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Article
Publication date: 28 August 2007

Luca Bruzzone

Abstract

Details

Industrial Robot: An International Journal, vol. 34 no. 5
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 3 August 2010

Luca Bruzzone and Giorgio Bozzini

The purpose of this paper is to report research which led to the realization of a robot for miniaturized assembly endowed with high‐accuracy and high‐operative flexibility.

Abstract

Purpose

The purpose of this paper is to report research which led to the realization of a robot for miniaturized assembly endowed with high‐accuracy and high‐operative flexibility.

Design/methodology/approach

The proposed solution is a microassembly system composed of a Cartesian parallel robot with flexure revolute joints and a modular gripper with metamorphic fingertips, capable of adapting their shape to different micro‐objects. The fingertips are realized by electro‐discharge machining from a sheet of superelastic alloy. Thanks to its modularity, the gripper can be arranged with two opposite fingers or three fingers placed at 120°. The fingers are actuated by a piezoelectric linear motor with nanometric accuracy.

Findings

The experimental results on the prototype are very interesting. The measured positioning accuracy of the linear motors is 0.5 μm; the end‐effector positioning accuracy is lower, due to the non‐perfect kinematics and hysteresis of the flexure joints; however, these effects can be compensated by the direct measurement of the end effector position or by visual feedback. The metamorphic design of the fingertips remarkably increases the grasping force; moreover, the grasping is more stable and reliable.

Practical implications

The introduction of this microassembly system can fulfil the needs of a wide range of industrial applications, thanks to its accurate positioning in a relatively large workspace. The cost of the machine is relatively low, thanks to its modularity.

Originality/value

The combination of Cartesian parallel kinematics, cog‐free linear motors and superelastic flexure revolute joints allows one to obtain high‐positioning accuracy; the metamorphic fingertips enhance the grasping effectiveness and flexibility.

Details

Assembly Automation, vol. 30 no. 3
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 1 October 2006

Luca Bruzzone and Rezia M. Molfino

Aims to discuss how a Cartesian parallel robot with flexure revolute joints can effectively perform miniaturized assembly tasks.

Abstract

Purpose

Aims to discuss how a Cartesian parallel robot with flexure revolute joints can effectively perform miniaturized assembly tasks.

Design/methodology/approach

The results of the test and validation phase of a Cartesian parallel robot designed for miniaturized assembly are shown. The workspace volume is a cube with 30 mm side and the target accuracy is 1 μm. Each of the three robot legs has a prismatic‐planar architecture, with a cog‐free linear motor and a planar joint realized using ten superelastic flexure revolute joints. Flexure joints are adopted in order to avoid stick‐slip phenomena and reach high positioning accuracy; their patented construction is relatively low‐cost and allows a quick replacement in case of fatigue failure.

Findings

The tests on the prototype are very encouraging: the measured positioning accuracy of the linear motors is ±0.5 μm; on the other hand, the effects of unwanted rotations of flexure joints and hysteresis of the superelastic material are not negligible and must be properly compensated for in order to fully exploit the potential performance of the machine.

Practical implications

The introduction of this robotic architecture can fulfil the needs of a wide range of industrial miniaturized assembly applications, thanks to its accurate positioning in a relatively large workspace. The cost of the machine is low thanks to its extreme modularity.

Originality/value

The combination of Cartesian parallel kinematics, cog‐free linear motors and superelastic flexure revolute joints allows one to obtain very good positioning performance.

Details

Assembly Automation, vol. 26 no. 4
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 14 January 2014

Luca Bruzzone and Pietro Fanghella

The aim of the research is the development of a small-scale ground mobile robot for surveillance and inspection; the main design goals are mobility in indoor environments…

Abstract

Purpose

The aim of the research is the development of a small-scale ground mobile robot for surveillance and inspection; the main design goals are mobility in indoor environments with step climbing ability, pivoting around a vertical axis and without oscillations for stable vision, mobility in unstructured environments, low mechanical and control complexity.

Design/methodology/approach

The proposed hybrid leg-wheel robot is characterized by a main body equipped with two actuated wheels and two praying Mantis rotating legs; a rear frame with two idle wheels is connected to the main body by a vertical revolute joint for steering; a second revolute joint allows the rear axle to roll. The geometrical synthesis of the robot has been performed using a nondimensional approach for generality's sake.

Findings

The experimental campaign on the first prototype confirms the fulfilment of the design objectives; the robot can efficiently walk in unstructured environments realizing a mixed wheeled-legged locomotion.

Practical implications

Thanks to the operative flexibility of Mantis in indoor and outdoor environments, the range of potential applications is wide: surveillance, inspection, monitoring of dangerous locations, intervention in case of terroristic attacks, military tasks.

Originality/value

Different from other robots of similar size, Mantis combines high speed and energetic efficiency, stable vision, capability of climbing over high steps, obstacles and unevenness.

Details

Industrial Robot: An International Journal, vol. 41 no. 1
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 18 April 2008

Gabriella Acaccia, Luca Bruzzone and Roberto Razzoli

The aim of this paper is the development of a modular robotic system for generic industrial applications, including assembly.

Abstract

Purpose

The aim of this paper is the development of a modular robotic system for generic industrial applications, including assembly.

Design/methodology/approach

A library of robotic modules has been designed; they are divided into two categories: link modules, not actuated, and joint modules, actuated; the library is characterized by a relatively low number of elements, but allows the assembly of a wide variety of medium‐size serial robots.

Findings

The prototypes of two joint modules (a revolute joint module and a wrist module) and of some link modules have been realized. The behaviour of several serial robots composed of the designed modules has been assessed by multibody simulation. The results confirm the goodness of the proposed approach.

Research limitations/implications

The two prototype modules are under test in combination with simplified modules. The further steps of the research programme will be the completion of the prototype library, and an experimental campaign on different serial chains.

Practical implications

Modularity allows one to achieve a great variety of robots starting from a small set of modules, in order to match different operative requirements. Moreover, modularity dramatically reduces the time‐to‐repair of the robot and consequently improves its overall availability; this is a fundamental feature for modern industrial enterprises aiming at maximizing the resources availability.

Originality/value

The proposed mechanical design of the revolute joint modules, based on a harmonic drive that connects two bodies in relative rotational motion, is compact and robust. Modularity is not restricted to mechanics: a distributed control system is adopted to make the reconfiguration of the robot easier and quicker.

Details

Assembly Automation, vol. 28 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 3 May 2011

Giuseppe Quaglia, Luca Bruzzone, Giorgio Bozzini, Riccardo Oderio and Roberto P. Razzoli

The purpose of this paper is to describe the development of a robot for surveillance able to move in structured and unstructured environments and able to overcome…

Abstract

Purpose

The purpose of this paper is to describe the development of a robot for surveillance able to move in structured and unstructured environments and able to overcome obstacles with high energetic efficiency.

Design/methodology/approach

The proposed Epi.q‐TG hybrid robot combines wheeled and legged locomotion. It is equipped with four three‐wheeled locomotion units; traction is generated by the two forecarriage units, while the two rear ones have same geometry but are idle. Each front unit is actuated by a single motor with the interposition of an epicyclical gearing, accurately designed in order to suitably switch between wheeled and legged motion. The robot changes locomotion mode from rolling on wheels (advancing mode) to stepping on legs (automatic climbing mode) according to local friction and dynamic conditions.

Findings

The experimental results confirm the design objectives. In advancing mode, the robot behaves like a four‐wheeled vehicle, with high speed and energetic efficiency. In automatic climbing mode, the robot can walk on uneven and soft terrains and overcome steps with remarkable height with respect to its dimensions (up to 84 per cent of the locomotion unit height).

Practical implications

Besides surveillance, Epi.q‐TG can be successfully used in many tasks in which it is useful to combine the advantages of wheeled and legged locomotion, e.g. unmanned inspection of nuclear and chemical sites, minesweeping, and intervention in disaster zones.

Originality/value

The core of the project is the epicyclical mechanism of the locomotion unit, which switches between advancing mode and automatic climbing mode without control action. This solution limits the control and actuation complexity and consequently the robot cost, widening the range of possible applications.

Details

Industrial Robot: An International Journal, vol. 38 no. 3
Type: Research Article
ISSN: 0143-991X

Keywords

Content available
Article
Publication date: 19 June 2009

Abstract

Details

Industrial Robot: An International Journal, vol. 36 no. 4
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 10 April 2007

Luca Di Rienzo and Jens Haueisen

To define a methodology for comparing sensor arrays for solving magnetostatic linear inverse problems.

Abstract

Purpose

To define a methodology for comparing sensor arrays for solving magnetostatic linear inverse problems.

Design/methodology/approach

A singular value decomposition related projection method is used for comparing sensor arrays and we applied it to a biomagnetic inverse problem, as an example. Furthermore, a theoretical reference sensor system is introduced and used as a benchmark for the analysed sensor arrays.

Findings

The method has turned out to be effective in comparing three different theoretical sensor arrays, showing the superiority of the two arrays constituted by three‐axial sensors.

Research limitations/implications

The method has been applied only to the case of over‐determined problems. The underdetermined case will be considered in future work.

Practical implications

From the applicative point of view, the illustrated methodology is useful when one has to choose between existing sensor arrays or in the design phase of a new sensor array.

Originality/value

A new methodology is proposed for comparing sensor arrays. The advantage of the methodology are to take into account the regularization in the solution of the inverse problem and to be general, not depending on a particular source configuration.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 26 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 27 September 2011

Ryspek Usubamatov and K.W. Leong

The purpose of this paper is to investigate theoretically the process of jamming in the peg‐hole type parts and to derive a mathematical model of jamming.

Abstract

Purpose

The purpose of this paper is to investigate theoretically the process of jamming in the peg‐hole type parts and to derive a mathematical model of jamming.

Design/methodology/approach

The mathematical model of the jamming of the peg‐hole type parts in assembly process was performed and its boundary conditions, which lead to jamming, defined.

Findings

The equation of the critical angles of declination for the peg, which leads to the peg‐hole jam, was derived. The boundary condition of the angles of declination and the depth of the peg insertion into the hole were defined.

Research limitations/implications

A mathematical model is developed for rigid parts with a hole and for the peg clamped in the rigid assembly mechanisms. The research has not considered flexible deformations and stiffness of the assembly mechanisms, which result in the peg's declination in the assembly process.

Practical implications

The results are represented in the form of the peg's critical angles of declination and critical depth of insertion into the hole, which leads to jamming of the peg‐hole type parts to be assembled. On the basis of the obtained results, it is possible to formulate the tolerances of the declination angles for the assembly mechanisms, which clamp the peg‐type parts.

Originality/value

The proposed method calculating the critical angles of the peg's declination and critical depth of the peg's insertion into the hole for assembly of the peg‐hole type parts, enables one to increase the reliability of the assembly process in the manufacturing industry.

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Article
Publication date: 27 April 2012

Chu Xiaobing, Gao Feng and Ge Hao

The purpose of this paper is to present the direct kinematic analysis of a heavy‐payload forging manipulator. In the grasping stage, the manipulator is equivalent to a…

Abstract

Purpose

The purpose of this paper is to present the direct kinematic analysis of a heavy‐payload forging manipulator. In the grasping stage, the manipulator is equivalent to a 3‐DOF under‐actuated mechanism. In order to deal with the direct position kinematics of the under‐actuated mechanism, the analysis is performed in two steps.

Design/methodology/approach

The paper analyzes the direct position kinematics of the 3‐DOF under‐actuated mechanism as follows: first, the authors add a virtual constraint on the mechanism, convert it to a 2‐DOF fully actuated mechanism and calculate the direct kinematics of the constrained mechanism. Then, the constraint is applied to many different positions and the corresponding direct kinematics of the constrained mechanism are calculated, respectively. Finally, the mechanism with lower gravitational potential energy than any other constrained mechanism is chosen, and its direct position is what is needed for the 3‐DOF underactuated mechanism.

Findings

The paper provides a solution for the direct kinematic analysis of a heavy‐payload forging manipulator in the grasping stage. Furthermore, the simulation and experiment results confirm the effectiveness of the solution.

Originality/value

The paper proposes a methodology to deal with the direct position kinematics of the 3‐DOF under‐actuated mechanism in two steps.

Details

Industrial Robot: An International Journal, vol. 39 no. 3
Type: Research Article
ISSN: 0143-991X

Keywords

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