Abstract: A method for calibrating a first co-ordinate frame of a robot and effector in a second frame of reference of a sensor when the sensor is substantially rigidly attached to the robot and effector, including the steps of measuring first positions of a plurality of first light sources relative to the sensor, with the first positions corresponding to a first absolute position of the robot and effector, moving the robot and effector, measuring second positions of the plurality of first light sources, which second positions correspond to the desired second absolute position of the robot and effector and the sensor, repeating the measurement of and movement from the first to second positions so as to provide at least two sets of measurements of first and second positions corresponding to at least two movements, each of which at least two movements is a known, unique transform, combining the at least two sets of measurements of first and second positions so as to calibrate the first co-ordinate frame in the second fra

Abstract: One embodiment of the invention relates to a digital data signal comprising: a first data set of source data (1) and control data (2), said source data being modified in accordance with said control data to generate an intermediate set (3) of modified data when said data signal is copied by equipment adapted to read data on a block by block basis; and a second data set (4) associated with said first data set, said second data set being provided to enable modifications made, or modifications that otherwise would be made to said first data set to generate said intermediate data set upon copying of said signal by said equipment, to be at least substantially negated. Other embodiments of the invention relate to a carrier having a data signal recorded thereon, to a method of generating such a data signal, to a method of copying such a signal, to a computer program, to data copying apparatus and to a data transfer system.

Abstract: A method for calibrating position (11) of each light source in a first set of light sources (1) on a first part (2) when the first set (1) are attached thereto, including the steps of measuring first positions (3i) of each of the light sources in the first set (1), each of said light sources (1) being either an active light source or an illuminable reflecting point, generating a first set of light sources to facet mapping (4), which first set to facet mapping (4) specifies which facet (9i) of the first part (2) each of the light sources in the first set (1) are located on, estimating a transformation (5) that transforms the first positions (3i) into a co-ordinate frame of the first part (7), thereby generating estimated positions (6i) of each of the light sources in the first set (1) on the first part (2), which estimated positions (6i) are in the co-ordinate frame of the first part (7), calculating (10a) first distances (8i) from the estimated positions (6i) to respective facets (9i) of the first part (2), i

Abstract: An optical target (1) including a positioning sub target (2) for determining position, and a plurality of identifying sub targets (3) for identifying one optical target (1) from another, each of which plurality of identifying sub targets (3) is a different color from the positioning sub target (2).