Development Of A Novel Intelligent Metal Detector

Metal detector now comes into many aspects of our everyday life. It is widely used in detecting from landmine underground to rare metal mine embedded under the earth, from food safety to costume product, from rubber purity to lumber machining. It does work well in these fields and the improvement of its function is becoming to the main question customers care.This paper offers a realizable scheme of a novel intelligent metal detector, composed of digital signal processing, microprocessor, direct digital synthesizer etc. Now many industries, such as food, medicine, costume manufacturer, apply it to detect and eliminate the metal impurity merging into products. Compared with analog-circuit metal detector, the distinct characteristic is its capacity of automatic parameter adjustment of digital sine wave created by DDS and DSP. DDS creates a sine wave whose phase and frequency parameters can be linearly and digitally modified. At the same time ,it has the advantage of high sensitivity , good stability and convenient man-machine conversation. And the important point is its ability to automatically distinguish which are product effect or impurity signal and to storage correlative parameters. The metal detector adopts TMS320LF2407 and AT89C55 to compose the core controlling system. The function of digital data processing(DSP) is to implement sampling, data processing & judgment and parameter auto-setting. The function of microprocessor (MPU) is to control the LED display and the keyboard input. Maxim RS485 implements the communication between DSP and MPU. The sample machine has been made when the item ends. Many product experiments prove that this scheme could get the expected results. The highest value of Fe sensitivity isΦ1.0, that of Sus is Φ2.0. It can storage over 20 kinds of product parameter. The stability and anti-jamming ability could get better than before.