I am currently reviewing a path accuracy algorithm. The measured data are points in the 7 dimensional joint space (the robot under test is a 7 axes robot). As far as I know path accuracy is measured and assessed in configuration (3 D) space. Therefore I am wondering if a path accuracy definition in joint angle space has any practical value. Sure, if one looks at the joint angle space as a 7 dimensional vector space (with Euclidean distance measure) one can do formally the math. But this seems very odd to me. For instance, an angle discrepancy between measured and expected for the lowest axis is of much more significance than a discrepancy for the axis near the actuator end effector.

So here is my Question: Can anyone point me to references where path accuracy in joint space and/or algorithms for its calculation is discussed ?

(I am not quite sure what tags to use. Sorry if I misused some.)