Metal Detector Design Based On DSP

Metal detector is widely used in various industries, but its detection accuracy is not good because it is easy to prone to omission and misstatement which are made by its bad testing environment, serious electromagnetic interference. This paper has designed a kind metal detectors, which has the abilities of stability and higher testing precision, to solve above problems.Firstly, this paper introduces the physical and mathematical models for the process of metal piece through the test coil. And the modified principle of balanced detection is deduced in detail. In order to reduce power consumption and improve the anti-interference ability, a pulse signal is used instead of a sine AC signal on the principle design. Because of the high accuracy and fast computing speed of digital signal processor, taking the digital signal processor as the master control chip on hardware.At the same time, it is equipped with a transmitting module, a receiving module(amplification filter circuit), A/D conversion module, human-computer interaction module, communication module, output driver module and so on, all those form a complete detection system.In order to facilitates the early programming and debugging,on software, the whole program is made up of main module, transmitting module, signal acquisition module, communication module and human-computer interaction module, etc. After the hardware and software are finished, the panel controller, launch panel, receive panels, mount are assembled into a metal detection prototype.The whole debugging is divided into two stages: the first stage,testing all technical indexes of metal detector in the laboratory and then getting its the highest sensitivity detector; the second stage, fully simulating the industrial field, it retests the sensitivity of the detector and anti-interference ability at the background of a conveyor belt and ore.Finally, through the result of verification, metal detector which the paper has designed is able to work under the conditions of high sensitivity stability. Because it take advantages of metal detectors at home and abroad in the design, the designed metal detector has innovativeness frontier and huge market prospects. At the same time, it brakes the monopoly of foreign high-precision detection and fills the gaps In the domestic. indicate the direction for future software upgrades and the overall improvement. And the paper summarizes the advantages and disadvantages of the detector for indicating the direction for future software upgrades and the overall improvement.