Denso Robot Accuracy vs. Robot Repeatability/Precision

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Two common terms you’ll hear when discussing any robot arm will be robot accuracy and robot repeatability. 

Accuracy is the difference between what you asked the robot to do, versus what it did.  For example, if you asked the robot to move to a point 300 mm along the X-axis. How close does the robot get to that 300 mm destination?  Accuracy, we'd define as a "relative" move; or "offset move".

Repeatability (or precision) is the ability of the robot to repeatedly execute the same task.  For example: if you teach a point and tell the robot to go there over and over and over again, how close to that taught point will it be each time.  Repeatibility is measured between a move from a known absolute (taught) position, to the next specified known absolute (taught) position.   A->B.  

In general, most, if not all, robots are not rated for accuracy, as it varies with location, speed, loading, etc..; they are generally rated with a repeatability spec alone.