US 6,438,860 B1 · Device and process for determining position between two parts which are movable relative to one another

Abstract

A device for determining position between two parts which are movable relative to one another, comprises a linear sensor arrangement, a length scale or angle scale comprising a sequence of transparent and non-transparent fields, an illumination device and elements for imaging at least one section of the scale on the sensor arrangement. The entire length scale or angle scale is divided into n graduation portions of equal length, wherein every portion contains a sequence of transparent and non-transparent marks, and the sequence is successively a number which is binary-coded with k bits and correlated with the respective portion as rough value code and a fixedly recurring number which is likewise binary-coded with k bits as a reference mark (reference mark with length of k bits). Every code bit is of equal length and is formed of a transparent and a non-transparent field (half-bit) of equal length, wherein the binary information comes from a sequence of two half-bits. A process for relative position determination shows how the sensing of the graduation and the evaluation and determination of the measurement values is carried out.

Claims11

Dependent claims

A device for determining position between two parts which are movable relative to one another, comprising:

a linear optoelectronic sensor line arrangement, a length scale or angle scale having a code graduation and comprising a sequence of transparent and non-transparent fields;
an illumination device;
imaging elements for imaging at least one section of the code graduation on the linear sensor arrangement;
said entire length scale or angle scale being divided into n graduation portions of equal length, wherein every portion contains a sequence of transparent and non-transparent marks;
said sequence being successively a number which is binary-coded with k bits and correlated with the respective portion as rough value code and a fixedly recurring number which is likewise binary-coded with k bits as a reference mark with length of k bits;
and
every code bit being of equal length and being formed of a transparent and a non-transparent field, half bit, of equal length, wherein the binary information comes from a sequence of two half-bits.

4 more elements

A process for determining relative position between two parts which are movable relative to one another with a device comprising a linear optoelectronic sensor line arrangement, a bar-coded graduation scale comprising a sequence of transparent and non-transparent fields, and an illumination device for illuminating and imaging at least one section of the code graduation on the linear sensor arrangement, said process comprising the steps of:

separately determining or determining prior to each measurement for at least approximately knowing a generally fractional quantity of sensor elements which are covered (imaging scale a) by the image of a mark with the smallest bar width h on the sensor line arrangement;
providing a trigger threshold located approximately centrally with respect to the modulation amplitude of the electric signals of the sensor elements of the linear sensor arrangement, by which the analog level of the individual sensor elements are transformed into logical high or low levels;
determining relative position or interpolation value of a selected sensor element of the sensor arrangement within the smallest bar width h by averaging the differences between the whole-number sensor element numbers at every high-low or low-high transition or flank and the element of a numeric comparison raster which is closest in terms of amount, this numeric comparison raster being formed by whole-number multiples of the imaging scale a;
and
standardizing in that this formed average is subsequently standardized to the imaging scale a.

2 more elements

Dependencies are inferred from the claim text.

Device and process for determining position between two parts which are movable relative to one another

Life of this patent

Device and process for determining position between two parts which are movable relative to one another

Life of this patent

Abstract

Claims11