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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

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

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