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Though, Denavit-Hartenberg notation is commonly used to describe the kinematics of robot manipulator, some researcher prefer the product of exponential instead; and even the claim that it's better.

Which one should I use, and which one is generally better; is final solution same for both kinematics and dynamics?

Any suggestions? A mathematical introduction to robotic manipulation

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They are two different ways of getting the same thing. Correctly set D-H parameters will give the exact same kinematics and dynamics as correctly set POE parameters. There are well-defined (although tedious) ways to convert between the two.

So "better" or not purely is up to user preference. Some people prefer D-H because for many setups they give a unique set of parameters to describe the system. There are some configurations, though, for which D-H parameters are not unique.

The big advantage of POE is you just define the 6-DOF relationship between two joints. Often this ends up being more intuitive than using D-H parameters. The downside is two different people might define that differently. The resulting dynamics are exactly the same, though.

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  • $\begingroup$ How about the Jacobian matrix, is it same? Because I saw that, in POE, once you've the Jacobian, then the dynamics is ready (straight forward); this may be an advantage over DH !! $\endgroup$ – AlFagera Feb 15 '15 at 0:54
  • $\begingroup$ I can't say for sure; if the definition of output coordinate frame and actuator input is the same then you'll get the same Jacobian. I'm not sure, but it might be possible to define things such that coordinate frames are different which would change the specifics of the Jacobian, but in both cases they would still describe the same physical dynamics. Since the dynamics have to be the same, go ahead and use the POE Jacobian matrix if you find it easier (that's also my preference). $\endgroup$ – ryan0270 Feb 15 '15 at 4:36
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I recently worked with DH parameters to define kinematics of my Dual Arm Robot. As per my knowledge and experience, for kinematics I can say that DH Param will be good to use it since that gives you exact location and orientation (provided the table you made is correct) of each link of the robot. I had to work for collision detection between both the arms of the robot. So using Forward Kinematics, I calculated Cartesian location of each joint and compared all joints of one arm to the other's. You can calculate it with matrix multiplication in a sequence starting from the base of the manipulator to the end. At last, you will need to identify the Coordinate axes of Manipulator and the one in your analysis, and take values accordinngly. Also, there is a freeware called "Roboanalyzer" . Use that software, you will understand the application of DH parameters to calculate matrices. Though there are minor flaws, but it is awesome for basic understanding.
Hope it will help you a bit.

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