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elephantrobotics / pymycobot

This is a python API for ElephantRobotics product.
MIT License
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dh parameters #7

Closed mfkenson closed 3 years ago

mfkenson commented 3 years ago

May I have the dh parameters of the arm? I would like to work on trajectory generation.

zlj-zz commented 3 years ago

what's the dh parameters?

karaage0703 commented 3 years ago

dh parameters is "Denavit-Hartenberg parameters". For example, we can make original myCobot simulator from scratch by using dh parameters.

I made myCobot simulator. https://github.com/karaage0703/mycobot_pi

My understanding, myCobot dh parameters is similar to UR5(reference)

myCobot dh parameters which I estimate is below. https://docs.google.com/presentation/d/17b-rVN2hMOyrtATXlfU7OeVewjkEbSOUjrN6cOPCY6U/

This is Not official information. I want to know official myCobot dh parameters, too.

zlj-zz commented 3 years ago

WechatIMG3274 Maybe you can refer to this. More details need to wait.

kotai2003 commented 3 years ago

dh parameters is "Denavit-Hartenberg parameters". For example, we can make original myCobot simulator from scratch by using dh parameters.

I made myCobot simulator. https://github.com/karaage0703/mycobot_pi

My understanding, myCobot dh parameters is similar to UR5(reference)

myCobot dh parameters which I estimate is below. https://docs.google.com/presentation/d/17b-rVN2hMOyrtATXlfU7OeVewjkEbSOUjrN6cOPCY6U/

This is Not official information. I want to know official myCobot dh parameters, too.

Hello. Let me ask a question on your simulator. In your code, you define the DH parameter as follows.

# myCobot DH parameters # [theta, alpha, a, d]

mycobot_sim = NLinkArm([[0., math.pi / 2, 0, 0.13156], [0., 0., -0.1104, 0.], [0., 0., -0.096, 0.], [0., math.pi / 2, 0., 0.06639], [0., -math.pi / 2, 0., 0.07318], [0., 0., 0., 0.0436]])

I am wondering why you put zeros in theta in DH parameter instead of the values in your DH table? Is there any special technique to update theta by setting up zeros initially?

Thanks.

karaage0703 commented 3 years ago

@kotai2003 Hi, thanks for your comment. To tell the truth, I'm not familiar with DH parameter. I made my software according to real robot and basic robotics text. Please refer to official information. And if you can fix my mistake, please give me Pull Request. Sorry for I can't answer your question directly.