Advice for Quadruped (QSR-X1)

Quadruped Robots

Re: Advice for Quadruped (QSR-X1)

Postby clh6685 » Thu Apr 01, 2010 2:18 pm

Image

Hi all,

Show your guys some of my work, IK i develop in excel.
And some of my hardware. I had tested in single channel via rs-232 and my IK excel and servo controller i develop myself. Its work jz fine.. :D But need some improvement...
Following goal is try on my servo controller with multi channel running simultaneously...

Chok
Last edited by clh6685 on Sun Aug 14, 2016 8:31 am, edited 3 times in total.
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Re: Advice for Quadruped (QSR-X1)

Postby clh6685 » Sat Apr 03, 2010 1:19 pm

Serial servo controller testing


Here is the testing video...
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Re: Advice for Quadruped (QSR-X1)

Postby douglaslps » Sat Jun 19, 2010 11:29 am

cyberdead wrote:Hi,

About the simultaneus PWM signals, there are very effective software methods. I have to make in my octoped 24 signals.
Here is a link, which is my software based on. I haven't tried it yet to make on higher language like C. But it works without any error in asm too.

http://www.dattalo.com/technical/software/pic/pwm8.asm

Best regards
Pete


Hi Pete,

[UPDATE]: I just saw that it is a very old thread. But anyway the info bellow is still valid.

the problem with your approach is that it drives all servos at once. It is very severe opperation for your Quad batteries. What I believe you should do is what Matt explained to Chok.
Start four servos at once. After positioning them (something between 1ms and 2ms) you start next 4 servos. This way you drain current on 4 servos at time only (instead of all 24).

Let'me try to ilustrate:

Servo01..........: _|~|_____________
Servo02 to 04...: _|~~|____________ (each of them can have different width)
Servo05..........: _____|~~|________
Servo06 to 08...: _____|~|_________ (each of them can have different width)
Servo09 .........: _________|~|_____
Servo10 to 12...: _________|~~|____ (each of them can have different width)

And so on. PS.: Consider each ~ equal to 1ms

The same approach can be applied to less servos operation. In that case, reduce the number of sevos started each time.
You might be wondering why I choose the magic number of 4 servos at time. That is because you have to recicle your servos each 20ms. That means that if you continue the diagram I drawn above, you will realize that after your last set of 4 servos you will have to get back and recicle servos 1 to 4.

Hope you got the idea.
Regards,
Douglas
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Re: Advice for Quadruped (QSR-X1)

Postby clh6685 » Sun Jul 18, 2010 1:29 pm

hi all,

Help need here!

Currently I'm debugging my serial servo controller assembly code.(PIC16F84A)
The overall concept as follow:
1. The main program is looping unconditioned.
2. There is small loop program inside the main loop program that process servo pulse out delay. This loop carry new variable that capture from the main loop code and process the decrement count in servo HI delay.

The problem is when i feed variable data into the controller, the servo delay time like multiply by many times, it delay very long and not match with what it should be.

If purposely put the variable into a fix value every time in the main loop program, it function correctly.
I had check the input string from PC serial. It should be no problem.

Any one got any idea where goes wrong?

Rgds,
Chok
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Re: Advice for Quadruped (QSR-X1)

Postby clh6685 » Tue Dec 07, 2010 7:47 am

Hi All,

Is being long time no progress on my Quad, really busy on my job.
Recently I bough a cheap 16ch serial servo controller when sales.

Image

I just tested out. It works fine, but the servo resolution up to 12bits, i have to modify my excel sheet output string to suit this protocol.
=.=! I should give up my own design serial servo controller since I not much time to debug it.
Last edited by clh6685 on Sun Aug 14, 2016 8:43 am, edited 3 times in total.
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Re: Advice for Quadruped (QSR-X1)

Postby clh6685 » Fri Mar 18, 2011 2:58 pm

Huh,

Finally, i able to split 12bits servo position to 2bytes 8bits in my I.K excel. (top right corner)

Next is to wire up my pc comm data pin to my servo controller. :D
Last edited by clh6685 on Sun Aug 14, 2016 8:43 am, edited 2 times in total.
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Re: Advice for Quadruped (QSR-X1)

Postby clh6685 » Sun Mar 20, 2011 11:08 am

Hurray!!

my excel IK can link with my new servo controller now...tested yesterday night...it works fine...but seems the 12 bits split to 2 byte 8 bits subroutine cause the pc slow down all calculation and cause the data feed slow to my controller..so just able to test in slow motion IK..any way, god bless its work. :D now left is to scaling, offset, and reverse all servo to match rotation direction.

any know how to convert 12bits number in excel to each individual binary bits by simple way? you may post me reply.
because i use a very long routine to convert 12bits number to individual binary bits then only split the bits out. This is because what i know excel have a function to convert maximum 9 bits number to binary.and the result binary cannot be split out individual.
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Re: Advice for Quadruped (QSR-X1)

Postby clh6685 » Fri Mar 25, 2011 11:11 am

Help needed!

my quad goes cramp as i connected all 12 servos to my servo controller(all servo turn to full one direction). less servo show less chance goes cramp.
i suspect is noise coming from the servos affect the controller. currently i share the supply with the servo battery.
anyone can hind me some idea about the noise problem or how your deal with it?

Thanks
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Re: Advice for Quadruped (QSR-X1)

Postby clh6685 » Fri Mar 25, 2011 1:56 pm

Finally, the servo cramp really came from servo if i share my supply with servo controller. Now i split out the servo circuit supply by using battery and servo supply using external power supply. It just solved the problem. Got to implement some noise filtering circuit in future if need share the supply source.

Now....show time....1st ever capture life Inverse Kinematic testing on my Quad (QSR-X1) is now rocks! 8-)

Qudruped robot (QSR-X1) Z axis translate testing

Quadruped robot (QSR-X1) X-Y axis translate testing

Qudruped robot (QSR-X1) X-Y-Z axis translate testing
Last edited by clh6685 on Fri Sep 16, 2016 12:07 pm, edited 3 times in total.
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Re: Advice for Quadruped (QSR-X1)

Postby clh6685 » Sat Sep 24, 2011 12:19 pm

Image

Some size comparison with my Honey bee king 2 helicopter in solid works... 8-)
Last edited by clh6685 on Sun Jan 04, 2015 10:58 am, edited 2 times in total.
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