Robot work envelope Automation New – Better Definition
The space in which a robot can operate is its
work envelope, which encloses its workspace. While the workspace of the robot
defines positions and orientations that it can achieve to accomplish a task,
the work envelope also includes the volume of space the robot itself occupies
as it moves. This envelope is defined by the types of joints, their range of movement and the lengths of the links
that connect them. The physical size of
this envelope and the loads on the robot within this envelope are of primary
consideration in the design of the mechanical structure of a robot.
Robot work envelope layouts must include
considerations of regions of limited accessibility where the mechanical
structure may experience movement limitations. These constraints arise from
limited joint travel range, link lengths, the angles between axes, or a combination
of these. Revolute joint manipulators generally work better in the middle of
their work envelopes than at extremes. Manipulator link lengths and joint
travel should be chosen to leave margins for variable sensor-guided controlled
path motions and for tool or end-effector changes, as offsets and length
differences will often alter the work envelope.
(Springer Handbook of Robotics, 2008, Bruno
Siciliano, Oussama Khatib, P 68)
Previous:
Robot reach or more commonly referred to as the work envelope describes the operational range of an industrial robot. All robots have a work envelope or reach capability dependant upon their particular design. For example, Cartesian robots work within a cube as shown in figure 12.5. (Computer Integrated Manufacturing - Alavudeen and Venkateshwaran - page 251 )
Operatin hazard analysis (OHA)
Management Analysis
New- Better Definition
Purpose:The purpose of the OHA is to
identify and analyze hazards associated with personnel and procedures during
production, installation, testing, training, operations, maintenance, and
emergencies.
Procedure: The OHA will be conducted on all tasks and
human actions, including acts of omission and commission, by persons
interacting with the system, subsystems and assemblies, al any level. When the
OHA indicates a potential safety hazard, it will be made known to the
responsible engineer to initiate a design review or a system safely working
group action item. The OHA will be reviewed on a continuous basis to provide
for design modifications, procedures, testing, etc.. that do not create
hazardous conditions.
Results: The OHA will provide for corrective or
preventive measures to be taken to minimize the possibility that any human
error or procedure will result in injury or system damage. The OHA will provide
inputs for recommendations for changes or improvements in design or procedures
to improve efficiency and safety, development of warning and caution notes to
be included in manuals and procedures, and the requirement of special training
of personnel who will carry out the operation and maintenance of the system.
(Hazard analysis guidelines
for transit projects, DIANE Publishing, P21)
Previous:
The purpose of the operating and support hazard analysis, sometimes called the operating hazard analysis, is to
1. Identify all hazard in the operation of a system tahat are inherently dangerous to personnel, or in which a human error could be hazardous to equipment or people
2. Provide recommended risk reduction alternatives during all phases of tasks or operations that are controlledby written procedures
Simply stated, the O&SHA encompassed an analytical review of the controlling documents to ensure hazard elimination or control and concentrates heavily on the performance of people (human factors and human behaviors) and their relationship to the hazards within the task. The focus is primarily on the maintenance and operation of the system, rather than the system components themselves. ( Basic Guide to System safety - Jeffrey W.Vincoli - page 93)
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