tool center point with respect to a workpiece under load. For machine tools, it directly affects the geometric dimensions and surface properties of the parts, i.e. how closely the parts match their design drawi...

The accuracy of a three-dimensional (3D) positioning system can ultimately be evaluated via measurement of a 3D vector between command and actual end-effector positions at arbitrary points over the entire workspace. This is a simple, yet challenging, metrological problem. The motion accuracy of a machine tool is traditionally evaluated on an axis-t...

The manufacturing accuracy of modern machine tools strongly depends on the placement of the machine tool structure on the factory’s foundation. Civil engineering knows a variety of foundation types and factory planners must carefully consider local circumstances such as the size and the properties of the regional subsoil as well as the individual r...

The included angle of a V-groove on a large ceramic workpiece with a length of 500 mm is measured on an ultra-precision surface grinding machine. A pair of electronic dial gauges is mounted on the grinding wheel head to detect the ground flank surfaces of the groove. A calibrated artefact with identical material and nominal geometry but a shorter l...

Hardness measurement is a vital step for quality assurance in manufacturing of a wide range of products. Today, the standard hardness measurement tests, such as Vickers, are based on microscope image-based evaluation methods. Since these methods are limited to the geometry of the indentation in 2D images, their precision are highly dependent on the...

Additive manufacturing (AM) has recently been accorded considerable interest by manufacturers. Many manufacturing industries, amongst others in the aerospace sector, are already using AM parts or are investing in such manufacturing methods. Important material properties, such as microstructures, residual stress, and surface topography, can be affec...

Controlling friction and wear are essential for reducing energy loss and lengthening the life span of friction pairs in sliding contacts. Surface texturing is an effective and efficient way to reduce friction and wear, especially under lubricated conditions. Dimple texture on friction pair surfaces has been verified to enhance the lubrication condi...

Machining vibrations is a critical phenomenon in the industry as they negatively affect the quality and tool-life. One common avoidance strategy for machining vibrations is the fine-tuning of process parameters, thus leading to longer production time. Our research addresses this challenge and uses different streams of data to classify problematic p...

Machining of parts by using dedicated production systems has been, and continues to be, a viable manufacturing method. There are situations, however, where this type of system is not feasible due to changes in product type, customer demand, work-piece material, or design specification. From a competitive manufacturing environment, production system...

This paper presents a novel methodology to measure the compliance of articulated serial robots based on the Elastically Linked Systems concept. The idea behind the methodology is to measure serial articulated robots with customized external wrench vectors under a closed-force-loop. The methodology proposes to measure robots in use-case defined conf...

Manufacturers need online methods that give up-to-date information of system capabilities to know and predict the performance of their machine tools. Use of an inertial measurement unit (IMU) is attractive for on-machine condition monitoring, so methods based on spatial filters were developed to determine rail wear conditions of linear guideways of...

The accuracy of multi-axis machine tools is affected to a large extent by the behavior of the system’s axes and their error sources. In this paper, a novel methodology using circular inertial measurements quantifies changes in squareness between two axes of linear motion. Conclusions are reached through direct utilization of measured accelerations...

In this chapter the subject of statistical dynamics are discussed and non- parametric and parametric models for machining system identification are derived. The common characteristic for all discussed models is that they may be used for computing the operational dynamic parameters (ODP) of the closed loop machining system. Though the input to these...

This work focuses on the modelling, measurement and identification of the change of the kinematic chain of serial articulated industrial robots based on thermo-mechanical deformations due to self-heating. The Denavit Hartenberg convention is used to describe the kinematics of the manipulator, but the link lengths and the joint offsets are functions...

Detailed description of the multi-axis repeatability performance and the modelling of non-systematic variations in the positioning performance of machine tools can support the understanding of root-causes of capability variations in manufacturing processes. Kinematic characterization is implemented through repeated measurements, which include varia...

The key to solve manufacturing quality and productivity problems in the machining of parts is to understand the physical attributes’ geometric/kinematic, static, dynamic, and thermal behavior of machine tools. In this chapter basic definitions, error sources, and instruments and methodologies for the identification and evaluation of machine tools’...

Public final report of the DAIMP research project.

Transition toward circular-economy model is a must to sustain the planet resources. Under circular economy model wastewater is transformed from a waste into a resource. Therefore, a comprehensive circular economy index; the Circonomics Index, is proposed to measure circularity of wastewater industry. The component indicators of the index are linked...

Smart manufacturing and predictive maintenance are current trends in the manufacturing industry. However, the holistic understanding of the machine tool health condition in terms of accuracy, functions, process and availability is still unclear. This uncertainty renders the development of models and the data acquisition related to machine tool heal...

Abrasive waterjet technology is one of the fastest growing metal cutting technologies. When used in conjunction with conventional metal cutting methods, abrasive waterjet cutting can be both cost saving and environmentally favorable. This paper shows that when processing hard to cut alloys, abrasive waterjet will be an excellent hybrid alternative....

A thick 400-micron amorphous carbon nitride (a-CNX) coating material was synthesized by means of plasma-enhanced chemical vapor deposition process. High-power impulse magnetron sputtering technique was used to sputter a pure graphite target plate in reactive argon (Ar), nitrogen (N2) and acetylene (C2H2) environment for depositing the composite coa...

Integration of machine tool specific capability information related to a manufactured part’s accuracy can significantly support the decision-making in production, help to understand root-cases of quality loss and optimize cutting processes. In this paper, a systematic methodology is proposed to bridge the gap between machine tool specific capabilit...

This paper presents a novel Virtual Machining System Simulator (VMSS) which quantifies and visualizes the effect of machine tool errors under quasi-static load conditions on the machine tool’s accuracy. The VMSS is a generalized machine tool model that incorporates geometric errors and static loads to simulate the interaction between the machine to...

Abrasive Waterjet technology is one of the fastest growing metal cutting technologies. Even so, very little published material is available on hybrid processing where abrasive waterjet cutting is one of two or more metal cutting methods. There is also limited published material on thin-walled components cut with abrasive waterjet technology. This p...

Machine tool testing and accuracy analysis has become increasingly important over the years as it offers machine tool manufacturers and end-users updated information on a machine’s capability. A machine tooĺs capability may be determined by mapping the distribution of deformations and their variation range, in the machine tool workspace, under the...

Modelling of non-systematic variations in the positioning performance of machine tools can support the understanding of capability variation in manufacturing processes. Kinematic characterisation is implemented through repeated measurements, which include variations connected to the performance of the machine tool. This paper addresses the integrat...

One of the greatest challenges in the manufacturing industry is to increase the understanding of the error sources and their effect on machine tool capability. This challenge is raised by the complexity of machining systems and the high requirements on accuracy. In this paper, a mechanistic evaluation approach is developed to handle the complexity...

The accuracy of machine tools is affected to a large extent by the behavior of the system's joints. In this paper the equivalent stiffness approach identifies and calculates the contribution of joint error sources to the total deviation measured between toolholder and workpiece under loaded conditions. The force–deviation functions are measured at...

For proper characterisation of different physical quantities in machine tools, it is necessary to report the uncertainties associated to the measurements. The uncertainty evaluation, according to international standards, expresses information of the quality and the reliability of the measurement result. Applications like calibration and compensatio...

Machining systems (i.e., machine tools, cutting processes and their interaction) cannot produce accurate parts if performance degradation due to wear in their subsystems (e.g., feed-drive systems and spindle units) is not identified, monitored and controlled. Appropriate maintenance actions delay the possible deterioration and minimize/avoids the m...

Dynamic characteristics of machine tools and cutting tools have gained much attention from researchers and industry as it is one of the major factors limiting productivity due to excessive vibrations such as chatter during the cutting process. Numerous factors have to be taken into consideration when selecting material of the cutter body. This pape...

Machine tools degrade during operations, yet knowledge of degradation is elusive; accurately detecting degradation of machines’ components such as linear axes is typically a manual and time-consuming process. Thus, manufacturers need automated, efficient, and robust methods to diagnose the condition of their machine tool linear axes with minimal di...

Vibration analysis and the Shock Pulse Method (SPM) are two of the most popular condition monitoring techniques used in Condition-Based Maintenance (CBM) policy, especially for rotating equipment. To illustrate the extent to which advanced CBM techniques (in this case, vibration analysis and SPM) are applicable and cost effective in a manufacturing...

An increasing number of Higher Education professionals have embraced the Constructivism theory in contrast with the traditional transmissive pedagogy approach where the focal figure is the teacher. Constructivists emphasizes that the learners acquire, or construct, knowledge through their own activities and previous knowledge. Teacher role is to se...

Titanium alloys are known to produce shear-localized chips during machining, resulting in cyclic variations in cutting forces which in turn could cause severe problems with vibrations. However, at low cutting speeds and feed rates, continuous chips are formed, with an increase in both parameters favoring the transition to shear-localized chips. Thi...

Machine tools degrade during operations, yet knowledge of degradation is elusive; accurately detecting degradation of linear axes is typically a manual and time-consuming process. Manufacturers need automated and efficient methods to diagnose the condition of their machine tool linear axes with minimal disruptions to production. A method was develo...

High speed film of chip formation in coarse and fine microstructures.

In this paper a measurement approach and instrumentation for capturing the dynamic stiffness of a linked system is proposed. The approach is based on the loaded double ball bar (LDBB) in combination with an integral dynamic shaker. The innovation is the introduction of a dynamic load besides the static one given by the LDBB and consequently able to...

The increasing demands for precision and efficiency in machining call for effective control strategies based on the identification of static and dynamic characteristics under operational conditions. The capability of a machining system is significantly determined by its static and dynamic stiffness. The aim of this paper is to introduce novel conce...

Monitoring and control of micromilling process represents a challenging task in metal cutting. The lack of static and dynamic stiffness due to the small tool size represents one of the most important issues that has to be tackled in order to provide satisfactory control of the process. In this paper different methods for identifying micro-end milli...

A novel methodology for linking machining system capability to the accuracy of a machined part is presented. Using special testing equipment, force-deviation functions in the real machine workspace are obtained. An elastically linked multi-body simulation and FE model evaluates the volumetric deviations. The deviation values are then calculated for...

The demand for enhanced performance of production systems in terms of quality, cost and reliability is ever increasing while, at the same time, there is a demand for shorter design cycles, longer operating life, minimisation of inspection and maintenanceneeds. Experimental testing and system identification in operational conditions still represent...

The paper introduces the concept of Elastically Linked Systems (ELS) to directly relate the machine tool positional and static accuracy to the machined part's geometric errors and form deviation. Practical implementation of the ELS concept resulted in a novel test equipment, Loaded Double Ball Bar (LDBB) which is a precision mechatronic device with...

The spindle system is a critical part of a machine tool structure and its dynamic properties are important for the performance of the whole machining system. Currently the only way to extract the dynamic properties of a given structure is via experimental modal analysis. This approach, however, can only be employed on idle systems and is performed...

With advances in material technology come challenges to productivity. New materials are, in fact, more difficult to machine with regards to tool wear and especially machine tool stability. This paper proposes to extend the stability limits of the machining system by enhancing the structure’s damping capability. The aim of the research work presente...

Vibration in metal cutting processes have been studied to a great extent resulting in for instance stability lobe diagrams under which stable machining parameters can be selected. One limitation of accurately estimated stability diagrams is the change in process and dynamic characteristics of the machine tool under operation. The machine tool dynam...

The demand for enhanced performance of production systems in terms of quality, cost and reliability is ever increasing while, at the same time, there is a demand forshorter design cycles, longer operating life, minimisation of inspection and maintenance needs. Experimental testing and system identification in operational conditionsstill represent a...

This paper presents a novel test device for the evaluation of the accuracy of machine tools. The design concept is similar to a double ball bar (DBB) with the difference that an adjustable load generated by the device can be applied between spindle nose and machine tool table. The device, called Loaded Double Ball Bar (LDBB), can be used either as...

This paper presents a study where acoustic imaging technology was employed for problem identification and high damping interfaces (HDI) were implemented in the machine tool structure to improve performance of process machine interaction, in bevel gear cutting, in terms of resistance to instability. Chatter marks at the gear root and tool fracturing...

The aim of this paper is to introduce a novel methodology, based on a finite element (FE) computation engine for simulation of process machine interaction occurring in machining systems. FE modelling of the milling process has the purpose of being accountable for a thorough validation of the parametric identification approach, and of providing a go...

The aim of this paper is to introduce a novel methodology, based on a finite element (FE) computation engine for validating of real-time identification schemes applied in machining. FE modelling of the milling process has the purpose of being accountable for a thorough validation of the parametric identification approach, and of providing a good ph...

The dynamics of many practical engineering systems change during operation. Identification and analysis of time-varying systems require carefully designed system parameters tracking schemes. In machining systems, one important area where time-varying identification methods may be applied is dynamic stability control. The paper presents the computat...

This paper presents a novel test concept for the evaluation of the accuracy of NC machine tools. The evaluation of machine tools deformations is performed by help of a device similar to the double ball bar (DBB) with the difference that an adjustable load generated by the device can be applied between spindle nose and machine tool table. This load...

In today’s highly competitive environment there is a need for fast and accurate methods to assess the capability of manufacturing units. The traditional estimation of the dynamic properties of machine tools is usually time consuming and assumes time-invariant properties. In this paper a method for analyzing machine tool structure dynamic properties...

Cryogenic machining of super alloys increases tool life and improves surface integrity as compared to dry machining. A simultaneous increase in cutting speed and delivery of cryogenic fluid can lead to decreased friction in the cutting zone, which may induce negative process damping effect. At the same time, cryogenic conditions may increase cuttin...

Models of manufacturing resources as machine tools, fixtures and cutting tools contribute to efficient and simplified operation planning. With operation planning domain concept, defined in ontology and used during modelling of coherent ISO 10303 214 conforming data models of manufacturing resources, stable implementation solutions are ensured while...

The key concept of the identification procedure in this paper is to find a feature of the measured random response (sound pressure) that can be used to discriminate between stable and unstable process-machine interaction (PMI) in milling. The dynamic condition of the machining system is represented by the operational dynamic parameters (ODP), which...

This paper introduces a novel design for parting-off tools and the method to characterize their performance. The principle followed in the design phase was to enhance the damping capability minimizing the loss in static stiffness through implementation of composite material interfaces. The tool has been characterized by the dynamic characteristics...

Two important attributes in today’s component manufacturing are high productivity and process accuracy. It has been said, that implementation of CGI as engine material, will reduce these parameters. Nevertheless, the limiting factor is posed by the dynamic effects brought about by the interaction between structural and process parameters during the...

This paper introduces a novel design for boring bar with enhanced damping capability. The principle followed in the design phase was to enhance the damping capability minimizing the loss in static stiffness through implementation of composite material interfaces. The newly designed tool has been compared to a conventional tool. The evaluation crite...

The increasing demands for precision and efficiency of machining ask for development of new control strategies of a machining system based on the identification of its static and dynamic characteristics under operational conditions. This paper presents a procedure for formulating an analytic model of the dynamics of the machining system based on th...