Real Time Flutter Monitoring System for Turbomachinery

Author(s):  
Harbans S. Dhadwal ◽  
Marc Radzikowski ◽  
Dmitri Strukov ◽  
Anatole Kurkov

A fiber optic laser probe based system is described for real time monitoring of flutter in rotating turbomachinery. The digital flutter monitoring system is designed for continuous processing of blade tip timing data at a rate of 10 MB/s. A USB2.0 interface provides un-interrupted real time processing of the data. The blade tip arrival times are measured with a 50 MHz bscillator and a 24-bit pipelined counter architecture. A graphical user interface provides on-line interrogation of any blade tip from any light probe sensor. Alternatively, data from all blades can be superimposed into a single composite scatter plot displaying the vibration amplitude of each blade. A hardware platform was developed to simulate a seventy two bladed turbine operating at 15,000 rpm. Blade tip responses from three light probes were generated in an infinite loop, providing reproducible and controlled conditions for testing the vibration monitoring system. Time interval measurements were consistently made with a single count error in a 24-bit count vector. Real time testing was done using a two blade rotor mounted in an evacuated chamber at the Spin Rig Facility at the NASA Glen Research Center. The shaft in this facility was suspended by two radial magnetic bearings and the nonsynchronous vibration was communicated to the blades through the magnetic bearing. The shaft motion was much smaller than the blade vibratory amplitude, realistically simulating flutter vibrations. Nonsynchronous vibratory amplitudes for the first mode were of the order of twenty mils and for the second mode of the order of a few mils.

1999 ◽  
Vol 39 (9) ◽  
pp. 201-207
Author(s):  
Andreas Cassar ◽  
Hans-Reinhard Verworn

Most of the existing rainfall runoff models for urban drainage systems have been designed for off-line calculations. With a design storm or a historical rain event and the model system the rainfall runoff processes are simulated, the faster the better. Since very recently, hydrodynamic models have been considered to be much too slow for real time applications. However, with the computing power of today - and even more so of tomorrow - very complex and detailed models may be run on-line and in real time. While the algorithms basically remain the same as for off-line simulations, problems concerning timing, data management and inter process communication have to be identified and solved. This paper describes the upgrading of the existing hydrodynamic rainfall runoff model HYSTEM/EXTRAN and the decision finding model INTL for real time performance, their implementation on a network of UNIX stations and the experiences from running them within an urban drainage real time control project. The main focus is not on what the models do but how they are put into action and made to run smoothly embedded in all the processes necessary in operational real time control.


2012 ◽  
Vol 503-504 ◽  
pp. 1651-1654
Author(s):  
Guo Yong Zhang ◽  
Shuo Wu

The vibration can influence the running of devices in the engine room. It is necessary to monitor the vibration state of all running machineries. Through integrating the Bluetooth technology into the common vibration sensor, a wireless on-line vibration monitoring system is designed to monitor all devices. It will be helpful to avoid severe failure and improve the cruising ability.


Author(s):  
Henry Jones

A technique for measuring turbine engine rotor blade vibrations has been developed as an alternative to conventional strain-gage measurement systems. Light probes are mounted on the periphery of the engine rotor casing to sense the precise blade passing times of each blade in the row. The timing data are processed on-line to identify (1) individual blade vibration amplitudes and frequencies, (2) interblade phases, (3) system modal definitions, and (4) blade static deflection. This technique has been effectively applied to both turbine engine rotors and plant rotating machinery.


Author(s):  
Michael R. Hummels ◽  
Raymond J. Cipra

Abstract An on-line trajectory modification and path planning strategy is developed which will allow a robot to respond in an efficient manner to real time sensory input. The approach developed here eliminates the need for solving many equations by developing a closed form algorithm. It uses two fourth order curves for the transition phases with a constant velocity section in between. Although this is done by providing additional constraints to the curve, it makes the problem of determining the trajectory much easier to solve, while providing continuous higher derivatives. It also provides a safe and efficient way of modifying trajectories based on the robots joint rate limits, joint acceleration limits, jerk limits, and desired time interval between trajectory modifications for a 4-1-4 trajectory. This method involves the solution of one second order equation and is directed toward real time applications.


2010 ◽  
Vol 450 ◽  
pp. 259-262 ◽  
Author(s):  
Chao Ching Ho ◽  
Tzu Hsin Kuo ◽  
Tsung Ting Tsai

Designing a robust condition monitoring system for a machine tool spindle is an important task because the spindle has a significant effect on the processing quality. In this study, a solar-powered wireless sensor system is installed inside the spindle and is used to monitor the machine tool processing state in real time, thereby improving the processing quality. Accelerometer sensors are employed to estimate tool wear; these sensors monitor the vibration of the spindle. The vibration monitoring data of the high-speed spindle is wirelessly transmitted to an external information device in real time. As an alternative to sensors that employ wired power transmission, a solar energy transmission system has been developed to provide the required electric power to the sensor system. The experimental results show that the proposed system successfully measures the vibration frequency of the rotational machine tool spindle.


Author(s):  
Norikazu Ikoma ◽  
◽  
Gefan Zhang

Decorations of face such as enlarging eyes, whitening skin, rendering face slim, and so on are commercially successful in amusement arcades especially in Japan for still image and off-line processing. This paper proposes to decorate human face in video on-line and in real-time processing. Face posture estimation using particle filter plays a key role to decorate the face by precisely determining position of the eyes as well as determining regional position of face. Our proposed method conducts two decorations, enlarging eyes and whitening skin, based on the estimation result of face posture. Real-time implementation of the proposed method has been demonstrated for real scenes of indoor situation.


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