2,871 research outputs found
A Sensor Classification Strategy for Robotic Manipulators
In practice the robotic manipulators present some degree of unwanted vibrations. The
advent of lightweight arm manipulators, mainly in the aerospace industry, where weight is
an important issue, leads to the problem of intense vibrations. On the other hand, robots
interacting with the environment often generate impacts that propagate through the
mechanical structure and produce also vibrations.
In order to analyze these phenomena a robot signal acquisition system was developed. The
manipulator motion produces vibrations, either from the structural modes or from endeffector
impacts. The instrumentation system acquires signals from several sensors that
capture the joint positions, mass accelerations, forces and moments, and electrical currents
in the motors. Afterwards, an analysis package, running off-line, reads the data recorded by
the acquisition system and extracts the signal characteristics.
Due to the multiplicity of sensors, the data obtained can be redundant because the same
type of information may be seen by two or more sensors. Because of the price of the sensors,
this aspect can be considered in order to reduce the cost of the system. On the other hand,
the placement of the sensors is an important issue in order to obtain the suitable signals of
the vibration phenomenon. Moreover, the study of these issues can help in the design
optimization of the acquisition system. In this line of thought a sensor classification scheme
is presented.
Several authors have addressed the subject of the sensor classification scheme. White
(White, 1987) presents a flexible and comprehensive categorizing scheme that is useful for
describing and comparing sensors. The author organizes the sensors according to several
aspects: measurands, technological aspects, detection means, conversion phenomena, sensor
materials and fields of application. Michahelles and Schiele (Michahelles & Schiele, 2003)
systematize the use of sensor technology. They identified several dimensions of sensing that
represent the sensing goals for physical interaction. A conceptual framework is introduced
that allows categorizing existing sensors and evaluates their utility in various applications.
This framework not only guides application designers for choosing meaningful sensor subsets, but also can inspire new systems and leads to the evaluation of existing
applications.
Today’s technology offers a wide variety of sensors. In order to use all the data from the
diversity of sensors a framework of integration is needed. Sensor fusion, fuzzy logic, and
neural networks are often mentioned when dealing with problem of combing information
from several sensors to get a more general picture of a given situation. The study of data
fusion has been receiving considerable attention (Esteban et al., 2005; Luo & Kay, 1990). A
survey of the state of the art in sensor fusion for robotics can be found in (Hackett & Shah,
1990). Henderson and Shilcrat (Henderson & Shilcrat, 1984) introduced the concept of logic
sensor that defines an abstract specification of the sensors to integrate in a multisensor
system.
The recent developments of micro electro mechanical sensors (MEMS) with unwired
communication capabilities allow a sensor network with interesting capacity. This
technology was applied in several applications (Arampatzis & Manesis, 2005), including
robotics. Cheekiralla and Engels (Cheekiralla & Engels, 2005) propose a classification of the
unwired sensor networks according to its functionalities and properties.
This paper presents a development of a sensor classification scheme based on the frequency
spectrum of the signals and on a statistical metrics.
Bearing these ideas in mind, this paper is organized as follows. Section 2 describes briefly
the robotic system enhanced with the instrumentation setup. Section 3 presents the
experimental results. Finally, section 4 draws the main conclusions and points out future
work
Overcoming barriers and increasing independence: service robots for elderly and disabled people
This paper discusses the potential for service robots to overcome barriers and increase independence of
elderly and disabled people. It includes a brief overview of the existing uses of service robots by disabled and elderly
people and advances in technology which will make new uses possible and provides suggestions for some of these new
applications. The paper also considers the design and other conditions to be met for user acceptance. It also discusses
the complementarity of assistive service robots and personal assistance and considers the types of applications and
users for which service robots are and are not suitable
\u3cem\u3eGRASP News\u3c/em\u3e, Volume 8, Number 1
A report of the General Robotics and Active Sensory Perception (GRASP) Laboratory. Edited by Thomas Lindsay
Importance and applications of robotic and autonomous systems (RAS) in railway maintenance sector: a review
Maintenance, which is critical for safe, reliable, quality, and cost-effective service, plays a dominant role in the railway industry. Therefore, this paper examines the importance and applications of Robotic and Autonomous Systems (RAS) in railway maintenance. More than 70 research publications, which are either in practice or under investigation describing RAS developments in the railway maintenance, are analysed. It has been found that the majority of RAS developed are for rolling-stock maintenance, followed by railway track maintenance. Further, it has been found that there is growing interest and demand for robotics and autonomous systems in the railway maintenance sector, which is largely due to the increased competition, rapid expansion and ever-increasing expense
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