Introduction
© 2009 Hirschmann Automation and Control GmbH · Branch Office Ettlingen · eMail: [email protected] · www.hirschmann.com
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24 183 19 1012e (Generic) / 2009-02-26 / Rev. 01 / rk.
3.
SYSTEM DESCRIPTION
The iVISOR
mentor QVGA
load moment indicator system comprises a central microprocessor unit
with an integrated display and control console together with various sensors to record the measured
values.
Fig. 1: Components of the
iVISOR
mentor QVGA
LMI system (without optional extras)
The system operates on the principle of reference/real comparison. The actual value is compared
with the calculated reference values and evaluated by the system. An overload warning signal is
triggered on the display and operating console once limit values are reached. All crane movements
that increase the load moment are switched off at the same time.
The crane-specific data specified by the manufacturer, such as load capacity charts, boom weights,
centers of gravity and dimensions, are stored in the central data memory. This data is the reference
information used to calculate the operating conditions.
The boom angle and length is measured by means of an length/angle sensor that is mounted on the
boom. The crane load is determined indirectly with the aid of pressure transducers.
The operating console is located in the operator's cab in plain view of the crane operator. All displays
and operating elements have background illumination for enhanced ease of recognition. The console
contains various operating elements as well as a multifunction LC display, all of which are described
in detail in chapter 3.2
The contrast of the LC display is adjustable manually in accordance with ambient light levels.