Design And Implementation Of A Novel Monitoring System For Blet Conveyor

As the requirements for coal further increases in recent years, the tense situation of coal supply and demand further deteriorated, and coal economy continued to rise. In pursuit of greater economic efficiency, coal mining is increasing the amount of work while the production safety has been neglected, and dangerous accident rates are on the rise every year. Here the project aims to design a new kind of monitoring and warning system for coal conveyor belt, and this system serve as a warning of the role for those miners who climb the coal conveyor belt for saving time in well-ascending or well-descending, so that it can achieve the safe production purposes.This dissertation adopts the appropriate design techniques and monitoring & deciding methods, and can timely take reasonable and effective measures such as turning off conveyor power to prevent illegal passengers falling into the coal bin or reshipment warehouse.In different locations on the conveyor belt, four monitoring sites are designed, and each site uses pyroelectric infrared sensors to detect climbing staff. For the sites far away from the conveyor head, they are relatively safe places, where only the sound and light alarm is used to warn the detected personnel. For those miners neglecting the warning or sitting in a nap, the system controller is setup at the measuring sites near the danger zone of the head of conveyor belt. When the system detects someone sitting on the conveyor belt, it would automatically turn off the power to stop production in order to ensure the safety of personnel. To improve the detection sensitivity, let a special Fresnel lens filter cover the probe face of pyroelectric infrared sensors which has a different focal length (sensing distance), resulting in different monitoring fields. The more fields means the more tight contronl. Low-voltage and high-performance CMOS 8-bit microcontroller AT89S52 producted by U.S. ATMEL company is selected as the main control chip. To add program monitoring system (watchdog) is an effective solution to control-chip dead cycles. A high-performance, small drive current passive photoelectric MOS relay is used, together with a coal mine-dedicated intrinsically safe power supply with a back-up battery.Finally,the sigle-chip computer programs are written according to the above design, and a prototype is given.