A position measuring device has an incremental dimensional standard, an associated scanning unit that emits at least two analog, phase-shifted, periodic output signals, and a monitoring device, and the value of the output signals codes a state of the monitoring device.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of a position measuring device in accordance with the present invention.
Claims
1. The position measuring device, comprising an incremental dimensional standard; an associated scanning unit that emits at least two analog, phase-shifted periodic output signals; and a monitoring device, wherein said scanning unit and said monitoring device being configured so that a value of said output signals emitted by said scanning unit codes a state of said monitoring device.
2. A position as defined in claim 1, wherein said scanning unit includes a sensor for scanning said dimensional standard, which generates at least one analog sample signal, while said evaluating unit, based on the sampled signal, determines a position value; and further comprising a synthesis device for synthesizing phase-shift, periodic output signals based on the position value.
3. A position as defined in claim 2, wherein said synthesis device synthesizes the phase-shifted periodic output signals formed as a sine signal and a cosine signal.
4. A position as defined in claim 2, wherein said evaluating unit includes an analog-digital convertor for converting the analog sampled signal to a digital intermediate signal, and an evaluating arithmetic unit for generating a digital position value based on the digital intermediate signal.
5. A position as defined in claim 2, wherein said synthesis device includes a synthesis arithmetic unit for calculating at least two digital signal values based on the position value, a coding factor specified by said monitoring device, and at least one digital-analog convertor for converting the digital signal values into the analog output signals.
6. A position as defined in claim 5, wherein said synthesis arithmetic unit includes at least two tables that assign a function value to at least each position value, and wherein when the digital signal values are generated, the coding factor reduces the function values or leaves them unchanged.
7. A position as defined in claim 6, wherein said coding factor reduces the function values by at least 50%.
8. A position as defined in claim 6, wherein said coding factor reduces the function values by 100%.
9. A position as defined in claim 1, wherein said monitoring device is configured to determine at least one of parameters selected from the group consisting of a voltage supplied to the position measuring device, a distance between said sensor and said dimensional standard, an amplitude of the analog sample signals or digital intermediate signals, an ambient temperature or a temperature of said scanning unit, an extent to which a digital value range is utilized by the digital intermediate signals, a position value, a speed value, and an acceleration value; and further comprising means for comparing at least one of said parameters with a corresponding reference parameter or comparing a plurality of said parameters with a set of reference parameters so that the value of said output signals is selected according to a result of the comparison.
Patent Application
20070216399
