1,720,978 research outputs found
Design of a device for stability control system, to decouple loads, for an optimised maintenance in hostile environment
No full textA lunar rover leg: Optimal design of a decoupling joint
No full textThe development of vehicles for the exploration in the lunar environment is a topic of great interest. In particular, recently, there has been a growing attention toward the lunar rovers for working missions since the building of lunar bases is a primary objective for the lunar exploration. However, these vehicles have peculiar requirements to be taken into account in the design of each component. In this paper a particular component of a worker rover, developed as a collaboration between two academic institutions, has been designed for an optimal functionality. Each leg of this rover comprises a mechanism for lifting weights and the component considered, a decoupling joint, is a part of this mechanism. The design optimization was performed by means of parametric modelling and numerical simulations
A working lunar rover: passive gripper mechanism and actuated leg
No full textIn this paper two particular subsystems of a worker rover, developed as a collaboration between two academic institutions, has been described for an optimal functionality. The rover has a gripper mechanism and four legs: these components are the on board mechanical subsystems. The gripper mechanism, described in the paper, is designed to operate without motors and the leg of this rover comprises a mechanism for lifting weights and has a decoupling structural joint. The design optimization was performed by means of parametric modelling and numerical simulations
Design of a prototype system operant in lunar environment
No full textIn this paper, the design of a prototype system developed for a rover intended for the removal and transport of rocks on lunar soil is reported. The part of the rover dedicated to some of the main tasks, i.e. the lifting of objects and moving on rugged terrain, while controlling of the balance of the vehicle, is considered. These tasks are accomplished through the mechanical components assembled in a column connected to wheels. The study has been conducted with the aim of obtaining a simple and lightweight structure satisfying the requirements necessary to operate on the lunar soil. After a description of the architecture of the rover, the layout of the components of the column is detailed. A compliant, spiral-spring wheel is proposed to complete the mobility system. The primary components of the column are then structurally assessed by means of FEM numerical simulations. A numerical model of the wheel has also been implemented, in order to define in detail the wheel geometry and performance. The proposed layout could be promising for lunar applications since it has a configuration suitable for the specific characteristics of the environment it has to operate
A working lunar rover: Passive gripper mechanism and actuated leg
No full textIn this paper two particular subsystems of a worker rover, developed as a collaboration between two academic institutions, has been described for an optimal functionality. The rover has a gripper mechanism and four legs: these components are the on board mechanical subsystems. The gripper mechanism, described in the paper, is designed to operate without motors and the leg of this rover comprises a mechanism for lifting weights and has a decoupling structural joint. The design optimization was performed by means of parametric modelling and numerical simulations. © 2010 IEEE
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
An integrated device for saffron flowers detaching and harvesting
No full textThis work is concerned with a mechanical system designed to harvest Crocus Sativus (saffron) flowers. The system is conceived as a shoulder portable device with two main parts: the first one is specifically designed to detach the flower containing three stigmas, which are the costly final product; the second one is aimed to collect the detached flower through a vacuum collector. The system is carried by the human operator on his back. This paper describes the operating principle of the detaching and of the harvesting devices. The former device imitates one of the procedures followed by the pickers but with the peculiarity that allows to harvest the flower without separating it from its leaves, which is a significant advantage since it simplifies the mechanical detachment of the flower. The paper also deals with some experimental tests in the laboratory carried out in order to highlight the dynamic behaviour of the detaching and of the harvesting devices. © 2010 IEEE
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