Software Design

Computer loaded with LabView software

All data collection and processing is automated. In data acquisition mode, at a given frequency, flux measurements are triggered by the encoder. The data we collect will be flux as function of shaft angle, because we use the encoder as a trigger we ensure that the difference between the angles at which two flux measurements are taken is constant, thus eliminating errors introduced by variations in motor speed. Because shaft angle is a function of time we can obtain flux as a function of time, taking into consideration that the speed of the motor is variable.

The LabView application will be used to configure the DAQ board, control the motor, collect data from the slip rings, and save it to an external file.

Motor drive algorithm:

- At the beginning of a cycle the program enters data acquisition mode

- At each frequency we test the program waits for the shaft to stabilize

- Data is collected during three revolutions

- When data acquisition ends the program enters accelerated ware mode and the shaft speed is maintained at 10 Hz

- After a certain number of revolutions the cycle is finished and the next is one starts

LabView 

LabView will save the data for each cycle in a different file, the file will be compressed using zip algorithm and sent to the processing server (PUB) via HTTP for analysis. To avoid data corruption we calculate the MD5 checksum before sending it and check that the file received has the same MD5 checksum. The data will remain as backup on the acquisition server until the Romanian team confirms that the data received is ok.

One data collection cycle may generate at most 25MB of raw data (in text format). We expect to compress it to less than 10MB. The testing system will achieve about 34 measurement cycles per day. For a 100 day test period, the amount of data expected to be received and stored is of the order of 500MB - 1GB.

These calculations are based on a 20000 revolution test cycle. At this rate we expect to achieve 68 million revolutions in 100 days.

For detailed data acquisition and processing, please refer to the following link: Full software design 

LabView screen shot