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Post by hexpod on May 10, 2016 15:56:48 GMT
Hi all,
I made a small attempt to the "conversion to centimeters" that was already mentioned by Thanos somewhere in this forum.
The final goal would be to provide not only geometrically accurate driving solution but also a ultimate design software. In fact, with a couple of small code changes, every builder, could almost get rid of complicated 3d design, and the difficult task of finding the best compromise, ("size/motion range/joints limitations") could became a piece of cake.
I've reported base and platform attach points on a coordinates system while scaled to ratio 1:1. and it looks like this:
Than I've modified it in a way, that both, base and platform fit into a circle of 100 units.
By doing this, instead of complicated ratio relations, you have a clear units displayed in the GUI.
ex. ratio 0.89 means 89cm and platform height and lever length are now in cm.
Actually, to make out of this plugin a complete design/driving solution, couple of variables has to be added.
1.) priority
Two sliders in the GUI, with ability to change the motor and upper joints spacing, without increasing the coordinate circle.
(The main issue is, that for now, if you want to increase base or platform circle, the spacing between the motors or/and upper joints are increasing proportionally to the circle. In order to provide the design flexibility this has to be dissociated.)
2.) priority
Two sliders with "starting position offset" (heave and surge) and the ability to save the offset in the .ini file. (the variable exist already in the code)
3.)
One slider for servo orientation for a complete design flexibility. (the variable exist already in the code)
4.) Also, the sensitivity to the "out of reach" limiter could be added, in order to provide to the user the choice between "pure dof response" and better motion range.
That's all.
all the best
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Post by vicpopo on May 10, 2016 19:06:27 GMT
Hi Hexapod,
Just try to play with it. One first notice , why for the pitch the forward angle isn't the same as the backward .With the other plugin both are the same with one set parameters ? and sorry but not really understood your explaination to describe what you changed !
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Post by hexpod on May 10, 2016 19:37:26 GMT
Hi Hexapod, Just try to play with it. One first notice , why for the pitch the forward angle isn't the same as the backward .With the other plugin both are the same with one set parameters ? and sorry but not really understood your explaination to describe what you changed ! Put the surge center of gravity to -8.0y (the slider in the middle). To make it precisely, click first with the mouse on the slider (not on the value box) and use the left/right arrows to make your adjustments.
Increase knee cap limit to 110 deg.
Than press the "optimize" button and wait a bit until the software has calculated the starting position by applying an offset.
In this configuration (base 100cm platform 75cm) you should get a symmetrical angular range around 30 deg.
"not really understood your explaination to describe what you changed !"
At the beginning, the guys who developed this 3d model had made it for a small scale model. For some obscure reason, they choose 185mm for the base and 112mm for the platform and they scale those dimensions to ratio 1.
This makes the value conversion to the full scale platform nearly impossible.
My idea was, that by scaling the base ratio :1 from 185 to 100 and the platform ratio :1 from 112 to 100, that could make those values understandable.
Somebody has to check if this procedure is reliable, but normally instead of bullshit you should get centimeters. ;-)
The purpose of it, is to give a starting point for a talented programmer to put the hands in the code.
cheers
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Post by vicpopo on May 10, 2016 19:56:44 GMT
ok Thanks ! I 've got -35 to + 33 degrees pitch angle with out of reach for the last values angles backward and forward !
will giva try now !
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Post by tronicgr on May 10, 2016 20:21:24 GMT
Ignacy, you nailed it. That was exactly the problem I had and could not correlate the dimensions.
I hope there is an easy way to redefine that 1:1 dimension to something more useful, like cm. Actually all dimensions have to be redefined, as many of the values are in mm in relation to the original dimensions mini prototype, so not even exactly mm.
Thanks Thanos
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Post by hexpod on May 10, 2016 22:04:51 GMT
Ignacy, you nailed it. That was exactly the problem I had and could not correlate the dimensions. I hope there is an easy way to redefine that 1:1 dimension to something more useful, like cm. Actually all dimensions have to be redefined, as many of the values are in mm in relation to the original dimensions mini prototype, so not even exactly mm. Thanks Thanos "I hope there is an easy way to redefine that 1:1 dimension to something more useful, like cm."
As the "servo arm" and "platform height" are designed in mm, and the ratios are now scaled to 100mm, don't you think that after my modification everything is automatically corrected?
Maybe I wasn't explicit enough but I think, that now, if you simply consider the "servo arm" and "platform height" as a value in cm, you just have to simply consider the ratio value as a value in meters.
for ex. ratio 0.78 = 0.78m = 78cm. for ex. ratio 1.22 = 1.22m = 122cm
I have to double-check but this method seems crystal clear and looks very coherent.
So following my method, in the Gui, in the design column you just have to change the names from:
"servo arm" to servo arm in cm "platform height" to platform height in cm "base ratio" to base size in meters "platform ratio" to platform size in meters
and you are all set.
Just to precise again. In every design, you always have to take the center of the servo as the base attachment points, not the heim joints .
cheers - I.
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Post by vicpopo on May 11, 2016 9:42:37 GMT
The center of the servo is the blue circle in your attached picture of the 3D simulation ? Thanks
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Post by hexpod on May 11, 2016 10:36:09 GMT
The center of the servo is the blue circle in your attached picture of the 3D simulation ? Thanks Yes.
Small circle, in the upper left rectangle corner, is the servo attach point. You have to draw the big circle over all 6 of them, and report the size in meters in the Gui.
I hope it's clear.
cheers.
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Post by hexpod on May 11, 2016 10:57:38 GMT
After my small modification, the ratio 1 in the code became 100mm. So now, if you consider 100mm (ratio 1) as 1 meter, you also have to apply the same factor x10 to the other values in mm. This way, we can get our centimeters. You can also consider that by changing the ratios, you are actually changing the size in meters.
Thanos, that is pretty clear. Isn't it?
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Post by tronicgr on May 11, 2016 15:09:32 GMT
Yes it's very clear now. Thanks
I'll try to help with the GUI changes as soon I get some spare time.
If we get it right, I can send it to Martin to update the 6DOF plugin finally.
Thanks Thanos
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Post by vicpopo on May 11, 2016 16:17:04 GMT
If you do that Thanos , maybe you can change the surge and sway title in the GUI because surge and sway are inverted ( Just the name obviously ;-) ) @hexapod : thanks , now it's clear for me for the blue circle.
one more notice more is the lenght of the servo arm. it s a little bit surprising to leave the range from 10 cm to 300 cm . My servo arm is 11 cm and i don t know someone who would have 300 cm arm lenght !!
edit : same notice form the plateform height - range form 50 cm ( my case on my 6dof ) to 400 cm .
many thanks hexapod to improve the plugin ;-)
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Post by hexpod on May 13, 2016 10:57:57 GMT
Small cosmetic update:
- perspective reduced to minimum - surge/ sway sliders inverted - corrected order in "servo position" column - corrected order in "KneeCap Angle" column - scaling to meters/centimeters in "design" column - corrected servo arm/platform height range - top of the cube colors corrected (red motor 1, orange motor 2) - you can rotate the model with keyboard arrows keys - you can save/write surge and heave offset to the ini file (priority development point Nr.2 solved)
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Post by hexpod on May 13, 2016 11:45:04 GMT
Thanos, any idea how to save/read to/from .ini file, the heave and surge offset applied after hitting "Optimise" button??
We need a code line for that...
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Post by hexpod on May 14, 2016 0:38:16 GMT
Thanos, any idea how to save/read to/from .ini file, the heave and surge offset applied after hitting "Optimise" button??
We need a code line for that... Forget it. I got it. download link updated.
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Post by hexpod on May 16, 2016 15:14:45 GMT
X-sim plugin / .exe file software Mod.
Notice:
While modifying the size of the platform/base the spacing is modified proportionally. When the base size is set to 1.0, the spacing of the center of the motors is 50cm. When the platform size is set to 1.0, the spacing between the upper joints is 10cm.
To fit the 3d model properly, consider the size of the circle through your lower joints, when the crank levers are full vertical.
www.dropbox.com/s/6satzcyjoz4njpz/6dof%20heXpod%20MOD.zip?dl=0
To make the software complete, the sliders to modify platform/base spacing and motor orientation should be added.
Please report incoherencies if any.
Test first the .exe version before updating the .dll file to x-sim folder.
Thanks.
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