Position-measuring device and method for position measuring

• US 20060009947A1
• Filed: 07/11/2005
• Published: 01/12/2006
• Est. Priority Date: 07/09/2004
• Status: Active Grant

• Current Assignee: Dr. Johannes Heidenhain GmbH
• Original Assignee: Dr. Johannes Heidenhain GmbH
• Inventors: Mayer, Elmar, Strasser, Erich
• Granted Patent: US 7,787,970 B2
• Time in Patent Office: Days
• US Class Current: 702/150
• CPC Class Codes: G01D 18/00 Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
• CPC Class Codes: G01D 5/24461 by redundancy or plausibility
• CPC Class Codes: H03M 1/108 Converters having special provisions for facilitating access for testing purposes
• CPC Class Codes: H03M 1/22 pattern-reading type

Abstract

A position-measuring device having integrated function testing includes a position-recording unit, a processing unit, and a control-word generator. In a positional-data request, a positional-data word is first generated in the position-recording unit and output to the processing unit. There, the position data word is processed into a position value. Subsequently, a control-data word is generated in the position-recording unit according to the specification of the control-word generator and output to the processing unit. The processing unit processes the control-data word into a control value which has a defined mathematical relationship to the position value.

Claims

1. A position-measurement device including integrated function testing, comprising:

a position-recording unit;

a processor unit, the position-recording unit connected to the processor unit; and

a control-word generator;

wherein the position-recording unit is configured to generate a positional-data word, including an instantaneous position value, and a control-data word, the positional-data word and the control-data word outputtable to the processing unit, the processor unit configured to generate a position value from the positional-data word and a control value from the control-data word, the control value and the position value having a defined mathematical relationship to one another, the control-word generator configured to adjust whether the positional-data word or the control-data word is output by the position-recording unit.

2. The position-measurement device according to claim 1, further comprising:

a result memory configured to store the position value; and

a control-value memory configured to store the control value.

3. The position-measurement device according to claim 2, further comprising an interface unit configured to transmit contents of the result memory and the control-value memory to sequential electronics via a data-transmission line.

4. The position-measurement device according to claim 1, wherein the position-recording unit is configured to overwrite the positional-data word with the control-data word.

5. The position-measurement device according to claim 4, wherein the position-recording unit includes a voltage-current transformer and at least one current node configured to overwrite the positional-data word with the control-data word.

6. The position-measurement device according to claim 1, further comprising an arrangement configured to force an invalid position value in the position-recording unit.

7. The position-measurement device according to claim 6, wherein the arrangement includes a switch line between a sensor element of the position-recording unit and the control-word generator, the sensor element deactivatable via the switch line.

8. A method for position-measurement in a position-measurement device including integrated function testing, the position-measurement device including a position-recording unit, a processor unit and a control-word generator, comprising:

generating a positional-data word in the position-recording unit;

outputting the positional-data word to the processing unit;

processing the positional-data word into a position value in the processor unit;

generating a control-data word in the position-recording unit as specified by the control-word generator;

outputting the control-data word to the processing unit; and

processing the control-data word in the processing unit into a control value that has a defined mathematical relationship to the position value.

9. The method according to claim 8, further comprising:

storing the position value in a result memory; and

storing the control value in a control-value memory.

10. The method according to claim 9, further comprising transmitting the position value stored in the result memory and the control value stored in the control-value memory from an interface unit to sequential electronics via a signal transmission line.

11. The method according to claim 8, further comprising overwriting the positional-data word by the control-data word in the position-recording unit.

12. The method according to claim 8, the control-data word is generated in the control-data word generating step by forcing an invalid position value by the control-word generator in the position-recording unit.

13. The method according to claim 12, wherein the invalid position value is forced by deactivating a sensing element in the position-recording unit via a switch line.

14. The method according to claim 12, wherein the control-data word processing step includes adding an offset value to a previously ascertained position value to generate the control value if the control-data word does not include any valid position value.