System and method for weighing items such as mailpieces in the presence of external vibration
US6839694B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 2002 |
| Grant date | Jan 4, 2005 |
| Priority date | — |
| Expiry date | Jan 1, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07B2017/00701
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A system and method for weighing of items such as mailpieces in the presence of external vibration such as ground noise. The system includes a scale system having a platform connected to a load cell, which provides an output signal to an analog-to-digital converter. The resulting digital output signal is processed by a low pass filter and analyzed by a microprocessor to determine weights of items on the platform. The microprocessor also determines postage amounts as functions of the weights and outputs these postage amounts to a postage meter. The microprocessor determines the weights as the median of the peak to valley difference of the digital output signal when the digital output signal peak to valley difference is less than a predetermined value. The microprocessor identifies peaks and valleys of the digital output signal by determining when the derivative of the signal changes sign. The microprocessor estimates the weight as an average of a sum of medians for N preceding cycles if the digital output signal does not converge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.