Configuration Space

Hello,

I have a confusion in configuration space for a robotics arm.

I know C-space have the dimension of number of joints in a robot. for example 7-DOF robot will have 7-D C-Space.

So when we implement motion planning algorithms like RRT, PRM or any other planning algorithms in C-Space, if choose a random point in C-space (say for example 5.5) how does a single random point corresponds to 7-D C-space. I mean don’t we need to specify a vector 7 different random points to denote a point in C-Space?

If I understand you correctly, you confuse a point with a scalar, a scalar is just one number or in other words: a one element vector; in a one dimensional space a point can be represented with a one element vector, in a higher dimensional space like 3 you need a 3 element vector (x,y,z), in a 7 dimensional space you need a 7 element vector(x1,x2,x3,x4,x5,x6,x7), in general: in a N dimensional space you represent a point with a N element vector. If you want to sample a random point inside a N dimensional unit cube, you just pick a random number between 0-1, for each of your N element vector.

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