PROCESS AND INCREMENTAL TRANSDUCER FOR DETERMINING AN ACTUAL POSITION OF A BODY ALONG A MEASURING PATH OF A MATERIAL MEASURE HAVING AT LEAST ONE GAP

• US 20120124849A1
• Filed: 11/21/2011
• Published: 05/24/2012
• Est. Priority Date: 11/22/2010
• Status: Active Grant

• Current Assignee: Baumer Germany GmbH & Company KG
• Original Assignee: Baumer Innotec AG
• Inventors: HILLER, Bernhard, LOHARENS, Axel, KIRCHBERGER, Roland, SCHNEIDER, Michael
• Granted Patent: US 8,732,967 B2
• Time in Patent Office: Days
• US Class Current: 33/1.PT
• CPC Class Codes: G01D 2205/774 Profiles with a discontinuity, e.g. edge or stepped profile
• CPC Class Codes: G01D 5/24476 Signal processing G01D5/2448 - G01D5/24495 take precedence
• CPC Class Codes: G01D 5/2451 Incremental encoders G01D5/2454 takes precedence
• CPC Class Codes: G01D 5/248 by varying pulse repetition frequency
• CPC Class Codes: G01D 5/2497 Absolute encoders G01D5/2454 takes precedence
• CPC Class Codes: G01D 5/347 using displacement encoding scales
• CPC Class Codes: G01D 5/34707 Scales; Discs, e.g. fixation, fabrication, compensation

Abstract

An incremental transducer (1) as well as a process (D1) are provided for determining an actual position of a body (5) along a measuring path (W) and/or a change therein. A position code (7) of the incremental transducer (1) has a gap (10). To make it possible to use the incremental transducer (1) as flexibly as possible and to operate it despite dimensional tolerances of the body (5), provisions are made for converting an actual location frequency (Fi) of the position code (7) into a desired location frequency (Fs) that is independent from the length (L) of the gap (10) to generate a position signal (S) representative of the actual position or the change therein.

Claims

1. A process for determining an actual position of a body along a measuring path and/or a change in a position of the body along the measuring path, the process comprising the steps of:

scanning a position code having a plurality of position markers arranged with a predetermined actual location frequency and having at least one gap between ends of said position code;

generating a position signal representative of an actual position and/or a change in the actual position of the position code, wherein to generate the position signal, the actual location frequency is converted into a desired location frequency that is independent from a length of the gap.

2. A process in accordance with claim 1, wherein:

said position code with said plurality of position markers is arranged along a measured material element applied to the body with a connection device for connecting said ends of the measured material element adjoining the gap to one another, said connection device being elastically compliant at least partly along the measured material element in a state in which said connection device is captively connected to said ends; and

to generate the position signal, a predetermined section of the measuring path, which section contains the at least one gap, is scanned and a length of the section including the gap is determined in actual location periods of the position markers arranged with the actual location frequency.

3. A process in accordance with claim 2, wherein the length of the section is determined during the operation.

4. A process in accordance with claim 2, wherein a part of the position code corresponding to the gap is scanned to determined the length of the gap.

5. A process in accordance with claim 2, wherein the overall length of the measuring path including the gap is determined as a total number of actual location periods.

6. A process in accordance with claim 2, wherein to generate the signal, the number of actual location periods is compared with a desired quantity of desired location periods and a conversion rule is determined therefrom for the actual location frequency.

7. An incremental transducer for determining an actual position of a body along a measuring path and/or a change in position of the body along the measuring path;

a measured material element, which extends along the measuring path and which is interrupted by at least one gap and is provided with a position code having a plurality of position markers arranged along the measuring path with a preset actual location frequency;

a position signal generator, of the incremental transducer that sends a position signal representative of the actual position and/or change in position of the body along the measuring path during an operation, including two sensor arrays for scanning the position code, said two sensor arrays being arranged at spaced locations from one another along the measuring path such that at least one of said two sensor arrays is always arranged outside of the gap during operation; and

a conversion unit, by which the actual location frequency scanned by the two sensor arrays is converted into a desired location frequency.

8. An incremental transducer in accordance with claim 7, wherein:

at least one sensor signal is fed, during the operation, to and an input side of said conversion unit, with the actual location frequency of at least one of said two sensor arrays; and

an output signal in which the desired location frequency, derived from the actual location frequency, is contained, is present at a signal output of said conversion unit.

9. An incremental transducer in accordance with claim 7, wherein the position markers are arranged along the measuring path with an actual location period that depends on the actual location frequency.

10. An incremental transducer in accordance with claim 7, wherein the position code is interrupted by the gap, and areas of the gap adjoining the position code are formed with an end position code differing from the position code.

11. An incremental transducer in accordance with claim 10, wherein the end position code has end position markers, which are arranged along the measuring path with a location frequency differing from said actual location frequency of the position code.

12. An incremental transducer in accordance with claim 7, further comprising a connection device wherein ends of the measured material element adjoining the gap are connected to one another captively by said connection device, wherein said connection device is made elastically compliant at least partly along the measuring path.

13. An incremental transducer in accordance with claim 12, wherein an elastic area of the connection device is designed such that the connection device compensates mechanical stresses caused by heat in the measured material element mounted along the measuring path.

14. An incremental transducer in accordance with claim 12, wherein the connection device is arranged outside a collision area of the at least two sensor arrays.

15. A measured material element that can be arranged along a measuring path for an incremental transducer, the measured material element comprising:

a position code with a plurality of position markers arranged along the measured material element, the position markers having a preset actual location frequency, the measured material element having ends and being applied for operation of an incremental transducer with at least one gap between said ends;

a connection device for connecting said ends of the measured material element adjoining the gap to one another, said connection device being elastically compliant at least partly along the measured material element in a state in which said connection device is captively connected to said ends.