Chatter is a self-excited vibration that can occur during machining operations and become a common limitation to productivity and part quality. For this reason, it has been a topic of industrial and academic interest in the manufacturing sector for many years. A great deal of research has been carried out since the late 1950s to solve the chatter problem. Researchers have studied how to detect, identify, avoid, prevent, reduce, control, or suppress chatter. This paper reviews the state of research on the chatter problem and classifies the existing methods developed to ensure stable cutting into those that use the lobbing effect, out-of-process or in-process, and those that, passively or actively, modify the system behaviour.

Chatter in machining processes: A review

Chatter suppression techniques in metal cutting

Chatter vibrations are present in almost all cutting operations and they are major obstacles in achieving desired productivity. Regenerative chatter is the most detrimental to any process as it creates excessive vibration between the tool and the workpiece, resulting in a poor surface finish, high-pitch noise and accelerated tool wear which in turn reduces machine tool life, reliability and safety of the machining operation. There are various techniques proposed by several researchers to predict and detect chatter where the objective is to avoid chatter occurrence in the cutting process in order to obtain better surface finish of the product, higher productivity and tool life. In this paper, some of the chatter stability prediction, chatter detection and chatter control techniques for the turning process are reviewed to summarize the status of current research in this field. The objective of this review work is to compare different chatter stability prediction, chatter detection and chatter control techniques to find out most suitable technique/s and to identify a research scope in this area. One scope of research has been identified as establishing a theoretical relationship between chatter vibration and tool wear in order to predict tool wear and tool life in the presence of chatter vibration.

A review of chatter vibration research in turning

Recent advances in micro-vibration isolation

Vibration absorbers for chatter suppression: A new analytical tuning methodology

A six-axis single-stage active vibration isolator based on Stewart platform

The motivation of the work is twofold: (a) understand the physics behind regenerative chatter and the influence of structural damping and (b) demonstrate an active damping technique based on collocated actuator/sensor pairs. A numerical stability analysis is performed using the root locus method and it is shown that, along with the structural poles, eigenvalues due to the delay parameter may contribute to instability. Since experimental demonstration of chatter in real machines is difficult, an alternative way of demonstration via a mechatronic simulator is presented, using the ‘hardware-in-the-loop’ concept. The mathematical model of the regenerative cutting process in turning is simulated in a computer and this is interfaced to a beam, representing the structural dynamics of the machine, via a displacement sensor and force actuator. In this way, a hardware and a software loop are combined. In a second step, an additional control loop is added, consisting of an accelerometer sensor and a collocat...

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Active damping of chatter in machine tools: demonstration with a “hardware-in-the-loop” simulator

This paper presents the development of SAM, the Sensoric Arm Master, a 7-DOF portable exoskeleton with integrated actuation and sensors. Local joint control is implemented to improve performances of the device. Some experiments have been conducted with the system to show the functionality of the exoskeleton device linked to a virtual reality.

SAM : A 7-DOF portable arm exoskeleton with local joint control

This aricle presents a novel, computer controlled, magneto-rheological (MR) brake actuated, muscular rehabilitation, and evaluation device. The first part discusses various MR brake architectures and compares them. Simple analytical formulae are developed for a set of figures of merit, which point out the role played by the various parameters. Based on this analysis, a prototype with a T-shaped rotor has been designed, built and integrated into a portable rehabilitation device. In the second part of the article, the various exercise modes of the device and its control are described. Finally, results validating the performances of the device for the pronation/supination motion of the wrist are shown.

Computer Controlled Rotational MR-brake for Wrist Rehabilitation Device

This paper describes a passive six-axis vibration isolation system for space applications. The system consists of a Stewart platform with cubic architecture; each leg is equipped with an electromagnetic transducer connected to a RL circuit. The system behaves like a relaxation isolator and its transmissibility exhibits an asymptotic decay rate of ―40 dB/decade. The performances are very similar to that of an active isolator based on a skyhook controller.

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Mihaita Horodinca

Papers

A six-axis single-stage active vibration isolator based on Stewart platform

Active damping of chatter in machine tools: demonstration with a “hardware-in-the-loop” simulator

SAM : A 7-DOF portable arm exoskeleton with local joint control

Computer Controlled Rotational MR-brake for Wrist Rehabilitation Device

Vibration Isolation of Precision Payloads: A Six-axis Electromagnetic Relaxation Isolator