With my a-spinnaker up in 6 knots of breeze I have no problem with my
autopilot, but when I went out yesterday in 15 knots, my autopilot was
not assertive enough to control the boat.

When I set it to keep the 120 degrees off the wind, it completly failed
to do that. Tending to head down, even after the chute collapsed, it
wouldn't return to 120 degrees. If I had not taken control it would
have jibbed.

When instead I set a specific course, it headed up (slowly at first),
not using enough rudder to prevent the boat from heading up and not
reacting at all to puffs that rounded the boat up faster. I repeated
going to standby, turning my boat until about 115 degrees off the wind,
and pressing AUTO again. Each time I repeated this, I experienced
1. The moment I press auto, she instantly reduces the amount of rudder
I was giving by just a little bit, but enough to cause the boat to
start heading up.
2. The autopilot eventually give more rudder, but reacts too slowly to
prevent us from rounding into the wind.

I have a ST-7001, S1G core pack + added gyro, and auto learn feature.
Since the boat handles so differently under sail, then under motor, I
wonder if the "autolearn" feature has taught itself to not be aggresive
enough.

What's the solution ?

"b393capt" wrote in
oups.com:

With my a-spinnaker up in 6 knots of breeze I have no problem with my
autopilot, but when I went out yesterday in 15 knots, my autopilot was
not assertive enough to control the boat.

When I set it to keep the 120 degrees off the wind, it completly failed
to do that. Tending to head down, even after the chute collapsed, it
wouldn't return to 120 degrees. If I had not taken control it would
have jibbed.

When instead I set a specific course, it headed up (slowly at first),
not using enough rudder to prevent the boat from heading up and not
reacting at all to puffs that rounded the boat up faster. I repeated
going to standby, turning my boat until about 115 degrees off the wind,
and pressing AUTO again. Each time I repeated this, I experienced
1. The moment I press auto, she instantly reduces the amount of rudder
I was giving by just a little bit, but enough to cause the boat to
start heading up.
2. The autopilot eventually give more rudder, but reacts too slowly to
prevent us from rounding into the wind.

I have a ST-7001, S1G core pack + added gyro, and auto learn feature.
Since the boat handles so differently under sail, then under motor, I
wonder if the "autolearn" feature has taught itself to not be aggresive
enough.

What's the solution ?

I would experiment with the Rudder Gain and Response settings. You probably
need to increase the Reponse level.

-- Geoff

I would experiment with the Rudder Gain and Response settings. You
probably
need to increase the Reponse level.

Yes, those would certainly affect it. Do you have the installation manual
for the autopilot? It details how to set these values during the Sea Trial
Calibration. I did just the same thing last week for our S1 equipped
powerboat.

-Bill Kearney

Yes,

I have the instructions, and have done the seatrial, the deviation
result was 3. I have been happy with the results since. I had settled
on a response level of 5 out of 9 (the gyro changes the range from 1-3,
to 1-9), but did not try in the middle of my a-spinnaker troubles
yesterday.

Besed on this feedback, I will read up on Rudder Gain, and be ready to
change that and Response next time this occurs.

Dan


Bill Kearney wrote:
I would experiment with the Rudder Gain and Response settings. You
probably
need to increase the Reponse level.

Yes, those would certainly affect it. Do you have the installation manual
for the autopilot? It details how to set these values during the Sea Trial
Calibration. I did just the same thing last week for our S1 equipped
powerboat.

-Bill Kearney

b393capt wrote:
Yes,

I have the instructions, and have done the seatrial, the deviation
result was 3. I have been happy with the results since. I had settled
on a response level of 5 out of 9 (the gyro changes the range from
1-3, to 1-9), but did not try in the middle of my a-spinnaker troubles
yesterday.

Besed on this feedback, I will read up on Rudder Gain, and be ready to
change that and Response next time this occurs.

Dan


Bill Kearney wrote:
I would experiment with the Rudder Gain and Response settings. You
probably need to increase the Reponse level.

Yes, those would certainly affect it. Do you have the installation
manual for the autopilot? It details how to set these values during
the Sea Trial Calibration. I did just the same thing last week for
our S1 equipped powerboat.

-Bill Kearney

My memory of sailing a yawing boat under spinnaker is that anticipation of
what the boat was going to do next was the main problem, but the old
brainbox used to anticipate after a short period at the helm. With wind and
sea state variations to contend with, it's asking a lot to program these
into a piece of hardware, no matter what you do! Do computers really
anticipate and react to what the future is about to bestow on us?

Dennis.

I don't think I am asking to much. The autopilot does a mighty fine job
(after I added the gyro) of keeping the boat steady in many sea states,
including following seas.

Dennis Pogson wrote:
b393capt wrote:
Yes,

I have the instructions, and have done the seatrial, the deviation
result was 3. I have been happy with the results since. I had settled
on a response level of 5 out of 9 (the gyro changes the range from
1-3, to 1-9), but did not try in the middle of my a-spinnaker troubles
yesterday.

Besed on this feedback, I will read up on Rudder Gain, and be ready to
change that and Response next time this occurs.

Dan


Bill Kearney wrote:
I would experiment with the Rudder Gain and Response settings. You
probably need to increase the Reponse level.

Yes, those would certainly affect it. Do you have the installation
manual for the autopilot? It details how to set these values during
the Sea Trial Calibration. I did just the same thing last week for
our S1 equipped powerboat.

-Bill Kearney

My memory of sailing a yawing boat under spinnaker is that anticipation of
what the boat was going to do next was the main problem, but the old
brainbox used to anticipate after a short period at the helm. With wind and
sea state variations to contend with, it's asking a lot to program these
into a piece of hardware, no matter what you do! Do computers really
anticipate and react to what the future is about to bestow on us?

Dennis.

b393capt wrote:
With my a-spinnaker up in 6 knots of breeze I have no problem with my
autopilot, but when I went out yesterday in 15 knots, my autopilot was
not assertive enough to control the boat.

When I set it to keep the 120 degrees off the wind, it completly failed
to do that. Tending to head down, even after the chute collapsed, it
wouldn't return to 120 degrees. If I had not taken control it would
have jibbed.

When instead I set a specific course, it headed up (slowly at first),
not using enough rudder to prevent the boat from heading up and not
reacting at all to puffs that rounded the boat up faster. I repeated
going to standby, turning my boat until about 115 degrees off the wind,
and pressing AUTO again. Each time I repeated this, I experienced
1. The moment I press auto, she instantly reduces the amount of rudder
I was giving by just a little bit, but enough to cause the boat to
start heading up.
2. The autopilot eventually give more rudder, but reacts too slowly to
prevent us from rounding into the wind.

I have a ST-7001, S1G core pack + added gyro, and auto learn feature.
Since the boat handles so differently under sail, then under motor, I
wonder if the "autolearn" feature has taught itself to not be aggresive
enough.

What's the solution ?



Bump up the gain/rudder response. I used a Navico hydraulic pilot on
my last boat (30' cutter). Way overkill but I really had to increase
the gain when reaching with an oversize chute, even in flat water.

Evan Gatehouse

b393capt wrote:
With my a-spinnaker up in 6 knots of breeze I have no problem with my
autopilot, but when I went out yesterday in 15 knots, my autopilot was
not assertive enough to control the boat.

When I set it to keep the 120 degrees off the wind, it completly failed
to do that. Tending to head down, even after the chute collapsed, it
wouldn't return to 120 degrees. If I had not taken control it would
have jibbed.

When instead I set a specific course, it headed up (slowly at first),
not using enough rudder to prevent the boat from heading up and not
reacting at all to puffs that rounded the boat up faster. I repeated
going to standby, turning my boat until about 115 degrees off the wind,
and pressing AUTO again. Each time I repeated this, I experienced
1. The moment I press auto, she instantly reduces the amount of rudder
I was giving by just a little bit, but enough to cause the boat to
start heading up.
2. The autopilot eventually give more rudder, but reacts too slowly to
prevent us from rounding into the wind.

I have a ST-7001, S1G core pack + added gyro, and auto learn feature.
Since the boat handles so differently under sail, then under motor, I
wonder if the "autolearn" feature has taught itself to not be aggresive
enough.

What's the solution ?


As I understand you use your autopilot with a wind-vane and I am not
even sure that, in this configuration, the signal from the gyro is used
at all. If it is so, you should be aware that the wind-vane is sensitive
to the direction and intensity solely of the "apparent wind"; it is a
well known issue that wind steering has problems when going downwind due
by the "funny" behavior of the vector composition of the real-wind plus
the velocity-wind. Not to mention the wind disturbance at the vane
produced by rolling and yawing which may be quite important in some
situations.
Beside this, as an old timer wind-sailor, I would never rely on an
autopilot under spinnaker especially on a wind higher than, say, 10-12
knots.
So I am afraid that the solution is: under spinnaker, switch off the
autopilot and use a good helmsman... :-)

Regards
Daniel

Daniele Fua wrote:
b393capt wrote:
With my a-spinnaker up in 6 knots of breeze I have no problem with
my autopilot, but when I went out yesterday in 15 knots, my
autopilot was not assertive enough to control the boat.

When I set it to keep the 120 degrees off the wind, it completly
failed to do that. Tending to head down, even after the chute
collapsed, it wouldn't return to 120 degrees. If I had not taken
control it would have jibbed.

When instead I set a specific course, it headed up (slowly at first),
not using enough rudder to prevent the boat from heading up and not
reacting at all to puffs that rounded the boat up faster. I repeated
going to standby, turning my boat until about 115 degrees off the
wind, and pressing AUTO again. Each time I repeated this, I
experienced
1. The moment I press auto, she instantly reduces the amount of
rudder I was giving by just a little bit, but enough to cause the
boat to start heading up.
2. The autopilot eventually give more rudder, but reacts too slowly
to prevent us from rounding into the wind.

I have a ST-7001, S1G core pack + added gyro, and auto learn feature.
Since the boat handles so differently under sail, then under motor, I
wonder if the "autolearn" feature has taught itself to not be
aggresive enough.

What's the solution ?


As I understand you use your autopilot with a wind-vane and I am not
even sure that, in this configuration, the signal from the gyro is
used at all. If it is so, you should be aware that the wind-vane is
sensitive to the direction and intensity solely of the "apparent
wind"; it is a well known issue that wind steering has problems when
going downwind due by the "funny" behavior of the vector composition
of the real-wind plus the velocity-wind. Not to mention the wind
disturbance at the vane produced by rolling and yawing which may be
quite important in some situations.
Beside this, as an old timer wind-sailor, I would never rely on an
autopilot under spinnaker especially on a wind higher than, say, 10-12
knots.
So I am afraid that the solution is: under spinnaker, switch off the
autopilot and use a good helmsman... :-)

Regards
Daniel

I've already told him this but he has flatly rejected my contention that
computers can't anticipate, which is what a good helmsman can do! You are
wasting your time on this one.

Dennis,

This was insulting.

Dan

Dennis Pogson wrote:
I've already told him this but he has flatly rejected my contention that
computers can't anticipate, which is what a good helmsman can do! You are
wasting your time on this one.