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Speed variation x number of servos in use

Hitec robotics including ROBONOVA humanoid, HSR-8498HB servos, MR C-3024 Controllers and RoboBasic
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5 postsPage 1 of 1

Speed variation x number of servos in use

Post by My Bear » Sat May 10, 2008 7:20 pm

Post by My Bear
Sat May 10, 2008 7:20 pm

Hi Guys

Thanks you for previous help ref RoboBASIC programming, I'm now creating moves and all is responding as directed, with the exception of one reoccuring theme in everything I've done so far.

SPEED variation which appears to correspond to the number of servos in use.

Example: four servos in legs moving at speed 5, constant.

I then add arm movement (four servos) and head movement (two servos)

The leg movement reduces in speed noticeably, probably equivalent to Speed 3

As soon as the head and arm movement finish the legs speed up again.

Is this normal? drain on power or something, or have I missed something fundamental in the programming?

All MOVE G24
WAIT etc

Any advice would be gratefully received.
Hi Guys

Thanks you for previous help ref RoboBASIC programming, I'm now creating moves and all is responding as directed, with the exception of one reoccuring theme in everything I've done so far.

SPEED variation which appears to correspond to the number of servos in use.

Example: four servos in legs moving at speed 5, constant.

I then add arm movement (four servos) and head movement (two servos)

The leg movement reduces in speed noticeably, probably equivalent to Speed 3

As soon as the head and arm movement finish the legs speed up again.

Is this normal? drain on power or something, or have I missed something fundamental in the programming?

All MOVE G24
WAIT etc

Any advice would be gratefully received.
My Bear
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Re: Speed variation x number of servos in use

Post by tum » Sun May 11, 2008 5:34 am

Post by tum
Sun May 11, 2008 5:34 am

Are you running off the stock battery or a power supply? A power supply is going to need to supply around 8A at peek times.

My Bear wrote:Hi Guys

Thanks you for previous help ref RoboBASIC programming, I'm now creating moves and all is responding as directed, with the exception of one reoccuring theme in everything I've done so far.

SPEED variation which appears to correspond to the number of servos in use.

Example: four servos in legs moving at speed 5, constant.

I then add arm movement (four servos) and head movement (two servos)

The leg movement reduces in speed noticeably, probably equivalent to Speed 3

As soon as the head and arm movement finish the legs speed up again.

Is this normal? drain on power or something, or have I missed something fundamental in the programming?

All MOVE G24
WAIT etc

Any advice would be gratefully received.
Are you running off the stock battery or a power supply? A power supply is going to need to supply around 8A at peek times.

My Bear wrote:Hi Guys

Thanks you for previous help ref RoboBASIC programming, I'm now creating moves and all is responding as directed, with the exception of one reoccuring theme in everything I've done so far.

SPEED variation which appears to correspond to the number of servos in use.

Example: four servos in legs moving at speed 5, constant.

I then add arm movement (four servos) and head movement (two servos)

The leg movement reduces in speed noticeably, probably equivalent to Speed 3

As soon as the head and arm movement finish the legs speed up again.

Is this normal? drain on power or something, or have I missed something fundamental in the programming?

All MOVE G24
WAIT etc

Any advice would be gratefully received.
tum
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Post by i-Bot » Sun May 11, 2008 9:42 am

Post by i-Bot
Sun May 11, 2008 9:42 am

You need to take time to understand how the point to point moves work, and the effect of different settings on them.

If you have point to point off (both PTP ALLOFF and PTP SETOFF) then the servos will all move at the speed you set in the SPEED parameter.

If you set PTP SETON, then for the group of servos you select (G6A etc). The servo with the furthest angle to move will move at the SPEED setting. The other servos in the group will move at a speed in proportion to this depending on the angle they should move. They should all stop at the same time.

If you set PTP ALLON, then the point to point calculation is done over all 24 servos, not just the group you send.

HIGHSPEED SETON simply multiples the speed by 3, but does not affect anything else. However at higher SPEED settings the speed of the servo in HIGHSPEED is limited by the servo capability.

All this means you need to think carefully about the state of the PTP, and select carefully you choice of groups to move.
You need to take time to understand how the point to point moves work, and the effect of different settings on them.

If you have point to point off (both PTP ALLOFF and PTP SETOFF) then the servos will all move at the speed you set in the SPEED parameter.

If you set PTP SETON, then for the group of servos you select (G6A etc). The servo with the furthest angle to move will move at the SPEED setting. The other servos in the group will move at a speed in proportion to this depending on the angle they should move. They should all stop at the same time.

If you set PTP ALLON, then the point to point calculation is done over all 24 servos, not just the group you send.

HIGHSPEED SETON simply multiples the speed by 3, but does not affect anything else. However at higher SPEED settings the speed of the servo in HIGHSPEED is limited by the servo capability.

All this means you need to think carefully about the state of the PTP, and select carefully you choice of groups to move.
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Speed variation x number of servos in use

Post by My Bear » Sun May 11, 2008 1:38 pm

Post by My Bear
Sun May 11, 2008 1:38 pm

Thank you again for your advice, I am running on the standard battery and I've just turned the point to point off and the difference is noticeable.

Thank you for the knowledge

I'll post a video of the robot 'bear' once I get the showreel together.

It's slightly unsettling.

If it doesn't entertain kids It'll definitely frighten them!

Cheers

Darren
Thank you again for your advice, I am running on the standard battery and I've just turned the point to point off and the difference is noticeable.

Thank you for the knowledge

I'll post a video of the robot 'bear' once I get the showreel together.

It's slightly unsettling.

If it doesn't entertain kids It'll definitely frighten them!

Cheers

Darren
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Post by DirtyRoboto » Tue May 13, 2008 6:14 am

Post by DirtyRoboto
Tue May 13, 2008 6:14 am

Again, i-Bot is on form.

With my custom moves I turn off ptp but then turn it back on for stock moves like walking.

Bear in mind that when you are making complex custom moves you might have many speed changes in a short amount of time and the wait command is critical wether ptp is on or off.

Another good tip is mirroring. When you make a custom move copy the code and create a new move below the first and paste the code. now just swap the group prefix left for right so G6A gets changed to G6D ect. now you have an alternate routine to call for no extra effort.
Again, i-Bot is on form.

With my custom moves I turn off ptp but then turn it back on for stock moves like walking.

Bear in mind that when you are making complex custom moves you might have many speed changes in a short amount of time and the wait command is critical wether ptp is on or off.

Another good tip is mirroring. When you make a custom move copy the code and create a new move below the first and paste the code. now just swap the group prefix left for right so G6A gets changed to G6D ect. now you have an alternate routine to call for no extra effort.
In servo's we trust!
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