In some papers and books we can see that authors using symbols to represent robot arms. My question is, is there a convention for such sketches? If so could you provide a reference which shows how these symbols should be used?
Symbolic Representaion of Links and Joints: How to sketch complex manipulators using simple symbols?
1 Answer
There are usually only two kinds of joints you would use in a robot - a revolute (rotational) joint and a prismatic (translational) joint. Every reference I've seen uses a cylinder to represent revolute joints and a cube or prism to represent a prismatic joint.
You might be able to argue that a cylinder should represent a cylindrical joint, but in reality a cylindrical joint is a combination revolute and prismatic joint.
There are spherical (ball) joints, but I have never seen an actuated spherical joint before. They're more used as a kinematic constraint in shoulder joints or suspension design, in which cases the joint is a pivot and the actuation is still done by prismatic joints.
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$\begingroup$ "Usually only two kinds of joints" - I guess I should say two kinds of actuated joints. $\endgroup$– Chuck ♦May 11, 2017 at 12:07
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$\begingroup$ Yes, however, the from a schematic point of view, active or passive joints are not graphically distingushed (the just have a "$q_i$" written next to them sometimes) $\endgroup$– 50k4May 11, 2017 at 14:28