The main problem on sorting out the wood logs in traditional wood industry was that the process should be done manually. Hence, it required an automated system to perform sorting process with a higher precision level. The purpose of this research was to create a simulation of automated wood log sorting process based on specified length and thickness. The sorting system consisted of AT89C51 microcontroller system, keypad (in order to enter the required value of length and thickness), LCD (in order to display the result of sorting process), conveyor belt, two pairs of light sensor (consisting of photodiode and LED, each), and three DC motors which were driven by five relay circuits. At the beginning of sorting process, an operator was to type the selection range (i.e. the minimum and maximum value of required length and thickness) via the keypad provided. The wood log mounted on conveyor belt would be measured by light sensors to determine the value of length and thickness. Based on the values, AT89C51 microcontroller system would then compare them to the selection range. If the log being sorted out fulfilled the requirements, it would be directed to "Accepted" compartment, or else to "Rejected" one. From the test performed, it was concluded that the length measurement was more precise for short logs. While the error rate was much higher for thin logs on thickness measurement. The process of sorting out and counting the wood logs was performed successfully. The system could use the narrowing mechanism at the mounting part of conveyor belt and better supporting ace on thickness sensor, in order to minimize the error rate on length and thickness measurement, respectively. In addition, the system could be developed to measure the volume of an object, providing that the object being measured was having a square or full-circle cross-sectional area.
Wood Log Sorting System, AT89C51 Microcontroller.