System and method for compressing production data stream and filtering compressed data with different criteria

摘要

Production data are streamed by a shop floor (a field) of a plant towards a data compression processor inside a MES/ERP server. The data stream is segmented in field data intervals of variable duration, each one carrying a tag composed of initial timespan s°, final timespan e°, and the variation v° undergone by the monitored variable. The processor takes a first incoming tag and calculates a data compression interval of constant duration y which is a function of e°, then it creates a vector [s°, e°, v°, m=v°, n=e°−s°]. Until the incoming tags fall into the current compression interval, subsequent variations v° are summed up and subsequent s° and e° updated, obtaining an updated vector [s, e, v, m, n], otherwise the compression vector is stored in a SQL database and a new compression interval entered.

主权项

1. A system for compressing a data stream coming from a shop floor defined as a field of a plant, the data stream being segmented in field data intervals, each of the field data intervals carrying a tag composed of at least a value v° associated to a monitored variable and a timestamp when the monitored variable was recorded or calculated, the system comprising:
a first buffering device for temporarily storing tags coming from the field; a programmable processing device containing firmware configured for having access to said first buffering device and taking the subsequent values v° and accumulating the values within compression time intervals as summation data values v being compressed values v; a second buffering device; a database accessible by said programmable processing device for storing the compressed values v taken from said second buffering device; a post-processing device for querying said database; said firmware of said programmable processing device programmed to:
calculate an end value w of a current compression interval by means of the following function:
w(e°)=z+ceiling[(e°−z)/y]×y in which: z indicates a start of a compression process, y is a predetermined constant indicating a duration of each compression interval, e° is a timestamp indicating an end of a current field data interval entering a current compression interval at first and further including a timestamp s° indicating the start;calculate a duration n=e°−s° of a data interval entering the current compression interval at first; andcompare every subsequent timestamp e° with the end value w and updating s°, e° until e°≦w is detected, as soon as the condition is false storing in said database a vector [s, e, v, v°, n] wherein s, e, v, are updated s°, e° and accumulated v°, and entering a new compression interval, a metric v°/n constituting a multiplier usable, whenever requested, for linearly interpolating the value v° across at least one of two ends of at least one filtering interval to be prefigured for postponed aggregation of entering compressed values v.