Development and validation of a programmable logic device (PLD) based sensor and processor microarchitecture system for equilibrium moisture content calculation in wood industries

Abstract

Equilibrium Moisture Content (EMC) is a metric affecting the performance of wood in many applications. EMC value is a function of the temperature and the relative humidity of the surrounding air of wood. Knowing this value while processing wood is extremely important. This paper addresses the development and experimental validation of a small hand-held special purpose sensor and processor system used to sense, calculate and display the value of EMC of wood depending on surrounding environmental conditions. An appropriate temperature and humidity sensor is chosen for the system. Calculation of EMC requires many arithmetic operations with stringent precision requirements. Various arithmetic algorithms and systems are compared and a suitable choice is made. Two resulting processor organizations, microarchitectures and designs are developed and compared based on accuracy, performance and implementation cost. The designs are captured in a Hardware Description Language (HDL), then synthesized and functionally validated and performance evaluated via HDL virtual prototype simulation. Experimental hardware prototypes of both microarchitectures were implemented to Programmable Logic Device (PLD) technology (specifically Field Programmable Gate Array (FPGA) technology) and used for final experimental hardware prototype functional and performance testing and evaluation. A best processor microarchitecture for the EMC sensor and processor system was selected based on computational accuracy, performance and cost.