Set The Following Error Parameters - Curtis 1222 Manual

Curtis 1222 Manual,
os 15
2 9 J A N U A R Y 2 0 1 3 D R A F T

Set the Following Error parameters

bl
Setting up the following-error function involves setting three parameters:
Supervision» Following Error»
.
Error Time
The parameters
Error Tolerance (deg)
through the equation:
≤
Speed Tolerance (deg/s) Error Tolerance (deg)
360 RPM 360 deg
* * *
1 deg 1
where Gear Ratio = Motor Revs .
Wheel Revs
Note that
ErrorTolerance (deg)
second. ,
LS Sensitivity HS Sensitivity
be entered in decimal form in this equation (e.g., 50% = 0.5). It is recom-
mended that
Speed Tolerance (deg/s)
above equation, to allow some safety factor.
If the gear ratio is not known, it may be determined experimentally by
adjusting the Encoder3 Counts/Degree
after multiple revolutions. The gear ratio can then be calculated as:
Gear Ratio =
Likewise, if the gear ratio is known,
by the above equation. If we then combine these two equations and include
the suggested safety factor of 1/2, we get:
= 0.5 *
Speed Tolerance (deg/s)
Encoder3 Steps
* *
Position Kp
Encoder3 Counts/Degree
The value should be not too large to accept the steady state
Error Tolerance (deg)
error, and not too small to accept the resulting
an of 20° means that no fault will be detected as long as the
Error Tolerance (deg)
is within ±20° of
Wheel Position (deg)
of 20° is allowed, which is probably too high for most applications. If we choose
instead an
Error Tolerance (deg)
for some typical settings of
ance (deg/s)
= 50%, and a gear ratio of 132, we get a
HS Sensitivity
2.9 deg/s. For most applications this is probably too slow for the wheel to be
moving in the right direction without a fault being issued. For most applica-
tions, an
Error Tolerance (deg)
of at least 10 deg/s is often needed to be acceptable.
Tolerance (deg/s)
(see page 47)
Error Tolerance (deg)
and
Speed Tolerance (deg/s)
* Min(
LS Sensitivity
1 Min 1
,
*
Rev 60 s Gear Ratio
is in degrees and
SpeedTolerance (deg/s)
, and
Position Kp
be set to about half the value given by the
Encoder 3 Position (deg)
until the
360 deg .
Encoder3 Counts/Degree
*
* 4 1 Rev
Encoder3 Steps
Encoder3 Counts/Degree
* Min(
Error Tolerance (deg)
.
SpeedTolerance (deg/s)
Steer Command (deg)
of only 2° and calculate the resulting
Position Kp
between 5° and 10° works well. Likewise, a
5 — COMMISSIONING
, , and
Speed Tolerance (deg/s)
are related
, ) *
HS Sensitivity Position Kp
is in degrees/
are all in percent, and should
looks close
may be determined
, )
LS Sensitivity HS Sensitivity
. For example,
. Thus a steady state error
Speed Toler-
= 35%, = 70%,
LS Sensitivity
Speed Tolerance (deg/s)
Speed
of
91