Technology has supplied the drives and motors that operate critical
components within a huge wind simulator capable of recreating the conditions of
a category five hurricane. Motor Technology worked with
Cambridge Consultants who designed a unique wind simulation system for The
University of Western Ontario, in Canada, for use in their pioneering research
into wind damage to domestic housing, known as the Three Little Pigs project.
The vast simulator was designed to operate within the Insurance Research Lab for
Better Homes, a facility big enough for a full size house to be tested. The idea
was to recreate severe wind conditions and monitor their affects on the
structural integrity of complete buildings to the point of destruction.
The unique system designed by Cambridge Consultants involves a series of 100
pressure loading actuators, which are mounted against the walls and roof of the
structure to be tested. Within each actuator is a rapid acting valve system that
allows the simulation of wind pressures, with rates of change up to seven times
a second. Each actuator is linked to a sophisticated control system that
recreates the complex, rapidly changing pressures that would occur in a real
storm, across the entire surface of the house.
Motor Technology supplied a motor and drive
solution for each of the actuators, which would be capable of delivering the
rapid pressure changes. Despite the high performance required Cambridge
Consultants specified a low power consumption requirement because during the
test cycles all 100 drives and motors would be operating at the same time.
To achieve this Motor Technology’s team
designed a custom brushless servo motor, providing 12Nm at 1,000rpm, in a direct
drive configuration to eliminate power losses of around 4% from a gearbox. By
doing this the team were able to reduce current requirement by 15%, achieving a
power saving of 40Amps across all 100 drives.
By utilizing the flexibility of a Metronix servo drive the team were able to use
the standard resolver in the servo drive as an absolute feedback device. This
eliminated the need for separate encoders and made a huge cost saving for the
project. Additionally Metronix expanded the Ethernet capability of the drives to
enable full control over Ethernet. This included full control over the control
loops, power stage, and positioning control, etc.
Thanks to the elimination of unnecessary components such as the gearboxes and
encoders each drive system is completely maintenance free and all drive/motor
packages have operated perfectly since installation. The data collected by
researchers working on the Three Little Pigs project will enable them to better
understand the behaviour of domestic housing during storm conditions. In the
long term this will enable improved building techniques and materials in areas
where destructive storms are common.
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Metronix ARS2000 and Servo Commander PC
Research Lab for Better Homes (1)
Research Lab for Better Homes (2)
Customised motor fitted to pressure loading