The manipulator discussed in the paper titled “Kinematics of a New High-Precision Three-Degree-of-Freedom Parallel Manipulator” (1) is a three-degree-of-freedom simplification of a six-degree-of-freedom parallel minimanipulator, which is protected by a US patent (2). Between 1991 and 1995, late Professor Lung-Wen Tsai and I published several papers on various aspects of this six-degree-of-freedom minimanipulator (3,4,5,6,7,8). It is important to note that all of these papers (3,4,5,6,7 8) were published prior to each and every reference mentioned by the commentary of Carretero et al.
Having used the six-degree-of-freedom minimanipulator (2,3,4,5,6,7,8) for some optical alignment tasks, I came across other applications in which only tip, tilt, and piston motions are important (e.g., alignment...
