Add-ins for FlexPro
23 March 2007
Reviewed by Felix Grant
FlexPro is a databased analytic product with particular strength in signal-oriented work, project documentation, direct data acquisition, and industrial applications. I recently reviewed release 7 on this site. While it is an extremely capable and usable package straight from the box, a set of add-ins enhances its power with ready-made solutions for particular purposes. These ‘options’ are on the FlexPro distribution disk, to be unlocked by separately purchased codes. There are six of these add-ins at the moment: five of them oriented towards signal or signal-related applications: the sixth being generic, generally benefiting from the central FlexPro Analysis Wizard.
The generic option is a set of inductive statistical tools which, given FlexPro’s emphases, lean towards industrial process control although they can, of course, be applied to any relevant context. A variety of tests and various ANOVA models are combined with calculations on continuous and discrete theoretical distributions.
Central to signal analysis is the counting and ordering of oscillation components, and there is an add-in devoted to each. Counting involves searching for, and classifying, particular function events such as peaks, crossing of a specified value boundaries, and so on. Order tracking of oscillations by time or angle at a particular speed is followed by application of an FFT, then isolation of spectral lines corresponding to base frequency multiples to produce an output set, plotting amplitude and order against either speed or frequency.
FlexPro’s counting procedures are primarily Rainflow-based, although older DIN 45667 methods are used where no equivalent solutions are otherwise available. Class definition can be determined automatically or controlled by various means including reference to external data, and degrees of significant function change tuned by a range filter.
The ‘digital filters’ option offers finite and infinite impulse response (IIR and FIR) filters additional to those in the main product. A well implemented serial graphic assembly line wizard simplifies control of their specification, and there is a useful tutorial to ease the learning curve. Local regression (Savitzky-Golay) provides sophistication in smoothing of peaked data, preserving structure often degraded by moving average approaches. FIRs can be designed using either window (eight types) or constant ripple approaches, either way benefiting from helper environments.
The acoustics option also emphasises wizard-driven ease of use, with a range of graphical and numerical views onto incoming data. With range and resolution of time domain filters set, octave analytic calculations are painless. Calibration is calculated by FlexPro from a test signal taken directly from the microphone (though this can be overridden if required for some reason), and multiple channels are viewable with little more than a click.
Spectral analysis makes use of the same approach, providing the same visual overview and, through it, a streamlined analytic regime as approaches and strategies are varied. A good selection of procedures is available, including the most current developments for difficult or noisy data structures. A (real) cepstrum analysis function provides access to echo handling, speech examination, and other deconvolved applications.
These additional options are substantial entities. In some cases the descriptions ‘add in’ or ‘option’, while technically correct, under-describe them. Spectral analysis, in particular, is an application in its own right, apart from its dependence on the FlexPro host. Weisang updates these additional options independently of FlexPro itself: the digital filters option, for example, has been significantly upgraded just as I was finalising this review. For anyone working in the areas which they cover, they provide considerable extension to the power of the FlexPro platform.