Three Strand Boundary Wire

veritas
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Inscription : sam. janv. 11, 2014 10:18 pm

Three Strand Boundary Wire

Message par veritas »

Thank you for guiding me back to the Husqvarna UK website. I see that there have been recent revisions to the UK market offerings. The 330X now joins the 305 as a second third generation entry. I also have a choice of the 220AC and the 265ACX.

The 265ACX is in a different price league, so the choice is between the 220AC and the 330X, which are priced close enough for me to be considered the same at this stage.

Just looking at the feature comparison, I would prefer the 330X on the grounds of its Li-ion battery, greater gradient capability, lower noise level, two guide wires, longer loop wire and higher cutting capacity in case I get to a 1-robot / 2-base station installation where we will have greater flexibility to manage the inevitable down time with this arrangement.

You may have other views based on experience, however. I am open to advice. I have a nagging feeling I read somewhere that the 330X had suffered some field problems???

Despite these Husqvarna robot mowers being made in the UK, it is a very undeveloped market here compared to reports from mainland Europe where robots are claimed to be a rapidly growing sector. I doubt whether Bosch or Honda would have joined the rush based on what they saw happening in the UK. It is very difficult to find any enthusiasm in the retail network. I am guessing that equipment cost is a great customer deterrent along with fear that they might not work quite as well as claimed, becoming a nightmare to get good technical help in the field.

[URL=http://www.hostingpics.net/viewer.php?id=437753RobotLawnmowerPlan7.jpg][IMG]http://img11.hostingpics.net/pics/437753RobotLawnmowerPlan7.jpg[/IMG][/URL]

With scanner, printer, glue and scissors I have managed to make you a larger scale map and still show the scale bar. Let me know if this is sill not adequate. It is a Government agency that produced the original lines of this map so it ought to be representative.

Oh! I see you have done as good a job by yourself, now. I will study and come back when I have some questions.
South of England
Tired - need of New Approach
JPMalef
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Inscription : dim. avr. 10, 2011 3:59 pm

Three Strand Boundary Wire

Message par JPMalef »

Oh, I didn't look at the products offering in UK, which is very restricted to compare with the continent.

The only issue with the 330X, was in 2013, a restricted availability. This model is supposed to have, in 2014, additional features like ultrasonic sensors. But the few that got one, are very happy.
AM 220AC v2.80
avril 2011
Gembloux (Belgique)
450 m²+700m2
2 pelouses en alternance
automatique
5j/sem. 6 heures
veritas
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Messages : 13
Inscription : sam. janv. 11, 2014 10:18 pm

Three Strand Boundary Wire

Message par veritas »

I need to fully understand the function of the guide wire. Once I understand this better I will be asking if we could gain any advantage from the 330X being able to offer two of these guide wires. For example, could they be used to cut the 85-90cms path between to two main flowerbeds ?

Here is my understanding so far:

Function 1) to provide a faster and more certain return track back to the charging station from wherever the robot is when its battery charge falls below a pre-determined level. This benefit is often identified but seems to me to be quite marginal compared to the alternative way of following the boundary wire back to the charging station. OK it is a shorter route, but would the extra energy drain or time lost by going the longer way round really be significant?

Function 2) to provide a more certain way for the robot to go into narrow areas or areas beyond a narrow bottleneck. I assume the random method finds it hard at the entrance to these areas offering the possibility of missing these altogether. This is obviously an important advantage over the random method, making complex shapes more accessible.


I am still puzzled how this is arranged. You only need to look at the tutorial on the magnetic fields to realise that the robot is expected to ignore the guide wire for lots of its operational time but at other times to react to the guide wires using a different navigational method.

Can you explain how the selectivity works and when it works, including a comment on which operational periods the grass cutting action occurs?
South of England
Tired - need of New Approach
JPMalef
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Inscription : dim. avr. 10, 2011 3:59 pm

Three Strand Boundary Wire

Message par JPMalef »

Well, yes I can. BD

As you perfectly understand, the guide is used to rapidly help the robot to come back to his charging station once the battery fall under a certain level. But it is smarter than that. That certain level is determined historically over the last, let say 18 last grass cutting exercise. It remember the time needed to reach the base station, and deduct this time from his autonomy level, to make sure it will be back on time. Clever isn't?
So, assume there his no guide, it will need a long time to find, randomly, his base station, and reduce his cutting grass time by this amount. So, yes, the installation of a guide is mandatory.
I stress this point because too many vendors pretend that the installation of this guide is not necessary. _o_ I remember somebody's installation where the robot was used to search his base during 35 minutes. After our recommendations, the robot find his station in less than 5 minutes, giving a lot more time to cut the grass.

The next function of the guide is to allow the robot to reach quickly a destination before starting to cut the grass. Let say, in your case, the external part of your land (outside of the moat).

Unfortunately, during the time it is following the guide, it is not cutting the grass. So, no hope to cut the grass between your flowers bed. _o_

To be complete in my explanation, there is another way to come back to the station, the peripheral wire. But in this case, it is not smart. When the robot sense that his battery reach the level of return, and there is no guide, when it reaches the peripheral wire, it follows this wire, randomly, to the right or to the left, and could be forced to make a trip around your property, although it was only 10 meters away from his base.
AM 220AC v2.80
avril 2011
Gembloux (Belgique)
450 m²+700m2
2 pelouses en alternance
automatique
5j/sem. 6 heures
veritas
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Messages : 13
Inscription : sam. janv. 11, 2014 10:18 pm

Three Strand Boundary Wire

Message par veritas »

I read somewhere on this forum that the guide wire feature was a Husqvarna patent. Does this mean that all the other competitor robot lawnmower systems, such as Honda, John Deere, Bosch, Belrobotics or Robomo work without a guide wire, and as a consequence are less efficient or offer less access to small corridors ??

I have another How Does It Work question relevant to my layout.

The charging station is in a main area, but there is also a secondary area joined by a narrow bottleneck. So the guide wire takes the outbound robot through a difficult bottleneck to a small secondary area that normally would not be found if it had not been for the help of the guide wire. The robot starts cutting in this small area randomly. But the guide wire is not in operation, so the robot cannot get back through the bottleneck to the main area until the battery is low and the guide wire becomes operational, taking the robot quickly back to the charging station in the main area. How does the main area ever get cut??

With my charging station at A, the guide wire would take the robot through the bottleneck just to the west side of the Garden Room to the secondary area on the west side of the house.
South of England
Tired - need of New Approach
JPMalef
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Inscription : dim. avr. 10, 2011 3:59 pm

Three Strand Boundary Wire

Message par JPMalef »

From your first paragraph, I don't know how others do. I didn't study them, I am a simple user of the Husqvarna brand. And by personal ethics, I don't criticize others.

Do you remember :
[quote le 18/01/2014 à 11:19:08, JPMalef a dit :]OK, let's start with the inner garden first. [/quote]

From your original drawing, I see up to 5 other spots that could need some grass cutting job, but separated by walking / car driving corridors. To clarify your need/hope, could you please clarify your outer garden needs?

I would suggest you download the manual from the Husqvarna site. I am ready to answer additional questions, and suggest tricks to solve potential issues.

AM 220AC v2.80
avril 2011
Gembloux (Belgique)
450 m²+700m2
2 pelouses en alternance
automatique
5j/sem. 6 heures
veritas
Tondeur débutant
Messages : 13
Inscription : sam. janv. 11, 2014 10:18 pm

Three Strand Boundary Wire

Message par veritas »

Before I move on to the outer garden, do you have an answer to help my understanding of the Guide Wire in the inner garden. Perhaps I was not clear enough in my prior posting.

My lack of understanding is generic as well as applying specifically to my inner garden.

The Guide Wire helps to transport the robot through narrow bottlenecks to cut grass areas beyond it that might not be cut if the robot cut in a random pattern shortly after leaving the charging station.

The system does this because initially, for a period after charging, there is a unique interaction between the robot and guide wire during the journey to, through and beyond the bottleneck. During this period the robot does not cut grass. After this the unique interaction ceases, the robot starts to cut the difficult-to-access area in a random pattern.

My lack of understanding is how the robot gets back through the bottleneck to cut the main area. Just as it was unlikely to go into the difficult-to-access when cutting in a random pattern, surely it will be equally unlikely to come out and will need the unique guide wire interaction again to achieve this.

But the next time the unique interaction between the robot and the guide wire occurs is when the battery is low, after which, the robot travels back along the guide wire to the charging station to begin the cycle again.

If I am seeing this correctly, it would be fair to think that the main grass area around the charging station never gets cut. Where have I gone wrong?

South of England
Tired - need of New Approach
JPMalef
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Messages : 8846
Inscription : dim. avr. 10, 2011 3:59 pm

Three Strand Boundary Wire

Message par JPMalef »

By reading the manual BD, you will discover that you can program the way it will start his job by deciding that in let say 50% of the time it will follow guide 1 during 45 meters (then start to cut), and 20% it will follow peripheral left during 32 meters, and 30% of the time it will start cutting immediately after leaving his station with an angle of 60 degree. .

On the way back, when battery reach the low level, there is another programmable way to decide how it will get back. Search station during X minutes, if not found, search guide for y minutes, else search peripheral.
AM 220AC v2.80
avril 2011
Gembloux (Belgique)
450 m²+700m2
2 pelouses en alternance
automatique
5j/sem. 6 heures
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