Measurement of absolute longitudinal position, e.g. the position of a push saddle used with a machine tool, using an absolutely coded linear scale in conjunction with a scanning head and an absolute angle coder

摘要

Absolute length measurement system comprises a section-wise absolutely coded linear scale (12) with a scanning head (23), an absolute angle coder (22) and an analysis device (21) that generates an absolute position from the linear and rotation sampling of the scale. Scanning head (23) and angle coder (22) are integrated in a single scanning unit (20). The linear scale has traces (g, h, i, j) with divisions of 16, 128, 1024, and 8192 microns and can also have a pseudo random code trace.