Customer Solutions
LabVIEW Datalogging and Supervisory Control Module Saves Downtime on Aerospace Milling Machine
Author(s):
Don Seidenspinner, Spincraft Engineering
Industry:
Aerospace/Avionics, Government/Defense, Industrial Controls/ Devices/ Systems, Machines/Mechanics
Product:
Data Acquisition, LabVIEW, LabVIEW Datalogging and Supervisory Control
The Challenge:
Developing a maintenance system to predict failure of critical mill components.
The Solution:
Using National Instruments LabVIEW Datalogging and Supervisory Control Module and data acquisition (DAQ) boards to create a PC-based monitoring system with accelerometers from Endevco.
The Boeing Corp. plant at Huntington Beach, CA, uses a Cincinnati Milacron Skin Mill to perform the precision shaping of large aluminum extrusions. The aluminum material is fastened to a "bed" that is more than 20 by 40 ft long. After shaping, the final product acts as the "skin" of spacecraft and aircraft, hence the name "Skin Mill." The failure of critical machine components was causing unacceptable downtime, costly repairs, plus loss of material.
System Configuration
Spincraft Engineering Inc., a full-service systems integration company, was invited to study the problem faced by Boeing, and to suggest a practical, reliable solution. We chose to use National Instruments LabVIEW Datalogging and Supervisory Control Module and data acquisition (DAQ) boards to create a predictive maintenance system. This system continuously monitors signals from seven Endevco accelerometers mounted in close proximity to the motor-shaft bearings, drill bit, and other critical areas on the machine. These Endevco piezoelectric sensors generate analog signals that measure the component vibration. The pre-amplifier, also made by Endevco, powers the sensors. We found typical signal amplitudes in the order of 1 mV, corresponding to a force of approximately 1 g of component vibration, with a spectral content ranging from 1 Hz to 10 kHz fundamental frequencies.
The outputs from the sensors are fed to a National Instruments AT-MIO-16E-2 board. The board generates 16-bit digitized data. The resultant signatures, or wave envelopes, are then displayed on our rugged, "shoebox" PC, which includes a Pentium CPU local hard drive, network board, and 32 MB RAM.
We chose the National Instruments LabVIEW Datalogging and Supervisory Control Module graphical, SCADA development environment to create a user-friendly graphical user interface (GUI). We designed the GUI so that personnel of diverse technical backgrounds can operate the system.
With the final GUI, users have continuous graphical monitoring of the milling operation and can select various levels of response when registering anomalies or impending failure. Users can set the program to ignore a selected number of abnormal readings or to respond instantly to predetermined excursions from the norm. A typical system response is to alert the maintenance supervisor immediately for diagnosis or repair.
The system operator - a technician, maintenance person, or other designated person - is alerted to abnormal operation by a highly visible flashing light, audible signal, and on-screen warnings. Using the Internet Toolkit, you can monitor the system operational status using a Web browser. Dynamic vibration data plots are also available via the Web.
With the innovative Peak Detection VIs in the LabVIEW Datalogging and Supervisory Control Module , users can instantly compare dominant frequency peaks with established characteristic patterns produced during the milling operation. In addition, with LabVIEW Datalogging and Supervisory Control Module , users can accumulate data for historical review, with the capability of storing measurements made over a period of hours, days, or even years. Trend graphs can be displayed on the server, a remote view node, printed, or read off the Internet using a browser. We used the LabVIEW Datalogging and Supervisory Control Module to broadcast the graphs.
In addition to presentation of the data in graphical form, the vibration signature is analyzed for harmonic content because the harmonics are known to change with the mechanical wear. This analysis generally leads to the mechanical component that is wearing out. The Spincraft Engineering staff has consistently chosen LabVIEW Datalogging and Supervisory Control Module because of its flexible programming. With LabVIEW Datalogging and Supervisory Control Module , users can develop monitoring and automation systems that perform high-speed acquisition and manipulation of data as well as engineering of advanced process-control systems.
Spincraft Engineering, located in San Diego, is a supplier of demanding industrial systems for process control and data acquisition.
For more information, contact:
Don Seidenspinner
President, Spincraft Engineering, Inc.
13626 Via Viejo
San Diego, CA 92130
Tel: (858) 720-0107
E-mail: don@spincraft.com
