3.22EjemploDRM007 Co..

Introduction and Setup
Washing Machine Application’s Overview
follow different shapes, such as square, trapezoidal or sinusoidal
shapes. That is why the reference speeds in this design are taken from
a table, leaving the user to customize the movement and test different
patterns. From a mechanical point of view, a sinusoid agitator movement
has less clothes damage, due to the smooth movement of the washer.
1.6.2 Agitator Hits
When washing, there are two important design considerations on each
hit of the agitator:
• One is the angular displacement of the agitator in each hit.
Modifying the reference speeds curve and calculating the integral
of the entire hit can change this displacement.
• The other parameter is the frequency at which the table of
reference speeds is accessed, giving different hits per minute in
the washer.
1.6.3 Software
The software for this reference design drives a brushless dc motor in the
four quadrants, which means that the motor can be reversed without any
need of stopping the motor first. This driver capability is very useful in
washers because of the water inertia in the washing machine.
1.6.4 User’s Menu
A user menu with a 16 x 2 character display and two push buttons was
included in the reference design board. This menu provides useful
information during operation.
1.6.5 Control Scheme
The closed loop control scheme becomes necessary in this application
to have more robustness in the washer operation, such as load change,
input voltage variations, or mechanical degradations.
BLDC Motor Control Board for Industrial and Appliance Applications
DRM007
MOTOROLA Introduction and Setup 29