Abstract: A method of determining the positions and orientations of the base (8) and platform (10) of a parallel manipulator using an iterative calculation in which successive iterations calculate estimates of said positions and orientations, each estimate being determined from the previous estimate using an inverse of a derivative of an error function (F), that function also being used to determine error values for each estimate, wherein if the error values are deemed unacceptable a new derivative is calculated and the iteration is repeated, whereas if the error values are deemed acceptable the same derivative is used in a subsequent iteration. Thus the derivative need not be re-calculate for each iteration, whereby the process can operate more rapidly, e.g. in real time.

Abstract: A method of determining the positions and orientations of the base (8) and platform (10) of a parallel manipulator using an iterative calculation in which successive iterations calculate estimates of said positions and orientations, each estimate being determined from the previous estimate using an inverse of a derivative of an error function (F), that function also being used to determine error values for each estimate, wherein if the error values are deemed unacceptable a new derivative is calculated and the iteration is repeated, whereas if the error values are deemed acceptable the same derivative is used in a subsequent iteration. Thus the derivative need not be re-calculate for each iteration, whereby the process can operate more rapidly, e.g. in real time.