The invention discloses a
metal detection
system under multimode array excitation, wherein the
metal detection
system comprises a transmitting module, a receiving module and a multimode
signal processing module; the transmitting module comprises a
signal source and a transmitting array, the
signal source is used for generating a rectangular alternating pulse signal, and the transmitting array generates an alternating
magnetic field according to the rectangular alternating pulse signal; the receiving module comprises a receiving array and a
signal acquisition module, the receiving array is usedfor receiving an alternating
magnetic field with / without underground target interference and generating an induction signal, and the
signal acquisition module is used for acquiring the induction signal and transmitting the induction signal to the multimode
signal processing module. According to the invention, the
signal source generates a signal with an adjustable duty ratio, so that the interference of a
primary field is reduced; when the duty ratio of the signal is increased, the zero-level time of the transmitted signal is prolonged, the
observation time is also prolonged, the time for acquiring the induction signal is also prolonged, and the induction signal acquired in the earlier stage can be removed to reduce the interference.