Sawyer sensor for planar motion systems

Planar motion systems based on commercial Sawyer motors (1969, 1973, 1974) provide uniform performance over their entire workspace, offering fairly high speeds, accelerations, and precision. They also offer mechanical and kinematic simplicity, modularity, large motion ranges, and a short path to mechanical ground. On the other hand, primarily because they are operated as open-loop step motors, they can miss steps, have long settling times, and fall short of their potential capabilities. These motor performances are improved by using a novel, very high resolution (0.4 /spl mu/m), Sawyer planar sensor presented in this paper.<<ETX>>