Gripping action using sum of internal gains

[Ray]

By using the sum of gains of each servo, gripping object of variable size can be easily achieved, however, training is required to get good operation

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[mic2]

Cool! How you assign these PS gain? i.e. to control the specific servo? Please give more details.

In your final motion it pick up the box and then getup, how it can remember the variable width of the box? so that it can holding the box not too tight or too loose

Cheers

[Ray]

Hi mic,

The VS-RC003's latest firmware include a set of summing option of gains that bring up to 5 selected variables.

Please go to CPU option and select the servo setting as shown:



you can see, for example, vb3 is the feedback from PS2 Left joystick x-position (Vb3[246]). In order to give it different gain in different motion file situration, we need to assaign a Slider gain, Va3[61]. This gain can be set to zero. (This is very important, because, some time, you don't need the Analog stick to be active in other motion file) The above variable numbers should refer to your variable table in your RobovieMaker CD.


I use variable[65], [65] and [66] to remember the Joystick value in a repeted loop until the break point occurs (where you release your motion assigned key)---you can use other method such as pressing a key in your loop (you can become specialist if you can try more )



Cheer

Ray

[mic2]

Thanks Ray, finally now I can get the best use out of the analog controls. From your video there are few motions happened after it got up and holding the box i.e. walk forward, turn left right and then release the box. Is it all these motions in the same motion file? I can’t see any forward left right walk command in your program above? or does it actually exit to another motion with the recorded joystick value? So it cans still holding the box and waiting for the release command to complete the mission.

Cheers.

[Ray]

hi mic,

I divided the PS2 keys into different mode set, e.g. SELECT + X
When I enter this page, I can use my created variables for every motions file in this page.

Here, I can call this page as Box lifting page. when I created the posture of the hands, I can remain their position. unless I reset it or I leave this page. You can refer to RobovieMaker manual for details.

Ray

[mic2]

From my understanding after you release L2 it then getup and carry the joystick values, at this point does it exit the lift box page? Still not sure how you passing the values to the next motion. Also about the “Subtract Offset” from your program what -= 127 for?

[Ray]

Well, the variable va[65] is a user defined variable, in theory, this value will perminantly stored unless I turn of the Robot, so, I need to correct it.

But, anyway, I only use this variable in the Box lifting page.
when you leave the lift box routine, the variable still hold the value.

the hand is a combination of joystick values and user variable values.
The important point here is how to use the joystick to adust the hand to grip the box and then transfer this value to the user variables.

If this is not handling property, the transition will make the hand shake and loose the box. ( This is a very practical experiance, hard to explain )

The 127 value is a offset to first make the robot's hand horizon to prepare to hold the box. my variables doesn't record this and so finally should add the offset again.

well, my program may not be a good design, try yours and show my your algorithm


here is my routine for your reference:
http://robosavvy.com/Builders/Ray/Lift%20Box.txt


Ray

[mic2]

Thanks Ray, that should do the job

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[Ray]

Good work mic!