Method for generating a pulse signal sequence

Patent metadata

Field	Value
Publication number	US-9766160-B2
Application number	US-201214237877-A
Country	US
Kind code	B2
Filing date	Jul 17, 2012
Priority date	Aug 26, 2011
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A method for generating a pulse signal sequence using a processor unit is provided that allows calibrating a tip timing measurement system in a turbomachine in order to increase operational security and lifespan of the turbomachine. This is achieved by the method having the steps of: storing a number of wait time elements in a memory unit, creating a pulse signal in a signal output unit during at least one processor cycle, reading a wait time element from the memory unit, and creating a null signal in the signal output unit for a number of processor cycles derived from the wait time element read.

First claim

The invention claimed is:

1. A method for calibrating a tip timing measurement system in a turbomachine, wherein a blade vibration pattern with a plurality of pulse signals is created and fed into a blade vibration tip timing measurement (BVTTM) system, wherein creating a blade vibration pattern comprises generating a pulse signal sequence for each channel of a plurality of parallel channels using a processor unit, the method comprising:
storing a first array comprising a plurality of predefined pulse shape elements in a memory unit, the plurality of predefined pulse shape elements contain the pulse signal sequence of amplitude values that form a pulse shape;
storing a second array comprising a plurality of pulse shape identifier elements for the plurality of parallel channels in the memory unit, each pulse shape identifier comprises a reference to a predefined pulse shape element;
storing a third array of a plurality of wait time elements for the plurality of parallel channels in the memory unit, each wait time element comprising a time length; and
performing in parallel for each channel:
creating a pulse signal having a pulse length in a signal output unit during at least one processor cycle wherein the pulse signal includes a pulse shape having the amplitude values for the pulse length of a predefined pulse shape element referred to by the pulse shape identifier element of the respective channel read from the second array stored in the memory unit,
reading a wait time element from said memory unit, after creating the pulse signal of the respective channel,
waiting a wait time derived based on the time length of the wait time element for the respective channel read by the processor unit,
during the wait time, creating a null signal in said signal output unit for a number of processor cycles derived from said wait time element read,
feeding the signals created in said signal output unit for each cycle into a digital-to-analog converter, and
repeating the steps of creating a pulse signal, reading a wait time element, waiting, and creating a null signal for each pulse signal in the pulse signal sequence of said each channel.

2. A calibrating system for a tip timing measurement system in a turbomachine comprising
a pulse generator comprising a processor unit, a memory unit, a signal output unit and a digital-to-analog converter, the system configured to execute the method according to claim 1 .

3. The calibrating system of claim 2 , comprising a plurality of said pulse generators, wherein the pulse generator clock cycles are synchronized.

4. The method of claim 1 , wherein the null signal whose only characteristic is a length corresponding to the wait time between pulses.

5. The method of claim 1 , wherein the pulse shape includes an analogue sensor shaped signal.

6. The method of claim 1 , wherein tip timing sensors create defined pulses interspersed with null signal periods of varying length.

7. The method of claim 1 , wherein the pulse signal sequence being based on a blade vibration pattern.

Assignees

• Pfeifer Uwe
• Zidorn Michael
• Siemens Ag

Inventors

• Pfeifer Uwe
• Zidorn Michael

Classifications

• G01H1/006 Primary

  of the rotor of turbo machines · CPC title

• G06F1/022

  Waveform generators, i.e. devices for generating periodical functions of time, e.g. direct digital synthesizers (G06F1/025, G06F1/03 take precedence) · CPC title

• G01M15/042 Primary

  by monitoring a single specific parameter not covered by groups G01M15/06 - G01M15/12 · CPC title