Dynamic mass measurement using a discrete time-variant filter

Adaptive filtering approach to dynamic weighing: a checkweigher case study

“…Another possible method, widely used in industrial applications (McGuinness et al, 2005), is to determine the static weight of the object based on the analysis of the lowpass-filtered load cell signal. As reported in (Pietrzak, 2010) good results can be achieved using a cascade connection of the first-order IIR filters of the form…”

“…Unlike the first approach, the second approach to dynamic weighing is not based on any physically motivated model of the catchweighing instrument. Instead of this, a special linear lowpass filter is designed, with timevarying coefficients selected so as to quickly attenuate the narrowband disturbance component of the measured signal (Piskorowski, 2008), (Piskorowski & de Anda, 2009), (Pietrzak, 2010). The output of such a variable-bandwidth filter converges much faster to the steady state value of the system response than the analogous output of a conventional time-invariant (i.e., fixed-bandwidth) filter.…”

A Variational Approach for Designing Infinite Impulse Response Filters With Time-Varying Parameters

“…In the discrete-time domain, LTV filters are also implemented by FIR [23] and IIR [24] systems. Although, reports are focused on Notch filtering as described in [5], [25].…”

“…Although the proposed solutions in (23) and (24) for the characteristic frequency are obtained for finite bandwidth, it does not represent a stable filter. The next section is devoted to the analysis of stability, which in turn imposes an additional restriction on the characteristic frequency.…”

FPGA Based Processing Unit for a Checkweigher

“…Such measurements are realized by dynamic weighting systems called checkweigher. Checkweighers have been intensively developed for last 20 years [1,2]. As a result, the mechanical system of high quality industrial checkweigher guarantee low level of vibrations generated by belt-based weighted element transport system, high dynamic range of mass measurements, as well as effective vibration suppression.…”